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Differential D1719 Diff 5771 source/blender/blenlib/intern/math_color.c

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source/blender/blenlib/intern/math_color.c

Show First 20 Lines • Show All 449 Lines • ▼ Show 20 Linesvoid minmax_rgb(short c[3])
if (c[0] > 255) c[0] = 255; if (c[0] > 255) c[0] = 255;
else if (c[0] < 0) c[0] = 0; else if (c[0] < 0) c[0] = 0;
if (c[1] > 255) c[1] = 255; if (c[1] > 255) c[1] = 255;
else if (c[1] < 0) c[1] = 0; else if (c[1] < 0) c[1] = 0;
if (c[2] > 255) c[2] = 255; if (c[2] > 255) c[2] = 255;
else if (c[2] < 0) c[2] = 0; else if (c[2] < 0) c[2] = 0;
} }
/*If the requested RGB shade contains a negative weight for /* If the requested RGB shade contains a negative weight for
* one of the primaries, it lies outside the color gamut * one of the primaries, it lies outside the color gamut
* accessible from the given triple of primaries. Desaturate * accessible from the given triple of primaries. Desaturate
* it by adding white, equal quantities of R, G, and B, enough * it by adding white, equal quantities of R, G, and B, enough
* to make RGB all positive. The function returns 1 if the * to make RGB all positive. The function returns 1 if the
* components were modified, zero otherwise.*/ * components were modified, zero otherwise.*/
int constrain_rgb(float *r, float *g, float *b) int constrain_rgb(float *r, float *g, float *b)
{ {
float w; /* Amount of white needed */
const float w = -min_ffff(0.0f, *r, *g, *b);
/* Amount of white needed is w = - min(0, *r, *g, *b) */
w = (0 < *r) ? 0 : *r;
w = (w < *g) ? w : *g;
w = (w < *b) ? w : *b;
w = -w;
/* Add just enough white to make r, g, b all positive. */ /* Add just enough white to make r, g, b all positive. */
if (w > 0.0f) {
if (w > 0) {
*r += w; *r += w;
*g += w; *g += w;
*b += w; *b += w;
return 1; /* Color modified to fit RGB gamut */ return 1; /* Color modified to fit RGB gamut */
} }
return 0; /* Color within RGB gamut */ return 0; /* Color within RGB gamut */
} }
/* ********************************* lift/gamma/gain / ASC-CDL conversion ********************************* */ /* ********************************* lift/gamma/gain / ASC-CDL conversion ********************************* */
▲ Show 20 Lines • Show All 165 Lines • ▼ Show 20 Lines
} }
void rgb_to_lab(float r, float g, float b, float *ll, float *la, float *lb) void rgb_to_lab(float r, float g, float b, float *ll, float *la, float *lb)
{ {
float x, y, z; float x, y, z;
rgb_to_xyz(r, g, b, &x, &y, &z); rgb_to_xyz(r, g, b, &x, &y, &z);
xyz_to_lab(x, y, z, ll, la, lb); xyz_to_lab(x, y, z, ll, la, lb);
} }
static void xyz_to_lms(float x, float y, float z, float *l, float *m, float *s)
{
*l = 0.3897f * x + 0.6890f * y - 0.0787f * z;
*m = -0.2298f * x + 1.1834f * y + 0.0464f * z;
*s = z;
}
static void lms_to_xyz(float l, float m, float s, float *x, float *y, float *z)
{
*x = 1.9102f * l - 1.1121f * m + 0.2019f * s;
*y = 0.3709f * l + 0.6290f * m + 0.0000f * s;
*z = s;
}
static void normalize_rgb(float rgb[3])
{
const float max = max_fff(rgb[0], rgb[1], rgb[2]);
if (max > 0.0f) {
mul_v3_fl(rgb, 1.0f / max);
}
}
/* Color rendering of spectra, adapted from public domain code by John Walker,
* http://www.fourmilab.ch/
*/
static void spectrum_to_xyz(float temperature, float xyz[3])
{
int i;
float lambda, x = 0.0f, y = 0.0f, z = 0.0f, xyz_sum;
/* CIE colour matching functions xBar, yBar, and zBar for wavelengths from
* 380 through 780 nanometers, every 5 nanometers.
* For a wavelength lambda in this range:
*
* cie_colour_match[(lambda - 380) / 5][0] = xBar
* cie_colour_match[(lambda - 380) / 5][1] = yBar
* cie_colour_match[(lambda - 380) / 5][2] = zBar
*/
const 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}
};
for (i = 0, lambda = 380.0f; lambda < 780.1f; i++, lambda += 5.0f) {
/* wavelength in meter */
const float wlm = lambda * 1e-9f;
const float Me = (3.74183e-16f * powf(wlm, -5.0f)) / (expf(1.4388e-2f / (wlm * temperature)) - 1.0f);
x += Me * cie_colour_match[i][0];
y += Me * cie_colour_match[i][1];
z += Me * cie_colour_match[i][2];
}
xyz_sum = (x + y + z);
xyz[0] = x / xyz_sum;
xyz[1] = y / xyz_sum;
xyz[2] = z / xyz_sum;
}
void generate_spectrum_table(unsigned char *r_table, int width, float min, float max)
{
int i, j = 0, dj = 1;
float rgb[3], xyz[3], lms[3], lms_w[3];
float bb_temp;
if (min < max) {
SWAP(float, min, max);
j = width - 1;
dj = -1;
}
for (i = 0; i < width; i++, j += dj) {
bb_temp = min + (max - min) / (float)width * (float)i;
/* integrate blackbody radiation spectrum to XYZ */
spectrum_to_xyz(bb_temp, xyz);
/* normalize highest temperature to white (in LMS system) */
xyz_to_lms(xyz[0], xyz[1], xyz[2], &lms[0], &lms[1], &lms[2]);
if (i == 0) {
lms_w[0] = 1.0f / lms[0];
lms_w[1] = 1.0f / lms[1];
lms_w[2] = 1.0f / lms[2];
}
mul_v3_v3(lms, lms_w);
lms_to_xyz(lms[0], lms[1], lms[2], &xyz[0], &xyz[1], &xyz[2]);
/* convert to RGB */
xyz_to_rgb(xyz[0], xyz[1], xyz[2], &rgb[0], &rgb[1], &rgb[2], BLI_XYZ_CIE);
constrain_rgb(&rgb[0], &rgb[1], &rgb[2]);
normalize_rgb(rgb);
F3TOCHAR3(rgb, &r_table[(j << 2)]);
if (rgb[2] > 0.1f)
r_table[(j << 2) + 3] = FTOCHAR(rgb[2]);
else
r_table[(j << 2) + 3] = 0;
}
}