/**
* Converts an RGB color value to HSV. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSV_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and v in the set [0, 1].
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSV representation
*/
void RGBConverter::rgbToHsv(byte r, byte g, byte b, double hsv[]) {
double rd = (double) r/255;
double gd = (double) g/255;
double bd = (double) b/255;
double max = threeway_max(rd, gd, bd), min = threeway_min(rd, gd, bd);
double h, s, v = max;
double d = max - min;
s = max == 0 ? 0 : d / max;
if (max == min) {
h = 0; // achromatic
} else {
if (max == rd) {
h = (gd - bd) / d + (gd < bd ? 6 : 0);
} else if (max == gd) {
h = (bd - rd) / d + 2;
} else if (max == bd) {
h = (rd - gd) / d + 4;
}
h /= 6;
}
hsv[0] = h;
hsv[1] = s;
hsv[2] = v;
}
// This function is by Robert Atkins
// https://github.com/ratkins/RGBConverter
void ClydeDev::rgb2hsv(uint8_t r, uint8_t g, uint8_t b, double *hsv) {
double rd = (double) r/255;
double gd = (double) g/255;
double bd = (double) b/255;
double max = threeway_max(rd, gd, bd), min = threeway_min(rd, gd, bd);
double h, s, v = max;
double d = max - min;
s = max == 0 ? 0 : d / max;
if (max == min) {
h = 0; // achromatic
} else {
if (max == rd) {
h = (gd - bd) / d + (gd < bd ? 6 : 0);
} else if (max == gd) {
h = (bd - rd) / d + 2;
} else if (max == bd) {
h = (rd - gd) / d + 4;
}
h /= 6;
}
hsv[0] = h;
hsv[1] = s;
hsv[2] = v;
}
/**
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and l in the set [0, 1].
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSL representation
*/
void RGBConverter::rgbToHsl(byte r, byte g, byte b, double hsl[]) {
double rd = (double) r/255;
double gd = (double) g/255;
double bd = (double) b/255;
double max = threeway_max(rd, gd, bd);
double min = threeway_min(rd, gd, bd);
double h, s, l = (max + min) / 2;
if (max == min) {
h = s = 0; // achromatic
} else {
double d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
if (max == rd) {
h = (gd - bd) / d + (gd < bd ? 6 : 0);
} else if (max == gd) {
h = (bd - rd) / d + 2;
} else if (max == bd) {
h = (rd - gd) / d + 4;
}
h /= 6;
}
hsl[0] = h;
hsl[1] = s;
hsl[2] = l;
}
