#include <SDL.h>
#include <string.h>
+#include <math.h>
#include "color.h"
return result;
}
+/* TODO(#928): Should the Hue in HSLA representation be in degrees? */
+Color hsla(float h, float s, float l, float a)
+{
+ h = fmodf(h, 360.0f);
+
+ const float c = (1.0f - fabsf(2.0f * l - 1.0f)) * s;
+ const float x = c * (1 - fabsf(fmodf(h / 60.0f, 2.0f) - 1.0f));
+ const float m = l - c / 2.0f;
+
+ Color color = {0.0f, 0.0f, 0.0f, a};
+
+ if (0.0f <= h && h < 60.0f) {
+ color = rgba(c, x, 0.0f, a);
+ } else if (60.0f <= h && h < 120.0f) {
+ color = rgba(x, c, 0.0f, a);
+ } else if (120.0f <= h && h < 180.0f) {
+ color = rgba(0.0f, c, x, a);
+ } else if (180.0f <= h && h < 240.0f) {
+ color = rgba(0.0f, x, c, a);
+ } else if (240.0f <= h && h < 300.0f) {
+ color = rgba(x, 0.0f, c, a);
+ } else if (300.0f <= h && h < 360.0f) {
+ color = rgba(c, 0.0f, x, a);
+ }
+
+ color.r += m;
+ color.g += m;
+ color.b += m;
+
+ return color;
+}
+
static Uint8 hex2dec_digit(char c)
{
if (c >= '0' && c <= '9') {
SDL_Color sdl = color_for_sdl(color);
return fprintf(stream, "%02x%02x%02x", sdl.r, sdl.g, sdl.b);
}
+
+int color_hex_to_string(Color color, char *buffer, size_t buffer_size)
+{
+ SDL_Color sdl = color_for_sdl(color);
+ return snprintf(buffer, buffer_size, "%02x%02x%02x", sdl.r, sdl.g, sdl.b);
+}
+
+Color rgba_to_hsla(Color color)
+{
+ const float max = fmaxf(color.r, fmaxf(color.g, color.b));
+ const float min = fminf(color.r, fminf(color.g, color.b));
+ const float c = max - min;
+ float hue = 0.0f;
+ float saturation = 0.0f;
+ const float lightness = (max + min) * 0.5f;
+
+ if (fabsf(c) > 1e-6) {
+ if (fabs(max - color.r) <= 1e-6) {
+ hue = 60.0f * fmodf((color.g - color.b) / c, 6.0f);
+ } else if (fabs(max - color.g) <= 1e-6) {
+ hue = 60.0f * ((color.b - color.r) / c + 2.0f);
+ } else {
+ hue = 60.0f * ((color.r - color.g) / c + 4.0f);
+ }
+
+ saturation = c / (1.0f - fabsf(2.0f * lightness - 1.0f));
+ }
+
+ // TODO(#929): Color struct is used not only for RGBA
+ // But also for HSLA. We should make another similar struct but for HSLA
+ return rgba(hue, saturation, lightness, color.a);
+}