fill_rainbow_circular() [1/2]

void fill_rainbow_circular	(	struct CHSV *	targetArray,
		int	numToFill,
		uint8_t	initialhue,
		bool	reversed = false )

Fill a range of LEDs with a rainbow of colors, so that the hues are continuous between the end of the strip and the beginning.

The colors making up the rainbow are at full saturation and full value (brightness).

Parameters

targetArray	a pointer to the LED array to fill
numToFill	the number of LEDs to fill in the array
initialhue	the starting hue for the rainbow
reversed	whether to progress through the rainbow hues backwards

Definition at line 124 of file colorutils.cpp.

{
    if (numToFill == 0) return;  // avoiding div/0
 
    CHSV hsv;
    hsv.hue = initialhue;
    hsv.val = 255;
    hsv.sat = 240;
 
    const uint16_t hueChange = 65535 / (uint16_t) numToFill;  // hue change for each LED, * 256 for precision (256 * 256 - 1)
    uint16_t hueOffset = 0;  // offset for hue value, with precision (*256)
 
    for (int i = 0; i < numToFill; ++i) {
        targetArray[i] = hsv;
        if (reversed) hueOffset -= hueChange;
        else hueOffset += hueChange;
        hsv.hue = initialhue + (uint8_t)(hueOffset >> 8);  // assign new hue with precise offset (as 8-bit)
    }
}