Add colors toolbox (rgb and hsv)

2026-07-27 01:58:09 -07:00 · 2023-08-14 01:17:37 +02:00
parent 6f64300aa9
commit 5e8efe8281
3 changed files with 116 additions and 0 deletions
@@ -0,0 +1,87 @@
+// https://stackoverflow.com/a/14733008
+
+#include "colors.h"
+
+RgbColor hsv2rgb(HsvColor hsv) {
+    RgbColor rgb;
+    uint8_t region, remainder, p, q, t;
+
+    if(hsv.s == 0) {
+        rgb.r = hsv.v;
+        rgb.g = hsv.v;
+        rgb.b = hsv.v;
+        return rgb;
+    }
+
+    region = hsv.h / 43;
+    remainder = (hsv.h - (region * 43)) * 6;
+
+    p = (hsv.v * (255 - hsv.s)) >> 8;
+    q = (hsv.v * (255 - ((hsv.s * remainder) >> 8))) >> 8;
+    t = (hsv.v * (255 - ((hsv.s * (255 - remainder)) >> 8))) >> 8;
+
+    switch(region) {
+    case 0:
+        rgb.r = hsv.v;
+        rgb.g = t;
+        rgb.b = p;
+        break;
+    case 1:
+        rgb.r = q;
+        rgb.g = hsv.v;
+        rgb.b = p;
+        break;
+    case 2:
+        rgb.r = p;
+        rgb.g = hsv.v;
+        rgb.b = t;
+        break;
+    case 3:
+        rgb.r = p;
+        rgb.g = q;
+        rgb.b = hsv.v;
+        break;
+    case 4:
+        rgb.r = t;
+        rgb.g = p;
+        rgb.b = hsv.v;
+        break;
+    default:
+        rgb.r = hsv.v;
+        rgb.g = p;
+        rgb.b = q;
+        break;
+    }
+
+    return rgb;
+}
+
+HsvColor rgb2hsv(RgbColor rgb) {
+    HsvColor hsv;
+    uint8_t rgbMin, rgbMax;
+
+    rgbMin = rgb.r < rgb.g ? (rgb.r < rgb.b ? rgb.r : rgb.b) : (rgb.g < rgb.b ? rgb.g : rgb.b);
+    rgbMax = rgb.r > rgb.g ? (rgb.r > rgb.b ? rgb.r : rgb.b) : (rgb.g > rgb.b ? rgb.g : rgb.b);
+
+    hsv.v = rgbMax;
+    if(hsv.v == 0) {
+        hsv.h = 0;
+        hsv.s = 0;
+        return hsv;
+    }
+
+    hsv.s = 255 * ((long)rgbMax - (long)rgbMin) / hsv.v;
+    if(hsv.s == 0) {
+        hsv.h = 0;
+        return hsv;
+    }
+
+    if(rgbMax == rgb.r)
+        hsv.h = 0 + 43 * (rgb.g - rgb.b) / (rgbMax - rgbMin);
+    else if(rgbMax == rgb.g)
+        hsv.h = 85 + 43 * (rgb.b - rgb.r) / (rgbMax - rgbMin);
+    else
+        hsv.h = 171 + 43 * (rgb.r - rgb.g) / (rgbMax - rgbMin);
+
+    return hsv;
+}
@@ -0,0 +1,27 @@
+#pragma once
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct RgbColor {
+    uint8_t r;
+    uint8_t g;
+    uint8_t b;
+} RgbColor;
+
+typedef struct HsvColor {
+    uint8_t h;
+    uint8_t s;
+    uint8_t v;
+} HsvColor;
+
+RgbColor hsv2rgb(HsvColor hsv);
+
+HsvColor rgb2hsv(RgbColor rgb);
+
+#ifdef __cplusplus
+}
+#endif