GPU culling

lib/tests/wgsl_validate.rs

@@ -54,3 +54,34 @@ fn shadow_shader_is_valid_wgsl() {
         .collect();
     assert_eq!(entry_names, vec!["vs_main"], "only vs_main expected");
 }
+
+/// Parses and fully validates the embedded `gpu_driven.wgsl` compute shader (Phase 3, Step 15)
+/// via naga. The renderer compiles it directly into two `ComputePipeline`s (one per entry point),
+/// so this offline validation is the guarantee of its validity. The contract expects exactly the
+/// two compute entry points: `compute_matrices` and `cull`.
+#[test]
+fn gpu_driven_shader_is_valid_wgsl() {
+    let src = include_str!("../src/shaders/gpu_driven.wgsl");
+    let module = naga::front::wgsl::parse_str(src)
+        .unwrap_or_else(|e| panic!("gpu_driven.wgsl: parsing error: {e:?}"));
+
+    let mut validator = naga::valid::Validator::new(
+        naga::valid::ValidationFlags::all(),
+        naga::valid::Capabilities::all(),
+    );
+    validator
+        .validate(&module)
+        .unwrap_or_else(|e| panic!("gpu_driven.wgsl: validation failed: {e:?}"));
+
+    let mut entry_names: Vec<&str> = module
+        .entry_points
+        .iter()
+        .map(|ep| ep.name.as_str())
+        .collect();
+    entry_names.sort();
+    assert_eq!(
+        entry_names,
+        vec!["compute_matrices", "cull"],
+        "the two compute entry points are expected"
+    );
+}