Some renaming

betterRenderer/shaders/cubemap_utils.hlsli

@@ -0,0 +1,52 @@
+#define PI 3.1415926535897932384626433832795
+#define TWO_PI 6.283185307179586476925286766559
+#define ONE_OVER_PI 0.31830988618379067153776752674503
+#define TWO_OVER_PI 0.63661977236758134307553505349006
+#define ONE_OVER_TWO_PI 0.15915494309189533576888376337251
+
+float3 CalcNormal(in uint3 PixCoord);
+
+float2 EquirectFromNormal(in float3 Normal);
+
+float2 PixCoordToFloat(in uint2 Coord, in uint2 Size);
+
+float2 PixCoordToFloat(in uint2 Coord, in uint2 Size) {
+  return ((float2)Coord + .5.xx) / (float2)Size;
+}
+
+float3 CalcNormal(in uint3 PixCoord) {
+  static const float3x3 FaceTransform[6] = {
+    // +X
+    float3x3(  0.,  0., -1.,
+               0., -1.,  0., 
+               1.,  0.,  0. ),
+    // -X
+    float3x3(  0.,  0.,  1.,
+               0., -1.,  0., 
+              -1.,  0.,  0. ),
+    // +Y
+    float3x3(  1.,  0.,  0.,
+               0.,  0.,  1., 
+               0.,  1.,  0. ),
+    // -Y
+    float3x3(  1.,  0.,  0.,
+               0.,  0., -1., 
+               0., -1.,  0. ),
+    // +Z
+    float3x3(  1.,  0.,  0.,
+               0., -1.,  0., 
+               0.,  0.,  1. ),
+    // -Z
+    float3x3( -1.,  0.,  0.,
+               0., -1.,  0., 
+               0.,  0., -1. )
+  };
+  uint2 FaceSize;
+  uint Elements;
+  g_OutCubemap.GetDimensions(FaceSize.x, FaceSize.y, Elements);
+  return normalize(mul(float3(PixCoordToFloat(PixCoord.xy, FaceSize) * 2. - 1., 1.), FaceTransform[PixCoord.z]));
+}
+
+float2 EquirectFromNormal(in float3 Normal) {
+  return float2(atan2(Normal.x, Normal.z) * ONE_OVER_TWO_PI, -asin(Normal.y) * ONE_OVER_PI) + .5.xx;
+}