implemented instanced rendering

resources/shaders/source/rect.frag.glsl

@@ -4,56 +4,24 @@ layout(set = 3, binding = 0) uniform Viewport {
     ivec2 view;
 };
 
-layout(location = 0) in vec4 color;
-layout(location = 1) in vec2 local_position;
-layout(location = 2) in vec2 global_position;
-layout(location = 3) in float radius;
+layout(location = 0) in vec4 in_color;
+layout(location = 1) in vec4 in_quad_size; // x,y, w,h
+layout(location = 2) in float in_radius;
 
 layout(location = 0) out vec4 fragColor;
 
 // SDF for a rounded rectangle given the centerpoint, half size and radius, all in pixels
-float sdf_rr(vec2 p, vec2 center, vec2 half_size, float radius) {
-    // Translate fragment position to rectangle's coordinate system
-    p -= center;
-    // Adjust for rounded corners: shrink the rectangle by the radius
+float sdf_rr(vec2 p, vec2 half_size, float radius) {
     vec2 q = abs(p) - half_size + radius;
-    // Combine distance components:
-    // - max(q, 0.0) handles regions outside the rounded corners
-    // - min(max(q.x, q.y), 0.0) handles regions inside the rectangle
     return length(max(q, 0.0)) + min(max(q.x, q.y), 0.0) - radius;
 }
 
 void main()
 {
-    // local_position are normalized coordinates in the rectangle, passed from the
-    // vertex shader
-    /*
-     * Window
-     * +-----------------------+
-     * |              (1,1)    |
-     * |     +----------x      |
-     * |     |          |      |
-     * |     |          |      |
-     * |     |   Rect   |      |
-     * |     |          |      |
-     * |     |          |      |
-     * |     x----------+      |
-     * |  (-1,-1)              |
-     * |                       |
-     * +-----------------------+
-     */ 
+    vec2 centerpoint = in_quad_size.xy + in_quad_size.zw * 0.5;
+    vec2 half_size = in_quad_size.zw * 0.5;
+    float distance = sdf_rr(vec2(gl_FragCoord) - centerpoint, half_size, in_radius);
+    float alpha = 1.0 - smoothstep(0.0, 1.0, distance);
 
-    vec2 dx = dFdx(local_position);
-    vec2 dy = dFdy(local_position);
-    // Conversion from normalized coordinates to pixels
-    vec2 norm_to_px = 1.0 / vec2(length(dx), length(dy));
-	
-    vec2 centerpoint = global_position - local_position * norm_to_px;
-    // the half size of the rectangle is also norm_to_px
-    vec2 half_size = 1.0 * norm_to_px;
-
-    float distance = sdf_rr(global_position, centerpoint, half_size, radius);
-    float alpha = 1.0 - smoothstep(0.0, 1.0, max(distance, 0.0));
-
-	fragColor = vec4(color.rgb, color.a * alpha);
+    fragColor = vec4(in_color.rgb, in_color.a * alpha);
 }