Move math out of main

master
Kenny Levinsen 2020-09-13 03:22:18 +02:00
parent b2ebdea44a
commit 4f8559405f
4 changed files with 96 additions and 84 deletions

87
color_math.c 100644
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@ -0,0 +1,87 @@
#include <math.h>
#include <errno.h>
#include "color_math.h"
static int illuminant_d(int temp, double *x, double *y) {
// https://en.wikipedia.org/wiki/Standard_illuminant#Illuminant_series_D
if (temp >= 4000 && temp <= 7000) {
*x = 0.244063 + (0.09911e3/temp) + (2.9678e6/pow(temp, 2)) - (4.6070e9/pow(temp, 3));
} else if (temp > 7000 && temp <= 25000) {
*x = 0.237040 + (0.24748e3/temp) + (1.9018e6/pow(temp, 2)) - (2.0064e9/pow(temp, 3));
} else {
errno = EINVAL;
return -1;
}
*y = (-3 * pow(*x, 2)) + (2.870 * (*x)) - 0.275;
return 0;
}
static int planckian_locus(int temp, double *x, double *y) {
if (temp >= 1667 && temp <= 4000) {
*x = (-0.2661239e9/pow(temp, 3)) - (0.2343589e6/pow(temp, 2)) + (0.8776956e3/temp) + 0.179910;
if (temp <= 2222) {
*y = (-1.1064814 * pow(*x, 3)) - (1.34811020 * pow(*x, 2)) + (2.18555832 * (*x)) - 0.20219683;
} else {
*y = (-0.9549476 * pow(*x, 3)) - (1.37418593 * pow(*x, 2)) + (2.09137015 * (*x)) - 0.16748867;
}
} else if (temp > 4000 && temp < 25000) {
*x = (-3.0258469e9/pow(temp, 3)) + (2.1070379e6/pow(temp, 2)) + (0.2226347e3/temp) + 0.240390;
*y = (3.0817580 * pow(*x, 3)) - (5.87338670 * pow(*x, 2)) + (3.75112997 * (*x)) - 0.37001483;
} else {
errno = EINVAL;
return -1;
}
return 0;
}
static double srgb_gamma(double value, double gamma) {
// https://en.wikipedia.org/wiki/SRGB
if (value <= 0.0031308) {
return 12.92 * value;
} else {
return pow(1.055 * value, 1.0/gamma) - 0.055;
}
}
double clamp(double value) {
if (value > 1.0) {
return 1.0;
} else if (value < 0.0) {
return 0.0;
} else {
return value;
}
}
static void xyz_to_srgb(double x, double y, double z, double *r, double *g, double *b) {
// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
*r = srgb_gamma(clamp(3.2404542 * x - 1.5371385 * y - 0.4985314 * z), 2.2);
*g = srgb_gamma(clamp(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z), 2.2);
*b = srgb_gamma(clamp(0.0556434 * x - 0.2040259 * y + 1.0572252 * z), 2.2);
}
static void srgb_normalize(double *r, double *g, double *b) {
double maxw = fmaxl(*r, fmaxl(*g, *b));
*r /= maxw;
*g /= maxw;
*b /= maxw;
}
void calc_whitepoint(int temp, double *rw, double *gw, double *bw) {
if (temp == 6500) {
*rw = *gw = *bw = 1.0;
return;
}
double x = 1.0, y = 1.0;
if (temp > 1667 && temp <= 6500) {
planckian_locus(temp, &x, &y);
} else if (temp >= 6500 && temp <= 25000) {
illuminant_d(temp, &x, &y);
}
double z = 1.0 - x - y;
xyz_to_srgb(x, y, z, rw, gw, bw);
srgb_normalize(rw, gw, bw);
}

7
color_math.h 100644
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@ -0,0 +1,7 @@
#ifndef _COLOR_MATH_H
#define _COLOR_MATH_H
double clamp(double value);
void calc_whitepoint(int temp, double *rw, double *gw, double *bw);
#endif

84
main.c
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@ -13,6 +13,7 @@
#include <time.h>
#include <poll.h>
#include "wlr-gamma-control-unstable-v1-client-protocol.h"
#include "color_math.h"
enum state {
HIGH_TEMP,
@ -177,89 +178,6 @@ static void fill_gamma_table(uint16_t *table, uint32_t ramp_size, double rw, dou
}
}
static int illuminant_d(int temp, double *x, double *y) {
// https://en.wikipedia.org/wiki/Standard_illuminant#Illuminant_series_D
if (temp >= 4000 && temp <= 7000) {
*x = 0.244063 + (0.09911e3/temp) + (2.9678e6/pow(temp, 2)) - (4.6070e9/pow(temp, 3));
} else if (temp > 7000 && temp <= 25000) {
*x = 0.237040 + (0.24748e3/temp) + (1.9018e6/pow(temp, 2)) - (2.0064e9/pow(temp, 3));
} else {
errno = EINVAL;
return -1;
}
*y = (-3 * pow(*x, 2)) + (2.870 * (*x)) - 0.275;
return 0;
}
static int planckian_locus(int temp, double *x, double *y) {
if (temp >= 1667 && temp <= 4000) {
*x = (-0.2661239e9/pow(temp, 3)) - (0.2343589e6/pow(temp, 2)) + (0.8776956e3/temp) + 0.179910;
if (temp <= 2222) {
*y = (-1.1064814 * pow(*x, 3)) - (1.34811020 * pow(*x, 2)) + (2.18555832 * (*x)) - 0.20219683;
} else {
*y = (-0.9549476 * pow(*x, 3)) - (1.37418593 * pow(*x, 2)) + (2.09137015 * (*x)) - 0.16748867;
}
} else if (temp > 4000 && temp < 25000) {
*x = (-3.0258469e9/pow(temp, 3)) + (2.1070379e6/pow(temp, 2)) + (0.2226347e3/temp) + 0.240390;
*y = (3.0817580 * pow(*x, 3)) - (5.87338670 * pow(*x, 2)) + (3.75112997 * (*x)) - 0.37001483;
} else {
errno = EINVAL;
return -1;
}
return 0;
}
static double srgb_gamma(double value, double gamma) {
// https://en.wikipedia.org/wiki/SRGB
if (value <= 0.0031308) {
return 12.92 * value;
} else {
return pow(1.055 * value, 1.0/gamma) - 0.055;
}
}
static double clamp(double value) {
if (value > 1.0) {
return 1.0;
} else if (value < 0.0) {
return 0.0;
} else {
return value;
}
}
static void xyz_to_srgb(double x, double y, double z, double *r, double *g, double *b) {
// http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
*r = srgb_gamma(clamp(3.2404542 * x - 1.5371385 * y - 0.4985314 * z), 2.2);
*g = srgb_gamma(clamp(-0.9692660 * x + 1.8760108 * y + 0.0415560 * z), 2.2);
*b = srgb_gamma(clamp(0.0556434 * x - 0.2040259 * y + 1.0572252 * z), 2.2);
}
static void srgb_normalize(double *r, double *g, double *b) {
double maxw = fmaxl(*r, fmaxl(*g, *b));
*r /= maxw;
*g /= maxw;
*b /= maxw;
}
static void calc_whitepoint(int temp, double *rw, double *gw, double *bw) {
if (temp == 6500) {
*rw = *gw = *bw = 1.0;
return;
}
double x = 1.0, y = 1.0;
if (temp > 1667 && temp <= 6500) {
planckian_locus(temp, &x, &y);
} else if (temp >= 6500 && temp <= 25000) {
illuminant_d(temp, &x, &y);
}
double z = 1.0 - x - y;
xyz_to_srgb(x, y, z, rw, gw, bw);
srgb_normalize(rw, gw, bw);
}
static void set_temperature(struct context *ctx) {
double rw, gw, bw;
calc_whitepoint(ctx->cur_temp, &rw, &gw, &bw);

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@ -46,7 +46,7 @@ m = cc.find_library('m')
executable(
'wlsunset',
['main.c'],
['main.c', 'color_math.c'],
dependencies: [protocols_dep, m],
install: true
)