/* colorramp.c -- color temperature calculation source
 * This file is part of redshift-ng.
 * 
 * redshift-ng 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-ng 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-ng.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * Copyright (c) 2013, 2014  Jon Lund Steffensen <jonlst@gmail.com>
 * Copyright (c) 2013        Ingo Thies <ithies@astro.uni-bonn.de> [historical, no longer applies]
 * Copyright (c) 2016, 2025  Mattias Andrée <m@maandree.se>
 */
#include "common.h"

#if defined(__GNUC__)
# pragma GCC diagnostic ignored "-Wfloat-equal"
#endif


#define X(SUFFIX, TYPE, MAX, DEPTH)\
	/**
	 * Fill a gamma ramp
	 * 
	 * @param  ramp        The gamma ramp
	 * @param  size        The gamma ramp size (number of stops)
	 * @param  brightness  The brightness (between 0 and 1) of the channel, which is
	 *                     the overall applied brightness multiplied but the effect
	 *                     on the channel from the colour temperature
	 * @param  gamma       The gamma to apply to the channel
	 */\
	static void\
	fill_ramp_##SUFFIX(TYPE *ramp, size_t size, double brightness, double gamma)\
	{\
		size_t i;\
		double v;\
		brightness /= (size - 1U);\
		if (gamma == 1.0) {\
			brightness *= (MAX);\
			for (i = 0; i < size; i++)\
				ramp[i] = (TYPE)(i * brightness);\
		} else {\
			gamma = 1.0 / gamma;\
			for (i = 0; i < size; i++) {\
				v = pow(i * brightness, gamma) * (MAX);\
				ramp[i] = (TYPE)v;\
			}\
		}\
	}\
	\
	void\
	colorramp_fill_##SUFFIX(TYPE *gamma_r, TYPE *gamma_g, TYPE *gamma_b,\
	                        size_t size_r, size_t size_g, size_t size_b,\
	                        const struct color_setting *setting)\
	{\
		double r = 1, g = 1, b = 1;\
		libred_get_colour(setting->temperature, &r, &g, &b);\
		fill_ramp_##SUFFIX(gamma_r, size_r, setting->brightness * r, setting->gamma[0]);\
		fill_ramp_##SUFFIX(gamma_g, size_g, setting->brightness * g, setting->gamma[1]);\
		fill_ramp_##SUFFIX(gamma_b, size_b, setting->brightness * b, setting->gamma[2]);\
	}

LIST_RAMPS_STOP_VALUE_TYPES(X,)