Merge pull request #1 from Froxwin/bobbert

Bobbert

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>

shaders/selection.frag.glsl

@@ -0,0 +1,39 @@
+#version 320 es
+precision mediump float;
+
+in vec2 vPos;
+out vec4 FragColor;
+
+uniform float uTime;
+uniform vec4 uColor1;
+uniform vec4 uColor2;
+uniform vec2 uMin;
+uniform vec2 uMax;
+
+void main()
+{
+    float borderWidth = 0.008;
+
+
+    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.vert.glsl

@@ -7,9 +7,11 @@ 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

@@ -22,10 +22,16 @@ static void appstate_set_tool(GtkButton* button, gpointer user_data) {
     data->state->selectedTool = data->tool;
 
     // setting tool makes the sub-tools menu to close
-    gtk_revealer_set_reveal_child(data->revealer, FALSE);
+    // (ADD NEW REVEALERS HERE)
+    gtk_revealer_set_reveal_child(
+        data->state->widgetState->workspaceRevealerShapes, 
+        FALSE
+    );
 
     // setting tool also resets selected shape
-    data->state->selectedShape = NULL;
+    // 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) {
@@ -56,8 +62,8 @@ static void appstate_on_color_change(VektorColorWheel* wheel,
     gtk_editable_set_text(GTK_EDITABLE(appstate->widgetState->sidepanelEntryB),
                           str_b);
 
-    gtk_gl_area_queue_render(
+    /*gtk_gl_area_queue_render(
-        GTK_GL_AREA(appstate->widgetState->workspaceCanvas));
+        GTK_GL_AREA(appstate->widgetState->workspaceCanvas));*/
 }
 
 static void appstate_on_entry_update(GtkEntry* entry, gpointer user_data) {
@@ -69,7 +75,6 @@ static void appstate_on_entry_update(GtkEntry* entry, gpointer user_data) {
     unsigned char b = (unsigned char)atoi(
         gtk_editable_get_text(GTK_EDITABLE(widgetState->sidepanelEntryB)));
 
-    g_print("%d", r);
     vektor_color_wheel_set_color(
         VEKTOR_COLOR_WHEEL(widgetState->workspaceColorPicker),
         (VektorColor){.r = r, .g = g, .b = b});
@@ -94,7 +99,8 @@ static void canvas_onclick(GtkGestureClick* gesture, int n_press, double x,
 
     vektor_appstate_canvas_click(state, normalized_coords.x,
                                  normalized_coords.y);
-    gtk_gl_area_queue_render(GTK_GL_AREA(widget));
+
+    //gtk_gl_area_queue_render(GTK_GL_AREA(widget));
 }
 
 void vektor_appstate_canvas_click(VektorAppState* state, double x, double y) {
@@ -152,6 +158,43 @@ begin_click_dispatch:
         vektor_polygon_add_point(state->selectedShape->primitive.polygon, pos);
         vektor_shapes_update_bbox(state->shapeBuffer);
     }
+    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_shapebuffer_add_shape(
+            state->shapeBuffer, vektor_shape_new(rectPrimitive, style, 0));
+
+        state->selectedShape =
+            &(state->shapeBuffer->shapes[state->shapeBuffer->count - 1]);
+
+        vektor_rectangle_free(rect);
+
+
+        vektor_rectangle_set_start(&state->selectedShape->primitive.rectangle, pos);
+        vektor_rectangle_set_end(
+            &state->selectedShape->primitive.rectangle, 
+            vec2_add(pos, (V2){0.1f,0.1f})
+        );
+        //state->selectedShape = NULL;
+        vektor_shapes_update_bbox(state->shapeBuffer);
+    }
+    else if (state->selectedTool == VektorSelectionTool) {
+        for(size_t i = 0; i < state->shapeBuffer->count; i++) {
+            VektorBBox bbox = 
+                vektor_primitive_get_bbox(state->shapeBuffer->shapes[i].primitive);
+            if(vektor_bbox_isinside(bbox, pos)) {
+                state->selectedShape = &(state->shapeBuffer->shapes[i]);
+                g_print("%d", state->selectedShape == NULL);
+                return;
+            }
+        }
+        // was clicked outside any shapes - reset selection
+        state->selectedShape = NULL;
+    }
 }
 
 void vektor_appstate_new(VektorWidgetState* wstate, VektorAppState* stateOut) {
@@ -165,24 +208,41 @@ void vektor_appstate_new(VektorWidgetState* wstate, VektorAppState* 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;
+
     // populate appstate
+    stateOut->startupTime = g_get_monotonic_time();
+
     stateOut->shapeBuffer = malloc(sizeof(VektorShapeBuffer));
     *stateOut->shapeBuffer = (VektorShapeBuffer){0};
     stateOut->canvas = malloc(sizeof(VektorCanvas));
     stateOut->widgetState = wstate;
     stateOut->currentColor = vektor_color_solid(0, 0, 0);
     stateOut->selectedShape = NULL;
-    vektor_canvas_init(wstate, stateOut->canvas, stateOut->shapeBuffer);
+    VektorCanvasRenderInfo* renderInfo = malloc(sizeof(VektorCanvasRenderInfo));
+    renderInfo->selectedShape = &(stateOut->selectedShape);
+    renderInfo->shapes = stateOut->shapeBuffer;
+    renderInfo->startupTime = stateOut->startupTime;
+    vektor_canvas_init(wstate, stateOut->canvas, 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_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_linetool);
-    g_signal_connect(G_OBJECT(wstate->workspaceButtonCircletool), "clicked",
+    g_signal_connect(G_OBJECT(wstate->workspaceButtonPolygonTool), "clicked",
-                     G_CALLBACK(appstate_set_tool), data_linetool);
-    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",

src/application/applicationstate.h

@@ -7,11 +7,15 @@
 #include "src/core/raster.h"
 
 typedef enum VektorAppTool {
+    VektorSelectionTool,
     VektorLineTool,
     VektorPolygonTool,
+    VektorRectangleTool
 } VektorAppTool;
 
 typedef struct VektorAppState {
+    gint64 startupTime;
+
     VektorWidgetState* widgetState;
 
     VektorAppTool selectedTool;

src/core/primitives.c

@@ -49,6 +49,24 @@ void vektor_polygon_free(VektorPolygon* pg) {
     free(pg);
 }
 
+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);
+}
+
 void vektor_shapebuffer_add_shape(VektorShapeBuffer* buffer,
                                   VektorShape shape) {
     if (buffer->count >= buffer->capacity) {
@@ -59,7 +77,7 @@ void vektor_shapebuffer_add_shape(VektorShapeBuffer* buffer,
     buffer->shapes[buffer->count++] = shape;
 }
 
-VektorBBox polyline_mk_bbox(VektorPrimitive prim) {
+VektorBBox vektor_polyline_get_bbox(VektorPrimitive prim) {
     float min_x, max_x, min_y, max_y;
     for (size_t i = 0; i < prim.polyline->count; i++) {
         V2 p = prim.polyline->points[i];
@@ -72,27 +90,43 @@ VektorBBox polyline_mk_bbox(VektorPrimitive prim) {
     return (VektorBBox){(V2){min_x, min_y}, (V2){max_x, max_y}};
 }
 
-VektorBBox polygon_mk_bbox(VektorPrimitive prim) {
+VektorBBox vektor_polygon_get_bbox(VektorPrimitive prim) {
-    float min_x, max_x, min_y, max_y;
+    V2 first = prim.polygon->points[0];
-    for (size_t i = 0; i < prim.polygon->count; i++) {
+
+    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 = fminf(max_x, p.x);
+        max_x = fmaxf(max_x, p.x);
-        max_y = fminf(max_y, p.y);
+        max_y = fmaxf(max_y, p.y);
     }
+
     return (VektorBBox){(V2){min_x, min_y}, (V2){max_x, max_y}};
 }
 
-VektorBBox vektor_mk_bbox(VektorPrimitive prim) {
+VektorBBox vektor_rectangle_get_bbox(VektorPrimitive prim) {
+    return (VektorBBox){prim.rectangle.start, prim.rectangle.end};
+}
+
+VektorBBox vektor_primitive_get_bbox(VektorPrimitive prim) {
     switch (prim.kind) {
     case VEKTOR_POLYLINE:
-        return polyline_mk_bbox(prim);
+        return vektor_polyline_get_bbox(prim);
         break;
 
     case VEKTOR_POLYGON:
-        return polygon_mk_bbox(prim);
+        return vektor_polygon_get_bbox(prim);
+        break;
+
+    case VEKTOR_RECTANGLE:
+        return vektor_rectangle_get_bbox(prim);
         break;
 
     default:
@@ -101,13 +135,18 @@ VektorBBox vektor_mk_bbox(VektorPrimitive prim) {
     }
 }
 
+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;
+}
+
 VektorShape vektor_shape_new(VektorPrimitive prim, VektorStyle style,
                              int z_index) {
-    return (VektorShape){.primitive = prim, .style = style, .z_index = z_index, .bbox=vektor_mk_bbox(prim)};
+    return (VektorShape){.primitive = prim, .style = style, .z_index = z_index, .bbox=vektor_primitive_get_bbox(prim)};
 }
 
 void vektor_shapes_update_bbox(VektorShapeBuffer* buffer) {
     for (size_t i = 0; i < buffer->count; i++) {
-        buffer->shapes[i].bbox = vektor_mk_bbox(buffer->shapes[i].primitive);
+        buffer->shapes[i].bbox = vektor_primitive_get_bbox(buffer->shapes[i].primitive);
     }
 }

src/core/primitives.h

@@ -23,10 +23,16 @@ typedef struct {
     double radius;
 } VektorCircle;
 
+typedef struct {
+    V2 start;
+    V2 end;
+} VektorRectangle;
+
 typedef enum {
     VEKTOR_POLYLINE,
     VEKTOR_POLYGON,
-    VEKTOR_CIRCLE
+    VEKTOR_CIRCLE,
+    VEKTOR_RECTANGLE
 } VektorPrimitiveKind;
 
 typedef struct {
@@ -35,6 +41,7 @@ typedef struct {
         VektorPolyline* polyline;
         VektorPolygon* polygon;
         VektorCircle circle;
+        VektorRectangle rectangle;
     };
 } VektorPrimitive;
 
@@ -46,6 +53,11 @@ VektorPolygon* vektor_polygon_new(void);
 void vektor_polygon_add_point(VektorPolygon* pl, V2 point);
 void vektor_polygon_free(VektorPolygon* pl);
 
+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);
+
 typedef struct {
     VektorColor stroke_color;
     float stroke_width;
@@ -63,10 +75,12 @@ typedef struct {
     VektorPrimitive primitive;
 } VektorShape;
 
-VektorBBox polyline_mk_bbox(VektorPrimitive prim);
+VektorBBox vektor_polyline_get_bbox(VektorPrimitive prim);
-VektorBBox polygon_mk_bbox(VektorPrimitive prim);
+VektorBBox vektor_polygon_get_bbox(VektorPrimitive prim);
+VektorBBox vektor_rectangle_get_bbox(VektorPrimitive prim);
 
-VektorBBox vektor_mk_bbox(VektorPrimitive prim);
+VektorBBox vektor_primitive_get_bbox(VektorPrimitive prim);
+bool vektor_bbox_isinside(VektorBBox bbox, V2 point);
 
 VektorShape vektor_shape_new(VektorPrimitive prim, VektorStyle style,
                              int z_index);

src/core/raster.c

@@ -1,6 +1,7 @@
 #include "raster.h"
 #include "epoxy/gl.h"
 #include "primitives.h"
+#include "src/core/vector.h"
 #include "stddef.h"
 #include <stddef.h>
 
@@ -12,7 +13,7 @@ void vektor_edgebuffer_add_edge(EdgeBuffer* buffer, Edge edge) {
     buffer->edges[buffer->count++] = edge;
 }
 
-void vektor_polyline_flatten(EdgeBuffer* buffer, VektorPolyline* line,
+void vektor_polyline_tessellate(EdgeBuffer* buffer, VektorPolyline* line,
                              size_t j) {
     for (size_t i = 0; i + 1 < line->count; i++) {
         vektor_edgebuffer_add_edge(
@@ -20,7 +21,7 @@ void vektor_polyline_flatten(EdgeBuffer* buffer, VektorPolyline* line,
     }
 }
 
-void vektor_polygon_flatten(EdgeBuffer* buffer, VektorPolygon* polygon,
+void vektor_polygon_tessellate(EdgeBuffer* buffer, VektorPolygon* polygon,
                              size_t j) {
     for (size_t i = 0; i + 1 < polygon->count; i++) {
         vektor_edgebuffer_add_edge(
@@ -30,6 +31,20 @@ void vektor_polygon_flatten(EdgeBuffer* buffer, VektorPolygon* polygon,
         buffer, (Edge){polygon->points[polygon->count - 1], polygon->points[0], 0, j});
 }
 
+void vektor_rectangle_tessellate(EdgeBuffer* buffer, VektorRectangle* rct, size_t j) {
+    if (vec2_equals(rct->end, rct->start)) {return;}
+
+    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);
+}
+
 void vektor_rasterize(VertexBuffer* vb, VektorShapeBuffer* shapes) {
     EdgeBuffer edges = {0};
     for (size_t i = 0; i < shapes->count; i++) {
@@ -37,11 +52,15 @@ void vektor_rasterize(VertexBuffer* vb, VektorShapeBuffer* shapes) {
 
         switch (p->kind) {
         case VEKTOR_POLYLINE:
-            vektor_polyline_flatten(&edges, p->polyline, i);
+            vektor_polyline_tessellate(&edges, p->polyline, i);
             break;
 
         case VEKTOR_POLYGON:
-            vektor_polygon_flatten(&edges, p->polygon, i);
+            vektor_polygon_tessellate(&edges, p->polygon, i);
+            break;
+
+        case VEKTOR_RECTANGLE:
+            vektor_rectangle_tessellate(&edges, &p->rectangle, i);
             break;
 
         default:
@@ -53,7 +72,7 @@ void vektor_rasterize(VertexBuffer* vb, VektorShapeBuffer* shapes) {
     vektor_edges_to_triangles(vb, &edges, shapes);
 }
 
-void vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2, VektorColor color) {
+void vektor_vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2, VektorColor color) {
     if (vb->count + 3 >= vb->capacity) {
         vb->capacity = vb->capacity ? vb->capacity * 2 : 8;
         vb->vertices = realloc(vb->vertices, sizeof(Vertex) * vb->capacity);
@@ -63,6 +82,22 @@ void vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2, VektorColor color) {
     vb->vertices[vb->count++] = (Vertex){v2, color};
 }
 
+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);
+}
+
 void vektor_edge_to_triangles(VertexBuffer* vb, Edge e,
                               VektorShapeBuffer* shape_buffer) {
     float dx = e.p2.x - e.p1.x;
@@ -81,9 +116,9 @@ void vektor_edge_to_triangles(VertexBuffer* vb, Edge e,
     V2 v2 = {e.p2.x + px, e.p2.y + py};
     V2 v3 = {e.p2.x - px, e.p2.y - py};
 
-    vb_add_triangle(vb, v0, v1, v2,
+    vektor_vb_add_triangle(vb, v0, v1, v2,
                     shape_buffer->shapes[e.shape_id].style.stroke_color);
-    vb_add_triangle(vb, v2, v1, v3,
+    vektor_vb_add_triangle(vb, v2, v1, v3,
                     shape_buffer->shapes[e.shape_id].style.stroke_color);
 }
 

src/core/raster.h

@@ -23,8 +23,9 @@ typedef struct {
 
 void vektor_edgebuffer_add_edge(EdgeBuffer* edges, Edge edge);
 
-void vektor_polyline_flatten(EdgeBuffer* edges, VektorPolyline* line, size_t i);
+void vektor_polyline_tessellate(EdgeBuffer* edges, VektorPolyline* line, size_t i);
-void vektor_polygon_flatten(EdgeBuffer* buffer, VektorPolygon* line, size_t i);
+void vektor_polygon_tessellate(EdgeBuffer* buffer, VektorPolygon* polygon, size_t i);
+void vektor_rectangle_tessellate(EdgeBuffer* buffer, VektorRectangle* rct, size_t i);
 
 typedef struct {
     V2 coords;
@@ -37,7 +38,9 @@ typedef struct {
     size_t capacity;
 } VertexBuffer;
 
-void vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2, VektorColor color);
+void vektor_vb_add_triangle(VertexBuffer* vb, V2 v0, V2 v1, V2 v2, VektorColor color);
+void vektor_vb_add_quad(VertexBuffer* vb, V2 v0, V2 v1, VektorColor color);
+
 void vektor_edge_to_triangles(VertexBuffer* vb, Edge e,
                               VektorShapeBuffer* shape_buffer);
 void vektor_edges_to_triangles(VertexBuffer* vb, EdgeBuffer* edges,

src/core/vector.h

@@ -22,6 +22,10 @@ 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};
 }

src/main.c

@@ -1,3 +1,4 @@
+#include "glib.h"
 #include "gtk/gtk.h"
 #include "src/application/applicationstate.h"
 #include "src/core/primitives.h"
@@ -14,6 +15,13 @@ static void on_map(GtkWidget* window, gpointer user_data) {
     vektor_uictrl_map((VektorWidgetState*)user_data);
 }
 
+static int update_callback(gpointer 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) {
 
     VektorWidgetState* widget_state =
@@ -25,6 +33,8 @@ static void activate(GtkApplication* app, gpointer user_data) {
     g_signal_connect(widget_state->window, "map", G_CALLBACK(on_map),
                      widget_state);
 
+    g_timeout_add(1, update_callback, app_state);
+
     gtk_window_present(widget_state->window);
 }
 

src/ui/uicontroller.c

@@ -50,14 +50,16 @@ void vektor_uictrl_init(GtkApplication* app, VektorWidgetState* stateOut) {
         GTK_BUTTON(gtk_builder_get_object(builder, "button_shapetools"));
     stateOut->workspaceRevealerShapes =
         GTK_REVEALER(gtk_builder_get_object(builder, "shape_revealer"));
-    stateOut->workspaceButtonLinetool =
+    stateOut->workspaceButtonLineTool =
         GTK_BUTTON(gtk_builder_get_object(builder, "button_linetool"));
-    stateOut->workspaceButtonRecttool =
+    stateOut->workspaceButtonRectTool =
         GTK_BUTTON(gtk_builder_get_object(builder, "button_rectangletool"));
-    stateOut->workspaceButtonCircletool =
+    stateOut->workspaceButtonCircleTool =
         GTK_BUTTON(gtk_builder_get_object(builder, "button_circletool"));
-    stateOut->workspaceButtonPolygontool =
+    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"));
 

src/ui/uicontroller.h

@@ -17,10 +17,11 @@ typedef struct VektorWidgetState {
 
     GtkButton* workspaceButtonMasterShapes;
     GtkRevealer* workspaceRevealerShapes;
-    GtkButton* workspaceButtonLinetool;
+    GtkButton* workspaceButtonLineTool;
-    GtkButton* workspaceButtonRecttool;
+    GtkButton* workspaceButtonRectTool;
-    GtkButton* workspaceButtonCircletool;
+    GtkButton* workspaceButtonCircleTool;
-    GtkButton* workspaceButtonPolygontool;
+    GtkButton* workspaceButtonPolygonTool;
+    GtkButton* workspaceButtonSelectionTool;
 
     VektorColorWheel* workspaceColorPicker;
 

src/ui/vektorcanvas.c

@@ -1,8 +1,10 @@
 #include "epoxy/gl.h"
+#include "glib.h"
 #include "gtk/gtk.h"
 
 #include "../core/raster.h"
 #include "src/core/primitives.h"
+#include "src/util/color.h"
 #include "uicontroller.h"
 #include "vektorcanvas.h"
 #include <epoxy/gl_generated.h>
@@ -27,7 +29,19 @@ char* read_file(const char* path) {
     return buffer;
 }
 
-static GLuint shader_program;
+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_uC1Loc;
+static GLuint shader_selection_uC2Loc;
+static GLuint shader_selection_uMinLoc;
+static GLuint shader_selection_uMaxLoc;
+
 static GLuint vao;
 VertexBuffer vb;
 
@@ -46,17 +60,11 @@ static GLuint compile_shader(GLenum type, const char* src) {
     return shader;
 }
 
-static void init_shader(void) {
+static GLuint create_shader_program(char* frag, char* vert) {
-    char* vert_src = read_file("./shaders/triangle.vert.glsl");
+    GLuint vertex = compile_shader(GL_VERTEX_SHADER, vert);
-    char* frag_src = read_file("./shaders/triangle.frag.glsl");
+    GLuint fragment = compile_shader(GL_FRAGMENT_SHADER, frag);
 
-    if (!vert_src || !frag_src)
+    GLuint shader_program = glCreateProgram();
-        g_error("Failed to load shader files");
-
-    GLuint vertex = compile_shader(GL_VERTEX_SHADER, vert_src);
-    GLuint fragment = compile_shader(GL_FRAGMENT_SHADER, frag_src);
-
-    shader_program = glCreateProgram();
     glAttachShader(shader_program, vertex);
     glAttachShader(shader_program, fragment);
     glLinkProgram(shader_program);
@@ -71,6 +79,32 @@ static void init_shader(void) {
 
     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_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) {
@@ -92,32 +126,70 @@ static void init_geometry(void) {
 
     glBindVertexArray(0);
 }
-static gboolean render(GtkGLArea* area, GdkGLContext* context,
+static gboolean render(GtkGLArea* a, GdkGLContext* ctx, VektorCanvasRenderInfo* renderInfo) {
-                       VektorShapeBuffer* prims) {
-    
     vb.count = 0;
-    vektor_rasterize(&vb, prims);
+
+    vektor_rasterize(&vb, renderInfo->shapes);
+    size_t shape_vertex_count = vb.count; // remember how many vertices belong to shapes
+
+    // create selection quad if a shape is selected
+    if(renderInfo->selectedShape != NULL && 
+        *(renderInfo->selectedShape) != NULL) {
+        VektorBBox bbox = vektor_primitive_get_bbox(
+            (*(renderInfo->selectedShape))->primitive
+        );
+        
+        vektor_vb_add_quad(
+            &vb, 
+            bbox.min, 
+            bbox.max, 
+            vektor_color_new(255,255,255,255)
+        );
+    }
 
     glBufferData(GL_ARRAY_BUFFER, vb.count * sizeof(Vertex), vb.vertices,
                  GL_STATIC_DRAW);
 
-    glUseProgram(shader_program);
 
-    GLuint uProjectionLoc = glGetUniformLocation(shader_program, "uProjection");
+    // 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(uProjectionLoc, 1, GL_FALSE, projectionMatrix);
+    glUniformMatrix4fv(shader_standard_uProjMatrixLoc, 1, GL_FALSE, projectionMatrix);
 
     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, vb.count);
+    glDrawArrays(GL_TRIANGLES, 0, shape_vertex_count);
-    GLenum err = glGetError();
+
-    //printf("OpenGL error: %x\n", err);
+    // PASS 2 - draw selection quads
-    // glDrawElements(GL_TRIANGLES, 6, GL_UNSIGNED_INT, 0);
+    if (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))->primitive
+        );
+
+        glUseProgram(selection_shader_program);
+
+        float projectionMatrix[16] = {1, 0, 0, 0, 0, 1, 0, 0,
+                                    0, 0, 1, 0, 0, 0, 0, 1};
+
+        glUniformMatrix4fv(shader_selection_uProjMatrixLoc, 1, GL_FALSE, projectionMatrix);
+        glUniform1f(shader_selection_uTimeLoc, time);
+        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, 1);
+        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);
 
@@ -163,7 +235,7 @@ static void realize(GtkGLArea* area, gpointer user_data) {
 }
 
 void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut,
-                        VektorShapeBuffer* prims) {
+                        VektorCanvasRenderInfo* renderInfo) {
     canvasOut->canvasWidget = state->workspaceCanvas;
     canvasOut->width = VKTR_CANVAS_WIDTH;
     canvasOut->height = VKTR_CANVAS_HEIGHT;
@@ -178,5 +250,5 @@ void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut,
     g_signal_connect(canvasOut->canvasWidget, "realize", G_CALLBACK(realize),
                      NULL);
     g_signal_connect(canvasOut->canvasWidget, "render", G_CALLBACK(render),
-                     prims);
+                     renderInfo);
 }

src/ui/vektorcanvas.h

@@ -4,8 +4,10 @@
 #include "../core/raster.h"
 #include "../util/color.h"
 #include "gtk/gtk.h"
+#include "src/core/primitives.h"
 #include "uicontroller.h"
 
+
 typedef struct VektorCanvas {
     GtkGLArea* canvasWidget;
 
@@ -18,8 +20,16 @@ typedef struct VektorCanvas {
     int height;
 } VektorCanvas;
 
+typedef struct VektorCanvasRenderInfo {
+    gint64 startupTime;
+    VektorShapeBuffer* shapes;
+    
+    // a pointer to appstate->selectedShape
+    VektorShape** selectedShape;
+} VektorCanvasRenderInfo;
+
 void vektor_canvas_init(VektorWidgetState* state, VektorCanvas* canvasOut,
-                        VektorShapeBuffer* shapes);
+                        VektorCanvasRenderInfo* renderInfo);
 // void vektor_canvas_update(VektorCanvas* canvas);
 // void vektor_canvas_fill(VektorCanvas* canvas, VektorColor color);
 // void vektor_canvas_drawfrom(VektorFramebuffer* fb, VektorCanvas* canvas);

ui/main.ui

@@ -65,6 +65,14 @@
 
                                         <!--Tool buttons-->
 
+                                        <!--Select tool-->
+                                        <child>
+                                            <object class="GtkButton" id="button_selecttool">
+                                                <property name="icon-name">tool-select-symbolic</property>
+                                                <property name="halign">start</property>
+                                            </object>
+                                        </child>
+
                                         <!--Shape tool (row container)-->
                                         <child>
                                             <object class="GtkBox">