| 111 | } |
| 112 | |
| 113 | SampledSpectrum SampledSpectrum::FromRGB(const float rgb[3], |
| 114 | SpectrumType type) { |
| 115 | SampledSpectrum r; |
| 116 | if (type == SpectrumType::Reflectance) { |
| 117 | // Convert reflectance spectrum to RGB |
| 118 | if (rgb[0] <= rgb[1] && rgb[0] <= rgb[2]) { |
| 119 | // Compute reflectance _SampledSpectrum_ with _rgb[0]_ as minimum |
| 120 | r += rgb[0] * rgbRefl2SpectWhite; |
| 121 | if (rgb[1] <= rgb[2]) { |
| 122 | r += (rgb[1] - rgb[0]) * rgbRefl2SpectCyan; |
| 123 | r += (rgb[2] - rgb[1]) * rgbRefl2SpectBlue; |
| 124 | } else { |
| 125 | r += (rgb[2] - rgb[0]) * rgbRefl2SpectCyan; |
| 126 | r += (rgb[1] - rgb[2]) * rgbRefl2SpectGreen; |
| 127 | } |
| 128 | } else if (rgb[1] <= rgb[0] && rgb[1] <= rgb[2]) { |
| 129 | // Compute reflectance _SampledSpectrum_ with _rgb[1]_ as minimum |
| 130 | r += rgb[1] * rgbRefl2SpectWhite; |
| 131 | if (rgb[0] <= rgb[2]) { |
| 132 | r += (rgb[0] - rgb[1]) * rgbRefl2SpectMagenta; |
| 133 | r += (rgb[2] - rgb[0]) * rgbRefl2SpectBlue; |
| 134 | } else { |
| 135 | r += (rgb[2] - rgb[1]) * rgbRefl2SpectMagenta; |
| 136 | r += (rgb[0] - rgb[2]) * rgbRefl2SpectRed; |
| 137 | } |
| 138 | } else { |
| 139 | // Compute reflectance _SampledSpectrum_ with _rgb[2]_ as minimum |
| 140 | r += rgb[2] * rgbRefl2SpectWhite; |
| 141 | if (rgb[0] <= rgb[1]) { |
| 142 | r += (rgb[0] - rgb[2]) * rgbRefl2SpectYellow; |
| 143 | r += (rgb[1] - rgb[0]) * rgbRefl2SpectGreen; |
| 144 | } else { |
| 145 | r += (rgb[1] - rgb[2]) * rgbRefl2SpectYellow; |
| 146 | r += (rgb[0] - rgb[1]) * rgbRefl2SpectRed; |
| 147 | } |
| 148 | } |
| 149 | r *= .94f; |
| 150 | } else { |
| 151 | // Convert illuminant spectrum to RGB |
| 152 | if (rgb[0] <= rgb[1] && rgb[0] <= rgb[2]) { |
| 153 | // Compute illuminant _SampledSpectrum_ with _rgb[0]_ as minimum |
| 154 | r += rgb[0] * rgbIllum2SpectWhite; |
| 155 | if (rgb[1] <= rgb[2]) { |
| 156 | r += (rgb[1] - rgb[0]) * rgbIllum2SpectCyan; |
| 157 | r += (rgb[2] - rgb[1]) * rgbIllum2SpectBlue; |
| 158 | } else { |
| 159 | r += (rgb[2] - rgb[0]) * rgbIllum2SpectCyan; |
| 160 | r += (rgb[1] - rgb[2]) * rgbIllum2SpectGreen; |
| 161 | } |
| 162 | } else if (rgb[1] <= rgb[0] && rgb[1] <= rgb[2]) { |
| 163 | // Compute illuminant _SampledSpectrum_ with _rgb[1]_ as minimum |
| 164 | r += rgb[1] * rgbIllum2SpectWhite; |
| 165 | if (rgb[0] <= rgb[2]) { |
| 166 | r += (rgb[0] - rgb[1]) * rgbIllum2SpectMagenta; |
| 167 | r += (rgb[2] - rgb[0]) * rgbIllum2SpectBlue; |
| 168 | } else { |
| 169 | r += (rgb[2] - rgb[1]) * rgbIllum2SpectMagenta; |
| 170 | r += (rgb[0] - rgb[2]) * rgbIllum2SpectRed; |