Finish implementing burley per-channel histogram preserving blending operator

1 files changed, 12 insertions, 0 deletions

diff --git a/math.cginc b/math.cginc
index 0f5f8f5..6bca086 100755
--- a/math.cginc
+++ b/math.cginc
@@ -251,4 +251,16 @@ float median(float3 x) {
   return (x.r + x.g + x.b) - (x_min + x_max);
 }
 
+float3 linear_to_srgb(float3 linear_color) {
+  float3 lo = 12.92f * linear_color;
+  float3 hi = 1.055f * pow(linear_color, 1.0f / 2.4f) - 0.055f;
+  return lerp(lo, hi, step(0.0031308f, linear_color));
+}
+
+float3 srgb_to_linear(float3 srgb_color) {
+  float3 lo = srgb_color / 12.92f;
+  float3 hi = pow((srgb_color + 0.055f) / 1.055f, 2.4f);
+  return lerp(lo, hi, step(0.04045f, srgb_color));
+}
+
 #endif  // __MATH_INC