webgpu triangle

examples/VulkanTriangle/raygen.wgsl

@@ -0,0 +1,39 @@
+// WebGPU port of raygen.glsl. Mirrors the pinhole camera setup — the
+// Payload type is declared in closesthit.wgsl (concatenated earlier).
+
+fn raygen_main(gid: vec3<u32>) {
+    if (gid.x >= hdr.surfaceW || gid.y >= hdr.surfaceH) { return; }
+
+    let pixel = vec2<f32>(f32(gid.x), f32(gid.y));
+    let resolution = vec2<f32>(f32(hdr.surfaceW), f32(hdr.surfaceH));
+    let uv  = (pixel + vec2<f32>(0.5)) / resolution;
+    let ndc = uv * 2.0 - vec2<f32>(1.0);
+
+    let origin = vec3<f32>(0.0, 0.0, -300.0);
+    let aspect = resolution.x / resolution.y;
+    let fov = 60.0 * 3.14159265 / 180.0;
+    let tanHalfFov = tan(fov * 0.5);
+
+    let direction = normalize(vec3<f32>(
+        ndc.x * aspect * tanHalfFov,
+        -ndc.y * tanHalfFov,
+        1.0,
+    ));
+
+    var payload: Payload;
+    payload.color = vec3<f32>(0.0);
+
+    traceRay(
+        0u,            // tlasIdx (unused)
+        0u,            // ray flags
+        0xFFu,         // cull mask
+        0u, 0u, 0u,    // sbtRecordOffset, sbtRecordStride, missIndex
+        origin, 0.001,
+        direction, 10000.0,
+        &payload,
+    );
+
+    textureStore(outImage,
+                 vec2<i32>(i32(gid.x), i32(gid.y)),
+                 vec4<f32>(payload.color, 1.0));
+}