feat: add polygon tool

src/ui/uicontroller.c

@@ -56,6 +56,8 @@ void vektor_uictrl_init(GtkApplication* app, VektorWidgetState* stateOut) {
         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->workspaceColorPicker =
         VEKTOR_COLOR_WHEEL(gtk_builder_get_object(builder, "color_picker"));
 

src/ui/uicontroller.h

@@ -20,6 +20,7 @@ typedef struct VektorWidgetState {
     GtkButton* workspaceButtonLinetool;
     GtkButton* workspaceButtonRecttool;
     GtkButton* workspaceButtonCircletool;
+    GtkButton* workspaceButtonPolygontool;
 
     VektorColorWheel* workspaceColorPicker;
 

src/ui/vektorcanvas.c

@@ -94,6 +94,8 @@ static void init_geometry(void) {
 }
 static gboolean render(GtkGLArea* area, GdkGLContext* context,
                        VektorShapeBuffer* prims) {
+    
+    vb.count = 0;
     vektor_rasterize(&vb, prims);
 
     glBufferData(GL_ARRAY_BUFFER, vb.count * sizeof(Vertex), vb.vertices,