chore: add modifier pipeline

Bobbert

LICENSE

@@ -0,0 +1,661 @@
+                    GNU AFFERO GENERAL PUBLIC LICENSE
+                       Version 3, 19 November 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <https://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+                            Preamble
+
+  The GNU Affero General Public License is a free, copyleft license for
+software and other kinds of works, specifically designed to ensure
+cooperation with the community in the case of network server software.
+
+  The licenses for most software and other practical works are designed
+to take away your freedom to share and change the works.  By contrast,
+our General Public Licenses are intended to guarantee your freedom to
+share and change all versions of a program--to make sure it remains free
+software for all its users.
+
+  When we speak of free software, we are referring to freedom, not
+price.  Our General Public Licenses are designed to make sure that you
+have the freedom to distribute copies of free software (and charge for
+them if you wish), that you receive source code or can get it if you
+want it, that you can change the software or use pieces of it in new
+free programs, and that you know you can do these things.
+
+  Developers that use our General Public Licenses protect your rights
+with two steps: (1) assert copyright on the software, and (2) offer
+you this License which gives you legal permission to copy, distribute
+and/or modify the software.
+
+  A secondary benefit of defending all users' freedom is that
+improvements made in alternate versions of the program, if they
+receive widespread use, become available for other developers to
+incorporate.  Many developers of free software are heartened and
+encouraged by the resulting cooperation.  However, in the case of
+software used on network servers, this result may fail to come about.
+The GNU General Public License permits making a modified version and
+letting the public access it on a server without ever releasing its
+source code to the public.
+
+  The GNU Affero General Public License is designed specifically to
+ensure that, in such cases, the modified source code becomes available
+to the community.  It requires the operator of a network server to
+provide the source code of the modified version running there to the
+users of that server.  Therefore, public use of a modified version, on
+a publicly accessible server, gives the public access to the source
+code of the modified version.
+
+  An older license, called the Affero General Public License and
+published by Affero, was designed to accomplish similar goals.  This is
+a different license, not a version of the Affero GPL, but Affero has
+released a new version of the Affero GPL which permits relicensing under
+this license.
+
+  The precise terms and conditions for copying, distribution and
+modification follow.
+
+                       TERMS AND CONDITIONS
+
+  0. Definitions.
+
+  "This License" refers to version 3 of the GNU Affero General Public License.
+
+  "Copyright" also means copyright-like laws that apply to other kinds of
+works, such as semiconductor masks.
+
+  "The Program" refers to any copyrightable work licensed under this
+License.  Each licensee is addressed as "you".  "Licensees" and
+"recipients" may be individuals or organizations.
+
+  To "modify" a work means to copy from or adapt all or part of the work
+in a fashion requiring copyright permission, other than the making of an
+exact copy.  The resulting work is called a "modified version" of the
+earlier work or a work "based on" the earlier work.
+
+  A "covered work" means either the unmodified Program or a work based
+on the Program.
+
+  To "propagate" a work means to do anything with it that, without
+permission, would make you directly or secondarily liable for
+infringement under applicable copyright law, except executing it on a
+computer or modifying a private copy.  Propagation includes copying,
+distribution (with or without modification), making available to the
+public, and in some countries other activities as well.
+
+  To "convey" a work means any kind of propagation that enables other
+parties to make or receive copies.  Mere interaction with a user through
+a computer network, with no transfer of a copy, is not conveying.
+
+  An interactive user interface displays "Appropriate Legal Notices"
+to the extent that it includes a convenient and prominently visible
+feature that (1) displays an appropriate copyright notice, and (2)
+tells the user that there is no warranty for the work (except to the
+extent that warranties are provided), that licensees may convey the
+work under this License, and how to view a copy of this License.  If
+the interface presents a list of user commands or options, such as a
+menu, a prominent item in the list meets this criterion.
+
+  1. Source Code.
+
+  The "source code" for a work means the preferred form of the work
+for making modifications to it.  "Object code" means any non-source
+form of a work.
+
+  A "Standard Interface" means an interface that either is an official
+standard defined by a recognized standards body, or, in the case of
+interfaces specified for a particular programming language, one that
+is widely used among developers working in that language.
+
+  The "System Libraries" of an executable work include anything, other
+than the work as a whole, that (a) is included in the normal form of
+packaging a Major Component, but which is not part of that Major
+Component, and (b) serves only to enable use of the work with that
+Major Component, or to implement a Standard Interface for which an
+implementation is available to the public in source code form.  A
+"Major Component", in this context, means a major essential component
+(kernel, window system, and so on) of the specific operating system
+(if any) on which the executable work runs, or a compiler used to
+produce the work, or an object code interpreter used to run it.
+
+  The "Corresponding Source" for a work in object code form means all
+the source code needed to generate, install, and (for an executable
+work) run the object code and to modify the work, including scripts to
+control those activities.  However, it does not include the work's
+System Libraries, or general-purpose tools or generally available free
+programs which are used unmodified in performing those activities but
+which are not part of the work.  For example, Corresponding Source
+includes interface definition files associated with source files for
+the work, and the source code for shared libraries and dynamically
+linked subprograms that the work is specifically designed to require,
+such as by intimate data communication or control flow between those
+subprograms and other parts of the work.
+
+  The Corresponding Source need not include anything that users
+can regenerate automatically from other parts of the Corresponding
+Source.
+
+  The Corresponding Source for a work in source code form is that
+same work.
+
+  2. Basic Permissions.
+
+  All rights granted under this License are granted for the term of
+copyright on the Program, and are irrevocable provided the stated
+conditions are met.  This License explicitly affirms your unlimited
+permission to run the unmodified Program.  The output from running a
+covered work is covered by this License only if the output, given its
+content, constitutes a covered work.  This License acknowledges your
+rights of fair use or other equivalent, as provided by copyright law.
+
+  You may make, run and propagate covered works that you do not
+convey, without conditions so long as your license otherwise remains
+in force.  You may convey covered works to others for the sole purpose
+of having them make modifications exclusively for you, or provide you
+with facilities for running those works, provided that you comply with
+the terms of this License in conveying all material for which you do
+not control copyright.  Those thus making or running the covered works
+for you must do so exclusively on your behalf, under your direction
+and control, on terms that prohibit them from making any copies of
+your copyrighted material outside their relationship with you.
+
+  Conveying under any other circumstances is permitted solely under
+the conditions stated below.  Sublicensing is not allowed; section 10
+makes it unnecessary.
+
+  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
+
+  No covered work shall be deemed part of an effective technological
+measure under any applicable law fulfilling obligations under article
+11 of the WIPO copyright treaty adopted on 20 December 1996, or
+similar laws prohibiting or restricting circumvention of such
+measures.
+
+  When you convey a covered work, you waive any legal power to forbid
+circumvention of technological measures to the extent such circumvention
+is effected by exercising rights under this License with respect to
+the covered work, and you disclaim any intention to limit operation or
+modification of the work as a means of enforcing, against the work's
+users, your or third parties' legal rights to forbid circumvention of
+technological measures.
+
+  4. Conveying Verbatim Copies.
+
+  You may convey verbatim copies of the Program's source code as you
+receive it, in any medium, provided that you conspicuously and
+appropriately publish on each copy an appropriate copyright notice;
+keep intact all notices stating that this License and any
+non-permissive terms added in accord with section 7 apply to the code;
+keep intact all notices of the absence of any warranty; and give all
+recipients a copy of this License along with the Program.
+
+  You may charge any price or no price for each copy that you convey,
+and you may offer support or warranty protection for a fee.
+
+  5. Conveying Modified Source Versions.
+
+  You may convey a work based on the Program, or the modifications to
+produce it from the Program, in the form of source code under the
+terms of section 4, provided that you also meet all of these conditions:
+
+    a) The work must carry prominent notices stating that you modified
+    it, and giving a relevant date.
+
+    b) The work must carry prominent notices stating that it is
+    released under this License and any conditions added under section
+    7.  This requirement modifies the requirement in section 4 to
+    "keep intact all notices".
+
+    c) You must license the entire work, as a whole, under this
+    License to anyone who comes into possession of a copy.  This
+    License will therefore apply, along with any applicable section 7
+    additional terms, to the whole of the work, and all its parts,
+    regardless of how they are packaged.  This License gives no
+    permission to license the work in any other way, but it does not
+    invalidate such permission if you have separately received it.
+
+    d) If the work has interactive user interfaces, each must display
+    Appropriate Legal Notices; however, if the Program has interactive
+    interfaces that do not display Appropriate Legal Notices, your
+    work need not make them do so.
+
+  A compilation of a covered work with other separate and independent
+works, which are not by their nature extensions of the covered work,
+and which are not combined with it such as to form a larger program,
+in or on a volume of a storage or distribution medium, is called an
+"aggregate" if the compilation and its resulting copyright are not
+used to limit the access or legal rights of the compilation's users
+beyond what the individual works permit.  Inclusion of a covered work
+in an aggregate does not cause this License to apply to the other
+parts of the aggregate.
+
+  6. Conveying Non-Source Forms.
+
+  You may convey a covered work in object code form under the terms
+of sections 4 and 5, provided that you also convey the
+machine-readable Corresponding Source under the terms of this License,
+in one of these ways:
+
+    a) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by the
+    Corresponding Source fixed on a durable physical medium
+    customarily used for software interchange.
+
+    b) Convey the object code in, or embodied in, a physical product
+    (including a physical distribution medium), accompanied by a
+    written offer, valid for at least three years and valid for as
+    long as you offer spare parts or customer support for that product
+    model, to give anyone who possesses the object code either (1) a
+    copy of the Corresponding Source for all the software in the
+    product that is covered by this License, on a durable physical
+    medium customarily used for software interchange, for a price no
+    more than your reasonable cost of physically performing this
+    conveying of source, or (2) access to copy the
+    Corresponding Source from a network server at no charge.
+
+    c) Convey individual copies of the object code with a copy of the
+    written offer to provide the Corresponding Source.  This
+    alternative is allowed only occasionally and noncommercially, and
+    only if you received the object code with such an offer, in accord
+    with subsection 6b.
+
+    d) Convey the object code by offering access from a designated
+    place (gratis or for a charge), and offer equivalent access to the
+    Corresponding Source in the same way through the same place at no
+    further charge.  You need not require recipients to copy the
+    Corresponding Source along with the object code.  If the place to
+    copy the object code is a network server, the Corresponding Source
+    may be on a different server (operated by you or a third party)
+    that supports equivalent copying facilities, provided you maintain
+    clear directions next to the object code saying where to find the
+    Corresponding Source.  Regardless of what server hosts the
+    Corresponding Source, you remain obligated to ensure that it is
+    available for as long as needed to satisfy these requirements.
+
+    e) Convey the object code using peer-to-peer transmission, provided
+    you inform other peers where the object code and Corresponding
+    Source of the work are being offered to the general public at no
+    charge under subsection 6d.
+
+  A separable portion of the object code, whose source code is excluded
+from the Corresponding Source as a System Library, need not be
+included in conveying the object code work.
+
+  A "User Product" is either (1) a "consumer product", which means any
+tangible personal property which is normally used for personal, family,
+or household purposes, or (2) anything designed or sold for incorporation
+into a dwelling.  In determining whether a product is a consumer product,
+doubtful cases shall be resolved in favor of coverage.  For a particular
+product received by a particular user, "normally used" refers to a
+typical or common use of that class of product, regardless of the status
+of the particular user or of the way in which the particular user
+actually uses, or expects or is expected to use, the product.  A product
+is a consumer product regardless of whether the product has substantial
+commercial, industrial or non-consumer uses, unless such uses represent
+the only significant mode of use of the product.
+
+  "Installation Information" for a User Product means any methods,
+procedures, authorization keys, or other information required to install
+and execute modified versions of a covered work in that User Product from
+a modified version of its Corresponding Source.  The information must
+suffice to ensure that the continued functioning of the modified object
+code is in no case prevented or interfered with solely because
+modification has been made.
+
+  If you convey an object code work under this section in, or with, or
+specifically for use in, a User Product, and the conveying occurs as
+part of a transaction in which the right of possession and use of the
+User Product is transferred to the recipient in perpetuity or for a
+fixed term (regardless of how the transaction is characterized), the
+Corresponding Source conveyed under this section must be accompanied
+by the Installation Information.  But this requirement does not apply
+if neither you nor any third party retains the ability to install
+modified object code on the User Product (for example, the work has
+been installed in ROM).
+
+  The requirement to provide Installation Information does not include a
+requirement to continue to provide support service, warranty, or updates
+for a work that has been modified or installed by the recipient, or for
+the User Product in which it has been modified or installed.  Access to a
+network may be denied when the modification itself materially and
+adversely affects the operation of the network or violates the rules and
+protocols for communication across the network.
+
+  Corresponding Source conveyed, and Installation Information provided,
+in accord with this section must be in a format that is publicly
+documented (and with an implementation available to the public in
+source code form), and must require no special password or key for
+unpacking, reading or copying.
+
+  7. Additional Terms.
+
+  "Additional permissions" are terms that supplement the terms of this
+License by making exceptions from one or more of its conditions.
+Additional permissions that are applicable to the entire Program shall
+be treated as though they were included in this License, to the extent
+that they are valid under applicable law.  If additional permissions
+apply only to part of the Program, that part may be used separately
+under those permissions, but the entire Program remains governed by
+this License without regard to the additional permissions.
+
+  When you convey a copy of a covered work, you may at your option
+remove any additional permissions from that copy, or from any part of
+it.  (Additional permissions may be written to require their own
+removal in certain cases when you modify the work.)  You may place
+additional permissions on material, added by you to a covered work,
+for which you have or can give appropriate copyright permission.
+
+  Notwithstanding any other provision of this License, for material you
+add to a covered work, you may (if authorized by the copyright holders of
+that material) supplement the terms of this License with terms:
+
+    a) Disclaiming warranty or limiting liability differently from the
+    terms of sections 15 and 16 of this License; or
+
+    b) Requiring preservation of specified reasonable legal notices or
+    author attributions in that material or in the Appropriate Legal
+    Notices displayed by works containing it; or
+
+    c) Prohibiting misrepresentation of the origin of that material, or
+    requiring that modified versions of such material be marked in
+    reasonable ways as different from the original version; or
+
+    d) Limiting the use for publicity purposes of names of licensors or
+    authors of the material; or
+
+    e) Declining to grant rights under trademark law for use of some
+    trade names, trademarks, or service marks; or
+
+    f) Requiring indemnification of licensors and authors of that
+    material by anyone who conveys the material (or modified versions of
+    it) with contractual assumptions of liability to the recipient, for
+    any liability that these contractual assumptions directly impose on
+    those licensors and authors.
+
+  All other non-permissive additional terms are considered "further
+restrictions" within the meaning of section 10.  If the Program as you
+received it, or any part of it, contains a notice stating that it is
+governed by this License along with a term that is a further
+restriction, you may remove that term.  If a license document contains
+a further restriction but permits relicensing or conveying under this
+License, you may add to a covered work material governed by the terms
+of that license document, provided that the further restriction does
+not survive such relicensing or conveying.
+
+  If you add terms to a covered work in accord with this section, you
+must place, in the relevant source files, a statement of the
+additional terms that apply to those files, or a notice indicating
+where to find the applicable terms.
+
+  Additional terms, permissive or non-permissive, may be stated in the
+form of a separately written license, or stated as exceptions;
+the above requirements apply either way.
+
+  8. Termination.
+
+  You may not propagate or modify a covered work except as expressly
+provided under this License.  Any attempt otherwise to propagate or
+modify it is void, and will automatically terminate your rights under
+this License (including any patent licenses granted under the third
+paragraph of section 11).
+
+  However, if you cease all violation of this License, then your
+license from a particular copyright holder is reinstated (a)
+provisionally, unless and until the copyright holder explicitly and
+finally terminates your license, and (b) permanently, if the copyright
+holder fails to notify you of the violation by some reasonable means
+prior to 60 days after the cessation.
+
+  Moreover, your license from a particular copyright holder is
+reinstated permanently if the copyright holder notifies you of the
+violation by some reasonable means, this is the first time you have
+received notice of violation of this License (for any work) from that
+copyright holder, and you cure the violation prior to 30 days after
+your receipt of the notice.
+
+  Termination of your rights under this section does not terminate the
+licenses of parties who have received copies or rights from you under
+this License.  If your rights have been terminated and not permanently
+reinstated, you do not qualify to receive new licenses for the same
+material under section 10.
+
+  9. Acceptance Not Required for Having Copies.
+
+  You are not required to accept this License in order to receive or
+run a copy of the Program.  Ancillary propagation of a covered work
+occurring solely as a consequence of using peer-to-peer transmission
+to receive a copy likewise does not require acceptance.  However,
+nothing other than this License grants you permission to propagate or
+modify any covered work.  These actions infringe copyright if you do
+not accept this License.  Therefore, by modifying or propagating a
+covered work, you indicate your acceptance of this License to do so.
+
+  10. Automatic Licensing of Downstream Recipients.
+
+  Each time you convey a covered work, the recipient automatically
+receives a license from the original licensors, to run, modify and
+propagate that work, subject to this License.  You are not responsible
+for enforcing compliance by third parties with this License.
+
+  An "entity transaction" is a transaction transferring control of an
+organization, or substantially all assets of one, or subdividing an
+organization, or merging organizations.  If propagation of a covered
+work results from an entity transaction, each party to that
+transaction who receives a copy of the work also receives whatever
+licenses to the work the party's predecessor in interest had or could
+give under the previous paragraph, plus a right to possession of the
+Corresponding Source of the work from the predecessor in interest, if
+the predecessor has it or can get it with reasonable efforts.
+
+  You may not impose any further restrictions on the exercise of the
+rights granted or affirmed under this License.  For example, you may
+not impose a license fee, royalty, or other charge for exercise of
+rights granted under this License, and you may not initiate litigation
+(including a cross-claim or counterclaim in a lawsuit) alleging that
+any patent claim is infringed by making, using, selling, offering for
+sale, or importing the Program or any portion of it.
+
+  11. Patents.
+
+  A "contributor" is a copyright holder who authorizes use under this
+License of the Program or a work on which the Program is based.  The
+work thus licensed is called the contributor's "contributor version".
+
+  A contributor's "essential patent claims" are all patent claims
+owned or controlled by the contributor, whether already acquired or
+hereafter acquired, that would be infringed by some manner, permitted
+by this License, of making, using, or selling its contributor version,
+but do not include claims that would be infringed only as a
+consequence of further modification of the contributor version.  For
+purposes of this definition, "control" includes the right to grant
+patent sublicenses in a manner consistent with the requirements of
+this License.
+
+  Each contributor grants you a non-exclusive, worldwide, royalty-free
+patent license under the contributor's essential patent claims, to
+make, use, sell, offer for sale, import and otherwise run, modify and
+propagate the contents of its contributor version.
+
+  In the following three paragraphs, a "patent license" is any express
+agreement or commitment, however denominated, not to enforce a patent
+(such as an express permission to practice a patent or covenant not to
+sue for patent infringement).  To "grant" such a patent license to a
+party means to make such an agreement or commitment not to enforce a
+patent against the party.
+
+  If you convey a covered work, knowingly relying on a patent license,
+and the Corresponding Source of the work is not available for anyone
+to copy, free of charge and under the terms of this License, through a
+publicly available network server or other readily accessible means,
+then you must either (1) cause the Corresponding Source to be so
+available, or (2) arrange to deprive yourself of the benefit of the
+patent license for this particular work, or (3) arrange, in a manner
+consistent with the requirements of this License, to extend the patent
+license to downstream recipients.  "Knowingly relying" means you have
+actual knowledge that, but for the patent license, your conveying the
+covered work in a country, or your recipient's use of the covered work
+in a country, would infringe one or more identifiable patents in that
+country that you have reason to believe are valid.
+
+  If, pursuant to or in connection with a single transaction or
+arrangement, you convey, or propagate by procuring conveyance of, a
+covered work, and grant a patent license to some of the parties
+receiving the covered work authorizing them to use, propagate, modify
+or convey a specific copy of the covered work, then the patent license
+you grant is automatically extended to all recipients of the covered
+work and works based on it.
+
+  A patent license is "discriminatory" if it does not include within
+the scope of its coverage, prohibits the exercise of, or is
+conditioned on the non-exercise of one or more of the rights that are
+specifically granted under this License.  You may not convey a covered
+work if you are a party to an arrangement with a third party that is
+in the business of distributing software, under which you make payment
+to the third party based on the extent of your activity of conveying
+the work, and under which the third party grants, to any of the
+parties who would receive the covered work from you, a discriminatory
+patent license (a) in connection with copies of the covered work
+conveyed by you (or copies made from those copies), or (b) primarily
+for and in connection with specific products or compilations that
+contain the covered work, unless you entered into that arrangement,
+or that patent license was granted, prior to 28 March 2007.
+
+  Nothing in this License shall be construed as excluding or limiting
+any implied license or other defenses to infringement that may
+otherwise be available to you under applicable patent law.
+
+  12. No Surrender of Others' Freedom.
+
+  If conditions are imposed on you (whether by court order, agreement or
+otherwise) that contradict the conditions of this License, they do not
+excuse you from the conditions of this License.  If you cannot convey a
+covered work so as to satisfy simultaneously your obligations under this
+License and any other pertinent obligations, then as a consequence you may
+not convey it at all.  For example, if you agree to terms that obligate you
+to collect a royalty for further conveying from those to whom you convey
+the Program, the only way you could satisfy both those terms and this
+License would be to refrain entirely from conveying the Program.
+
+  13. Remote Network Interaction; Use with the GNU General Public License.
+
+  Notwithstanding any other provision of this License, if you modify the
+Program, your modified version must prominently offer all users
+interacting with it remotely through a computer network (if your version
+supports such interaction) an opportunity to receive the Corresponding
+Source of your version by providing access to the Corresponding Source
+from a network server at no charge, through some standard or customary
+means of facilitating copying of software.  This Corresponding Source
+shall include the Corresponding Source for any work covered by version 3
+of the GNU General Public License that is incorporated pursuant to the
+following paragraph.
+
+  Notwithstanding any other provision of this License, you have
+permission to link or combine any covered work with a work licensed
+under version 3 of the GNU General Public License into a single
+combined work, and to convey the resulting work.  The terms of this
+License will continue to apply to the part which is the covered work,
+but the work with which it is combined will remain governed by version
+3 of the GNU General Public License.
+
+  14. Revised Versions of this License.
+
+  The Free Software Foundation may publish revised and/or new versions of
+the GNU Affero General Public License from time to time.  Such new versions
+will be similar in spirit to the present version, but may differ in detail to
+address new problems or concerns.
+
+  Each version is given a distinguishing version number.  If the
+Program specifies that a certain numbered version of the GNU Affero General
+Public License "or any later version" applies to it, you have the
+option of following the terms and conditions either of that numbered
+version or of any later version published by the Free Software
+Foundation.  If the Program does not specify a version number of the
+GNU Affero General Public License, you may choose any version ever published
+by the Free Software Foundation.
+
+  If the Program specifies that a proxy can decide which future
+versions of the GNU Affero General Public License can be used, that proxy's
+public statement of acceptance of a version permanently authorizes you
+to choose that version for the Program.
+
+  Later license versions may give you additional or different
+permissions.  However, no additional obligations are imposed on any
+author or copyright holder as a result of your choosing to follow a
+later version.
+
+  15. Disclaimer of Warranty.
+
+  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
+THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Affero General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If your software can interact with users remotely through a computer
+network, you should also make sure that it provides a way for users to
+get its source.  For example, if your program is a web application, its
+interface could display a "Source" link that leads users to an archive
+of the code.  There are many ways you could offer source, and different
+solutions will be better for different programs; see section 13 for the
+specific requirements.
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU AGPL, see
+<https://www.gnu.org/licenses/>.

README.md

@@ -0,0 +1,7 @@
+<p align="center"><img width="50" height="50" alt="vektor" src="https://github.com/user-attachments/assets/d05df51f-c906-4a8f-a054-45e0d7e72326" /></p>
+
+<hr>
+
+<p align="center">Vektor: Modern Vector Graphics Editor</p>
+
+Vektor is a vector graphics editor built in C with GTK4, aiming for ease of creating graphics, simple user interface and lightweight size.

flake.nix

@@ -3,29 +3,33 @@
 
   inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
 
-  outputs = {
+  outputs =
-    self,
+    {
-    nixpkgs,
+      self,
-  }: let
+      nixpkgs,
-    system = "x86_64-linux";
+    }:
-    pkgs = import nixpkgs {inherit system;};
+    let
-  in {
+      system = "x86_64-linux";
-    devShells.${system}.default = pkgs.mkShell {
+      pkgs = import nixpkgs { inherit system; };
-      nativeBuildInputs = with pkgs; [
+    in
-        gcc
+    {
-        clang-tools
+      devShells.${system}.default = pkgs.mkShell {
-        lldb
+        nativeBuildInputs = with pkgs; [
+          gcc
+          clang-tools
+          lldb
 
-        meson
+          meson
-        ninja
+          ninja
-        pkg-config
+          pkg-config
 
-        gtk4
+          gtk4
+          libepoxy
 
-        gdb
+          gdb
-      ];
+        ];
 
-      shellHook = "";
+        shellHook = "";
+      };
     };
-  };
 }

icons/hicolor/scalable/actions/tool-brush-symbolic.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" viewBox="0 0 22 22">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="M 14.574219 1.0058594 C 13.520146 0.87298937 10.770478 2.75775 8.0605469 5.46875 C 6.8520776 6.67795 5.8032796 7.8729 5 9 C 5.9414561 9.29995 6.7002076 10.0582 7 11 C 8.1266713 10.19649 9.3243336 9.1522594 10.533203 7.9433594 C 13.607725 4.8675594 15.546263 1.8205187 14.863281 1.1367188 C 14.793083 1.0660188 14.697306 1.0216494 14.574219 1.0058594 z M 4.5 10.330078 L 4.5 10.332031 C 1.0001889 11.270271 3.6248533 13.4865 1 15 C 4.4998111 15 6.25 13.248178 6.25 12.080078 C 6.25 11.497798 6.3093545 10.426978 4.5 10.330078 z" transform="translate(3 3)"/>
+</svg>

icons/hicolor/scalable/actions/tool-circle-symbolic.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" version="1.1">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="m 12,5 a 7,7 0 0 0 -7,7 7,7 0 0 0 7,7 7,7 0 0 0 7,-7 7,7 0 0 0 -7,-7 z m 0,2 a 5,5 0 0 1 5,5 5,5 0 0 1 -5,5 5,5 0 0 1 -5,-5 5,5 0 0 1 5,-5 z"/>
+</svg>

icons/hicolor/scalable/actions/tool-line-symbolic.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" version="1.1">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="m 15.776522,16.777778 c 0,0 0.5,0.5 1,0 0.5,-0.5 0,-1 0,-1 L 6.2222222,5.2234778 c 0,0 -0.5,-0.5 -1,0 -0.5,0.5 0,1 0,1 z"/>
+</svg>

icons/hicolor/scalable/actions/tool-pencil-symbolic.svg

@@ -0,0 +1,10 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" version="1.1">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <g transform="translate(3,3)">
+  <path style="fill:currentColor" class="ColorScheme-Text" d="M 12.778,1.2222 C 12.778,1.2222 12.278,0.72224 11.778,1.2222 L 10,3 13,6 14.778,4.2222 C 15.278,3.7222 14.778,3.2222 14.778,3.2222 Z M 9,4 1,12 V 15 H 4 L 12,7 Z"/>
+ </g>
+</svg>

icons/hicolor/scalable/actions/tool-polygon-symbolic.svg

@@ -0,0 +1,9 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="24" height="24" version="1.1">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="M 16.98,6.5 5.9551,7.502 5.5,8 v 10 l 0.8203,0.385 5.7481,-4.7912 5.7086,2.8532 0.719,-0.502 -1,-8.9997 z m -0.423,1.043 0.845,7.6 -5.1793,-2.5903 -0.543,0.0625 L 6.5,16.932 V 8.457 Z"/>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="m 14,13 a 2,2 0 0 1 -2,2 2,2 0 0 1 -2,-2 2,2 0 0 1 2,-2 2,2 0 0 1 2,2 z M 8,8 A 2,2 0 0 1 6,10 2,2 0 0 1 4,8 2,2 0 0 1 6,6 2,2 0 0 1 8,8 Z m 0,10 a 2,2 0 0 1 -2,2 2,2 0 0 1 -2,-2 2,2 0 0 1 2,-2 2,2 0 0 1 2,2 z m 12,-2 a 2,2 0 0 1 -2,2 2,2 0 0 1 -2,-2 2,2 0 0 1 2,-2 2,2 0 0 1 2,2 z M 19,7 a 2,2 0 0 1 -2,2 2,2 0 0 1 -2,-2 2,2 0 0 1 2,-2 2,2 0 0 1 2,2 z"/>
+</svg>

icons/hicolor/scalable/actions/tool-rectangle-symbolic.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" version="1.1">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="M 4,4 V 18 H 18 V 4 Z M 6,6 H 16 V 16 H 6 Z"/>
+</svg>

icons/hicolor/scalable/actions/tool-select-symbolic.svg

@@ -0,0 +1,8 @@
+<svg xmlns="http://www.w3.org/2000/svg" width="22" height="22" viewBox="0 0 22 22">
+ <defs>
+  <style id="current-color-scheme" type="text/css">
+   .ColorScheme-Text { color:#444444; } .ColorScheme-Highlight { color:#4285f4; } .ColorScheme-NeutralText { color:#ff9800; } .ColorScheme-PositiveText { color:#4caf50; } .ColorScheme-NegativeText { color:#f44336; }
+  </style>
+ </defs>
+ <path style="fill:currentColor" class="ColorScheme-Text" d="M 3.9960938 1 L 4.0117188 12.535156 L 6.3339844 10.255859 L 6.7714844 9.8242188 L 7.0097656 10.404297 L 8.9023438 15 L 10.363281 14.328125 L 8.3808594 9.7792969 L 8.1347656 9.2128906 L 8.7285156 9.15625 L 11.996094 8.8457031 L 3.9960938 1 z" transform="translate(3 3)"/>
+</svg>

meson.build

@@ -10,22 +10,32 @@ project(
   ],
 )
 
-gtk = dependency('gtk4', required: true)
+c_args = meson.get_compiler('c').get_supported_arguments([
+  '-Wno-unused-variable',
+  '-Wno-unused-parameter',
+  '-Wno-pedantic'
+  ])
+add_project_arguments(c_args, language: 'c')
+
+gtk = dependency('gtk4', required: true, include_type: 'system')
+epoxy = dependency('epoxy', include_type: 'system')
 
 src = files(
   'src/main.c',
   'src/core/matrix.c',
   'src/core/primitives.c',
   'src/core/raster.c',
+  'src/core/modifier.c',
   'src/ui/uicontroller.c',
   'src/ui/vektorcanvas.c',
+  'src/ui/widgets/colorwheel.c',
   'src/application/applicationstate.c'
 )
 
 executable(
   'vektor',
   src,
-  dependencies: [gtk],
+  dependencies: [gtk, epoxy],
   link_args: ['-lm'],
   install: true,
 )

shaders/selection.frag.glsl

@@ -0,0 +1,40 @@
+#version 320 es
+precision mediump float;
+
+in vec2 vPos;
+out vec4 FragColor;
+
+uniform float uTime;
+uniform float uScale;
+uniform vec4 uColor1;
+uniform vec4 uColor2;
+uniform vec2 uMin;
+uniform vec2 uMax;
+
+void main()
+{
+    float borderWidth = 0.008 / uScale;
+
+
+    float distX = min(vPos.x - uMin.x, uMax.x - vPos.x);
+    float distY = min(vPos.y - uMin.y, uMax.y - vPos.y);
+    float dist  = min(distX, distY);
+
+    if (dist > borderWidth)
+        discard;
+
+    float dash_length = 0.025;
+    float gap_length  = 0.015;
+    float total       = dash_length + gap_length;
+
+    float speed       = 0.3;
+
+    float distance_along = (vPos.x + vPos.y) * 20.0;
+
+    float t = mod( distance_along * total + uTime * speed, total);
+
+    if (t < dash_length)
+        FragColor = uColor2;
+    else
+        FragColor = uColor1;
+}

shaders/triangle.frag.glsl

@@ -0,0 +1,10 @@
+#version 320 es
+precision mediump float;
+
+in vec4 vColor;
+out vec4 FragColor;
+
+void main()
+{
+    FragColor = vColor;
+}

shaders/triangle.vert.glsl

@@ -0,0 +1,17 @@
+#version 320 es
+precision mediump float;
+
+layout(location = 0) in vec2 aPos;
+layout (location = 1) in vec4 aColor;
+
+uniform mat4 uProjection;
+
+out vec4 vColor;
+out vec2 vPos;
+
+void main()
+{
+    gl_Position = uProjection * vec4(aPos, 0.0, 1.0);
+    vPos = aPos;
+    vColor = aColor;
+}

src/application/applicationstate.c

@@ -1,10 +1,20 @@
+#include "src/core/matrix.h"
+#include "src/core/modifier.h"
+#include "src/ui/uicontroller.h"
+#include "stdlib.h"
+
 #include "./applicationstate.h"
 #include "glib.h"
+#include "gtk/gtk.h"
+#include "gtk/gtkrevealer.h"
 #include "src/core/primitives.h"
-#include "src/core/raster.h"
+
 #include "src/ui/vektorcanvas.h"
+#include "src/ui/widgets/colorwheel.h"
+#include "src/util/color.h"
 
 typedef struct button_tool_set_data {
+    GtkRevealer* revealer;
     VektorAppState* state;
     VektorAppTool tool;
 } button_tool_set_data;
@@ -13,8 +23,60 @@ static void appstate_set_tool(GtkButton* button, gpointer user_data) {
     button_tool_set_data* data = (button_tool_set_data*)user_data;
     data->state->selectedTool = data->tool;
 
-    // setting tool also resets selected primitive
+    // setting tool makes the sub-tools menu to close
-    data->state->selectedPrimitive = NULL;
+    // (ADD NEW REVEALERS HERE)
+    gtk_revealer_set_reveal_child(
+        data->state->widgetState->workspaceRevealerShapes, FALSE);
+
+    // setting tool also resets selected shape
+    // NOTE: isn't needed anymore, as you would
+    // want to be able to select & edit existing shapes
+    // data->state->selectedShape = NULL;
+}
+
+static void appstate_reveal_subtools(GtkButton* button, gpointer user_data) {
+    GtkRevealer* revealer = (GtkRevealer*)user_data;
+    gboolean visible = gtk_revealer_get_reveal_child(revealer);
+    gtk_revealer_set_reveal_child(revealer, !visible);
+}
+
+static void appstate_on_color_change(VektorColorWheel* wheel,
+                                     gpointer user_data) {
+    VektorColor c = vektor_color_wheel_get_color(wheel);
+    VektorAppState* appstate = (VektorAppState*)user_data;
+    appstate->currentColor = c;
+
+    if (appstate->selectedShape != NULL) {
+        appstate->selectedShape->base->style.stroke_color = c;
+    }
+
+    // set entry fields under the color selector
+    char *str_r, *str_g, *str_b;
+    str_r = g_strdup_printf("%d", c.r);
+    str_g = g_strdup_printf("%d", c.g);
+    str_b = g_strdup_printf("%d", c.b);
+    gtk_editable_set_text(GTK_EDITABLE(appstate->widgetState->sidepanelEntryR),
+                          str_r);
+    gtk_editable_set_text(GTK_EDITABLE(appstate->widgetState->sidepanelEntryG),
+                          str_g);
+    gtk_editable_set_text(GTK_EDITABLE(appstate->widgetState->sidepanelEntryB),
+                          str_b);
+
+    vektor_canvas_geometry_changed(appstate->renderInfo);
+}
+
+static void appstate_on_entry_update(GtkEntry* entry, gpointer user_data) {
+    VektorWidgetState* widgetState = (VektorWidgetState*)user_data;
+    unsigned char r = (unsigned char)atoi(
+        gtk_editable_get_text(GTK_EDITABLE(widgetState->sidepanelEntryR)));
+    unsigned char g = (unsigned char)atoi(
+        gtk_editable_get_text(GTK_EDITABLE(widgetState->sidepanelEntryG)));
+    unsigned char b = (unsigned char)atoi(
+        gtk_editable_get_text(GTK_EDITABLE(widgetState->sidepanelEntryB)));
+
+    vektor_color_wheel_set_color(
+        VEKTOR_COLOR_WHEEL(widgetState->workspaceColorPicker),
+        (VektorColor){.r = r, .g = g, .b = b});
 }
 
 static void canvas_onclick(GtkGestureClick* gesture, int n_press, double x,
@@ -28,66 +90,321 @@ static void canvas_onclick(GtkGestureClick* gesture, int n_press, double x,
     int widget_w = gtk_widget_get_width(widget);
     int widget_h = gtk_widget_get_height(widget);
 
-    int canvas_w = state->canvas->width;
+    V2 normalized_coords =
-    int canvas_h = state->canvas->height;
+        (V2){(2 * (x / widget_w)) - 1, 1 - (2 * (y / widget_h))};
 
-    double sx = canvas_w / (double)widget_w;
+    vektor_appstate_canvas_click(state, normalized_coords.x,
-    double sy = canvas_h / (double)widget_h;
+                                 normalized_coords.y);
 
-    g_debug("<%f , %f>", x * sx, y * sy);
+    // technically there are cases when a click would not result in change of
-    vektor_appstate_canvas_click(state, x * sx, y * sy);
+    // the geometry but this is more concise then writing it inside that
+    // function a bunch of times and burder future click dispatches with
+    // handling this signal
+    vektor_canvas_geometry_changed(state->renderInfo);
 }
 
 void vektor_appstate_canvas_click(VektorAppState* state, double x, double y) {
-    V2 pos = (V2){x, y};
+    V2 pos =
+        m33_transform(m33_inverse(state->renderInfo->canvasMat), (V2){x, y});
 
 begin_click_dispatch:
     if (state->selectedTool == VektorLineTool) {
-        // create new polyline primitive if none is selected
+        // create new polyline shape if none is selected
-        if (state->selectedPrimitive == NULL) {
+        if (state->selectedShape == NULL) {
 
             VektorPolyline* line = vektor_polyline_new();
             VektorPrimitive linePrimitive =
                 (VektorPrimitive){.kind = VEKTOR_POLYLINE, .polyline = line};
-            vektor_primitivebuffer_add_primitive(state->primitiveBuffer,
+            VektorStyle style = (VektorStyle){
-                                                 linePrimitive);
+                .stroke_color = state->currentColor, .stroke_width = 0.01};
 
-            state->selectedPrimitive =
+            vektor_shapenodebuf_add(state->shapeBuffer,
-                &(state->primitiveBuffer
+                                    vektor_shapenode_new(vektor_shape_new(
-                      ->primitives[state->primitiveBuffer->count - 1]);
+                                        linePrimitive, style, 0)));
 
-        } else if (state->selectedPrimitive->kind != VEKTOR_POLYLINE) {
+            state->selectedShape =
+                &(state->shapeBuffer->nodes[state->shapeBuffer->count - 1]);
+
+        } else if (state->selectedShape->base->primitive.kind !=
+                   VEKTOR_POLYLINE) {
             // selecting a tool resets the selection, so this condition
             // should not happen
             g_warning("Invalid selected primitive; polyline expected");
-            state->selectedPrimitive = NULL;
+            vektor_appstate_deselect_shape(state);
             goto begin_click_dispatch; // retry
         }
 
-        vektor_polyline_add_point(state->selectedPrimitive->polyline, pos);
+        vektor_polyline_add_point(state->selectedShape->base->primitive.polyline,
-    }
+                                  pos);
+        state->selectedShape->base->bbox =
+            vektor_primitive_get_bbox(state->selectedShape->base->primitive);
 
-    vektor_framebuffer_rasterize(state->frameBuffer, state->primitiveBuffer);
+        // polyline's handle count is not fixed, so we have to add them manually
-    vektor_canvas_drawfrom(state->frameBuffer, state->canvas);
+        vektor_shape_add_handle(state->selectedShape->base, pos);
-    vektor_canvas_update(state->canvas);
+
+    } else if (state->selectedTool == VektorPolygonTool) {
+        // create new polygon shape if none is selected
+        if (state->selectedShape == NULL) {
+
+            VektorPolygon* polygon = vektor_polygon_new();
+            VektorPrimitive polygonPrimitive =
+                (VektorPrimitive){.kind = VEKTOR_POLYGON, .polygon = polygon};
+            VektorStyle style = (VektorStyle){
+                .stroke_color = state->currentColor, .stroke_width = 0.01};
+            vektor_shapenodebuf_add(state->shapeBuffer,
+                                    vektor_shapenode_new(vektor_shape_new(
+                                        polygonPrimitive, style, 0)));
+
+            state->selectedShape =
+                &(state->shapeBuffer->nodes[state->shapeBuffer->count - 1]);
+
+        } else if (state->selectedShape->base->primitive.kind !=
+                   VEKTOR_POLYGON) {
+            g_warning("Invalid selected primitive; polygon expected");
+            vektor_appstate_deselect_shape(state);
+            goto begin_click_dispatch; // retry
+        }
+
+        vektor_polygon_add_point(state->selectedShape->base->primitive.polygon,
+                                 pos);
+        state->selectedShape->base->bbox =
+            vektor_primitive_get_bbox(state->selectedShape->base->primitive);
+
+        // polygon's handle count is not fixed, so we have to add them manually
+        vektor_shape_add_handle(state->selectedShape->base, pos);
+
+    } else if (state->selectedTool == VektorCircleTool) {
+
+        VektorCircle* circle = vektor_circle_new();
+        VektorPrimitive circlePrimitive =
+            (VektorPrimitive){.kind = VEKTOR_CIRCLE, .circle = *circle};
+        VektorStyle style = (VektorStyle){.stroke_color = state->currentColor,
+                                          .stroke_width = 0.01};
+        vektor_shapenodebuf_add(
+            state->shapeBuffer,
+            vektor_shapenode_new(vektor_shape_new(circlePrimitive, style, 0)));
+
+        state->selectedShape =
+            &(state->shapeBuffer->nodes[state->shapeBuffer->count - 1]);
+
+        vektor_circle_free(circle);
+
+        vektor_circle_set_center(&state->selectedShape->base->primitive.circle,
+                                 pos);
+        vektor_circle_set_radius(&state->selectedShape->base->primitive.circle,
+                                 0.1f);
+
+        state->selectedShape->base->bbox =
+            vektor_primitive_get_bbox(state->selectedShape->base->primitive);
+
+        vektor_circle_create_handles(
+            &state->selectedShape->base->primitive.circle,
+            &state->selectedShape->base->handles,
+            &state->selectedShape->base->handleCount);
+    } else if (state->selectedTool == VektorRectangleTool) {
+
+        VektorRectangle* rect = vektor_rectangle_new();
+        VektorPrimitive rectPrimitive =
+            (VektorPrimitive){.kind = VEKTOR_RECTANGLE, .rectangle = *rect};
+        VektorStyle style = (VektorStyle){.stroke_color = state->currentColor,
+                                          .stroke_width = 0.01};
+        vektor_shapenodebuf_add(
+            state->shapeBuffer,
+            vektor_shapenode_new(vektor_shape_new(rectPrimitive, style, 0)));
+
+        state->selectedShape =
+            &(state->shapeBuffer->nodes[state->shapeBuffer->count - 1]);
+
+        vektor_rectangle_free(rect);
+
+        vektor_rectangle_set_start(
+            &state->selectedShape->base->primitive.rectangle, pos);
+        vektor_rectangle_set_end(
+            &state->selectedShape->base->primitive.rectangle,
+            vec2_add(pos, (V2){0.1f, 0.1f}));
+        vektor_rectangle_create_handles(
+            &state->selectedShape->base->primitive.rectangle,
+            &state->selectedShape->base->handles,
+            &state->selectedShape->base->handleCount);
+
+        state->selectedShape->base->bbox =
+            vektor_primitive_get_bbox(state->selectedShape->base->primitive);
+
+    } else if (state->selectedTool == VektorSelectionTool) {
+        for (size_t i = 0; i < state->shapeBuffer->count; i++) {
+            VektorBBox bbox = vektor_primitive_get_bbox(
+                state->shapeBuffer->nodes[i].base->primitive);
+
+            // expand the bbox a little so its not painful to
+            // try to grab handles located on the border of said bbox
+            bbox = vektor_bbox_expand(bbox, 0.02);
+
+            if (vektor_bbox_isinside(bbox, pos)) {
+                state->selectedShape = &(state->shapeBuffer->nodes[i]);
+                return;
+            }
+        }
+        // was clicked outside any shapes - reset selection
+        vektor_appstate_deselect_shape(state);
+    }
+}
+
+void vektor_appstate_canvas_drag_begin(GtkGestureDrag* gesture, gdouble x,
+                                       gdouble y, gpointer user_data) {
+    GtkWidget* widget =
+        gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(gesture));
+
+    VektorAppState* state = (VektorAppState*)user_data;
+
+    int widget_w = gtk_widget_get_width(widget);
+    int widget_h = gtk_widget_get_height(widget);
+
+    V2 position = (V2){(2 * (x / widget_w)) - 1, 1 - (2 * (y / widget_h))};
+    position = m33_transform(m33_inverse(state->renderInfo->canvasMat),
+                             (V2){position.x, position.y});
+
+    if (state->selectedShape != NULL) {
+        VektorShapeNode* selectedShape = state->selectedShape;
+
+        // get selected shape's handles and check
+        // if we click any of them
+        for (size_t i = 0; i < selectedShape->base->handleCount; i++) {
+            VektorBBox bbox =
+                vektor_shape_get_handle_bbox(selectedShape->base->handles[i]);
+            if (vektor_bbox_isinside(bbox, position)) {
+                // clicked inside handle
+                state->heldHandleIndex = i;
+                vektor_canvas_geometry_changed(state->renderInfo);
+                break;
+            }
+        }
+    }
+}
+
+void vektor_appstate_canvas_drag_update(GtkGestureDrag* gesture, gdouble x,
+                                        gdouble y, gpointer user_data) {
+
+    // ---- setup normalized coordinates (boilerplate) ----
+    gdouble start_x, start_y;
+    gtk_gesture_drag_get_start_point(gesture, &start_x, &start_y);
+
+    GtkWidget* widget =
+        gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(gesture));
+
+    VektorAppState* state = (VektorAppState*)user_data;
+
+    int widget_w = gtk_widget_get_width(widget);
+    int widget_h = gtk_widget_get_height(widget);
+
+    V2 position = (V2){(2 * ((x + start_x) / widget_w)) - 1,
+                       1 - (2 * ((y + start_y) / widget_h))};
+    position = m33_transform(m33_inverse(state->renderInfo->canvasMat),
+                             (V2){position.x, position.y});
+
+    // drag handle if selected
+    if (state->selectedShape != NULL && state->heldHandleIndex != -1) {
+        state->selectedShape->base->handles[state->heldHandleIndex] = position;
+        vektor_shape_handles_updated(state->selectedShape->base,
+                                     &state->heldHandleIndex);
+        vektor_canvas_geometry_changed(state->renderInfo);
+    }
+}
+
+void vektor_appstate_canvas_drag_end(GtkGestureDrag* gesture, gdouble x,
+                                     gdouble y, gpointer user_data) {
+
+    VektorAppState* state = (VektorAppState*)user_data;
+
+    // if we were dragging a handle
+    if (state->selectedShape != NULL && state->heldHandleIndex != -1) {
+        state->heldHandleIndex = -1; // ...then remove handle drag flag
+        vektor_canvas_geometry_changed(state->renderInfo);
+    }
 }
 
 void vektor_appstate_new(VektorWidgetState* wstate, VektorAppState* stateOut) {
     button_tool_set_data* data_linetool = malloc(sizeof(button_tool_set_data));
     data_linetool->state = stateOut;
     data_linetool->tool = VektorLineTool;
+    data_linetool->revealer = wstate->workspaceRevealerShapes;
+
+    button_tool_set_data* data_polygontool =
+        malloc(sizeof(button_tool_set_data));
+    data_polygontool->state = stateOut;
+    data_polygontool->tool = VektorPolygonTool;
+    data_polygontool->revealer = wstate->workspaceRevealerShapes;
+
+    button_tool_set_data* data_rectangletool =
+        malloc(sizeof(button_tool_set_data));
+    data_rectangletool->state = stateOut;
+    data_rectangletool->tool = VektorRectangleTool;
+    data_rectangletool->revealer = wstate->workspaceRevealerShapes;
+
+    button_tool_set_data* data_selecttool =
+        malloc(sizeof(button_tool_set_data));
+    data_selecttool->state = stateOut;
+    data_selecttool->tool = VektorSelectionTool;
+
+    button_tool_set_data* data_circletool =
+        malloc(sizeof(button_tool_set_data));
+    data_circletool->state = stateOut;
+    data_circletool->tool = VektorCircleTool;
+    data_circletool->revealer = wstate->workspaceRevealerShapes;
 
     // populate appstate
-    stateOut->primitiveBuffer = malloc(sizeof(VektorPrimitiveBuffer));
+    stateOut->startupTime = g_get_monotonic_time();
-    *stateOut->primitiveBuffer = (VektorPrimitiveBuffer){0};
+    stateOut->shapeBuffer = malloc(sizeof(VektorShapeNodeBuffer));
-    stateOut->frameBuffer = malloc(sizeof(VektorFramebuffer));
+    *stateOut->shapeBuffer = (VektorShapeNodeBuffer){0};
-    *stateOut->frameBuffer = vektor_framebuffer_new(400, 400);
     stateOut->canvas = malloc(sizeof(VektorCanvas));
-    vektor_canvas_init(wstate, stateOut->canvas);
+    stateOut->widgetState = wstate;
+    stateOut->currentColor = vektor_color_solid(0, 0, 0);
+    stateOut->selectedShape = NULL;
+    stateOut->heldHandleIndex = -1;
+
+    VektorCanvasRenderInfo* renderInfo = malloc(sizeof(VektorCanvasRenderInfo));
+    renderInfo->zoom = 1;
+    renderInfo->panX = 0;
+    renderInfo->panY = 0;
+    renderInfo->rotation = 0;
+    m33_to_gl4(m33_identity(), renderInfo->canvasTransform);
+    renderInfo->selectedShape = &(stateOut->selectedShape);
+    renderInfo->shapes = stateOut->shapeBuffer;
+    renderInfo->startupTime = stateOut->startupTime;
+    renderInfo->canvasMat = m33_identity();
+    vektor_canvas_init(wstate, stateOut->canvas, renderInfo);
+    stateOut->renderInfo = renderInfo;
 
     // link all the buttons
-    g_signal_connect(G_OBJECT(wstate->workspaceButtonLinetool), "clicked",
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonLineTool), "clicked",
                      G_CALLBACK(appstate_set_tool), data_linetool);
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonRectTool), "clicked",
+                     G_CALLBACK(appstate_set_tool), data_rectangletool);
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonCircleTool), "clicked",
+                     G_CALLBACK(appstate_set_tool), data_circletool);
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonPolygonTool), "clicked",
+                     G_CALLBACK(appstate_set_tool), data_polygontool);
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonSelectionTool), "clicked",
+                     G_CALLBACK(appstate_set_tool), data_selecttool);
+
+    // hook subtool revealers to their master buttons
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonMasterShapes), "clicked",
+                     G_CALLBACK(appstate_reveal_subtools),
+                     wstate->workspaceRevealerShapes);
+
+    // hook relevant stuff to master color picker
+    g_signal_connect(G_OBJECT(wstate->workspaceColorPicker), "color-changed",
+                     G_CALLBACK(appstate_on_color_change), stateOut);
+
+    // hook rgb entries change
+    g_signal_connect(G_OBJECT(wstate->sidepanelEntryR), "activate",
+                     G_CALLBACK(appstate_on_entry_update),
+                     stateOut->widgetState);
+    g_signal_connect(G_OBJECT(wstate->sidepanelEntryG), "activate",
+                     G_CALLBACK(appstate_on_entry_update),
+                     stateOut->widgetState);
+    g_signal_connect(G_OBJECT(wstate->sidepanelEntryB), "activate",
+                     G_CALLBACK(appstate_on_entry_update),
+                     stateOut->widgetState);
 
     // Add click gesture to canvas
     GtkGesture* canvasClickGesture = gtk_gesture_click_new();
@@ -95,4 +412,21 @@ void vektor_appstate_new(VektorWidgetState* wstate, VektorAppState* stateOut) {
                      G_CALLBACK(canvas_onclick), stateOut);
     gtk_widget_add_controller(GTK_WIDGET(wstate->workspaceCanvas),
                               GTK_EVENT_CONTROLLER(canvasClickGesture));
+
+    // Add drag gesture to canvas
+    GtkGesture* canvasDragGesture = gtk_gesture_drag_new();
+    g_signal_connect(G_OBJECT(canvasDragGesture), "drag-update",
+                     G_CALLBACK(vektor_appstate_canvas_drag_update), stateOut);
+    g_signal_connect(G_OBJECT(canvasDragGesture), "drag-begin",
+                     G_CALLBACK(vektor_appstate_canvas_drag_begin), stateOut);
+    g_signal_connect(G_OBJECT(canvasDragGesture), "drag-end",
+                     G_CALLBACK(vektor_appstate_canvas_drag_end), stateOut);
+
+    gtk_widget_add_controller(GTK_WIDGET(wstate->workspaceCanvas),
+                              GTK_EVENT_CONTROLLER(canvasDragGesture));
+}
+
+void vektor_appstate_deselect_shape(VektorAppState* state) {
+    state->heldHandleIndex = -1;
+    state->selectedShape = NULL;
 }

src/application/applicationstate.h

@@ -4,24 +4,36 @@
 #include "../core/primitives.h"
 #include "../ui/uicontroller.h"
 #include "../ui/vektorcanvas.h"
-#include "src/core/raster.h"
+#include "src/core/modifier.h"
 
-typedef enum VektorAppTool { VektorLineTool } VektorAppTool;
+typedef enum VektorAppTool {
+    VektorSelectionTool,
+    VektorLineTool,
+    VektorPolygonTool,
+    VektorRectangleTool,
+    VektorCircleTool
+} VektorAppTool;
 
 typedef struct VektorAppState {
+    gint64 startupTime;
+
+    VektorWidgetState* widgetState;
+
     VektorAppTool selectedTool;
-    VektorPrimitive* selectedPrimitive;
+    VektorShapeNode* selectedShape;
+    int heldHandleIndex;
+
+    VektorColor currentColor;
 
     // Logic space
-    VektorPrimitiveBuffer* primitiveBuffer;
+    VektorShapeNodeBuffer* shapeBuffer;
-    // Pixel space
-    VektorFramebuffer* frameBuffer;
     // View space
     VektorCanvas* canvas;
-
+    VektorCanvasRenderInfo* renderInfo;
 } VektorAppState;
 
 void vektor_appstate_new(VektorWidgetState* wstate, VektorAppState* stateOut);
 void vektor_appstate_canvas_click(VektorAppState* state, double x, double y);
+void vektor_appstate_deselect_shape(VektorAppState* state);
 
 #endif

src/core/matrix.c

@@ -87,3 +87,25 @@ V2 m33_transform(const M33 mat, const V2 v) {
     return (V2){mat.m[0][0] * v.x + mat.m[0][1] * v.y + mat.m[0][2],
                 mat.m[1][0] * v.x + mat.m[1][1] * v.y + mat.m[1][2]};
 }
+
+void m33_to_gl4(const M33 m, float out[16]) {
+    out[0] = m.m[0][0];
+    out[1] = m.m[1][0];
+    out[2] = 0.0f;
+    out[3] = 0.0f;
+
+    out[4] = m.m[0][1];
+    out[5] = m.m[1][1];
+    out[6] = 0.0f;
+    out[7] = 0.0f;
+
+    out[8] = 0.0f;
+    out[9] = 0.0f;
+    out[10] = 1.0f;
+    out[11] = 0.0f;
+
+    out[12] = m.m[0][2];
+    out[13] = m.m[1][2];
+    out[14] = 0.0f;
+    out[15] = 1.0f;
+}

src/core/matrix.h

@@ -22,4 +22,6 @@ M33 m33_inverse(const M33 m);
 
 V2 m33_transform(const M33 mat, const V2 v);
 
+void m33_to_gl4(const M33 m, float out[16]);
+
 #endif // MATRIX_H_

src/core/modifier.c

@@ -0,0 +1,83 @@
+#include "modifier.h"
+#include <glib.h>
+
+VektorShapeNode vektor_shapenode_new(VektorShape* shape) {
+    VektorShapeNode node = (VektorShapeNode){
+        .base = shape, 
+        .modifier_count = 0, 
+        .evaluated = shape,
+        .base_dirty = true
+    };
+    return node;
+}
+
+void vektor_shapenode_free(VektorShapeNode* shapeNode) {
+    if(shapeNode->base == shapeNode->evaluated) {
+        free(shapeNode->base); // avoid double free()
+    } else {
+        free(shapeNode->base);
+        free(shapeNode->evaluated);
+    }
+    free(shapeNode->modifiers);
+}
+
+VektorShape* vektor_shapenode_get_evaluated(VektorShapeNode* shapeNode) {
+    return shapeNode->evaluated;
+}
+
+VektorShape vektor_modifier_apply(VektorModifier* mod, VektorShape* input) {
+    mod->cachedEvaluatedShape = mod->apply(mod, input);
+    return mod->cachedEvaluatedShape;
+}
+
+// lots of copies by value here, could be problematic
+void vektor_shapenode_update(VektorShapeNode* shapeNode) {
+    // if the base is dirty, apply EVERY modifier
+    if(shapeNode->base_dirty) {
+        VektorShape* evaluated = shapeNode->base;
+        for(size_t i = 0; i < shapeNode->modifier_count; i++) {
+            *evaluated = vektor_modifier_apply(&shapeNode->modifiers[i], evaluated);
+            shapeNode->modifiers[i].dirty = false;
+        }
+        shapeNode->evaluated = evaluated;
+        shapeNode->base_dirty = false;
+        return;
+    }
+
+    // if the base is not dirty, start applying modifiers upstream
+    // starting from the first dirty
+    bool encountered_dirty = false;
+    
+    for(size_t i = 0; i < shapeNode->modifier_count; i++) {
+        if(shapeNode->modifiers[i].dirty) { encountered_dirty = true; }
+        if(encountered_dirty) {
+            if(i == 0) {
+                vektor_modifier_apply(&shapeNode->modifiers[i], shapeNode->base);
+            } else {
+                vektor_modifier_apply(&shapeNode->modifiers[i], &shapeNode->modifiers[i - 1].cachedEvaluatedShape);
+            }
+            shapeNode->modifiers[i].dirty = false;
+        }
+    }
+
+    if (encountered_dirty) {
+        *shapeNode->evaluated = shapeNode->modifiers[shapeNode->modifier_count - 1].cachedEvaluatedShape;
+    }
+
+}
+
+void vektor_shapenodebuf_add(VektorShapeNodeBuffer* buffer,
+                             VektorShapeNode node) {
+    if (buffer->count >= buffer->capacity) {
+        buffer->capacity = buffer->capacity ? buffer->capacity * 2 : 4;
+        buffer->nodes =
+            realloc(buffer->nodes, sizeof(VektorShapeNode) * buffer->capacity);
+    }
+    buffer->nodes[buffer->count++] = node;
+
+    if (buffer->count <= buffer->capacity / 4) {
+        buffer->capacity /= 2;
+        buffer->nodes =
+            realloc(buffer->nodes, sizeof(VektorShapeNode) * buffer->capacity);
+    }
+}

src/core/modifier.h

@@ -0,0 +1,53 @@
+#ifndef VKTR_MODIFIER_H
+#define VKTR_MODIFIER_H
+
+#include "src/core/primitives.h"
+
+typedef enum { 
+    VEKTOR_MODIFIER_IDENTITY,
+    VEKTOR_MODIFIER_BEVEL 
+} VektorModifierType;
+
+typedef struct VektorModifier {
+    VektorModifierType type;
+    bool enabled;
+    bool dirty;
+    void* parameters;
+
+    VektorShape (*apply)(struct VektorModifier* mod, VektorShape* input);
+    VektorShape cachedEvaluatedShape;
+
+} VektorModifier;
+
+typedef struct VektorShapeNode {
+    VektorShape* base;
+    VektorShape* evaluated;
+
+    VektorModifier* modifiers;
+    size_t modifier_count;
+
+    bool base_dirty;
+} VektorShapeNode;
+
+typedef struct VektorShapeNodeBuffer {
+    VektorShapeNode* nodes;
+    size_t count;
+    size_t capacity;
+} VektorShapeNodeBuffer;
+
+VektorShape vektor_modifier_apply(VektorModifier* mod, VektorShape* input);
+
+VektorShapeNode vektor_shapenode_new(VektorShape* shape);
+void vektor_shapenode_free(VektorShapeNode* shapeNode);
+VektorShape* vektor_shapenode_get_evaluated(VektorShapeNode* shapeNode);
+void vektor_shapenode_update(VektorShapeNode* shapeNode);
+void vektor_shapenode_modifier_add(VektorShapeNode* shapeNode,
+                                   VektorModifier* mod);
+void vektor_shapenode_modifier_remove(VektorShapeNode* shapeNode,
+                                      VektorModifier* mod);
+void vektor_shapenode_free(VektorShapeNode* shapeNode);
+
+void vektor_shapenodebuf_add(VektorShapeNodeBuffer* buffer,
+                             VektorShapeNode node);
+
+#endif

src/core/modifiers/m_identity.c

@@ -0,0 +1,16 @@
+#include "../modifier.h"
+
+static VektorShape vektor_m_identity_apply(VektorModifier* m, VektorShape* input) {
+    return *input;
+}
+
+VektorModifier vektor_m_identity_new() {
+    return (VektorModifier) {
+        .type = VEKTOR_MODIFIER_IDENTITY,
+        .enabled = true,
+        .dirty = true,
+        .parameters = NULL,
+        .apply = vektor_m_identity_apply
+    };
+}
+

src/core/primitives.c

@@ -1,4 +1,12 @@
 #include "primitives.h"
+#include "glib.h"
+#include "src/core/matrix.h"
+#include "src/core/vector.h"
+#include <assert.h>
+#include <math.h>
+#include <stddef.h>
+
+// ------ PER-PRIMITIVE METHODS ------
 
 VektorPolyline* vektor_polyline_new(void) {
     VektorPolyline* pl = malloc(sizeof(VektorPolyline));
@@ -14,6 +22,11 @@ void vektor_polyline_add_point(VektorPolyline* pl, V2 point) {
         pl->points = realloc(pl->points, sizeof(V2) * pl->capacity);
     }
     pl->points[pl->count++] = point;
+
+    if (pl->count <= pl->capacity / 4) {
+        pl->capacity /= 2;
+        pl->points = realloc(pl->points, sizeof(V2) * pl->capacity);
+    }
 }
 
 void vektor_polyline_free(VektorPolyline* pl) {
@@ -37,6 +50,11 @@ void vektor_polygon_add_point(VektorPolygon* pg, V2 point) {
         pg->points = realloc(pg->points, sizeof(V2) * pg->capacity);
     }
     pg->points[pg->count++] = point;
+
+    if (pg->count <= pg->capacity / 4) {
+        pg->capacity /= 2;
+        pg->points = realloc(pg->points, sizeof(V2) * pg->capacity);
+    }
 }
 
 void vektor_polygon_free(VektorPolygon* pg) {
@@ -46,12 +64,430 @@ void vektor_polygon_free(VektorPolygon* pg) {
     free(pg);
 }
 
-void vektor_primitivebuffer_add_primitive(VektorPrimitiveBuffer* buffer,
+VektorCircle* vektor_circle_new(void) {
-                                          VektorPrimitive prim) {
+    VektorCircle* circ = malloc(sizeof(VektorCircle));
+    circ->center = (V2){0, 0};
+    circ->radius = 0;
+    return circ;
+}
+
+void vektor_circle_set_center(VektorCircle* circle, V2 point) {
+    circle->center = point;
+}
+
+void vektor_circle_set_radius(VektorCircle* circle, double radius) {
+    circle->radius = radius;
+}
+
+void vektor_circle_free(VektorCircle* circle) { free(circle); }
+
+VektorRectangle* vektor_rectangle_new(void) {
+    VektorRectangle* rct = malloc(sizeof(VektorRectangle));
+    rct->start = (V2){.x = 0, .y = 0};
+    rct->end = (V2){.x = 0, .y = 0};
+    return rct;
+}
+
+void vektor_rectangle_set_end(VektorRectangle* rct, V2 point) {
+    rct->end = point;
+}
+void vektor_rectangle_set_start(VektorRectangle* rct, V2 point) {
+    rct->start = point;
+}
+
+void vektor_rectangle_free(VektorRectangle* rct) { free(rct); }
+
+VektorBBox vektor_polyline_get_bbox(VektorPrimitive prim) {
+    V2 first = prim.polyline->points[0];
+
+    float min_x = first.x;
+    float max_x = first.x;
+    float min_y = first.y;
+    float max_y = first.y;
+
+    for (size_t i = 1; i < prim.polygon->count; i++) {
+        V2 p = prim.polygon->points[i];
+
+        min_x = fminf(min_x, p.x);
+        min_y = fminf(min_y, p.y);
+
+        max_x = fmaxf(max_x, p.x);
+        max_y = fmaxf(max_y, p.y);
+    }
+
+    return (VektorBBox){(V2){min_x, min_y}, (V2){max_x, max_y}};
+}
+
+VektorBBox vektor_polygon_get_bbox(VektorPrimitive prim) {
+    V2 first = prim.polygon->points[0];
+
+    float min_x = first.x;
+    float max_x = first.x;
+    float min_y = first.y;
+    float max_y = first.y;
+
+    for (size_t i = 1; i < prim.polygon->count; i++) {
+        V2 p = prim.polygon->points[i];
+
+        min_x = fminf(min_x, p.x);
+        min_y = fminf(min_y, p.y);
+
+        max_x = fmaxf(max_x, p.x);
+        max_y = fmaxf(max_y, p.y);
+    }
+
+    return (VektorBBox){(V2){min_x, min_y}, (V2){max_x, max_y}};
+}
+
+VektorBBox vektor_rectangle_get_bbox(VektorPrimitive prim) {
+    return (VektorBBox){prim.rectangle.start, prim.rectangle.end};
+}
+
+VektorBBox vektor_circle_get_bbox(VektorPrimitive prim) {
+    return (VektorBBox){
+        vec2_sub(prim.circle.center, vec2_fromfloat(prim.circle.radius)),
+        vec2_add(prim.circle.center, vec2_fromfloat(prim.circle.radius))};
+}
+
+VektorBBox vektor_primitive_get_bbox(VektorPrimitive prim) {
+    switch (prim.kind) {
+    case VEKTOR_POLYLINE:
+        return vektor_polyline_get_bbox(prim);
+        break;
+
+    case VEKTOR_POLYGON:
+        return vektor_polygon_get_bbox(prim);
+        break;
+
+    case VEKTOR_RECTANGLE:
+        return vektor_rectangle_get_bbox(prim);
+        break;
+
+    case VEKTOR_CIRCLE:
+        return vektor_circle_get_bbox(prim);
+        break;
+
+    default:
+        // TODO: fill in all primitives
+        break;
+    }
+}
+
+// ------ PRIMITIVE HANDLES GENERATION ------
+
+/* [n]: polyline vertices */
+void vektor_polyline_create_handles(VektorPolyline* polyline, V2** handleArr,
+                                    size_t* count) {
+    *count = 0;
+    *handleArr = NULL;
+}
+
+/* [n]: polygon vertices */
+void vektor_polygon_create_handles(VektorPolygon* polygon, V2** handleArr,
+                                   size_t* count) {
+    *count = 0;
+    *handleArr = NULL;
+}
+
+/* [0]: center; [1]: radius */
+void vektor_circle_create_handles(VektorCircle* circle, V2** handleArr,
+                                  size_t* count) {
+    *count = 2;
+    *handleArr = (V2*)malloc(sizeof(V2) * (*count));
+    (*handleArr)[0] = circle->center;
+    (*handleArr)[1] = (V2){circle->radius + circle->center.x, circle->center.y};
+}
+
+/* [0]: center; [1-4]: corners (l2r, t2b); */
+void vektor_rectangle_create_handles(VektorRectangle* rectangle, V2** handleArr,
+                                     size_t* count) {
+    *count = 5;
+    free(*handleArr);
+    *handleArr = (V2*)malloc(sizeof(V2) * (*count));
+
+    V2 halfdist = vec2_scale(vec2_sub(rectangle->end, rectangle->start), 0.5f);
+    V2 center = vec2_add(rectangle->start, halfdist);
+
+    (*handleArr)[0] = center;
+    (*handleArr)[1] = vec2_add(center, vec2_mul(halfdist, (V2){-1.0f, 1.0f}));
+    (*handleArr)[2] = vec2_add(center, halfdist);
+    (*handleArr)[3] = vec2_add(center, vec2_mul(halfdist, (V2){-1.0f, -1.0f}));
+    (*handleArr)[4] = vec2_add(center, vec2_mul(halfdist, (V2){1.0f, -1.0f}));
+}
+
+void vektor_shape_create_handles(VektorShape* shape) {
+    switch (shape->primitive.kind) {
+    case VEKTOR_POLYLINE:
+        vektor_polyline_create_handles(shape->primitive.polyline,
+                                       &shape->handles, &shape->handleCount);
+        break;
+    case VEKTOR_POLYGON:
+        vektor_polygon_create_handles(shape->primitive.polygon, &shape->handles,
+                                      &shape->handleCount);
+        break;
+    case VEKTOR_CIRCLE:
+        vektor_circle_create_handles(&shape->primitive.circle, &shape->handles,
+                                     &shape->handleCount);
+        break;
+    case VEKTOR_RECTANGLE:
+        vektor_rectangle_create_handles(&shape->primitive.rectangle,
+                                        &shape->handles, &shape->handleCount);
+        break;
+    }
+}
+
+// ------ AUXILIARY HANDLE METHODS ------
+
+void vektor_shape_add_handle(VektorShape* shape, V2 handle) {
+    // could be optimised with capacity property
+    // but this function is only called when adding new
+    // points to polyline and polygon, so it should
+    // not be that much of an overhead
+    shape->handles =
+        realloc(shape->handles, sizeof(V2) * shape->handleCount + 1);
+    shape->handles[shape->handleCount++] = handle;
+}
+
+VektorBBox vektor_shape_get_handle_bbox(V2 handle) {
+    return vektor_bbox_fromcenter(handle, 0.02);
+}
+
+// ------ PRIMITIVE HANDLES UPDATING ------
+
+void vektor_polyline_handles_updated(VektorPolyline* polyline, V2** handles,
+                                     size_t* count, int* heldHandleIndex) {
+    if (*count != polyline->count) {
+        g_warning("handle count & point count mismatch in polyline");
+        return;
+    }
+    for (size_t i = 0; i < *count; i++) {
+        polyline->points[i] = (*handles)[i];
+    }
+}
+
+void vektor_polygon_handles_updated(VektorPolygon* polygon, V2** handles,
+                                    size_t* count, int* heldHandleIndex) {
+    if (*count != polygon->count) {
+        g_warning("handle count & point count mismatch in polygon");
+        return;
+    }
+    for (size_t i = 0; i < *count; i++) {
+        polygon->points[i] = (*handles)[i];
+    }
+}
+
+void vektor_circle_handles_updated(VektorCircle* circle, V2** handles,
+                                   size_t* count, int* heldHandleIndex) {
+    if (*count != 2) {
+        g_warning("unexpected circle handle count (%zu)", *count);
+        return;
+    }
+
+    if (*heldHandleIndex == 0) { // dragging center
+        V2 translation = vec2_sub((*handles)[0], circle->center);
+        circle->center = (*handles)[0];
+        (*handles)[1] = vec2_add(translation, (*handles)[1]);
+    } else {
+        circle->radius = vec2_length(vec2_sub((*handles)[0], (*handles)[1]));
+    }
+}
+
+// this shi is big because it dynamically handles handle remapping when
+// rectangle enters an invalid state (end < start)
+// creating the illusion of an invertable rect, while also keeping it
+// valid at all times
+void vektor_rectangle_handles_updated(VektorRectangle* rectangle, V2** handles,
+                                      size_t* count, int* heldHandleIndex) {
+    if (*count != 5) {
+        g_warning("unexpected rectangle handle count (%zu)", *count);
+        return;
+    }
+
+    V2 start = rectangle->start;
+    V2 end = rectangle->end;
+
+    switch (*heldHandleIndex) {
+    case 0: // center drag
+    {
+        V2 oldCenter = vec2_scale(vec2_add(start, end), 0.5f);
+        V2 newCenter = (*handles)[0];
+
+        V2 translation = vec2_sub(newCenter, oldCenter);
+
+        start = vec2_add(start, translation);
+        end = vec2_add(end, translation);
+        break;
+    }
+
+    case 1: // top-left
+        start.x = (*handles)[1].x;
+        end.y = (*handles)[1].y;
+        break;
+
+    case 2: // top-right
+        end.x = (*handles)[2].x;
+        end.y = (*handles)[2].y;
+        break;
+
+    case 3: // bottom-left
+        start.x = (*handles)[3].x;
+        start.y = (*handles)[3].y;
+        break;
+
+    case 4: // bottom-right
+        end.x = (*handles)[4].x;
+        start.y = (*handles)[4].y;
+        break;
+
+    default:
+        return;
+    }
+
+    // Store raw values before normalization
+    float raw_min_x = start.x;
+    float raw_max_x = end.x;
+    float raw_min_y = start.y;
+    float raw_max_y = end.y;
+
+    // Normalize rectangle
+    float min_x = fminf(start.x, end.x);
+    float max_x = fmaxf(start.x, end.x);
+    float min_y = fminf(start.y, end.y);
+    float max_y = fmaxf(start.y, end.y);
+
+    bool flipX = raw_min_x > raw_max_x;
+    bool flipY = raw_min_y > raw_max_y;
+
+    // Remap handle if we crossed axes
+    if (*heldHandleIndex != 0) {
+        if (flipX) {
+            switch (*heldHandleIndex) {
+            case 1:
+                *heldHandleIndex = 2;
+                break;
+            case 2:
+                *heldHandleIndex = 1;
+                break;
+            case 3:
+                *heldHandleIndex = 4;
+                break;
+            case 4:
+                *heldHandleIndex = 3;
+                break;
+            }
+        }
+
+        if (flipY) {
+            switch (*heldHandleIndex) {
+            case 1:
+                *heldHandleIndex = 3;
+                break;
+            case 3:
+                *heldHandleIndex = 1;
+                break;
+            case 2:
+                *heldHandleIndex = 4;
+                break;
+            case 4:
+                *heldHandleIndex = 2;
+                break;
+            }
+        }
+    }
+
+    VektorRectangle properRect = {.start = {min_x, min_y},
+                                  .end = {max_x, max_y}};
+
+    vektor_rectangle_set_start(rectangle, properRect.start);
+    vektor_rectangle_set_end(rectangle, properRect.end);
+
+    // regenerate handle positions
+    vektor_rectangle_create_handles(&properRect, handles, count);
+}
+
+void vektor_shape_handles_updated(VektorShape* shape, int* heldHandleIndex) {
+    switch (shape->primitive.kind) {
+    case VEKTOR_POLYLINE:
+        vektor_polyline_handles_updated(shape->primitive.polyline,
+                                        &shape->handles, &shape->handleCount,
+                                        heldHandleIndex);
+        break;
+    case VEKTOR_POLYGON:
+        vektor_polygon_handles_updated(shape->primitive.polygon,
+                                       &shape->handles, &shape->handleCount,
+                                       heldHandleIndex);
+        break;
+    case VEKTOR_CIRCLE:
+        vektor_circle_handles_updated(&shape->primitive.circle, &shape->handles,
+                                      &shape->handleCount, heldHandleIndex);
+        break;
+    case VEKTOR_RECTANGLE:
+        vektor_rectangle_handles_updated(&shape->primitive.rectangle,
+                                         &shape->handles, &shape->handleCount,
+                                         heldHandleIndex);
+        break;
+    }
+}
+
+// ------ BBOX METHODS ------
+
+bool vektor_bbox_isinside(VektorBBox bbox, V2 point) {
+    return point.x >= bbox.min.x && point.y >= bbox.min.y &&
+           point.x <= bbox.max.x && point.y <= bbox.max.y;
+}
+
+VektorBBox vektor_bbox_fromcenter(V2 center, float dist) {
+    V2 v2dist = vec2_fromfloat(dist);
+    V2 min = vec2_sub(center, v2dist);
+    V2 max = vec2_add(center, v2dist);
+    return (VektorBBox){min, max};
+}
+
+VektorBBox vektor_bbox_expand(VektorBBox bbox, float val) {
+    return (VektorBBox){vec2_sub(bbox.min, vec2_fromfloat(val)),
+                        vec2_add(bbox.max, vec2_fromfloat(val))};
+}
+
+// ------ SHAPE METHODS ------
+
+VektorShape* vektor_shape_new(VektorPrimitive prim, VektorStyle style,
+                             int z_index) {
+    VektorShape* shape = malloc(sizeof(VektorShape));
+    *shape = (VektorShape){.primitive = prim,
+                                      .style = style,
+                                      .transform = m33_identity(),
+                                      .z_index = z_index,
+                                      .bbox = vektor_primitive_get_bbox(prim)};
+
+    /*
+    create_handles() allocates new buffer for handles,
+    and even if the local shape variable goes out of scope and deallocates,
+    the passed value's pointer to an array of handles remains valid in the
+    passed copy.
+    */
+    vektor_shape_create_handles(shape);
+    return shape;
+}
+
+void vektor_shapes_update_bbox(VektorShapeBuffer* buffer) {
+    for (size_t i = 0; i < buffer->count; i++) {
+        buffer->shapes[i].bbox =
+            vektor_primitive_get_bbox(buffer->shapes[i].primitive);
+    }
+}
+
+void vektor_shapebuffer_add_shape(VektorShapeBuffer* buffer,
+                                  VektorShape shape) {
     if (buffer->count >= buffer->capacity) {
         buffer->capacity = buffer->capacity ? buffer->capacity * 2 : 4;
-        buffer->primitives = realloc(
+        buffer->shapes =
-            buffer->primitives, sizeof(VektorPrimitive) * buffer->capacity);
+            realloc(buffer->shapes, sizeof(VektorShape) * buffer->capacity);
     }
-    buffer->primitives[buffer->count++] = prim;
+    buffer->shapes[buffer->count++] = shape;
-}
+
+    if (buffer->count <= buffer->capacity / 4) {
+        buffer->capacity /= 2;
+        buffer->shapes =
+            realloc(buffer->shapes, sizeof(VektorShape) * buffer->capacity);
+    }
+}

src/core/primitives.h

@@ -1,15 +1,12 @@
 #ifndef PRIMITIVES_H_
 #define PRIMITIVES_H_
 
+#include "src/core/matrix.h"
+#include "src/util/color.h"
 #include "stddef.h"
 #include "stdlib.h"
 #include "vector.h"
 
-typedef struct {
-    V2 p1;
-    V2 p2;
-} VektorLine;
-
 typedef struct {
     V2* points;
     size_t count;
@@ -27,23 +24,49 @@ typedef struct {
     double radius;
 } VektorCircle;
 
+typedef struct {
+    V2 start;
+    V2 end;
+} VektorRectangle;
+
 typedef enum {
-    VEKTOR_LINE,
     VEKTOR_POLYLINE,
     VEKTOR_POLYGON,
-    VEKTOR_CIRCLE
+    VEKTOR_CIRCLE,
+    VEKTOR_RECTANGLE
 } VektorPrimitiveKind;
 
 typedef struct {
     VektorPrimitiveKind kind;
     union {
-        VektorLine line;
         VektorPolyline* polyline;
         VektorPolygon* polygon;
         VektorCircle circle;
+        VektorRectangle rectangle;
     };
 } VektorPrimitive;
 
+typedef struct {
+    VektorColor stroke_color;
+    float stroke_width;
+} VektorStyle;
+
+typedef struct {
+    V2 min;
+    V2 max;
+} VektorBBox;
+
+typedef struct {
+    VektorStyle style;
+    int z_index;
+    M33 transform;
+    VektorBBox bbox;
+    VektorPrimitive primitive;
+
+    V2* handles;
+    size_t handleCount;
+} VektorShape;
+
 VektorPolyline* vektor_polyline_new(void);
 void vektor_polyline_add_point(VektorPolyline* pl, V2 point);
 void vektor_polyline_free(VektorPolyline* pl);
@@ -52,13 +75,60 @@ VektorPolygon* vektor_polygon_new(void);
 void vektor_polygon_add_point(VektorPolygon* pl, V2 point);
 void vektor_polygon_free(VektorPolygon* pl);
 
+VektorCircle* vektor_circle_new(void);
+void vektor_circle_set_center(VektorCircle* circle, V2 point);
+void vektor_circle_set_radius(VektorCircle* circle, double radius);
+void vektor_circle_free(VektorCircle* circle);
+
+VektorRectangle* vektor_rectangle_new(void);
+void vektor_rectangle_set_end(VektorRectangle* rct, V2 point);
+void vektor_rectangle_set_start(VektorRectangle* rct, V2 point);
+void vektor_rectangle_free(VektorRectangle* rct);
+
+VektorShape* vektor_shape_new(VektorPrimitive prim, VektorStyle style,
+                             int z_index);
+
+VektorBBox vektor_polyline_get_bbox(VektorPrimitive prim);
+VektorBBox vektor_polygon_get_bbox(VektorPrimitive prim);
+VektorBBox vektor_circle_get_bbox(VektorPrimitive prim);
+VektorBBox vektor_rectangle_get_bbox(VektorPrimitive prim);
+
+VektorBBox vektor_primitive_get_bbox(VektorPrimitive prim);
+bool vektor_bbox_isinside(VektorBBox bbox, V2 point);
+VektorBBox vektor_bbox_fromcenter(V2 center, float dist);
+VektorBBox vektor_bbox_expand(VektorBBox bbox, float val);
+
+// shape handles
+void vektor_polyline_create_handles(VektorPolyline* polyline, V2** handleArr,
+                                    size_t* count);
+void vektor_polygon_create_handles(VektorPolygon* polygon, V2** handleArr,
+                                   size_t* count);
+void vektor_circle_create_handles(VektorCircle* circle, V2** handleArr,
+                                  size_t* count);
+void vektor_rectangle_create_handles(VektorRectangle* rectangle, V2** handleArr,
+                                     size_t* count);
+void vektor_shape_create_handles(VektorShape* shape);
+
+void vektor_shape_add_handle(VektorShape* shape, V2 handle);
+VektorBBox vektor_shape_get_handle_bbox(V2 handle);
+
+/* reconstructs the shape based on handles alone */
+void vektor_polyline_handles_updated(VektorPolyline* polyline, V2** handles,
+                                     size_t* count, int* heldHandleIndex);
+void vektor_polygon_handles_updated(VektorPolygon* polygon, V2** handles,
+                                    size_t* count, int* heldHandleIndex);
+void vektor_circle_handles_updated(VektorCircle* circle, V2** handles,
+                                   size_t* count, int* heldHandleIndex);
+void vektor_rectangle_handles_updated(VektorRectangle* rectangle, V2** handles,
+                                      size_t* count, int* heldHandleIndex);
+void vektor_shape_handles_updated(VektorShape* shape, int* heldHandleIndex);
+
 typedef struct {
-    VektorPrimitive* primitives;
+    VektorShape* shapes;
     size_t count;
     size_t capacity;
-} VektorPrimitiveBuffer;
+} VektorShapeBuffer;
-
-void vektor_primitivebuffer_add_primitive(VektorPrimitiveBuffer* edges,
-                                          VektorPrimitive edge);
 
+void vektor_shapebuffer_add_shape(VektorShapeBuffer* buffer, VektorShape shape);
+void vektor_shapes_update_bbox(VektorShapeBuffer* buffer);
 #endif // PRIMITIVES_H_

src/core/raster.c

@@ -1,8 +1,16 @@
 #include "raster.h"
+#include "epoxy/gl.h"
+#include "glib.h"
 #include "primitives.h"
+#include "src/core/matrix.h"
+#include "src/core/modifier.h"
+#include "src/core/vector.h"
 #include "stddef.h"
+#include <math.h>
 #include <stddef.h>
 
+#define PI 3.14159265358979323846
+
 void vektor_edgebuffer_add_edge(EdgeBuffer* buffer, Edge edge) {
     if (buffer->count >= buffer->capacity) {
         buffer->capacity = buffer->capacity ? buffer->capacity * 2 : 4;
@@ -11,116 +19,232 @@ void vektor_edgebuffer_add_edge(EdgeBuffer* buffer, Edge edge) {
     buffer->edges[buffer->count++] = edge;
 }
 
-void vektor_line_flatten(EdgeBuffer* buffer, VektorLine line) {
+void vektor_polyline_tessellate(EdgeBuffer* buffer, VektorPolyline* line,
-    vektor_edgebuffer_add_edge(buffer, (Edge){line.p1, line.p2, 0});
+                                size_t j, double scale) {
-}
-
-void vektor_polyline_flatten(EdgeBuffer* buffer, VektorPolyline* line) {
     for (size_t i = 0; i + 1 < line->count; i++) {
         vektor_edgebuffer_add_edge(
-            buffer, (Edge){line->points[i], line->points[i + 1], 0});
+            buffer, (Edge){line->points[i], line->points[i + 1], 0, j});
     }
 }
 
-void vektor_polygon_flatten(EdgeBuffer* buffer, VektorPolygon* pg) {
+void vektor_polygon_tessellate(EdgeBuffer* buffer, VektorPolygon* polygon,
-    size_t n = pg->count;
+                               size_t j, double scale) {
-    if (n < 3)
+    for (size_t i = 0; i + 1 < polygon->count; i++) {
+        vektor_edgebuffer_add_edge(
+            buffer, (Edge){polygon->points[i], polygon->points[i + 1], 0, j});
+    }
+    vektor_edgebuffer_add_edge(
+        buffer,
+        (Edge){polygon->points[polygon->count - 1], polygon->points[0], 0, j});
+}
+
+void vektor_circle_tessellate(EdgeBuffer* buffer, VektorCircle* circle,
+                              size_t j, double scale) {
+    double err = 0.0025;
+    size_t res = PI * sqrt((scale * circle->radius) / (2 * err));
+    for (size_t i = 0; i < res; i++) {
+        double theta1 = (2 * PI * i) / res;
+        double theta2 = (2 * PI * (i + 1)) / res;
+        V2 p1 = (V2){circle->center.x + circle->radius * cos(theta1),
+                     circle->center.y + circle->radius * sin(theta1)};
+        V2 p2 = (V2){circle->center.x + circle->radius * cos(theta2),
+                     circle->center.y + circle->radius * sin(theta2)};
+        vektor_edgebuffer_add_edge(buffer, (Edge){p1, p2, 0, j});
+    }
+}
+
+void vektor_rectangle_tessellate(EdgeBuffer* buffer, VektorRectangle* rct,
+                                 size_t j, double scale) {
+    if (vec2_equals(rct->end, rct->start)) {
         return;
-
-    for (size_t i = 0; i < n; i++) {
-        V2 p1 = pg->points[i];
-        V2 p2 = pg->points[(i + 1) % n];
-        int winding = (p1.y < p2.y) ? +1 : -1;
-        vektor_edgebuffer_add_edge(buffer, (Edge){p1, p2, winding});
     }
+
+    Edge top = (Edge){rct->start, (V2){rct->end.x, rct->start.y}, 0, j};
+    Edge right = (Edge){(V2){rct->end.x, rct->start.y}, rct->end, 0, j};
+    Edge bottom = (Edge){(V2){rct->start.x, rct->end.y}, rct->end, 0, j};
+    Edge left = (Edge){rct->start, (V2){rct->start.x, rct->end.y}, 0, j};
+
+    vektor_edgebuffer_add_edge(buffer, top);
+    vektor_edgebuffer_add_edge(buffer, right);
+    vektor_edgebuffer_add_edge(buffer, bottom);
+    vektor_edgebuffer_add_edge(buffer, left);
 }
 
-inline VektorFramebuffer vektor_framebuffer_new(unsigned int W,
+void vektor_vb_rasterize(VertexBuffer* vb, VektorShapeNodeBuffer* nodebuf,
-                                                unsigned int H) {
+                         double scale) {
-    VektorFramebuffer fb = {
+    for (size_t i = 0; i < nodebuf->count; i++) {
-        .width = W, .height = H, .pixels = calloc(W * H * 4, 1)};
+        EdgeBuffer edges = {0};
-    return fb;
-}
 
-inline void vektor_framebuffer_putpixel(VektorFramebuffer* fb, int x, int y,
+        vektor_shapenode_update(&nodebuf->nodes[i]);
-                                        VektorColor color) {
+        VektorShape* currentShape = vektor_shapenode_get_evaluated(&nodebuf->nodes[i]);
-    if ((unsigned)x >= fb->width || (unsigned)y >= fb->height)
-        return;
 
-    int i = (y * fb->width + x) * 4;
+        VektorPrimitive* p = &currentShape->primitive;
-    fb->pixels[i + 0] = color.r;
+        VektorStyle style = currentShape->style;
-    fb->pixels[i + 1] = color.g;
+        M33 transform = currentShape->transform;
-    fb->pixels[i + 2] = color.b;
-    fb->pixels[i + 3] = color.a;
-}
-
-void draw_filled_circle(VektorFramebuffer* fb, int cx, int cy, int r,
-                        VektorColor color) {
-    for (int y = -r; y <= r; y++) {
-        int dx = (int)sqrt(r * r - y * y);
-        for (int x = -dx; x <= dx; x++) {
-            vektor_framebuffer_putpixel(fb, cx + x, cy + y, color);
-        }
-    }
-}
-
-void vektor_framebuffer_drawline(VektorFramebuffer* fb, V2 a, V2 b,
-                                 VektorColor color, double thickness) {
-    int x0 = (int)a.x;
-    int y0 = (int)a.y;
-    int x1 = (int)b.x;
-    int y1 = (int)b.y;
-
-    int dx = abs(x1 - x0);
-    int sx = x0 < x1 ? 1 : -1;
-    int dy = -abs(y1 - y0);
-    int sy = y0 < y1 ? 1 : -1;
-    int err = dx + dy;
-
-    for (;;) {
-        draw_filled_circle(fb, x0, y0, thickness / 2, color);
-        if (x0 == x1 && y0 == y1)
-            break;
-
-        int e2 = 2 * err;
-        if (e2 >= dy) {
-            err += dy;
-            x0 += sx;
-        }
-        if (e2 <= dx) {
-            err += dx;
-            y0 += sy;
-        }
-    }
-}
-
-void vektor_framebuffer_rasterize(VektorFramebuffer* fb,
-                                  VektorPrimitiveBuffer* prims) {
-    EdgeBuffer edges = {0};
-    for (size_t i = 0; i < prims->count; i++) {
-        VektorPrimitive* p = &prims->primitives[i];
 
         switch (p->kind) {
-        case VEKTOR_LINE:
-            vektor_line_flatten(&edges, p->line);
-            break;
-
         case VEKTOR_POLYLINE:
-            vektor_polyline_flatten(&edges, p->polyline);
+            vektor_polyline_tessellate(&edges, p->polyline, i, scale);
+            vektor_edges_to_triangles(vb, &edges, &transform, style, FALSE);
             break;
 
         case VEKTOR_POLYGON:
-            vektor_polygon_flatten(&edges, p->polygon);
+            vektor_polygon_tessellate(&edges, p->polygon, i, scale);
+            vektor_edges_to_triangles(vb, &edges, &transform, style, TRUE);
+            break;
+
+        case VEKTOR_CIRCLE:
+            vektor_circle_tessellate(&edges, &p->circle, i, scale);
+            vektor_edges_to_triangles(vb, &edges, &transform, style, TRUE);
+            break;
+
+        case VEKTOR_RECTANGLE:
+            vektor_rectangle_tessellate(&edges, &p->rectangle, i, scale);
+            vektor_edges_to_triangles(vb, &edges, &transform, style, TRUE);
             break;
 
         default:
-            // TODO fill in all primitives
+            // TODO: fill in all primitives
             break;
         }
     }
+}
 
-    for (size_t i = 0; i < edges.count; i++) {
+void vektor_vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2,
-        vektor_framebuffer_drawline(fb, edges.edges[i].p1, edges.edges[i].p2,
+                            VektorColor color) {
-                                    vektor_color_solid(255, 0, 255), 4);
+    if (vb->count + 3 >= vb->capacity) {
+        vb->capacity = vb->capacity ? vb->capacity * 2 : 8;
+        vb->vertices = realloc(vb->vertices, sizeof(Vertex) * vb->capacity);
+    }
+    vb->vertices[vb->count++] = (Vertex){v0, color};
+    vb->vertices[vb->count++] = (Vertex){v1, color};
+    vb->vertices[vb->count++] = (Vertex){v2, color};
+
+    if (vb->count <= vb->capacity / 4) {
+        vb->capacity /= 2;
+        vb->vertices = realloc(vb->vertices, sizeof(Vertex) * vb->capacity);
+    }
+}
+
+void vektor_vb_add_quad(VertexBuffer* vb, V2 a, V2 b, VektorColor color) {
+
+    float minx = fminf(a.x, b.x);
+    float maxx = fmaxf(a.x, b.x);
+    float miny = fminf(a.y, b.y);
+    float maxy = fmaxf(a.y, b.y);
+
+    V2 tl = {minx, miny};
+    V2 bl = {minx, maxy};
+    V2 br = {maxx, maxy};
+    V2 tr = {maxx, miny};
+
+    vektor_vb_add_triangle(vb, tl, bl, br, color);
+    vektor_vb_add_triangle(vb, tl, br, tr, color);
+}
+
+Edge edge_transform(const Edge* e, const M33* t) {
+    Edge out = *e;
+    out.p1 = m33_transform(*t, e->p1);
+    out.p2 = m33_transform(*t, e->p2);
+    return out;
+}
+
+V2 line_intersection(V2 p, V2 r, V2 q, V2 s) {
+    float t = vec2_cross(vec2_sub(q, p), s) / vec2_cross(r, s);
+    return vec2_add(p, vec2_scale(r, t));
+}
+
+void vektor_edges_to_triangles(VertexBuffer* vb, EdgeBuffer* edges,
+                               M33* transform, VektorStyle style, bool closed) {
+    if (!edges || edges->count < 1)
+        return;
+
+    float hw = style.stroke_width * 0.5f;
+
+    for (size_t i = 0; i < edges->count; i++) {
+        Edge e = edge_transform(&edges->edges[i], transform);
+
+        V2 d = vec2_normalize(vec2_sub(e.p2, e.p1));
+        V2 n = vec2_perp(d);
+        V2 off = vec2_scale(n, hw);
+
+        V2 v0 = vec2_add(e.p1, off);
+        V2 v1 = vec2_sub(e.p1, off);
+        V2 v2 = vec2_add(e.p2, off);
+        V2 v3 = vec2_sub(e.p2, off);
+
+        vektor_vb_add_triangle(vb, v0, v1, v2, style.stroke_color);
+        vektor_vb_add_triangle(vb, v2, v1, v3, style.stroke_color);
+    }
+
+    size_t limit = closed ? edges->count : edges->count - 1;
+
+    for (size_t i = 0; i < limit; i++) {
+        Edge e1 = edge_transform(&edges->edges[i], transform);
+        Edge e2 =
+            edge_transform(&edges->edges[(i + 1) % edges->count], transform);
+
+        V2 corner = e1.p2;
+
+        V2 d1 = vec2_normalize(vec2_sub(e1.p2, e1.p1));
+        V2 d2 = vec2_normalize(vec2_sub(e2.p2, e2.p1));
+
+        V2 n1 = vec2_perp(d1);
+        V2 n2 = vec2_perp(d2);
+
+        V2 off1 = vec2_scale(n1, hw);
+        V2 off2 = vec2_scale(n2, hw);
+
+        V2 v10 = vec2_add(e1.p1, off1);
+        V2 v11 = vec2_sub(e1.p1, off1);
+        V2 v12 = vec2_add(e1.p2, off1);
+        V2 v13 = vec2_sub(e1.p2, off1);
+
+        V2 v20 = vec2_add(e2.p1, off2);
+        V2 v21 = vec2_sub(e2.p1, off2);
+        V2 v22 = vec2_add(e2.p2, off2);
+        V2 v23 = vec2_sub(e2.p2, off2);
+
+        V2 outer1 = vec2_add(corner, off1);
+        V2 outer2 = vec2_add(corner, off2);
+
+        V2 inner1 = vec2_sub(corner, off1);
+        V2 inner2 = vec2_sub(corner, off2);
+
+        float cos_theta = vec2_dot(d1, d2);
+        float sin_half = sqrtf((1.0f - cos_theta) * 0.5f);
+        float miter_len = hw / sin_half;
+
+        if (miter_len > 4.0 * hw || miter_len < 1.05 * hw) {
+            vektor_vb_add_triangle(vb, outer1, corner, outer2,
+                                   style.stroke_color);
+            vektor_vb_add_triangle(vb, inner1, corner, inner2,
+                                   style.stroke_color);
+            continue;
+        }
+
+        V2 outer_miter = line_intersection(vec2_add(corner, off1), d1,
+                                           vec2_add(corner, off2), d2);
+
+        V2 inner_miter = line_intersection(vec2_sub(corner, off1), d1,
+                                           vec2_sub(corner, off2), d2);
+
+        V2 mo = vec2_sub(outer_miter, corner);
+        V2 mi = vec2_sub(inner_miter, corner);
+
+        V2 vo1 = line_intersection(corner, vec2_normalize(vec2_perp(mo)),
+                                   vec2_add(corner, off1), d1);
+        V2 vo2 = line_intersection(corner,
+                                   vec2_negate(vec2_normalize(vec2_perp(mo))),
+                                   vec2_add(corner, off2), d2);
+
+        V2 vi1 = line_intersection(corner, vec2_normalize(vec2_perp(mi)),
+                                   vec2_sub(corner, off1), d1);
+        V2 vi2 = line_intersection(corner,
+                                   vec2_negate(vec2_normalize(vec2_perp(mi))),
+                                   vec2_sub(corner, off2), d2);
+
+        vektor_vb_add_triangle(vb, vo1, outer_miter, vo2, style.stroke_color);
+        vektor_vb_add_triangle(vb, vi1, inner_miter, vi2, style.stroke_color);
     }
 }

src/core/raster.h

@@ -3,14 +3,17 @@
 
 #include "primitives.h"
 
-#include "src/util/color.h"
+#include "../util/color.h"
+#include "src/core/modifier.h"
 #include "stddef.h"
 #include "vector.h"
+#include <stddef.h>
 
 typedef struct {
     V2 p1;
     V2 p2;
     int winding;
+    size_t shape_id;
 } Edge;
 
 typedef struct {
@@ -21,26 +24,35 @@ typedef struct {
 
 void vektor_edgebuffer_add_edge(EdgeBuffer* edges, Edge edge);
 
-void vektor_line_flatten(EdgeBuffer* edges, VektorLine line);
+void vektor_polyline_tessellate(EdgeBuffer* edges, VektorPolyline* line,
-void vektor_polyline_flatten(EdgeBuffer* edges, VektorPolyline* line);
+                                size_t i, double scale);
-void vektor_polygon_flatten(EdgeBuffer* buffer, VektorPolygon* line);
+void vektor_polygon_tessellate(EdgeBuffer* buffer, VektorPolygon* polygon,
+                               size_t i, double scale);
+void vektor_circle_tessellate(EdgeBuffer* buffer, VektorCircle* circle,
+                              size_t i, double scale);
+void vektor_rectangle_tessellate(EdgeBuffer* buffer, VektorRectangle* rct,
+                                 size_t i, double scale);
 
 typedef struct {
-    unsigned int width;
+    V2 coords;
-    unsigned int height;
+    VektorColor color;
-    unsigned char* pixels; // Flat RGBA8 array
+} Vertex;
-} VektorFramebuffer;
 
-VektorFramebuffer vektor_framebuffer_new(unsigned int width,
+typedef struct {
-                                         unsigned int height);
+    Vertex* vertices;
+    size_t count;
+    size_t capacity;
+} VertexBuffer;
 
-void vektor_framebuffer_putpixel(VektorFramebuffer* fb, int x, int y,
+void vektor_vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2,
-                                 VektorColor color);
+                            VektorColor color);
+void vektor_vb_add_quad(VertexBuffer* vb, V2 v0, V2 v1, VektorColor color);
 
-void vektor_framebuffer_drawline(VektorFramebuffer* fb, V2 a, V2 b,
+void vektor_edge_to_triangles(VertexBuffer* vb, Edge e,
-                                 VektorColor color, double thickness);
+                              VektorShapeNodeBuffer* node_buffer);
-
+void vektor_edges_to_triangles(VertexBuffer* vb, EdgeBuffer* edges,
-void vektor_framebuffer_rasterize(VektorFramebuffer* fb,
+                               M33* transform, VektorStyle style, bool closed);
-                                  VektorPrimitiveBuffer* primitives);
+void vektor_vb_rasterize(VertexBuffer* vb, VektorShapeNodeBuffer* shapes,
+                         double scale);
 
 #endif // RASTER_H_

src/core/vector.h

@@ -4,8 +4,8 @@
 #include "math.h"
 
 typedef struct {
-    double x;
+    float x;
-    double y;
+    float y;
 } V2;
 
 typedef struct {
@@ -14,14 +14,24 @@ typedef struct {
     double z;
 } V3;
 
+static inline V2 vec2_fromfloat(const float f) { return (V2){f, f}; }
+
 static inline V3 vec2_vector(const V2 v) { return (V3){v.x, v.y, 0}; }
 
 static inline V3 vec2_point(const V2 v) { return (V3){v.x, v.y, 1}; }
 
+static inline V2 vec2_perp(const V2 v) { return (V2){-v.y, v.x}; }
+
+static inline V2 vec2_negate(const V2 v) { return (V2){-v.x, -v.y}; }
+
 static inline V2 vec2_add(const V2 v1, const V2 v2) {
     return (V2){v1.x + v2.x, v1.y + v2.y};
 }
 
+static inline bool vec2_equals(const V2 v1, const V2 v2) {
+    return (bool)(v1.x == v2.x && v1.y == v2.x);
+}
+
 static inline V2 vec2_sub(const V2 v1, const V2 v2) {
     return (V2){v1.x - v2.x, v1.y - v2.y};
 }
@@ -42,16 +52,16 @@ static inline double vec2_cross(const V2 a, const V2 b) {
     return a.x * b.y - a.y * b.x;
 }
 
-static inline double vec2_norm(const V2 v) {
+static inline double vec2_length(const V2 v) {
     return sqrt(v.x * v.x + v.y * v.y);
 }
 
-static inline double vec2_quadrance(const V2 v) {
+static inline double vec2_lengthsq(const V2 v) {
     return (v.x * v.x + v.y * v.y);
 }
 
 static inline V2 vec2_normalize(const V2 v) {
-    return vec2_scale(v, 1 / vec2_norm(v));
+    return vec2_scale(v, 1 / vec2_length(v));
 }
 
 #endif // VECTOR_H_

src/main.c

@@ -1,17 +1,17 @@
+#include "glib.h"
 #include "gtk/gtk.h"
 #include "src/application/applicationstate.h"
-#include "src/core/primitives.h"
 #include "stdio.h"
 #include "stdlib.h"
 
 #include "./application/applicationstate.h"
-#include "./core/raster.h"
 #include "./ui/uicontroller.h"
-#include "./ui/vektorcanvas.h"
-#include "./util/color.h"
 
-static void on_map(GtkWidget* window, gpointer user_data) {
+static int update_callback(gpointer data) {
-    vektor_uictrl_map((VektorWidgetState*)user_data);
+    VektorAppState* appstate = (VektorAppState*)data;
+    gtk_gl_area_queue_render(
+        GTK_GL_AREA(appstate->widgetState->workspaceCanvas));
+    return G_SOURCE_CONTINUE;
 }
 
 static void activate(GtkApplication* app, gpointer user_data) {
@@ -22,8 +22,7 @@ static void activate(GtkApplication* app, gpointer user_data) {
     VektorAppState* app_state = (VektorAppState*)malloc(sizeof(VektorAppState));
     vektor_appstate_new(widget_state, app_state);
 
-    g_signal_connect(widget_state->window, "map", G_CALLBACK(on_map),
+    g_timeout_add(1, update_callback, app_state);
-                     widget_state);
 
     gtk_window_present(widget_state->window);
 }

src/ui/uicontroller.c

@@ -3,8 +3,12 @@
 #include "glib-object.h"
 #include "gtk/gtk.h"
 #include "gtk/gtkcssprovider.h"
+#include "gtk/gtkrevealer.h"
+#include "src/ui/widgets/colorwheel.h"
 
 void vektor_uictrl_init(GtkApplication* app, VektorWidgetState* stateOut) {
+    g_type_ensure(VEKTOR_TYPE_COLOR_WHEEL);
+
     GtkBuilder* builder = gtk_builder_new();
     GError* error = NULL;
 
@@ -20,28 +24,55 @@ void vektor_uictrl_init(GtkApplication* app, VektorWidgetState* stateOut) {
         gdk_display_get_default(), GTK_STYLE_PROVIDER(provider),
         GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
 
+    // Load theme
+    gtk_icon_theme_add_search_path(
+        gtk_icon_theme_get_for_display(gdk_display_get_default()), "icons");
+
+    GtkIconTheme* theme =
+        gtk_icon_theme_get_for_display(gdk_display_get_default());
+
     // populate state
     stateOut->window =
         GTK_WINDOW(gtk_builder_get_object(builder, "main_window"));
     stateOut->workspacePaned =
         GTK_PANED(gtk_builder_get_object(builder, "workspace_paned"));
+    stateOut->sidepanelPaned =
+        GTK_PANED(gtk_builder_get_object(builder, "sidepanel"));
     stateOut->workspaceCanvas =
-        GTK_PICTURE(gtk_builder_get_object(builder, "workspace"));
+        GTK_GL_AREA(gtk_builder_get_object(builder, "workspace"));
-    stateOut->workspaceButtonLinetool =
+
+    stateOut->workspaceButtonMasterShapes =
+        GTK_BUTTON(gtk_builder_get_object(builder, "button_shapetools"));
+    stateOut->workspaceRevealerShapes =
+        GTK_REVEALER(gtk_builder_get_object(builder, "shape_revealer"));
+    stateOut->workspaceButtonLineTool =
         GTK_BUTTON(gtk_builder_get_object(builder, "button_linetool"));
+    stateOut->workspaceButtonRectTool =
+        GTK_BUTTON(gtk_builder_get_object(builder, "button_rectangletool"));
+    stateOut->workspaceButtonCircleTool =
+        GTK_BUTTON(gtk_builder_get_object(builder, "button_circletool"));
+    stateOut->workspaceButtonPolygonTool =
+        GTK_BUTTON(gtk_builder_get_object(builder, "button_polygontool"));
+    stateOut->workspaceButtonSelectionTool =
+        GTK_BUTTON(gtk_builder_get_object(builder, "button_selecttool"));
+    stateOut->workspaceColorPicker =
+        VEKTOR_COLOR_WHEEL(gtk_builder_get_object(builder, "color_picker"));
+
+    stateOut->sidepanelEntryR =
+        GTK_ENTRY(gtk_builder_get_object(builder, "spin_color_r"));
+    stateOut->sidepanelEntryG =
+        GTK_ENTRY(gtk_builder_get_object(builder, "spin_color_g"));
+    stateOut->sidepanelEntryB =
+        GTK_ENTRY(gtk_builder_get_object(builder, "spin_color_b"));
 
     // Set window properties
     gtk_window_set_application(stateOut->window, app);
     gtk_window_set_title(stateOut->window, "Vektor");
     gtk_window_set_default_size(stateOut->window, 800, 600);
 
+    // Set dimensions
+    gtk_paned_set_position(stateOut->workspacePaned, 800 * .7);
+    gtk_paned_set_position(stateOut->sidepanelPaned, 250);
+
     g_object_unref(builder);
 }
-
-void vektor_uictrl_map(VektorWidgetState* state) {
-
-    // set the workspace divider to 7:3 ratio
-    int window_width = gtk_widget_get_width(GTK_WIDGET(state->window));
-    g_print("%i", window_width);
-    gtk_paned_set_position(state->workspacePaned, 800 * .7);
-}

src/ui/uicontroller.h

@@ -2,6 +2,8 @@
 #define VKTR_UICTRL_H
 
 #include "gtk/gtk.h"
+#include "gtk/gtkrevealer.h"
+#include "src/ui/widgets/colorwheel.h"
 
 /*
 Global application widget state, holding references to
@@ -10,9 +12,22 @@ all the widgets used in internal logic of the program
 typedef struct VektorWidgetState {
     GtkWindow* window;
     GtkPaned* workspacePaned;
-    GtkPicture* workspaceCanvas;
+    GtkPaned* sidepanelPaned;
+    GtkGLArea* workspaceCanvas;
 
-    GtkButton* workspaceButtonLinetool;
+    GtkButton* workspaceButtonMasterShapes;
+    GtkRevealer* workspaceRevealerShapes;
+    GtkButton* workspaceButtonLineTool;
+    GtkButton* workspaceButtonRectTool;
+    GtkButton* workspaceButtonCircleTool;
+    GtkButton* workspaceButtonPolygonTool;
+    GtkButton* workspaceButtonSelectionTool;
+
+    VektorColorWheel* workspaceColorPicker;
+
+    GtkEntry* sidepanelEntryR;
+    GtkEntry* sidepanelEntryG;
+    GtkEntry* sidepanelEntryB;
 
     // GtkWidget* Workspace
 } VektorWidgetState;

src/ui/vektorcanvas.c

@@ -1,14 +1,373 @@
+#include "epoxy/gl.h"
+#include "glib.h"
 #include "gtk/gtk.h"
 
 #include "../core/raster.h"
+#include "src/core/matrix.h"
+#include "src/core/primitives.h"
+#include "src/util/color.h"
 #include "uicontroller.h"
 #include "vektorcanvas.h"
+#include <epoxy/gl_generated.h>
 
 #define VKTR_CANVAS_WIDTH 400
 #define VKTR_CANVAS_HEIGHT 400
 #define VKTR_CANVAS_SIZE (VKTR_CANVAS_WIDTH * VKTR_CANVAS_HEIGHT * 4)
 
-void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut) {
+char* read_file(const char* path) {
+    FILE* f = fopen(path, "rb");
+    if (!f)
+        return NULL;
+
+    fseek(f, 0, SEEK_END);
+    long size = ftell(f);
+    fseek(f, 0, SEEK_SET);
+
+    char* buffer = malloc(size + 1);
+    fread(buffer, 1, size, f);
+    buffer[size] = '\0'; // null-terminate
+    fclose(f);
+    return buffer;
+}
+
+static GLuint standard_shader_program;
+static GLuint selection_shader_program;
+
+// shader uniforms
+static GLuint shader_standard_uProjMatrixLoc;
+
+static GLuint shader_selection_uProjMatrixLoc;
+static GLuint shader_selection_uTimeLoc;
+static GLuint shader_selection_uScaleLoc;
+static GLuint shader_selection_uC1Loc;
+static GLuint shader_selection_uC2Loc;
+static GLuint shader_selection_uMinLoc;
+static GLuint shader_selection_uMaxLoc;
+
+static GLuint vao;
+VertexBuffer vb;
+static size_t shape_vertex_count = 0;
+
+static GLuint compile_shader(GLenum type, const char* src) {
+    GLuint shader = glCreateShader(type);
+    glShaderSource(shader, 1, &src, NULL);
+    glCompileShader(shader);
+
+    GLint success;
+    glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
+    if (!success) {
+        char info[512];
+        glGetShaderInfoLog(shader, 512, NULL, info);
+        g_error("Shader compile failed: %s", info);
+    }
+    return shader;
+}
+
+static GLuint create_shader_program(char* frag, char* vert) {
+    GLuint vertex = compile_shader(GL_VERTEX_SHADER, vert);
+    GLuint fragment = compile_shader(GL_FRAGMENT_SHADER, frag);
+
+    GLuint shader_program = glCreateProgram();
+    glAttachShader(shader_program, vertex);
+    glAttachShader(shader_program, fragment);
+    glLinkProgram(shader_program);
+
+    GLint success;
+    glGetProgramiv(shader_program, GL_LINK_STATUS, &success);
+    if (!success) {
+        char info[512];
+        glGetProgramInfoLog(shader_program, 512, NULL, info);
+        g_error("Shader link failed: %s", info);
+    }
+
+    glDeleteShader(vertex);
+    glDeleteShader(fragment);
+
+    return shader_program;
+}
+
+static void init_shader(void) {
+    char* vert_src = read_file("./shaders/triangle.vert.glsl");
+    char* frag_src = read_file("./shaders/triangle.frag.glsl");
+    char* selection_frag_src = read_file("./shaders/selection.frag.glsl");
+
+    if (!vert_src || !frag_src)
+        g_error("Failed to load shader files");
+
+    standard_shader_program = create_shader_program(frag_src, vert_src);
+    selection_shader_program =
+        create_shader_program(selection_frag_src, vert_src);
+
+    shader_standard_uProjMatrixLoc =
+        glGetUniformLocation(standard_shader_program, "uProjection");
+    shader_selection_uProjMatrixLoc =
+        glGetUniformLocation(selection_shader_program, "uProjection");
+    shader_selection_uTimeLoc =
+        glGetUniformLocation(selection_shader_program, "uTime");
+    shader_selection_uScaleLoc =
+        glGetUniformLocation(selection_shader_program, "uScale");
+    shader_selection_uC1Loc =
+        glGetUniformLocation(selection_shader_program, "uColor1");
+    shader_selection_uC2Loc =
+        glGetUniformLocation(selection_shader_program, "uColor2");
+
+    shader_selection_uMinLoc =
+        glGetUniformLocation(selection_shader_program, "uMin");
+    shader_selection_uMaxLoc =
+        glGetUniformLocation(selection_shader_program, "uMax");
+
+    if (shader_selection_uMinLoc == -1 || shader_selection_uMaxLoc == -1)
+        g_warning("Selection shader: uMin/uMax uniform not found in shader!");
+}
+
+static void init_geometry(void) {
+    GLuint vbo;
+
+    glGenVertexArrays(1, &vao);
+    glBindVertexArray(vao);
+
+    glGenBuffers(1, &vbo);
+    glBindBuffer(GL_ARRAY_BUFFER, vbo);
+
+    glEnableVertexAttribArray(0);
+    glVertexAttribPointer(0, 2, GL_FLOAT, GL_FALSE, sizeof(Vertex),
+                          (void*)offsetof(Vertex, coords));
+
+    glEnableVertexAttribArray(1);
+    glVertexAttribPointer(1, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(Vertex),
+                          (void*)offsetof(Vertex, color));
+
+    glBindVertexArray(0);
+}
+
+void vektor_canvas_geometry_changed(VektorCanvasRenderInfo* renderInfo) {
+    vb.count = 0;
+    vektor_vb_rasterize(&vb, renderInfo->shapes, renderInfo->zoom);
+    shape_vertex_count = vb.count;
+
+    if (renderInfo->selectedShape != NULL &&
+        *(renderInfo->selectedShape) != NULL) {
+
+        VektorShapeNode* selectedShape = *renderInfo->selectedShape;
+
+        // create handle quads if a shape is selected
+        for (size_t i = 0; i < selectedShape->base->handleCount; i++) {
+            V2 handle = selectedShape->base->handles[i];
+            VektorBBox handleBbox = vektor_shape_get_handle_bbox(handle);
+            vektor_vb_add_quad(&vb, handleBbox.min, handleBbox.max,
+                               vektor_color_new(255, 255, 255, 255));
+        }
+
+        shape_vertex_count = vb.count;
+
+        // create selection quad if a shape is selected
+        VektorBBox bbox =
+            vektor_primitive_get_bbox(selectedShape->base->primitive);
+        // expand it a little so it is not inset
+        bbox = vektor_bbox_expand(bbox, 0.03f);
+
+        vektor_vb_add_quad(&vb, bbox.min, bbox.max,
+                           vektor_color_new(255, 255, 255, 255));
+    }
+}
+
+static gboolean render(GtkGLArea* a, GdkGLContext* ctx,
+                       VektorCanvasRenderInfo* renderInfo) {
+    // vektor_canvas_geometry_changed(renderInfo);
+
+    glBufferData(GL_ARRAY_BUFFER, vb.count * sizeof(Vertex), vb.vertices,
+                 GL_STATIC_DRAW);
+
+    // PASS 1 - draw shape vertices
+    glUseProgram(standard_shader_program);
+
+    // float projectionMatrix[16] = {1, 0, 0, 0, 0, 1, 0, 0,
+    //                               0, 0, 1, 0, 0, 0, 0, 1};
+    glUniformMatrix4fv(shader_standard_uProjMatrixLoc, 1, GL_FALSE,
+                       renderInfo->canvasTransform);
+
+    glBindVertexArray(vao);
+    glDisable(GL_CULL_FACE);
+    // glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
+    glClearColor(0.1f, 0.1f, 0.1f, 1.0f);
+    glClear(GL_COLOR_BUFFER_BIT);
+
+    glDrawArrays(GL_TRIANGLES, 0, shape_vertex_count);
+
+    // PASS 2 - draw selection quads
+    if (vb.count > shape_vertex_count) {
+        // g_print("vdelta: %zu\n", vb.count - shape_vertex_count);
+        float time =
+            (g_get_monotonic_time() - renderInfo->startupTime) / 10000000.0f;
+
+        // re-fetch bbox (we know a shape is selected)
+        VektorBBox bbox = vektor_primitive_get_bbox(
+            (*(renderInfo->selectedShape))->base->primitive);
+        bbox = vektor_bbox_expand(bbox, 0.03f);
+
+        glUseProgram(selection_shader_program);
+
+        glUniformMatrix4fv(shader_selection_uProjMatrixLoc, 1, GL_FALSE,
+                           renderInfo->canvasTransform);
+        glUniform1f(shader_selection_uTimeLoc, time);
+        glUniform1f(shader_selection_uScaleLoc, renderInfo->zoom);
+        glUniform2f(shader_selection_uMinLoc, bbox.min.x, bbox.min.y);
+        glUniform2f(shader_selection_uMaxLoc, bbox.max.x, bbox.max.y);
+        glUniform4f(shader_selection_uC1Loc, 0, 0, 0, 0);
+        glUniform4f(shader_selection_uC2Loc, 0.46, 0.46, 1, 1);
+
+        glDrawArrays(GL_TRIANGLES, shape_vertex_count,
+                     vb.count - shape_vertex_count);
+    }
+
+    glBindVertexArray(0);
+    glUseProgram(0);
+
+    return TRUE;
+}
+
+static void dump_gl_info(GtkGLArea* area) {
+    gtk_gl_area_make_current(area);
+
+    if (gtk_gl_area_get_error(area)) {
+        g_warning("Failed to make GL context current");
+        return;
+    }
+
+    const GLubyte* renderer = glGetString(GL_RENDERER);
+    const GLubyte* vendor = glGetString(GL_VENDOR);
+    const GLubyte* version = glGetString(GL_VERSION);
+    const GLubyte* shading = glGetString(GL_SHADING_LANGUAGE_VERSION);
+
+    g_debug("GL Vendor    : %s", vendor);
+    g_debug("GL Renderer  : %s", renderer);
+    g_debug("GL Version   : %s", version);
+    g_debug("GLSL Version : %s", shading);
+
+    GLint n;
+    glGetIntegerv(GL_NUM_EXTENSIONS, &n);
+    g_debug("Supported extensions (%d):", n);
+    for (GLint i = 0; i < n; ++i) {
+        g_debug("  %s", glGetStringi(GL_EXTENSIONS, i));
+    }
+}
+
+static void realize(GtkGLArea* area, gpointer user_data) {
+    gtk_gl_area_make_current(area);
+
+    if (gtk_gl_area_get_error(area) != NULL)
+        return;
+
+    glEnable(GL_DEBUG_OUTPUT);
+    dump_gl_info(area);
+    init_shader();
+    init_geometry();
+}
+
+static void on_scroll(GtkEventControllerScroll* controller, double dx,
+                      double dy, gpointer user_data) {
+    VektorCanvasRenderInfo* s = user_data;
+
+    GdkModifierType state = gtk_event_controller_get_current_event_state(
+        GTK_EVENT_CONTROLLER(controller));
+
+    // if (state & GDK_CONTROL_MASK) {
+
+    if (dy < 0)
+        s->zoom *= 1.1f;
+    else if (dy > 0)
+        s->zoom *= 0.9f;
+
+    M33 mat =
+        m33_mul(m33_translate(s->panX, s->panY),
+                m33_mul(m33_rotate(s->rotation), m33_scale(s->zoom, s->zoom)));
+
+    m33_to_gl4(mat, s->canvasTransform);
+    s->canvasMat = mat;
+
+    GtkWidget* widget =
+        gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(controller));
+    
+    vektor_canvas_geometry_changed(s);
+
+}
+
+static void on_pan_begin(GtkGestureDrag* gesture, double start_x,
+                         double start_y, gpointer user_data) {
+    VektorCanvasRenderInfo* s = user_data;
+
+    GdkModifierType state = gtk_event_controller_get_current_event_state(
+        GTK_EVENT_CONTROLLER(gesture));
+
+    if (!(state & GDK_SHIFT_MASK)) {
+        s->drag_start_x = s->panX;
+        s->drag_start_y = s->panY;
+    } else {
+        double x, y;
+        gtk_gesture_drag_get_start_point(gesture, &x, &y);
+
+        s->mouse_start_x = x;
+        s->mouse_start_y = y;
+
+        double cx = VKTR_CANVAS_WIDTH * 0.5;
+        double cy = VKTR_CANVAS_HEIGHT * 0.5;
+
+        double dx = x - cx;
+        double dy = y - cy;
+
+        s->dragStartAngle = atan2(dy, dx);
+        s->dragStartRotation = s->rotation;
+    }
+}
+
+static void on_pan_drag(GtkGestureDrag* gesture, double offset_x,
+                        double offset_y, gpointer user_data) {
+    VektorCanvasRenderInfo* s = user_data;
+
+    GdkModifierType state = gtk_event_controller_get_current_event_state(
+        GTK_EVENT_CONTROLLER(gesture));
+
+    if (!(state & GDK_SHIFT_MASK)) {
+        s->panX = s->drag_start_x + offset_x / (80 * s->zoom);
+        s->panY = s->drag_start_y - offset_y / (80 * s->zoom);
+
+        M33 mat = m33_mul(
+            m33_translate(s->panX, s->panY),
+            m33_mul(m33_rotate(s->rotation), m33_scale(s->zoom, s->zoom)));
+        m33_to_gl4(mat, s->canvasTransform);
+        s->canvasMat = mat;
+    } else {
+        double x, y;
+        gtk_gesture_drag_get_offset(gesture, &x, &y);
+
+        double mx = s->mouse_start_x + x;
+        double my = s->mouse_start_y + y;
+
+        double cx = VKTR_CANVAS_WIDTH * 0.5;
+        double cy = VKTR_CANVAS_HEIGHT * 0.5;
+
+        double dx = mx - cx;
+        double dy = my - cy;
+
+        double angle = -atan2(dy, dx);
+
+        s->rotation = s->dragStartRotation + (angle - s->dragStartAngle);
+
+        M33 mat = m33_mul(
+            m33_translate(s->panX, s->panY),
+            m33_mul(m33_rotate(s->rotation), m33_scale(s->zoom, s->zoom)));
+        m33_to_gl4(mat, s->canvasTransform);
+        s->canvasMat = mat;
+    }
+    GtkWidget* widget =
+        gtk_event_controller_get_widget(GTK_EVENT_CONTROLLER(gesture));
+
+    //gtk_gl_area_queue_render(GTK_GL_AREA(widget));
+    vektor_canvas_geometry_changed(s);
+}
+
+void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut,
+                        VektorCanvasRenderInfo* renderInfo) {
     canvasOut->canvasWidget = state->workspaceCanvas;
     canvasOut->width = VKTR_CANVAS_WIDTH;
     canvasOut->height = VKTR_CANVAS_HEIGHT;
@@ -20,49 +379,24 @@ void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut) {
         VKTR_CANVAS_WIDTH, VKTR_CANVAS_HEIGHT, GDK_MEMORY_R8G8B8A8,
         canvasOut->canvasPixelBytes, VKTR_CANVAS_WIDTH * 4);
 
-    gtk_picture_set_paintable(canvasOut->canvasWidget,
+    g_signal_connect(canvasOut->canvasWidget, "realize", G_CALLBACK(realize),
-                              GDK_PAINTABLE(canvasOut->canvasTexture));
+                     NULL);
-    gtk_picture_set_content_fit(GTK_PICTURE(canvasOut->canvasWidget),
+    g_signal_connect(canvasOut->canvasWidget, "render", G_CALLBACK(render),
-                                GTK_CONTENT_FIT_CONTAIN);
+                     renderInfo);
-    // g_object_unref(bytes);
+
+    GtkEventController* scroll =
+        gtk_event_controller_scroll_new(GTK_EVENT_CONTROLLER_SCROLL_VERTICAL);
+
+    gtk_widget_add_controller(GTK_WIDGET(canvasOut->canvasWidget), scroll);
+
+    g_signal_connect(scroll, "scroll", G_CALLBACK(on_scroll), renderInfo);
+
+    GtkGesture* pan = gtk_gesture_drag_new();
+    gtk_gesture_single_set_button(GTK_GESTURE_SINGLE(pan), GDK_BUTTON_MIDDLE);
+
+    gtk_widget_add_controller(GTK_WIDGET(canvasOut->canvasWidget),
+                              GTK_EVENT_CONTROLLER(pan));
+
+    g_signal_connect(pan, "drag-begin", G_CALLBACK(on_pan_begin), renderInfo);
+    g_signal_connect(pan, "drag-update", G_CALLBACK(on_pan_drag), renderInfo);
 }
-
-/* Generate new texture based on canvasPixels*/
-void vektor_canvas_update(VektorCanvas* canvas) {
-    g_bytes_unref(canvas->canvasPixelBytes);
-    canvas->canvasPixelBytes =
-        g_bytes_new(canvas->canvasPixels, VKTR_CANVAS_SIZE);
-
-    g_object_unref(canvas->canvasTexture);
-    canvas->canvasTexture = gdk_memory_texture_new(
-        canvas->width, canvas->height, GDK_MEMORY_R8G8B8A8,
-        canvas->canvasPixelBytes, canvas->width * 4);
-
-    gtk_picture_set_paintable(canvas->canvasWidget,
-                              GDK_PAINTABLE(canvas->canvasTexture));
-}
-
-void vektor_canvas_fill(VektorCanvas* canvas, VektorColor color) {
-    for (int x = 0; x < VKTR_CANVAS_WIDTH; x++) {
-        for (int y = 0; y < VKTR_CANVAS_HEIGHT; y++) {
-            int i = (y * VKTR_CANVAS_WIDTH + x) * 4;
-            canvas->canvasPixels[i + 0] = color.r;
-            canvas->canvasPixels[i + 1] = color.g;
-            canvas->canvasPixels[i + 2] = color.b;
-            canvas->canvasPixels[i + 3] = color.a;
-        }
-    }
-}
-
-void vektor_canvas_drawfrom(VektorFramebuffer* fb, VektorCanvas* target) {
-    for (int x = 0; x < fb->width; x++) {
-        for (int y = 0; y < fb->height; y++) {
-
-            int i = (y * fb->width + x) * 4;
-            target->canvasPixels[i + 0] = (guchar)fb->pixels[i + 0];
-            target->canvasPixels[i + 1] = (guchar)fb->pixels[i + 1];
-            target->canvasPixels[i + 2] = (guchar)fb->pixels[i + 2];
-            target->canvasPixels[i + 3] = (guchar)fb->pixels[i + 3];
-        }
-    }
-}

src/ui/vektorcanvas.h

@@ -3,10 +3,14 @@
 
 #include "../core/raster.h"
 #include "../util/color.h"
+#include "gtk/gtk.h"
+#include "src/core/matrix.h"
+#include "src/core/modifier.h"
+#include "src/core/primitives.h"
 #include "uicontroller.h"
 
 typedef struct VektorCanvas {
-    GtkPicture* canvasWidget;
+    GtkGLArea* canvasWidget;
 
     // texture related stuff
     guchar* canvasPixels;
@@ -17,9 +21,33 @@ typedef struct VektorCanvas {
     int height;
 } VektorCanvas;
 
-void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut);
+typedef struct VektorCanvasRenderInfo {
-void vektor_canvas_update(VektorCanvas* canvas);
+    gint64 startupTime;
-void vektor_canvas_fill(VektorCanvas* canvas, VektorColor color);
+    VektorShapeNodeBuffer* shapes;
-void vektor_canvas_drawfrom(VektorFramebuffer* fb, VektorCanvas* canvas);
+
+    // a pointer to appstate->selectedShape
+    VektorShapeNode** selectedShape;
+    float zoom;
+    float panX;
+    float panY;
+    float rotation;
+
+    float dragStartRotation;
+    double dragStartAngle;
+    double drag_start_x;
+    double drag_start_y;
+    double mouse_start_x;
+    double mouse_start_y;
+
+    M33 canvasMat;
+    float canvasTransform[16];
+} VektorCanvasRenderInfo;
+
+void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut,
+                        VektorCanvasRenderInfo* renderInfo);
+void vektor_canvas_geometry_changed(VektorCanvasRenderInfo* renderInfo);
+// void vektor_canvas_update(VektorCanvas* canvas);
+// void vektor_canvas_fill(VektorCanvas* canvas, VektorColor color);
+// void vektor_canvas_drawfrom(VektorFramebuffer* fb, VektorCanvas* canvas);
 
 #endif

src/ui/widgets/colorwheel.c

@@ -0,0 +1,382 @@
+#include "colorwheel.h"
+#include "cairo.h"
+#include "gtk/gtk.h"
+#include "gtk/gtkshortcut.h"
+
+#define M_PI 3.14159265358979323846
+
+enum { COLOR_CHANGED, LAST_SIGNAL };
+static guint signals[LAST_SIGNAL];
+
+struct _VektorColorWheel {
+    GtkDrawingArea parent_instance;
+
+    double hue;
+    double saturation;
+    double lightness;
+
+    gboolean dragging_wheel;
+    gboolean dragging_triangle;
+};
+
+G_DEFINE_TYPE(VektorColorWheel, vektor_color_wheel, GTK_TYPE_DRAWING_AREA)
+
+static gboolean point_in_triangle(double px, double py, double ax, double ay,
+                                  double bx, double by, double cx, double cy,
+                                  double* u, double* v, double* w) {
+    double denom = (by - cy) * (ax - cx) + (cx - bx) * (ay - cy);
+
+    *u = ((by - cy) * (px - cx) + (cx - bx) * (py - cy)) / denom;
+
+    *v = ((cy - ay) * (px - cx) + (ax - cx) * (py - cy)) / denom;
+
+    *w = 1 - *u - *v;
+
+    return (*u >= 0 && *v >= 0 && *w >= 0);
+}
+
+static void closest_point_on_segment(double px, double py, double ax, double ay,
+                                     double bx, double by, double* rx,
+                                     double* ry) {
+    double abx = bx - ax;
+    double aby = by - ay;
+
+    double apx = px - ax;
+    double apy = py - ay;
+
+    double t = (apx * abx + apy * aby) / (abx * abx + aby * aby);
+
+    if (t < 0)
+        t = 0;
+    if (t > 1)
+        t = 1;
+
+    *rx = ax + abx * t;
+    *ry = ay + aby * t;
+}
+
+static void closest_point_on_triangle(double px, double py, double ax,
+                                      double ay, double bx, double by,
+                                      double cx, double cy, double* rx,
+                                      double* ry) {
+    double p1x, p1y;
+    double p2x, p2y;
+    double p3x, p3y;
+
+    closest_point_on_segment(px, py, ax, ay, bx, by, &p1x, &p1y);
+    closest_point_on_segment(px, py, bx, by, cx, cy, &p2x, &p2y);
+    closest_point_on_segment(px, py, cx, cy, ax, ay, &p3x, &p3y);
+
+    double d1 = (px - p1x) * (px - p1x) + (py - p1y) * (py - p1y);
+    double d2 = (px - p2x) * (px - p2x) + (py - p2y) * (py - p2y);
+    double d3 = (px - p3x) * (px - p3x) + (py - p3y) * (py - p3y);
+
+    if (d1 <= d2 && d1 <= d3) {
+        *rx = p1x;
+        *ry = p1y;
+    } else if (d2 <= d3) {
+        *rx = p2x;
+        *ry = p2y;
+    } else {
+        *rx = p3x;
+        *ry = p3y;
+    }
+}
+
+static void vektor_color_wheel_snapshot(GtkWidget* widget,
+                                        GtkSnapshot* snapshot) {
+    VektorColorWheel* self = VEKTOR_COLOR_WHEEL(widget);
+
+    int width = gtk_widget_get_width(widget);
+    int height = gtk_widget_get_height(widget);
+
+    graphene_rect_t bounds = GRAPHENE_RECT_INIT(0, 0, width, height);
+    cairo_t* cr = gtk_snapshot_append_cairo(snapshot, &bounds);
+
+    double cx = width / 2.0;
+    double cy = height / 2.0;
+
+    double outer_radius = MIN(width, height) / 2.0;
+    double wheel_radius = outer_radius * 0.95;
+    double inner_radius = wheel_radius * 0.9;
+
+    double triangle_radius = wheel_radius * 0.75;
+
+    // wheel draw
+    for (int a = 0; a < 360; a++) {
+        double angle_1 = a * (M_PI / 180.0);
+        double angle_2 = (a + 1) * (M_PI / 180.0);
+
+        cairo_new_path(cr);
+        cairo_arc(cr, cx, cy, wheel_radius, angle_1, angle_2);
+        cairo_arc_negative(cr, cx, cy, inner_radius, angle_2, angle_1);
+        cairo_close_path(cr);
+
+        float r, g, b;
+        gtk_hsv_to_rgb(a / 360.0, 1.0, 1.0, &r, &g, &b);
+
+        cairo_set_source_rgb(cr, r, g, b);
+        cairo_fill(cr);
+    }
+
+    // triangle draw
+    double ax = cx + triangle_radius;
+    double ay = cy;
+
+    double bx = cx - 0.5 * triangle_radius;
+    double by = cy + 0.866 * triangle_radius;
+
+    double cx2 = cx - 0.5 * triangle_radius;
+    double cy2 = cy - 0.866 * triangle_radius;
+
+    cairo_new_path(cr);
+
+    cairo_move_to(cr, ax, ay);
+    cairo_line_to(cr, bx, by);
+    cairo_line_to(cr, cx2, cy2);
+    cairo_close_path(cr);
+
+    cairo_save(cr);
+    cairo_clip(cr);
+
+    // base color (pure hue at full brightness)
+    float r, g, b;
+    gtk_hsv_to_rgb(self->hue, 1.0, 1.0, &r, &g, &b);
+    cairo_set_source_rgb(cr, r, g, b);
+    cairo_paint(cr);
+
+    // White gradient: from pure hue (right) → white (bottom)
+    cairo_pattern_t* white = cairo_pattern_create_linear(ax, ay, bx, by);
+    cairo_pattern_add_color_stop_rgba(white, 0.0, 1, 1, 1,
+                                      0.0); // transparent at pure hue
+    cairo_pattern_add_color_stop_rgba(white, 1.0, 1, 1, 1,
+                                      1.0); // opaque white at bottom
+    cairo_set_source(cr, white);
+    cairo_paint(cr);
+    cairo_pattern_destroy(white);
+
+    // Black gradient: from pure hue (right) → black (top)
+    cairo_pattern_t* black = cairo_pattern_create_linear(ax, ay, cx2, cy2);
+    cairo_pattern_add_color_stop_rgba(black, 0.0, 0, 0, 0,
+                                      0.0); // transparent at pure hue
+    cairo_pattern_add_color_stop_rgba(black, 1.0, 0, 0, 0,
+                                      1.0); // opaque black at top
+    cairo_set_source(cr, black);
+    cairo_paint(cr);
+    cairo_pattern_destroy(black);
+
+    cairo_restore(cr);
+
+    // triangle outline
+    cairo_set_source_rgb(cr, .1, .1, .1);
+    cairo_move_to(cr, ax, ay);
+    cairo_line_to(cr, bx, by);
+    cairo_line_to(cr, cx2, cy2);
+    cairo_close_path(cr);
+
+    cairo_set_source_rgb(cr, .1, .1, .1);
+    cairo_stroke(cr);
+
+    // selectors draw
+
+    // triangle selector
+    double chroma_weight = self->saturation * self->lightness;
+    double white_weight = (1.0 - self->saturation) * self->lightness;
+    double black_weight = 1.0 - self->lightness;
+
+    double px = ax * chroma_weight + bx * white_weight + cx2 * black_weight;
+    double py = ay * chroma_weight + by * white_weight + cy2 * black_weight;
+
+    cairo_arc(cr, px, py, 5, 0, 2 * M_PI);
+
+    float fr, fg, fb;
+    vektor_color_wheel_get_colorout(self, &fr, &fg, &fb);
+    cairo_set_source_rgb(cr, fr, fg, fb);
+    cairo_fill_preserve(cr);
+    cairo_set_source_rgb(cr, 0.1, 0.1, 0.1);
+    cairo_set_line_width(cr, 2.0);
+    cairo_stroke(cr);
+
+    // wheel selector
+    double selector_angle = self->hue * 2 * M_PI;
+    double selector_width = 0.08;
+
+    cairo_new_path(cr);
+
+    cairo_arc(cr, cx, cy, wheel_radius, selector_angle - selector_width,
+              selector_angle + selector_width);
+
+    cairo_arc_negative(cr, cx, cy, inner_radius,
+                       selector_angle + selector_width,
+                       selector_angle - selector_width);
+
+    cairo_close_path(cr);
+
+    cairo_set_source_rgb(cr, 1, 1, 1);
+    cairo_stroke(cr);
+
+    cairo_destroy(cr);
+}
+
+static void on_click(GtkGestureClick* gesture, int n_press, double x, double y,
+                     gpointer data) {
+    VektorColorWheel* wheel = VEKTOR_COLOR_WHEEL(data);
+    GtkWidget* widget = GTK_WIDGET(wheel);
+
+    int width = gtk_widget_get_width(widget);
+    int height = gtk_widget_get_height(widget);
+
+    double outer_radius = MIN(width, height) / 2.0;
+    double wheel_radius = outer_radius * 0.95;
+
+    double triangle_radius = wheel_radius * 0.75;
+
+    double cx = width / 2.0;
+    double cy = height / 2.0;
+
+    double ax = cx + triangle_radius;
+    double ay = cy;
+
+    double bx = cx - 0.5 * triangle_radius;
+    double by = cy + 0.866 * triangle_radius;
+
+    double cx2 = cx - 0.5 * triangle_radius;
+    double cy2 = cy - 0.866 * triangle_radius;
+
+    double u, v, w;
+    gboolean inside =
+        point_in_triangle(x, y, ax, ay, bx, by, cx2, cy2, &u, &v, &w);
+
+    if (wheel->dragging_triangle) {
+
+        if (!inside) { // if outside triangle, snap to its edge
+            double sx, sy;
+
+            closest_point_on_triangle(x, y, ax, ay, bx, by, cx2, cy2, &sx, &sy);
+
+            x = sx;
+            y = sy;
+
+            point_in_triangle(x, y, ax, ay, bx, by, cx2, cy2, &u, &v, &w);
+        }
+
+        double denom = u + v;
+        if (denom > 0.0001) { // avoid div-by-zero at black vertex
+            wheel->saturation = u / denom;
+        } else {
+            wheel->saturation = 0.0; // arbitrary, since S irrelevant at V=0
+        }
+        wheel->lightness = denom;
+
+    } else { // dragging wheel
+        double dx = x - cx;
+        double dy = y - cy;
+
+        double angle = atan2(dy, dx);
+        if (angle < 0) {
+            angle += 2 * M_PI;
+        }
+
+        wheel->hue = angle / (2 * M_PI);
+    }
+
+    g_signal_emit(wheel, signals[COLOR_CHANGED], 0);
+    gtk_widget_queue_draw(widget);
+}
+
+static void on_drag(GtkGestureDrag* gesture, double offset_x, double offset_y,
+                    gpointer data) {
+    double x, y;
+    gtk_gesture_drag_get_start_point(gesture, &x, &y);
+
+    x += offset_x;
+    y += offset_y;
+
+    on_click(NULL, 0, x, y, data);
+}
+
+static void on_drag_begin(GtkGestureDrag* gesture, gdouble start_x,
+                          gdouble start_y, gpointer user_data) {
+    // set dragging_wheel or dragging_triangle which are used
+    // to determine to where the cursor should snap to
+
+    VektorColorWheel* wheel = VEKTOR_COLOR_WHEEL(user_data);
+    GtkWidget* widget = GTK_WIDGET(wheel);
+
+    int width = gtk_widget_get_width(widget);
+    int height = gtk_widget_get_height(widget);
+
+    double cx = width / 2.0;
+    double cy = height / 2.0;
+
+    double dx = start_x - cx;
+    double dy = start_y - cy;
+    double dist = sqrt(dx * dx + dy * dy);
+
+    double outer_radius = MIN(width, height) / 2.0;
+    double wheel_radius = outer_radius * 0.95;
+    double inner_radius = wheel_radius * 0.9;
+
+    if (dist > inner_radius) {
+        wheel->dragging_wheel = TRUE;
+        wheel->dragging_triangle = FALSE;
+    } else if (dist < inner_radius) {
+        wheel->dragging_wheel = FALSE;
+        wheel->dragging_triangle = TRUE;
+    } else {
+        wheel->dragging_wheel = FALSE;
+        wheel->dragging_triangle = FALSE;
+    }
+}
+
+static void vektor_color_wheel_init(VektorColorWheel* self) {
+    GtkGesture* click = gtk_gesture_click_new();
+    gtk_widget_add_controller(GTK_WIDGET(self), GTK_EVENT_CONTROLLER(click));
+
+    g_signal_connect(click, "pressed", G_CALLBACK(on_click), self);
+
+    GtkGesture* drag = gtk_gesture_drag_new();
+    gtk_widget_add_controller(GTK_WIDGET(self), GTK_EVENT_CONTROLLER(drag));
+
+    g_signal_connect(drag, "drag-update", G_CALLBACK(on_drag), self);
+    g_signal_connect(drag, "drag-begin", G_CALLBACK(on_drag_begin), self);
+}
+
+static void vektor_color_wheel_class_init(VektorColorWheelClass* klass) {
+    GtkWidgetClass* widget_class = GTK_WIDGET_CLASS(klass);
+    widget_class->snapshot = vektor_color_wheel_snapshot;
+
+    signals[COLOR_CHANGED] =
+        g_signal_new("color-changed", G_TYPE_FROM_CLASS(klass),
+                     G_SIGNAL_RUN_FIRST, 0, NULL, NULL, NULL, G_TYPE_NONE, 0);
+}
+
+GtkWidget* vektor_color_wheel_new(void) {
+    return g_object_new(VEKTOR_TYPE_COLOR_WHEEL, NULL);
+}
+
+VektorColor vektor_color_wheel_get_color(VektorColorWheel* wheel) {
+    float r, g, b;
+    gtk_hsv_to_rgb(wheel->hue, wheel->saturation, wheel->lightness, &r, &g, &b);
+
+    return (VektorColor){.r = (unsigned char)(r * 255),
+                         .g = (unsigned char)(g * 255),
+                         .b = (unsigned char)(b * 255),
+                         .a = 255};
+}
+
+void vektor_color_wheel_get_colorout(VektorColorWheel* wheel, float* r,
+                                     float* g, float* b) {
+    gtk_hsv_to_rgb(wheel->hue, wheel->saturation, wheel->lightness, r, g, b);
+}
+
+void vektor_color_wheel_set_color(VektorColorWheel* wheel, VektorColor c) {
+    float h, s, v;
+    gtk_rgb_to_hsv(c.r / 255.0, c.g / 255.0, c.b / 255.0, &h, &s, &v);
+    wheel->hue = (float)h;
+    wheel->saturation = (float)s;
+    wheel->lightness = (float)v;
+
+    gtk_widget_queue_draw(GTK_WIDGET(wheel));
+    g_signal_emit(wheel, signals[COLOR_CHANGED], 0);
+}

src/ui/widgets/colorwheel.h

@@ -0,0 +1,17 @@
+#ifndef VKTR_COLORWHEEL_H
+#define VKTR_COLORWHEEL_H
+
+#include "gtk/gtk.h"
+#include "src/util/color.h"
+
+#define VEKTOR_TYPE_COLOR_WHEEL vektor_color_wheel_get_type()
+G_DECLARE_FINAL_TYPE(VektorColorWheel, vektor_color_wheel, VEKTOR, COLOR_WHEEL,
+                     GtkDrawingArea)
+
+GtkWidget* vektor_color_wheel_new(void);
+VektorColor vektor_color_wheel_get_color(VektorColorWheel* wheel);
+void vektor_color_wheel_get_colorout(VektorColorWheel* wheel, float* r,
+                                     float* g, float* b);
+void vektor_color_wheel_set_color(VektorColorWheel* wheel, VektorColor c);
+
+#endif

ui/main.css

@@ -5,5 +5,5 @@
 }
 
 button {
-    background: none;
+    /*background: none;*/
 }

ui/main.ui

@@ -31,6 +31,29 @@
                     </object>
                 </child>
 
+                <!--Another topbar for style control-->
+                <child>
+                    <object class="GtkBox">
+                        <property name="orientation">horizontal</property>
+                        <property name="hexpand">true</property>
+
+                        <child>
+                            <object class="GtkImage">
+                                <property name="icon-name">tool-pencil-symbolic</property>
+                                <property name="margin-start">10</property>
+                            </object>
+                        </child>
+
+                        <child>
+                            <object class="GtkEntry" id="thickness_entry">
+                                <property name="text">1</property>
+                                <property name="margin-start">10</property>
+                            </object>
+                        </child>
+
+                    </object>
+                </child>
+
                 <!--Main area below-->
                 <child>
                     <object class="GtkPaned" id="workspace_paned">
@@ -45,11 +68,9 @@
 
                                 <!--Main canvas-->
                                 <child>
-                                    <object class="GtkPicture" id="workspace">
+                                    <object class="GtkGLArea" id="workspace">
-                                        <property name="content-fit">contain</property>
                                         <property name="hexpand">true</property>
                                         <property name="vexpand">true</property>
-
                                     </object>
                                 </child>
 
@@ -66,15 +87,79 @@
                                         <property name="margin-bottom">12</property>
 
                                         <!--Tool buttons-->
+
+                                        <!--Select tool-->
                                         <child>
-                                            <object class="GtkButton" id="button_linetool">
+                                            <object class="GtkButton" id="button_selecttool">
-                                                <property name="icon-name">insert-object-symbolic</property>
+                                                <property name="icon-name">tool-select-symbolic</property>
+                                                <property name="halign">start</property>
                                             </object>
                                         </child>
 
+                                        <!--Shape tool (row container)-->
                                         <child>
-                                            <object class="GtkButton">
+                                            <object class="GtkBox">
+                                                <property name="orientation">horizontal</property>
+
+                                                    <!--Shape tool-->
+                                                    <child>
+                                                        <object class="GtkButton" id="button_shapetools">
+                                                            <property name="icon-name">tool-line-symbolic</property>
+                                                        </object>
+                                                    </child>
+                                                    
+                                                    <!--Shape subtools revealer-->
+                                                    <child>
+                                                        <object class="GtkRevealer" id="shape_revealer">
+                                                            <property name="transition-type">slide-right</property>
+
+                                                            <!--Subtool container-->
+                                                            <child>
+                                                                <object class="GtkBox">
+                                                                    <property name="orientation">horizontal</property>
+
+                                                                    <!--Line tool-->
+                                                                    <child>
+                                                                        <object class="GtkButton" id="button_linetool">
+                                                                            <property name="icon-name">tool-line-symbolic</property>
+                                                                        </object>
+                                                                    </child>
+
+                                                                    <!--Rectangle tool-->
+                                                                    <child>
+                                                                        <object class="GtkButton" id="button_rectangletool">
+                                                                            <property name="icon-name">tool-rectangle-symbolic</property>
+                                                                        </object>
+                                                                    </child>
+
+                                                                    <!--Polygon tool-->
+                                                                    <child>
+                                                                        <object class="GtkButton" id="button_polygontool">
+                                                                            <property name="icon-name">tool-polygon-symbolic</property>
+                                                                        </object>
+                                                                    </child>
+
+                                                                    <!--Circle tool-->
+                                                                    <child>
+                                                                        <object class="GtkButton" id="button_circletool">
+                                                                            <property name="icon-name">tool-circle-symbolic</property>
+                                                                        </object>
+                                                                    </child>
+
+                                                                </object>
+                                                            </child>
+
+                                                        </object>
+                                                    </child>
+
+                                            </object>
+                                        </child>
+
+                                        <!--Copy tool-->
+                                        <child>
+                                            <object class="GtkButton" id="button_copytool">
                                                 <property name="icon-name">edit-copy-symbolic</property>
+                                                <property name="halign">start</property>
                                             </object>
                                         </child>
 
@@ -86,8 +171,116 @@
 
                         <!--Sidepanel (layers & modifiers)-->
                         <child>
-                            <object class="GtkFrame" id="sidepanel">
+                            <object class="GtkPaned" id="sidepanel">
-                                <property name="label">Sidepanel</property>
+                                <property name="orientation">vertical</property>
+                                <property name="wide-handle">true</property>
+                                <property name="hexpand">true</property>
+
+                                <child>
+                                    <object class="GtkBox">
+                                        <property name="hexpand">true</property>
+                                        <property name="vexpand">true</property>
+                                        <property name="margin-start">6</property>
+                                        <property name="margin-end">6</property>
+                                        <property name="margin-top">6</property>
+                                        <property name="margin-bottom">6</property>
+
+                                        <child>
+                                            <object class="GtkBox">
+                                                <property name="orientation">vertical</property>
+
+                                                <child>
+                                                    <object class="VektorColorWheel" id="color_picker">
+                                                        <property name="hexpand">true</property>
+                                                        <property name="vexpand">true</property>
+                                                    </object>
+                                                </child>
+
+                                                <child>
+                                                    <object class="GtkBox">
+                                                        <property name="orientation">horizontal</property>
+                                                        <property name="halign">center</property>
+
+                                                        <child>
+                                                            <object class="GtkLabel">
+                                                                <property name="label">R</property>
+                                                                <property name="margin-start">6</property>
+                                                                <property name="margin-end">6</property>
+                                                            </object>
+                                                        </child>
+
+                                                        <child>
+                                                            <object class="GtkEntry" id="spin_color_r">
+                                                                <property name="text">0</property>
+                                                            </object>
+                                                        </child>
+
+                                                        <child>
+                                                            <object class="GtkLabel">
+                                                                <property name="label">G</property>
+                                                                <property name="margin-start">6</property>
+                                                                <property name="margin-end">6</property>
+                                                            </object>
+                                                        </child>
+
+                                                        <child>
+                                                            <object class="GtkEntry" id="spin_color_g">
+                                                                <property name="text">0</property>
+                                                            </object>
+                                                        </child>
+
+                                                        <child>
+                                                            <object class="GtkLabel">
+                                                                <property name="label">B</property>
+                                                                <property name="margin-start">6</property>
+                                                                <property name="margin-end">6</property>
+                                                            </object>
+                                                        </child>
+
+                                                        <child>
+                                                            <object class="GtkEntry" id="spin_color_b">
+                                                                <property name="text">0</property>
+                                                            </object>
+                                                        </child>
+
+                                                    </object>
+                                                </child>
+
+                                            </object>
+                                            
+                                        </child>
+
+                                    </object>
+                                </child>
+
+                                <child>
+                                    <object class="GtkFrame">
+                                        <property name="label">Modifiers</property>
+                                    </object>
+                                </child>
+
+                            </object>
+                        </child>
+
+                    </object>
+                </child>
+
+                <!--Footer-->
+                <child>
+                    <object class="GtkBox" id="footer">
+                        <style><class name="footer"/></style>
+
+                        <property name="orientation">horizontal</property>
+                        <property name="margin-start">6</property>
+                        <property name="margin-end">6</property>
+                        <property name="margin-top">3</property>
+                        <property name="margin-bottom">3</property>
+
+                        <!--Footer status bar-->
+                        <child>
+                            <object class="GtkLabel" id="footer_status">
+                                <property name="label">0 MiB</property>
+                                <property name="xalign">0</property>
                             </object>
                         </child>
 
@@ -98,4 +291,6 @@
         </child>
 
     </object>
+
+
 </interface>