/* 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) 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 <stdint.h>
#include <math.h>
#include <libred.h>

#include "colorramp.h"
#include "redshift.h"

/* Helper macro used in the fill functions */
#define F(Y, WP, C)  pow((Y) * setting->brightness * (WP), 1.0/setting->gamma[C])


#define X(SUFFIX, TYPE, MAX, TRUE_MAX, DEPTH)\
	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 color_setting_t *setting)\
	{\
		double r = 1, g = 1, b = 1;\
		size_t i;\
		libred_get_colour(setting->temperature, &r, &g, &b);\
		for (i = 0; i < size_r; i++) gamma_r[i] = F((double)i / size_r, r, 0) * (MAX);\
		for (i = 0; i < size_g; i++) gamma_g[i] = F((double)i / size_g, g, 1) * (MAX);\
		for (i = 0; i < size_b; i++) gamma_b[i] = F((double)i / size_b, b, 2) * (MAX);\
	}

LIST_RAMPS_STOP_VALUE_TYPES
#undef X

#undef F