2532

Dependencies:   QEI WS2812 PixelArray DFPlayerMini MODSERIAL PCA9685_ pca9685

Revision:
2:ed1f45f9b06a
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/rgbhsv.h	Sat Jun 22 17:24:44 2019 +0000
@@ -0,0 +1,117 @@
+typedef struct {
+    double r;       // a fraction between 0 and 1
+    double g;       // a fraction between 0 and 1
+    double b;       // a fraction between 0 and 1
+} rgb;
+
+typedef struct {
+    double h;       // angle in degrees
+    double s;       // a fraction between 0 and 1
+    double v;       // a fraction between 0 and 1
+} hsv;
+
+hsv   rgb2hsv(rgb in);
+rgb   hsv2rgb(hsv in);
+
+hsv rgb2hsv(rgb in)
+{
+    hsv         out;
+    double      min, max, delta;
+
+    min = in.r < in.g ? in.r : in.g;
+    min = min  < in.b ? min  : in.b;
+
+    max = in.r > in.g ? in.r : in.g;
+    max = max  > in.b ? max  : in.b;
+
+    out.v = max;                                // v
+    delta = max - min;
+    if (delta < 0.00001)
+    {
+        out.s = 0;
+        out.h = 0; // undefined, maybe nan?
+        return out;
+    }
+    if( max > 0.0 ) { // NOTE: if Max is == 0, this divide would cause a crash
+        out.s = (delta / max);                  // s
+    } else {
+        // if max is 0, then r = g = b = 0              
+        // s = 0, h is undefined
+        out.s = 0.0;
+        out.h = NAN;                            // its now undefined
+        return out;
+    }
+    if( in.r >= max )                           // > is bogus, just keeps compilor happy
+        out.h = ( in.g - in.b ) / delta;        // between yellow & magenta
+    else
+    if( in.g >= max )
+        out.h = 2.0 + ( in.b - in.r ) / delta;  // between cyan & yellow
+    else
+        out.h = 4.0 + ( in.r - in.g ) / delta;  // between magenta & cyan
+
+    out.h *= 60.0;                              // degrees
+
+    if( out.h < 0.0 )
+        out.h += 360.0;
+
+    return out;
+}
+
+
+rgb hsv2rgb(hsv in)
+{
+    double      hh, p, q, t, ff;
+    long        i;
+    rgb         out;
+
+    if(in.s <= 0.0) {       // < is bogus, just shuts up warnings
+        out.r = in.v;
+        out.g = in.v;
+        out.b = in.v;
+        return out;
+    }
+    hh = in.h;
+    if(hh >= 360.0) hh = 0.0;
+    hh /= 60.0;
+    i = (long)hh;
+    ff = hh - i;
+    p = in.v * (1.0 - in.s);
+    q = in.v * (1.0 - (in.s * ff));
+    t = in.v * (1.0 - (in.s * (1.0 - ff)));
+
+    switch(i) {
+    case 0:
+        out.r = in.v;
+        out.g = t;
+        out.b = p;
+        break;
+    case 1:
+        out.r = q;
+        out.g = in.v;
+        out.b = p;
+        break;
+    case 2:
+        out.r = p;
+        out.g = in.v;
+        out.b = t;
+        break;
+
+    case 3:
+        out.r = p;
+        out.g = q;
+        out.b = in.v;
+        break;
+    case 4:
+        out.r = t;
+        out.g = p;
+        out.b = in.v;
+        break;
+    case 5:
+    default:
+        out.r = in.v;
+        out.g = p;
+        out.b = q;
+        break;
+    }
+    return out;     
+}