92 lines
3.6 KiB
C
92 lines
3.6 KiB
C
|
#ifndef __INC_HSV2RGB_H
|
||
|
|
#define __INC_HSV2RGB_H
|
||
|
|
|
||
|
|
#include "FastLED.h"
|
||
|
|
|
||
|
|
#include "pixeltypes.h"
|
||
|
|
|
||
|
|
FASTLED_NAMESPACE_BEGIN
|
||
|
|
|
||
|
|
// hsv2rgb_rainbow - convert a hue, saturation, and value to RGB
|
||
|
|
// using a visually balanced rainbow (vs a straight
|
||
|
|
// mathematical spectrum).
|
||
|
|
// This 'rainbow' yields better yellow and orange
|
||
|
|
// than a straight 'spectrum'.
|
||
|
|
//
|
||
|
|
// NOTE: here hue is 0-255, not just 0-191
|
||
|
|
|
||
|
|
void hsv2rgb_rainbow( const struct CHSV& hsv, struct CRGB& rgb);
|
||
|
|
void hsv2rgb_rainbow( const struct CHSV* phsv, struct CRGB * prgb, int numLeds);
|
||
|
|
#define HUE_MAX_RAINBOW 255
|
||
|
|
|
||
|
|
|
||
|
|
// hsv2rgb_spectrum - convert a hue, saturation, and value to RGB
|
||
|
|
// using a mathematically straight spectrum (vs
|
||
|
|
// a visually balanced rainbow).
|
||
|
|
// This 'spectrum' will have more green & blue
|
||
|
|
// than a 'rainbow', and less yellow and orange.
|
||
|
|
//
|
||
|
|
// NOTE: here hue is 0-255, not just 0-191
|
||
|
|
|
||
|
|
void hsv2rgb_spectrum( const struct CHSV& hsv, struct CRGB& rgb);
|
||
|
|
void hsv2rgb_spectrum( const struct CHSV* phsv, struct CRGB * prgb, int numLeds);
|
||
|
|
#define HUE_MAX_SPECTRUM 255
|
||
|
|
|
||
|
|
|
||
|
|
// hsv2rgb_raw - convert hue, saturation, and value to RGB.
|
||
|
|
// This 'spectrum' conversion will be more green & blue
|
||
|
|
// than a real 'rainbow', and the hue is specified just
|
||
|
|
// in the range 0-191. Together, these result in a
|
||
|
|
// slightly faster conversion speed, at the expense of
|
||
|
|
// color balance.
|
||
|
|
//
|
||
|
|
// NOTE: Hue is 0-191 only!
|
||
|
|
// Saturation & value are 0-255 each.
|
||
|
|
//
|
||
|
|
|
||
|
|
void hsv2rgb_raw(const struct CHSV& hsv, struct CRGB & rgb);
|
||
|
|
void hsv2rgb_raw(const struct CHSV* phsv, struct CRGB * prgb, int numLeds);
|
||
|
|
#define HUE_MAX 191
|
||
|
|
|
||
|
|
|
||
|
|
// rgb2hsv_approximate - recover _approximate_ HSV values from RGB.
|
||
|
|
//
|
||
|
|
// NOTE 1: This function is a long-term work in process; expect
|
||
|
|
// results to change slightly over time as this function is
|
||
|
|
// refined and improved.
|
||
|
|
//
|
||
|
|
// NOTE 2: This function is most accurate when the input is an
|
||
|
|
// RGB color that came from a fully-saturated HSV color to start
|
||
|
|
// with. E.g. CHSV( hue, 255, 255) -> CRGB -> CHSV will give
|
||
|
|
// best results.
|
||
|
|
//
|
||
|
|
// NOTE 3: This function is not nearly as fast as HSV-to-RGB.
|
||
|
|
// It is provided for those situations when the need for this
|
||
|
|
// function cannot be avoided, or when extremely high performance
|
||
|
|
// is not needed.
|
||
|
|
//
|
||
|
|
// NOTE 4: Why is this 'only' an "approximation"?
|
||
|
|
// Not all RGB colors have HSV equivalents! For example, there
|
||
|
|
// is no HSV value that will ever convert to RGB(255,255,0) using
|
||
|
|
// the code provided in this library. So if you try to
|
||
|
|
// convert RGB(255,255,0) 'back' to HSV, you'll necessarily get
|
||
|
|
// only an approximation. Emphasis has been placed on getting
|
||
|
|
// the 'hue' as close as usefully possible, but even that's a bit
|
||
|
|
// of a challenge. The 8-bit HSV and 8-bit RGB color spaces
|
||
|
|
// are not a "bijection".
|
||
|
|
//
|
||
|
|
// Nevertheless, this function does a pretty good job, particularly
|
||
|
|
// at recovering the 'hue' from fully saturated RGB colors that
|
||
|
|
// originally came from HSV rainbow colors. So if you start
|
||
|
|
// with CHSV(hue_in,255,255), and convert that to RGB, and then
|
||
|
|
// convert it back to HSV using this function, the resulting output
|
||
|
|
// hue will either exactly the same, or very close (+/-1).
|
||
|
|
// The more desaturated the original RGB color is, the rougher the
|
||
|
|
// approximation, and the less accurate the results.
|
||
|
|
//
|
||
|
|
CHSV rgb2hsv_approximate( const CRGB& rgb);
|
||
|
|
|
||
|
|
FASTLED_NAMESPACE_END
|
||
|
|
|
||
|
|
#endif
|