Corrected depth-related GLSL definitions for Vulkan case

2 files changed, 30 insertions, 16 deletions

diff --git a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
index 8fb4fd70..35c4c839 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions.h
@@ -981,25 +981,32 @@ uvec4  _ToUvec( vec4  f4 ){ return _ToUvec4( f4.x, f4.y, f4.z, f4.w ); }
 
 // Helper functions
 
+#ifdef TARGET_API_VULKAN
+
+#define NDC_MIN_Z 0.0 // Minimal z in the normalized device space
+#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 1.0)
+
+#else
+
+#define NDC_MIN_Z -1.0 // Minimal z in the normalized device space
+#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 0.5)
+
+#endif
+
 float2 NormalizedDeviceXYToTexUV( float2 f2ProjSpaceXY )
 {
-    return float2(0.5,0.5) + float2(0.5,0.5) * f2ProjSpaceXY.xy;
+    return float2(0.5,0.5) + F3NDC_XYZ_TO_UVD_SCALE.xy * f2ProjSpaceXY.xy;
 }
 
 float NormalizedDeviceZToDepth(float fNDC_Z)
 {
-    return fNDC_Z * 0.5 + 0.5; // [-1, +1] -> [0, 1]
+    return (fNDC_Z - NDC_MIN_Z) * F3NDC_XYZ_TO_UVD_SCALE.z;
 }
-
 float DepthToNormalizedDeviceZ(float fDepth)
 {
-    return fDepth * 2.0 - 1.0; // [0, 1] -> [-1, +1]
+    return fDepth / F3NDC_XYZ_TO_UVD_SCALE.z + NDC_MIN_Z;
 }
 
-#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 0.5)
-
-#define NDC_MIN_Z -1.0 // Minimal z in the normalized device space
-
 #define MATRIX_ELEMENT(mat, row, col) mat[col][row]
 
 float4x4 MatrixFromRows(float4 row0, float4 row1, float4 row2, float4 row3)
diff --git a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
index cdbc0527..20b9e2f0 100644
--- a/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
+++ b/Graphics/HLSL2GLSLConverterLib/include/GLSLDefinitions_inc.h
@@ -981,25 +981,32 @@
 "\n"
 "// Helper functions\n"
 "\n"
+"#ifdef TARGET_API_VULKAN\n"
+"\n"
+"#define NDC_MIN_Z 0.0 // Minimal z in the normalized device space\n"
+"#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 1.0)\n"
+"\n"
+"#else\n"
+"\n"
+"#define NDC_MIN_Z -1.0 // Minimal z in the normalized device space\n"
+"#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 0.5)\n"
+"\n"
+"#endif\n"
+"\n"
 "float2 NormalizedDeviceXYToTexUV( float2 f2ProjSpaceXY )\n"
 "{\n"
-"    return float2(0.5,0.5) + float2(0.5,0.5) * f2ProjSpaceXY.xy;\n"
+"    return float2(0.5,0.5) + F3NDC_XYZ_TO_UVD_SCALE.xy * f2ProjSpaceXY.xy;\n"
 "}\n"
 "\n"
 "float NormalizedDeviceZToDepth(float fNDC_Z)\n"
 "{\n"
-"    return fNDC_Z * 0.5 + 0.5; // [-1, +1] -> [0, 1]\n"
+"    return (fNDC_Z - NDC_MIN_Z) * F3NDC_XYZ_TO_UVD_SCALE.z;\n"
 "}\n"
-"\n"
 "float DepthToNormalizedDeviceZ(float fDepth)\n"
 "{\n"
-"    return fDepth * 2.0 - 1.0; // [0, 1] -> [-1, +1]\n"
+"    return fDepth / F3NDC_XYZ_TO_UVD_SCALE.z + NDC_MIN_Z;\n"
 "}\n"
 "\n"
-"#define F3NDC_XYZ_TO_UVD_SCALE float3(0.5, 0.5, 0.5)\n"
-"\n"
-"#define NDC_MIN_Z -1.0 // Minimal z in the normalized device space\n"
-"\n"
 "#define MATRIX_ELEMENT(mat, row, col) mat[col][row]\n"
 "\n"
 "float4x4 MatrixFromRows(float4 row0, float4 row1, float4 row2, float4 row3)\n"