-#include <SDL2/SDL.h>
+#include <SDL.h>
#include <string.h>
+#include <math.h>
-#include "./color.h"
+#include "color.h"
-color_t color(float r, float g, float b, float a)
+Color rgba(float r, float g, float b, float a)
{
- const color_t result = {
+ const Color result = {
.r = r,
.g = g,
.b = b,
return result;
}
-color_t color256(Uint8 r, Uint8 g, Uint8 b, Uint8 a)
+/* TODO(#928): Should the Hue in HSLA representation be in degrees? */
+Color hsla(float h, float s, float l, float a)
{
- return color(
- (float) r / 255.0f,
- (float) g / 255.0f,
- (float) b / 255.0f,
- (float) a / 255.0f);
+ 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)
return (Uint8) (hex2dec_digit(component[0]) * 16 + hex2dec_digit(component[1]));
}
-color_t color_from_hexstr(const char *hexstr)
+Color hexstr(const char *hexstr)
{
if (strlen(hexstr) != 6) {
- return color(0.0f, 0.0f, 0.0f, 1.0f);
+ return rgba(0.0f, 0.0f, 0.0f, 1.0f);
}
- return color256(
- parse_color_component(hexstr),
- parse_color_component(hexstr + 2),
- parse_color_component(hexstr + 4),
- 255);
+ return rgba(
+ parse_color_component(hexstr) / 255.0f,
+ parse_color_component(hexstr + 2) / 255.0f,
+ parse_color_component(hexstr + 4) / 255.0f,
+ 1.0f);
}
-SDL_Color color_for_sdl(color_t color)
+SDL_Color color_for_sdl(Color color)
{
const SDL_Color result = {
.r = (Uint8)roundf(color.r * 255.0f),
return result;
}
-color_t color_desaturate(color_t c)
+Color color_desaturate(Color c)
{
const float k = (c.r + c.g + c.b) / 3.0f;
- return color(k, k, k, c.a);
+ return rgba(k, k, k, c.a);
+}
+
+Color color_darker(Color c, float d)
+{
+ return rgba(fmaxf(c.r - d, 0.0f),
+ fmaxf(c.g - d, 0.0f),
+ fmaxf(c.b - d, 0.0f),
+ c.a);
+}
+
+Color color_invert(Color c)
+{
+ return rgba(1.0f - c.r, 1.0f - c.g, 1.0f - c.b, c.a);
+}
+
+Color color_scale(Color c, Color fc)
+{
+ return rgba(
+ fmaxf(fminf(c.r * fc.r, 1.0f), 0.0f),
+ fmaxf(fminf(c.g * fc.g, 1.0f), 0.0f),
+ fmaxf(fminf(c.b * fc.b, 1.0f), 0.0f),
+ fmaxf(fminf(c.a * fc.a, 1.0f), 0.0f));
+}
+
+int color_hex_to_stream(Color color, FILE *stream)
+{
+ 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);
}