pythonarcade · einarf · Jun 7, 2025 · Jun 7, 2025
diff --git a/arcade/context.py b/arcade/context.py
@@ -170,8 +170,8 @@ def __init__(
         self.shape_rectangle_filled_unbuffered_program = self.load_program(
             vertex_shader=":system:shaders/shapes/rectangle/filled_unbuffered_vs.glsl",
             fragment_shader=":system:shaders/shapes/rectangle/filled_unbuffered_fs.glsl",
-            geometry_shader=":system:shaders/shapes/rectangle/filled_unbuffered_geo.glsl",
         )
+
         # Atlas shaders
         self.atlas_resize_program: Program = self.load_program(
             # NOTE: This is the geo shader version of the atlas resize program.
@@ -253,9 +253,36 @@ def __init__(
         )
         # rectangle filled
         self.shape_rectangle_filled_unbuffered_buffer = self.buffer(reserve=8)
+        # fmt: off
         self.shape_rectangle_filled_unbuffered_geometry: Geometry = self.geometry(
-            [BufferDescription(self.shape_rectangle_filled_unbuffered_buffer, "2f", ["in_vert"])]
+            [
+                # Instanced quad (triangle strip)
+                BufferDescription(
+                    self.buffer(
+                        data=array(
+                            "f",
+                            [
+                                -0.5, +0.5,  # Upper left
+                                -0.5, -0.5,  # lower left
+                                +0.5, +0.5,  # upper right
+                                +0.5, -0.5,  # lower right
+                            ],
+                        )
+                    ),
+                    "2f",
+                    ["in_vert"],
+                ),
+                # Per instance data
+                BufferDescription(
+                    self.shape_rectangle_filled_unbuffered_buffer,
+                    "2f",
+                    ["in_instance_pos"],
+                    instanced=True
+                ),
+            ],
+            mode=self.TRIANGLE_STRIP,
         )
+        # fmt: on
         self.geometry_empty: Geometry = self.geometry()
 
         self._atlas: TextureAtlasBase | None = None

diff --git a/arcade/draw/point.py b/arcade/draw/point.py
@@ -68,7 +68,6 @@ def draw_points(point_list: Point2List, color: RGBOrA255, size: float = 1.0) ->
 
     # Resize buffer
     data_size = num_points * 8
-    # if data_size > buffer.size:
     buffer.orphan(size=data_size)
 
     ctx.enable(ctx.BLEND)
@@ -79,6 +78,6 @@ def draw_points(point_list: Point2List, color: RGBOrA255, size: float = 1.0) ->
     buffer.write(data=point_array)
 
     # Only render the # of points we have complete data for
-    geometry.render(program, mode=ctx.POINTS, vertices=data_size // 8)
+    geometry.render(program, instances=num_points)
 
     ctx.disable(ctx.BLEND)
diff --git a/arcade/draw/rect.py b/arcade/draw/rect.py
@@ -395,7 +395,7 @@ def draw_rect_filled(rect: Rect, color: RGBOrA255, tilt_angle: float = 0) -> Non
     buffer.orphan()
     buffer.write(data=array.array("f", (rect.x, rect.y)))
 
-    geometry.render(program, mode=ctx.POINTS, vertices=1)
+    geometry.render(program, instances=1)
 
     ctx.disable(ctx.BLEND)
 

diff --git a/arcade/resources/system/shaders/shapes/rectangle/filled_unbuffered_geo.glsl b/arcade/resources/system/shaders/shapes/rectangle/filled_unbuffered_geo.glsl
diff --git a/arcade/resources/system/shaders/shapes/rectangle/filled_unbuffered_vs.glsl b/arcade/resources/system/shaders/shapes/rectangle/filled_unbuffered_vs.glsl
@@ -1,7 +1,24 @@
 #version 330
 
+uniform WindowBlock {
+    mat4 projection;
+    mat4 view;
+} window;
+
+// [w, h, tilt]
+uniform vec3 shape;
+
 in vec2 in_vert;
+in vec2 in_instance_pos;
 
 void main() {
-    gl_Position = vec4(in_vert, 0.0, 1.0);
+    float angle = radians(shape.z);
+    mat2 rot = mat2(
+        cos(angle), -sin(angle),
+        sin(angle),  cos(angle)
+    );
+    // vec2 size = shape.xy / 2.0;
+    mat4 mvp = window.projection * window.view;
+    vec2 pos = in_instance_pos + (in_vert * shape.xy);
+    gl_Position = mvp * vec4(rot * pos, 0.0, 1.0);
 }