Root cause of broken shadows: depth buffer stores non-linear NDC depth,
not linear distance. closestDepth * 60.0 was wrong conversion.
Fix: switch from depth-only to R32_SFLOAT color attachment approach:
- Shadow vertex shader outputs world position to fragment
- Shadow fragment shader writes length(fragPos - lightPos) / farPlane
- Main fragment shader samples cubemap, multiplies by FAR_PLANE=60
- Separate color cube (R32_SFLOAT, sampled) + depth cube (D32_SFLOAT, depth test)
- Shadow pipeline: 1 color attachment (R) + depth attachment
- Color clear = 1.0 (max distance), depth clear = 1.0
Tests: 227 total, all pass
- ShadowMapFaceDirectionTests: 6 face directions, 90° FOV, up vectors,
valid matrices, far plane consistency
- ShadowShaderTests: all 6 SPIR-V shaders exist
New test files:
- VulkanStructSizeTests.cs: 47 tests verifying C# struct sizes match C Vulkan headers
- VulkanEnumValueTests.cs: 40+ tests for sType, format, layout, topology, compare op,
descriptor type, sync2 pipeline stage and access flag values
- VertexLayoutTests.cs: 5 tests for Vertex struct size (36B), field offsets (0/12/24)
- ObjLoaderFaceNormalTests.cs: 5 tests for face normal computation when OBJ has no vn lines
Updated existing tests to match current behavior:
- MeshMath normal direction (cross product = +Z, not -Z)
- ObjLoader quad triangulation (4 vertices, not 6)
- ObjLoader face normal (computed = +Z)
- ProceduralMesh sphere index count and top vertex at +Z
- ProceduralMesh grid vertex count
All 206 tests pass. Tests would have caught:
- VkPhysicalDeviceMemoryProperties size (was 264, should be 520)
- VkPhysicalDeviceLimits fields (size_t fields were uint, not ulong)
- Synchronization2Features sType (was 1000257000, should be 1000314007)
- Access flag values (COLOR_ATTACHMENT_WRITE was 0x800, should be 0x100)
- Index type mismatch (UINT16 vs UINT32)