From bdab538b3019406cfbd53d99bc40c4dbae27393c Mon Sep 17 00:00:00 2001 From: Brecht Van Lommel Date: Mon, 23 May 2022 20:54:09 +0200 Subject: Fix Eevee blackbody wrong with non-default scene linear color space * Port over new code tables from Cycles * Convert Rec.709 to scene linear for lookup table. * Move code for wavelength and blackbody to IMB so they can access the required transforms, which are not in blenlib. * Remove clamping from blackbody shader to bypass the texture read. Since it's variable now easiest to just always read from the texture than pass additional parameters. * Fold XYZ to RGB conversion into the wavelength table. Ref T68926 --- source/blender/blenlib/intern/math_color.c | 155 ----------------------------- 1 file changed, 155 deletions(-) (limited to 'source/blender/blenlib/intern') diff --git a/source/blender/blenlib/intern/math_color.c b/source/blender/blenlib/intern/math_color.c index aeeaf47d813..0955f5d1b5a 100644 --- a/source/blender/blenlib/intern/math_color.c +++ b/source/blender/blenlib/intern/math_color.c @@ -597,158 +597,3 @@ void BLI_init_srgb_conversion(void) BLI_color_to_srgb_table[i] = (unsigned short)(b * 0x100); } } - -/* ****************************** blackbody ******************************** */ - -/* Calculate color in range 800..12000 using an approximation - * a/x+bx+c for R and G and ((at + b)t + c)t + d) for B - * Max absolute error for RGB is (0.00095, 0.00077, 0.00057), - * which is enough to get the same 8 bit/channel color. - */ - -static const float blackbody_table_r[6][3] = { - {2.52432244e+03f, -1.06185848e-03f, 3.11067539e+00f}, - {3.37763626e+03f, -4.34581697e-04f, 1.64843306e+00f}, - {4.10671449e+03f, -8.61949938e-05f, 6.41423749e-01f}, - {4.66849800e+03f, 2.85655028e-05f, 1.29075375e-01f}, - {4.60124770e+03f, 2.89727618e-05f, 1.48001316e-01f}, - {3.78765709e+03f, 9.36026367e-06f, 3.98995841e-01f}, -}; - -static const float blackbody_table_g[6][3] = { - {-7.50343014e+02f, 3.15679613e-04f, 4.73464526e-01f}, - {-1.00402363e+03f, 1.29189794e-04f, 9.08181524e-01f}, - {-1.22075471e+03f, 2.56245413e-05f, 1.20753416e+00f}, - {-1.42546105e+03f, -4.01730887e-05f, 1.44002695e+00f}, - {-1.18134453e+03f, -2.18913373e-05f, 1.30656109e+00f}, - {-5.00279505e+02f, -4.59745390e-06f, 1.09090465e+00f}, -}; - -static const float blackbody_table_b[6][4] = { - {0.0f, 0.0f, 0.0f, 0.0f}, - {0.0f, 0.0f, 0.0f, 0.0f}, - {0.0f, 0.0f, 0.0f, 0.0f}, - {-2.02524603e-11f, 1.79435860e-07f, -2.60561875e-04f, -1.41761141e-02f}, - {-2.22463426e-13f, -1.55078698e-08f, 3.81675160e-04f, -7.30646033e-01f}, - {6.72595954e-13f, -2.73059993e-08f, 4.24068546e-04f, -7.52204323e-01f}, -}; - -static void blackbody_temperature_to_rgb(float rgb[3], float t) -{ - if (t >= 12000.0f) { - rgb[0] = 0.826270103f; - rgb[1] = 0.994478524f; - rgb[2] = 1.56626022f; - } - else if (t < 965.0f) { - rgb[0] = 4.70366907f; - rgb[1] = 0.0f; - rgb[2] = 0.0f; - } - else { - int i = (t >= 6365.0f) ? 5 : - (t >= 3315.0f) ? 4 : - (t >= 1902.0f) ? 3 : - (t >= 1449.0f) ? 2 : - (t >= 1167.0f) ? 1 : - 0; - - const float *r = blackbody_table_r[i]; - const float *g = blackbody_table_g[i]; - const float *b = blackbody_table_b[i]; - - const float t_inv = 1.0f / t; - rgb[0] = r[0] * t_inv + r[1] * t + r[2]; - rgb[1] = g[0] * t_inv + g[1] * t + g[2]; - rgb[2] = ((b[0] * t + b[1]) * t + b[2]) * t + b[3]; - } -} - -void blackbody_temperature_to_rgb_table(float *r_table, int width, float min, float max) -{ - for (int i = 0; i < width; i++) { - float temperature = min + (max - min) / (float)width * (float)i; - - float rgb[3]; - blackbody_temperature_to_rgb(rgb, temperature); - - copy_v3_v3(&r_table[i * 4], rgb); - r_table[i * 4 + 3] = 0.0f; - } -} - -/* ****************************** wavelength ******************************** */ -/* Wavelength to RGB. */ - -/** - * CIE color matching functions `xBar`, `yBar`, and `zBar` for - * wavelengths from 380 through 780 nanometers, every 5 nanometers. - * - * For a wavelength lambda in this range: - * \code{.txt} - * cie_color_match[(lambda - 380) / 5][0] = xBar - * cie_color_match[(lambda - 380) / 5][1] = yBar - * cie_color_match[(lambda - 380) / 5][2] = zBar - * \endcode - */ - -static float cie_colour_match[81][3] = { - {0.0014f, 0.0000f, 0.0065f}, {0.0022f, 0.0001f, 0.0105f}, {0.0042f, 0.0001f, 0.0201f}, - {0.0076f, 0.0002f, 0.0362f}, {0.0143f, 0.0004f, 0.0679f}, {0.0232f, 0.0006f, 0.1102f}, - {0.0435f, 0.0012f, 0.2074f}, {0.0776f, 0.0022f, 0.3713f}, {0.1344f, 0.0040f, 0.6456f}, - {0.2148f, 0.0073f, 1.0391f}, {0.2839f, 0.0116f, 1.3856f}, {0.3285f, 0.0168f, 1.6230f}, - {0.3483f, 0.0230f, 1.7471f}, {0.3481f, 0.0298f, 1.7826f}, {0.3362f, 0.0380f, 1.7721f}, - {0.3187f, 0.0480f, 1.7441f}, {0.2908f, 0.0600f, 1.6692f}, {0.2511f, 0.0739f, 1.5281f}, - {0.1954f, 0.0910f, 1.2876f}, {0.1421f, 0.1126f, 1.0419f}, {0.0956f, 0.1390f, 0.8130f}, - {0.0580f, 0.1693f, 0.6162f}, {0.0320f, 0.2080f, 0.4652f}, {0.0147f, 0.2586f, 0.3533f}, - {0.0049f, 0.3230f, 0.2720f}, {0.0024f, 0.4073f, 0.2123f}, {0.0093f, 0.5030f, 0.1582f}, - {0.0291f, 0.6082f, 0.1117f}, {0.0633f, 0.7100f, 0.0782f}, {0.1096f, 0.7932f, 0.0573f}, - {0.1655f, 0.8620f, 0.0422f}, {0.2257f, 0.9149f, 0.0298f}, {0.2904f, 0.9540f, 0.0203f}, - {0.3597f, 0.9803f, 0.0134f}, {0.4334f, 0.9950f, 0.0087f}, {0.5121f, 1.0000f, 0.0057f}, - {0.5945f, 0.9950f, 0.0039f}, {0.6784f, 0.9786f, 0.0027f}, {0.7621f, 0.9520f, 0.0021f}, - {0.8425f, 0.9154f, 0.0018f}, {0.9163f, 0.8700f, 0.0017f}, {0.9786f, 0.8163f, 0.0014f}, - {1.0263f, 0.7570f, 0.0011f}, {1.0567f, 0.6949f, 0.0010f}, {1.0622f, 0.6310f, 0.0008f}, - {1.0456f, 0.5668f, 0.0006f}, {1.0026f, 0.5030f, 0.0003f}, {0.9384f, 0.4412f, 0.0002f}, - {0.8544f, 0.3810f, 0.0002f}, {0.7514f, 0.3210f, 0.0001f}, {0.6424f, 0.2650f, 0.0000f}, - {0.5419f, 0.2170f, 0.0000f}, {0.4479f, 0.1750f, 0.0000f}, {0.3608f, 0.1382f, 0.0000f}, - {0.2835f, 0.1070f, 0.0000f}, {0.2187f, 0.0816f, 0.0000f}, {0.1649f, 0.0610f, 0.0000f}, - {0.1212f, 0.0446f, 0.0000f}, {0.0874f, 0.0320f, 0.0000f}, {0.0636f, 0.0232f, 0.0000f}, - {0.0468f, 0.0170f, 0.0000f}, {0.0329f, 0.0119f, 0.0000f}, {0.0227f, 0.0082f, 0.0000f}, - {0.0158f, 0.0057f, 0.0000f}, {0.0114f, 0.0041f, 0.0000f}, {0.0081f, 0.0029f, 0.0000f}, - {0.0058f, 0.0021f, 0.0000f}, {0.0041f, 0.0015f, 0.0000f}, {0.0029f, 0.0010f, 0.0000f}, - {0.0020f, 0.0007f, 0.0000f}, {0.0014f, 0.0005f, 0.0000f}, {0.0010f, 0.0004f, 0.0000f}, - {0.0007f, 0.0002f, 0.0000f}, {0.0005f, 0.0002f, 0.0000f}, {0.0003f, 0.0001f, 0.0000f}, - {0.0002f, 0.0001f, 0.0000f}, {0.0002f, 0.0001f, 0.0000f}, {0.0001f, 0.0000f, 0.0000f}, - {0.0001f, 0.0000f, 0.0000f}, {0.0001f, 0.0000f, 0.0000f}, {0.0000f, 0.0000f, 0.0000f}}; - -static void wavelength_to_xyz(float xyz[3], float lambda_nm) -{ - float ii = (lambda_nm - 380.0f) * (1.0f / 5.0f); /* Scaled 0..80. */ - int i = (int)ii; - - if (i < 0 || i >= 80) { - xyz[0] = 0.0f; - xyz[1] = 0.0f; - xyz[2] = 0.0f; - } - else { - ii -= (float)i; - const float *c = cie_colour_match[i]; - xyz[0] = c[0] + ii * (c[3] - c[0]); - xyz[1] = c[1] + ii * (c[4] - c[1]); - xyz[2] = c[2] + ii * (c[5] - c[2]); - } -} - -void wavelength_to_xyz_table(float *r_table, int width) -{ - for (int i = 0; i < width; i++) { - float temperature = 380 + 400 / (float)width * (float)i; - - float rgb[3]; - wavelength_to_xyz(rgb, temperature); - - copy_v3_v3(&r_table[i * 4], rgb); - r_table[i * 4 + 3] = 0.0f; - } -} -- cgit v1.2.3