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Diffstat (limited to 'Runtime/Math/ColorSpaceConversion.h')
| -rw-r--r-- | Runtime/Math/ColorSpaceConversion.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/Runtime/Math/ColorSpaceConversion.h b/Runtime/Math/ColorSpaceConversion.h new file mode 100644 index 0000000..4eb11da --- /dev/null +++ b/Runtime/Math/ColorSpaceConversion.h @@ -0,0 +1,123 @@ +#pragma once + +#include "Color.h" + +enum ColorSpace { kUninitializedColorSpace = -1, kGammaColorSpace = 0, kLinearColorSpace, kMaxColorSpace }; + +ColorSpace GetActiveColorSpace (); + + +// http://www.opengl.org/registry/specs/EXT/framebuffer_sRGB.txt +// http://www.opengl.org/registry/specs/EXT/texture_sRGB_decode.txt +// { cs / 12.92, cs <= 0.04045 } +// { ((cs + 0.055)/1.055)^2.4, cs > 0.04045 } + +inline float GammaToLinearSpace (float value) +{ + if (value <= 0.04045F) + return value / 12.92F; + else if (value < 1.0F) + return pow((value + 0.055F)/1.055F, 2.4F); + else + return pow(value, 2.4F); +} + +// http://www.opengl.org/registry/specs/EXT/framebuffer_sRGB.txt +// http://www.opengl.org/registry/specs/EXT/texture_sRGB_decode.txt +// { 0.0, 0 <= cl +// { 12.92 * c, 0 < cl < 0.0031308 +// { 1.055 * cl^0.41666 - 0.055, 0.0031308 <= cl < 1 +// { 1.0, cl >= 1 <- This has been adjusted since we want to maintain HDR colors + +inline float LinearToGammaSpace (float value) +{ + if (value <= 0.0F) + return 0.0F; + else if (value <= 0.0031308F) + return 12.92F * value; + else if (value <= 1.0F) + return 1.055F * powf(value, 0.41666F) - 0.055F; + else + return powf(value, 0.41666F); +} + +inline float GammaToLinearSpaceXenon(float val) +{ + float ret; + if (val < 0) + ret = 0; + else if (val < 0.25f) + ret = 0.25f * val; + else if (val < 0.375f) + ret = (1.0f/16.0f) + 0.5f*(val-0.25f); + else if (val < 0.75f) + ret = 0.125f + 1.0f*(val-0.375f); + else if (val < 1.0f) + ret = 0.5f + 2.0f*(val-0.75f); + else + ret = 1.0f; + return ret; +} + +inline float LinearToGammaSpaceXenon(float val) +{ + float ret; + if (val < 0) + ret = 0; + else if (val < (1.0f/16.0f)) + ret = 4.0f * val; + else if (val < (1.0f/8.0f)) + ret = (1.0f/4.0f) + 2.0f*(val-(1.0f/16.0f)); + else if (val < 0.5f) + ret = 0.375f + 1.0f*(val-0.125f); + else if (val < 1.0f) + ret = 0.75f + 0.5f*(val-0.50f); + else + ret = 1.0f; + + return ret; +} + +inline ColorRGBAf GammaToLinearSpace (const ColorRGBAf& value) +{ + return ColorRGBAf(GammaToLinearSpace(value.r), GammaToLinearSpace(value.g), GammaToLinearSpace(value.b), value.a); +} + +inline ColorRGBAf LinearToGammaSpace (const ColorRGBAf& value) +{ + return ColorRGBAf(LinearToGammaSpace(value.r), LinearToGammaSpace(value.g), LinearToGammaSpace(value.b), value.a); +} + +inline ColorRGBAf GammaToLinearSpaceXenon (const ColorRGBAf& value) +{ + return ColorRGBAf(GammaToLinearSpaceXenon(value.r), GammaToLinearSpaceXenon(value.g), GammaToLinearSpaceXenon(value.b), value.a); +} + +inline ColorRGBAf LinearToGammaSpaceXenon (const ColorRGBAf& value) +{ + return ColorRGBAf(LinearToGammaSpaceXenon(value.r), LinearToGammaSpaceXenon(value.g), LinearToGammaSpaceXenon(value.b), value.a); +} + +inline float GammaToActiveColorSpace (float value) +{ + if (GetActiveColorSpace () == kLinearColorSpace) + return GammaToLinearSpace(value); + else + return value; +} + +inline ColorRGBAf GammaToActiveColorSpace (const ColorRGBAf& value) +{ + if (GetActiveColorSpace () == kLinearColorSpace) + return GammaToLinearSpace(value); + else + return value; +} + +inline ColorRGBAf ActiveToGammaColorSpace (const ColorRGBAf& value) +{ + if (GetActiveColorSpace () == kLinearColorSpace) + return LinearToGammaSpace(value); + else + return value; +}
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