Files
zdwm/src/color.c

88 lines
2.7 KiB
C

#include "color.h"
#include "utils.h"
/**
* @brief 将 16 进制的颜色配置转换成 uint32 格式的 rgba数据
*
* @param hex 16 进制的颜色表示,支持的格式有
* RGB/RGBA/RRGGBB/RRGGBBAA/#RGB/#RGBA/#RRGGBB/#RRGGBBAA
* @param rgba 返回数据的指针,解析结果会放到这个指针指向的内存中
* @return 如果 hex 是一个能正常解析的颜色,返回 true ,否则返回 false
*/
static bool hex_color_to_rgba(const char *hex, uint32_t *rgba);
/**
* @brief 将 rgba 通道顺序的颜色转换成 argb 顺序
* @description xcb 库用到的颜色需要是 argb 通道顺序
*/
static uint32_t rgba_to_argb(uint32_t rgba);
/**
* @brief 提取颜色中的各个颜色通道数值
* @param rgba uint32 表示的颜色
* @param red red channel, range 0~1
* @param green green channel, range 0~1
* @param blue blue channel, range 0~1
* @param alpha alpha channel, range 0~1
*/
static void extract_color_channel(const uint32_t rgba, double *red,
double *green, double *blue, double *alpha);
void color_parse(const char *hex, color_t *const color) {
bool success = hex_color_to_rgba(hex, &color->rgba);
if (!success) fatal("invalid hex color: %s", hex);
color->argb = rgba_to_argb(color->rgba);
extract_color_channel(color->rgba, &color->red, &color->green, &color->blue,
&color->alpha);
}
bool hex_color_to_rgba(const char *hex, uint32_t *rgba) {
if (hex[0] == '#') hex++;
size_t len = strlen(hex);
char extended[9] = {0};
uint32_t color = 0x00000000;
if (len == 3 || len == 4) {
extended[0] = extended[1] = hex[0];
extended[2] = extended[3] = hex[1];
extended[4] = extended[5] = hex[2];
if (len == 3) {
extended[6] = extended[7] = 'F';
} else {
extended[6] = extended[7] = hex[3];
}
} else if (len == 6) {
strncpy(extended, hex, len);
extended[6] = extended[7] = 'F';
} else if (len == 8) {
strncpy(extended, hex, len);
} else {
return false;
}
color = strtoul(extended, nullptr, 16) & 0xffffffff;
*rgba = color;
return true;
}
#define EXTRACE_COLOR_BIT(C, R) (((C) >> (R)) & 0xff)
uint32_t rgba_to_argb(uint32_t rgba) {
uint32_t r = EXTRACE_COLOR_BIT(rgba, 24);
uint32_t g = EXTRACE_COLOR_BIT(rgba, 16);
uint32_t b = EXTRACE_COLOR_BIT(rgba, 8);
uint32_t a = EXTRACE_COLOR_BIT(rgba, 0);
uint32_t argb = (a << 24) | (r << 16) | (g << 8) | b;
return argb;
}
#define COLOR_SPLIT(C, R) (EXTRACE_COLOR_BIT((C), (R)) / (double)0xff)
void extract_color_channel(const uint32_t rgba, double *red, double *green,
double *blue, double *alpha) {
*red = COLOR_SPLIT(rgba, 24);
*green = COLOR_SPLIT(rgba, 16);
*blue = COLOR_SPLIT(rgba, 8);
*alpha = COLOR_SPLIT(rgba, 0);
}