Some renaming

betterRenderer/shaders/manul/math.hlsli

@@ -0,0 +1,28 @@
+#ifndef MATH_HLSLI
+#define MATH_HLSLI
+
+#define PI 3.1415926535897932384626433832795
+#define TWO_PI 6.283185307179586476925286766559
+#define PI_OVER_TWO 1.5707963267948966192313216916398
+#define PI_OVER_THREE 1.0471975511965977461542144610932
+#define PI_OVER_SIX 0.52359877559829887307710723054658
+#define ONE_OVER_PI 0.31830988618379067153776752674503
+#define TWO_OVER_PI 0.63661977236758134307553505349006
+#define ONE_OVER_TWO_PI 0.15915494309189533576888376337251
+
+float3 UnpackNormalXY(in float2 normal) {
+  float3 result;
+  result.xy = 2. * (normal - .5);
+  result.z = sqrt(saturate(1. - dot(result.xy, result.xy)));
+  return result;
+}
+
+float3 UnpackNormalXYZ(in float3 normal) {
+  return normalize(normal - .5);
+}
+
+float InvLerp(float a, float b, float v) {
+    return (v - a) / (b - a);
+}
+
+#endif