Move math out of main

color_math.c

@@ -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);
+}
+

color_math.h

@@ -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

main.c

@@ -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);

meson.build

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