Working self contained rendering (simple circle)

examples/shaders/circle.wgsl

@@ -0,0 +1,39 @@
+struct VertexOutput {
+    @builtin(position) position: vec4f,
+    @location(0) uv: vec2f,
+};
+
+@vertex
+fn vs_main(@builtin(vertex_index) vertex_index: u32) -> VertexOutput {
+    var output: VertexOutput;
+    // Hardcoded fullscreen quad layout using 4 vertices (Triangle Strip)
+    // Indexes: 0: Top-Left, 1: Bottom-Left, 2: Top-Right, 3: Bottom-Right
+    var pos = array<vec2f, 4>(
+        vec2f(-1.0,  1.0),
+        vec2f(-1.0, -1.0),
+        vec2f( 1.0,  1.0),
+        vec2f( 1.0, -1.0)
+    );
+    
+    output.position = vec4f(pos[vertex_index], 0.0, 1.0);
+    output.uv = pos[vertex_index]; // Ranges cleanly from -1.0 to 1.0
+    return output;
+}
+
+@fragment
+fn fs_main(input: VertexOutput) -> @location(0) vec4f {
+    // Distance from the center (0,0)
+    let distance = length(input.uv);
+    let radius = 0.5;
+    
+    // Smooth out pixel edges (anti-aliasing)
+    let edge_softness = 0.005;
+    let alpha = 1.0 - smoothstep(radius - edge_softness, radius + edge_softness, distance);
+    
+    if (alpha <= 0.0) {
+        discard; 
+    }
+    
+    // Draw a sharp/smooth red circle
+    return vec4f(1.0, 0.3, 0.3, alpha);
+}