feat: add text rendering with SDF's

destrum/assets_src/shaders/shape2d.vert

@@ -7,27 +7,35 @@ layout (location = 0) out vec2 outLocalPos;
 layout (location = 1) out vec2 outQuadPos;
 layout (location = 2) flat out uint outShapeIndex;
 
-// Room for the antialiased edge outside the shape's bounds
 const float EDGE_MARGIN = 1.0;
 
-const vec2 CORNERS[6] = vec2[](
+const vec2 QUAD_CORNERS[6] = vec2[](
     vec2(-1.0, -1.0), vec2(1.0, -1.0), vec2(1.0, 1.0),
     vec2(-1.0, -1.0), vec2(1.0, 1.0), vec2(-1.0, 1.0)
 );
 
+vec2 rotate(vec2 position, float angle)
+{
+    float cosAngle = cos(angle);
+    float sinAngle = sin(angle);
+
+    return vec2(
+        position.x * cosAngle - position.y * sinAngle,
+        position.x * sinAngle + position.y * cosAngle
+    );
+}
+
 void main()
 {
     Shape2D shape = pcs.shapeBuffer.shapes[gl_InstanceIndex];
 
-    vec2 corner = CORNERS[gl_VertexIndex];
-    vec2 localPos = corner * (shape.halfSize + EDGE_MARGIN);
+    vec2 corner = QUAD_CORNERS[gl_VertexIndex];
+    vec2 localPosition = corner * (shape.halfSize + EDGE_MARGIN);
+    vec2 screenPosition = shape.center + rotate(localPosition, shape.rotation);
 
-    float c = cos(shape.rotation);
-    float s = sin(shape.rotation);
-    vec2 rotated = vec2(localPos.x * c - localPos.y * s, localPos.x * s + localPos.y * c);
+    gl_Position = pcs.projection * vec4(screenPosition, 0.0, 1.0);
 
-    gl_Position = pcs.projection * vec4(shape.center + rotated, 0.0, 1.0);
-    outLocalPos = localPos;
-    outQuadPos = localPos / max(shape.halfSize, vec2(1e-6)) * 0.5 + 0.5;
+    outLocalPos = localPosition;
+    outQuadPos = localPosition / max(shape.halfSize, vec2(1e-6)) * 0.5 + 0.5;
     outShapeIndex = gl_InstanceIndex;
 }