aboutsummaryrefslogtreecommitdiffstats
path: root/src/blackbody.c
diff options
context:
space:
mode:
authorMattias Andrée <maandree@member.fsf.org>2016-01-04 20:54:03 +0100
committerMattias Andrée <maandree@member.fsf.org>2016-01-04 20:54:03 +0100
commit575a3003dc87bbc3c5c23f45289dccfad1301a7c (patch)
treec6416dd1e16e4f37e45aaba610d2e22709ae7408 /src/blackbody.c
parentsplit out libhaiku from radharc (diff)
downloadradharc-575a3003dc87bbc3c5c23f45289dccfad1301a7c.tar.gz
radharc-575a3003dc87bbc3c5c23f45289dccfad1301a7c.tar.bz2
radharc-575a3003dc87bbc3c5c23f45289dccfad1301a7c.tar.xz
m + split out libred
Signed-off-by: Mattias Andrée <maandree@member.fsf.org>
Diffstat (limited to '')
-rw-r--r--src/blackbody.c130
1 files changed, 0 insertions, 130 deletions
diff --git a/src/blackbody.c b/src/blackbody.c
deleted file mode 100644
index d393686..0000000
--- a/src/blackbody.c
+++ /dev/null
@@ -1,130 +0,0 @@
-/**
- * Copyright © 2016 Mattias Andrée <maandree@member.fsf.org>
- *
- * This program 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.
- *
- * This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
- */
-#include "blackbody.h"
-#include "macros.h"
-#include <math.h>
-#include <errno.h>
-
-
-
-/**
- * Convert from CIE xyY to [0, 1] sRGB.
- *
- * @param x The 'x' component.
- * @param y The 'y' component.
- * @param Y The 'Y' component.
- * @param r Output parameter for the “red” value.
- * (Seriously, sRGB red is orange, just look at it fullscreen.)
- * @param g Output parameter for the green value.
- * @param b Output parameter for the blue value.
- */
-void
-ciexyy_to_srgb(double x, double y, double Y, double *r, double *g, double *b)
-{
-#define SRGB(C) (((C) <= 0.0031308) ? (12.92 * (C)) : ((1.0 + 0.055) * pow((C), 1.0 / 2.4) - 0.055))
- double X, Z;
-
- /* Convert CIE xyY to CIE XYZ. */
- X = Y * (y == 0.0 ? 0.0 : (x / y));
- Z = Y * (y == 0.0 ? 0.0 : ((1.0 - x - y) / y));
-
- /* Convert CIE XYZ to [0, 1] linear RGB. (ciexyz_to_linear) */
- *r = ( 3.240450 * X) + (-1.537140 * Y) + (-0.4985320 * Z);
- *g = (-0.969266 * X) + ( 1.876010 * Y) + ( 0.0415561 * Z);
- *b = (0.0556434 * X) + (-0.204026 * Y) + ( 1.0572300 * Z);
-
- /* Convert [0, 1] linear RGB to [0, 1] sRGB. */
- SRGB(*r), SRGB(*g), SRGB(*b);
-}
-
-
-/**
- * Perform linear interpolation (considered very good)
- * between the CIE xyY values for two colour temperatures
- * and convert the result to sRGB. The two colours should
- * be the closest below the desired colour temperature,
- * and the closest above the desired colour temperature.
- *
- * @param x1 The 'x' component for the low colour.
- * @param y1 The 'y' component for the low colour.
- * @param x2 The 'x' component for the high colour.
- * @param y2 The 'y' component for the high colour.
- * @param temp The desired colour temperature.
- * @param r Output parameter for the “red” value.
- * @param g Output parameter for the green value.
- * @param b Output parameter for the blue value.
- */
-static void
-interpolate(double x1, double y1, double x2, double y2, double temp, double *r, double *g, double *b)
-{
- double weight = fmod(temp, (double)DELTA_TEMPERATURE) / (double)DELTA_TEMPERATURE;
- double x = x1 * (1 - weight) + x2 * weight;
- double y = y1 * (1 - weight) + y2 * weight;
- ciexyy_to_srgb(x, y, 1.0, r, g, b);
-}
-
-
-/**
- * Get the [0, 1] sRGB values of a colour temperature.
- *
- * @param fd File descriptor for the colour table.
- * @param temp The desired colour temperature.
- * @param r Output parameter for the “red” value.
- * @param g Output parameter for the green value.
- * @param b Output parameter for the blue value.
- * @return 0 on succeess, -1 on error.
- *
- * @throws 0 The file did not have the expected size.
- * @throws EDOM The selected temperature is below 1000 K.
- */
-int
-get_colour(int fd, long int temp, double *r, double *g, double *b)
-{
- double values[10]; /* low:x,y,r,g,b + high:x,y,r,g,b */
- off_t offset;
- double max;
-
- /* We do not have any values for above 40 000 K, but
- * the differences will be unnoticeable, perhaps even
- * unencodeable. */
- if (temp > HIGHEST_TEMPERATURE) temp = HIGHEST_TEMPERATURE;
- /* Things do not glow below 1000 K. Yes, fire is hot! */
- if (temp < LOWEST_TEMPERATURE) t ((errno = EDOM));
-
- /* Read table. */
- offset = ((off_t)temp - LOWEST_TEMPERATURE) / DELTA_TEMPERATURE;
- offset *= (off_t)(sizeof(values) / 2);
- errno = 0; xpread(fd, values, sizeof(values), offset);
-
- /* Get colour. */
- if (temp % DELTA_TEMPERATURE)
- interpolate(values[0], values[1], values[6], values[7], (double)temp, r, g, b);
- else
- *r = values[2], *g = values[3], *b = values[4];
-
- /* Adjust colours for use. */
- max = fmax(fmax(fabs(*r), fabs(*g)), fabs(*b));
- if (max != 0) *r /= max, *g /= max, *b /= max;
- *r = *r > 0.0 ? *r : 0.0;
- *g = *g > 0.0 ? *g : 0.0;
- *b = *b > 0.0 ? *b : 0.0;
-
- return 0;
-fail:
- return -1;
-}
-