kiwmi/kiwmi/color.c
2021-08-13 08:36:00 +00:00

42 lines
885 B
C

/* Copyright (c), Charlotte Meyer <dev@buffet.sh>
*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this file,
* You can obtain one at https://mozilla.org/MPL/2.0/.
*/
#include "color.h"
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
bool
color_parse(const char *hex, float color[static 4])
{
if (hex[0] == '#') {
++hex;
}
int len = strlen(hex);
if (len != 6 && len != 8) {
return false;
}
uint32_t rgba = (uint32_t)strtoul(hex, NULL, 16);
if (len == 6) {
rgba = (rgba << 8) | 0xff;
}
for (size_t i = 0; i < 4; ++i) {
color[3 - i] = (rgba & 0xff) / 255.0;
rgba >>= 8;
}
// premultiply alpha
color[0] *= color[3];
color[1] *= color[3];
color[2] *= color[3];
return true;
}