1 | // |
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2 | // Lol Engine |
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3 | // |
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4 | // Copyright: (c) 2010-2012 Sam Hocevar <sam@hocevar.net> |
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5 | // This program is free software; you can redistribute it and/or |
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6 | // modify it under the terms of the Do What The Fuck You Want To |
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7 | // Public License, Version 2, as published by Sam Hocevar. See |
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8 | // http://www.wtfpl.net/ for more details. |
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9 | // |
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10 | |
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11 | // |
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12 | // The Color class |
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13 | // --------------- |
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14 | // Provides various color conversion routines. |
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15 | // |
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16 | |
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17 | #if !defined __LOL_IMAGE_COLOR_H__ |
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18 | #define __LOL_IMAGE_COLOR_H__ |
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19 | |
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20 | #include <lol/math/vector.h> |
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21 | |
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22 | namespace lol |
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23 | { |
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24 | |
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25 | class Color |
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26 | { |
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27 | public: |
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28 | /* |
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29 | * Convert linear RGB to sRGB |
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30 | */ |
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31 | static vec3 LinearRGBTosRGB(vec3 c) |
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32 | { |
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33 | using std::pow; |
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34 | vec3 ret = 12.92 * c; |
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35 | if (c.r > 0.0031308) |
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36 | ret.r = 1.055 * pow(c.r, 1.0 / 2.4) - 0.055; |
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37 | if (c.g > 0.0031308) |
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38 | ret.g = 1.055 * pow(c.g, 1.0 / 2.4) - 0.055; |
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39 | if (c.b > 0.0031308) |
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40 | ret.b = 1.055 * pow(c.b, 1.0 / 2.4) - 0.055; |
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41 | return ret; |
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42 | } |
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43 | |
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44 | static vec4 LinearRGBTosRGB(vec4 c) |
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45 | { |
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46 | return vec4(LinearRGBTosRGB(c.rgb), c.a); |
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47 | } |
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48 | |
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49 | /* |
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50 | * Convert sRGB to linear RGB |
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51 | */ |
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52 | static vec3 sRGBToLinearRGB(vec3 c) |
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53 | { |
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54 | using std::pow; |
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55 | vec3 ret = 1.0 / 12.92 * c; |
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56 | if (c.r > 0.04045) |
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57 | ret.r = pow(c.r + 0.055, 2.4) / pow(1.055, 2.4); |
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58 | if (c.g > 0.04045) |
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59 | ret.g = pow(c.g + 0.055, 2.4) / pow(1.055, 2.4); |
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60 | if (c.b > 0.04045) |
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61 | ret.b = pow(c.b + 0.055, 2.4) / pow(1.055, 2.4); |
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62 | return ret; |
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63 | } |
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64 | |
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65 | static vec4 sRGBToLinearRGB(vec4 c) |
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66 | { |
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67 | return vec4(sRGBToLinearRGB(c.rgb), c.a); |
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68 | } |
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69 | |
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70 | /* |
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71 | * Convert linear RGB to CIE XYZ |
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72 | */ |
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73 | static vec3 LinearRGBToCIEXYZ(vec3 c) |
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74 | { |
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75 | mat3 m(vec3(3.2406, -0.9689, 0.0557), |
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76 | vec3(-1.5372, 1.8758, -0.2040), |
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77 | vec3(-0.4986, 0.0415, 1.0570)); |
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78 | return m * c; |
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79 | } |
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80 | |
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81 | static vec4 LinearRGBToCIEXYZ(vec4 c) |
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82 | { |
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83 | return vec4(LinearRGBToCIEXYZ(c.rgb), c.a); |
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84 | } |
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85 | |
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86 | /* |
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87 | * Convert CIE XYZ to linear RGB |
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88 | */ |
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89 | static vec3 CIEXYZToLinearRGB(vec3 c) |
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90 | { |
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91 | mat3 m(vec3(0.4124, 0.2126, 0.0193), |
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92 | vec3(0.3576, 0.7152, 0.1192), |
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93 | vec3(0.1805, 0.0722, 0.9505)); |
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94 | return m * c; |
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95 | } |
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96 | |
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97 | static vec4 CIEXYZToLinearRGB(vec4 c) |
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98 | { |
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99 | return vec4(CIEXYZToLinearRGB(c.rgb), c.a); |
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100 | } |
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101 | }; |
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102 | |
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103 | } /* namespace lol */ |
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104 | |
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105 | #endif // __LOL_IMAGE_COLOR_H__ |
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106 | |
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