Move RandR code to separate file.

1 files changed, 150 insertions, 0 deletions

diff --git a/colorramp.c b/colorramp.c
new file mode 100644
index 0000000..2743036
--- /dev/null
+++ b/colorramp.c
@@ -0,0 +1,150 @@
+/* colorramp.c -- color temperature calculation source
+   This file is part of Redshift.
+
+   Redshift is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation, either version 3 of the License, or
+   (at your option) any later version.
+
+   Redshift is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with Redshift.  If not, see <http://www.gnu.org/licenses/>.
+
+   Copyright (c) 2009  Jon Lund Steffensen <jonlst@gmail.com>
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <math.h>
+
+
+/* Source: http://www.vendian.org/mncharity/dir3/blackbody/
+   Rescaled to make exactly 6500K equal to full intensity in all channels. */
+static const float blackbody_color[] = {
+	1.0000, 0.0425, 0.0000, /* 1000K */
+	1.0000, 0.0668, 0.0000, /* 1100K */
+	1.0000, 0.0911, 0.0000, /* 1200K */
+	1.0000, 0.1149, 0.0000, /* ... */
+	1.0000, 0.1380, 0.0000,
+	1.0000, 0.1604, 0.0000,
+	1.0000, 0.1819, 0.0000,
+	1.0000, 0.2024, 0.0000,
+	1.0000, 0.2220, 0.0000,
+	1.0000, 0.2406, 0.0000,
+	1.0000, 0.2630, 0.0062,
+	1.0000, 0.2868, 0.0155,
+	1.0000, 0.3102, 0.0261,
+	1.0000, 0.3334, 0.0379,
+	1.0000, 0.3562, 0.0508,
+	1.0000, 0.3787, 0.0650,
+	1.0000, 0.4008, 0.0802,
+	1.0000, 0.4227, 0.0964,
+	1.0000, 0.4442, 0.1136,
+	1.0000, 0.4652, 0.1316,
+	1.0000, 0.4859, 0.1505,
+	1.0000, 0.5062, 0.1702,
+	1.0000, 0.5262, 0.1907,
+	1.0000, 0.5458, 0.2118,
+	1.0000, 0.5650, 0.2335,
+	1.0000, 0.5839, 0.2558,
+	1.0000, 0.6023, 0.2786,
+	1.0000, 0.6204, 0.3018,
+	1.0000, 0.6382, 0.3255,
+	1.0000, 0.6557, 0.3495,
+	1.0000, 0.6727, 0.3739,
+	1.0000, 0.6894, 0.3986,
+	1.0000, 0.7058, 0.4234,
+	1.0000, 0.7218, 0.4485,
+	1.0000, 0.7375, 0.4738,
+	1.0000, 0.7529, 0.4992,
+	1.0000, 0.7679, 0.5247,
+	1.0000, 0.7826, 0.5503,
+	1.0000, 0.7970, 0.5760,
+	1.0000, 0.8111, 0.6016,
+	1.0000, 0.8250, 0.6272,
+	1.0000, 0.8384, 0.6529,
+	1.0000, 0.8517, 0.6785,
+	1.0000, 0.8647, 0.7040,
+	1.0000, 0.8773, 0.7294,
+	1.0000, 0.8897, 0.7548,
+	1.0000, 0.9019, 0.7801,
+	1.0000, 0.9137, 0.8051,
+	1.0000, 0.9254, 0.8301,
+	1.0000, 0.9367, 0.8550,
+	1.0000, 0.9478, 0.8795,
+	1.0000, 0.9587, 0.9040,
+	1.0000, 0.9694, 0.9283,
+	1.0000, 0.9798, 0.9524,
+	1.0000, 0.9900, 0.9763,
+	1.0000, 1.0000, 1.0000, /* 6500K */
+	0.9771, 0.9867, 1.0000,
+	0.9554, 0.9740, 1.0000,
+	0.9349, 0.9618, 1.0000,
+	0.9154, 0.9500, 1.0000,
+	0.8968, 0.9389, 1.0000,
+	0.8792, 0.9282, 1.0000,
+	0.8624, 0.9179, 1.0000,
+	0.8465, 0.9080, 1.0000,
+	0.8313, 0.8986, 1.0000,
+	0.8167, 0.8895, 1.0000,
+	0.8029, 0.8808, 1.0000,
+	0.7896, 0.8724, 1.0000,
+	0.7769, 0.8643, 1.0000,
+	0.7648, 0.8565, 1.0000,
+	0.7532, 0.8490, 1.0000,
+	0.7420, 0.8418, 1.0000,
+	0.7314, 0.8348, 1.0000,
+	0.7212, 0.8281, 1.0000,
+	0.7113, 0.8216, 1.0000,
+	0.7018, 0.8153, 1.0000,
+	0.6927, 0.8092, 1.0000,
+	0.6839, 0.8032, 1.0000,
+	0.6755, 0.7975, 1.0000,
+	0.6674, 0.7921, 1.0000,
+	0.6595, 0.7867, 1.0000,
+	0.6520, 0.7816, 1.0000,
+	0.6447, 0.7765, 1.0000,
+	0.6376, 0.7717, 1.0000,
+	0.6308, 0.7670, 1.0000,
+	0.6242, 0.7623, 1.0000,
+	0.6179, 0.7579, 1.0000,
+	0.6117, 0.7536, 1.0000,
+	0.6058, 0.7493, 1.0000,
+	0.6000, 0.7453, 1.0000,
+	0.5944, 0.7414, 1.0000 /* 10000K */
+};
+
+
+static void
+interpolate_color(float a, const float *c1, const float *c2, float *c)
+{
+	c[0] = (1.0-a)*c1[0] + a*c2[0];
+	c[1] = (1.0-a)*c1[1] + a*c2[1];
+	c[2] = (1.0-a)*c1[2] + a*c2[2];
+}
+
+void
+colorramp_fill(uint16_t *gamma_r, uint16_t *gamma_g, uint16_t *gamma_b,
+	       int size, int temp, float gamma[3])
+{
+	/* Calculate white point */
+	float white_point[3];
+	float alpha = (temp % 100) / 100.0;
+	int temp_index = ((temp - 1000) / 100)*3;
+	interpolate_color(alpha, &blackbody_color[temp_index],
+			  &blackbody_color[temp_index+3], white_point);
+
+	for (int i = 0; i < size; i++) {
+		gamma_r[i] = pow((float)i/size, 1.0/gamma[0]) *
+			UINT16_MAX * white_point[0];
+		gamma_g[i] = pow((float)i/size, 1.0/gamma[1]) *
+			UINT16_MAX * white_point[1];
+		gamma_b[i] = pow((float)i/size, 1.0/gamma[2]) *
+			UINT16_MAX * white_point[2];
+	}
+}