color_utils.h File Reference

Detailed Description

Design Philosophy

These are a collection of functions to convert from red, green, blue (RGB) to hue, saturation, value (HSV) color spaces.

Functions can also convert between the paletteColor_t enum and the RGB color space.

Usage

Call the functions as necessary.

Example

// HSV to RGB, three different output formats
uint8_t hue = 0xFF;
uint8_t sat = 0xFF;
uint8_t val = 0xFF;
 
uint32_t rgb        = EHSVtoHEXhelper(hue, sat, val, true);
led_t ledVal        = LedEHSVtoHEXhelper(hue, sat, val, true);
paletteColor_t pCol = paletteHsvToHex(hue, sat, val);
 
// Palette to RGB and back
paletteColor_t pCol = RGBtoPalette(0x123456);
uint32_t rgbCol     = paletteToRGB(c345);

Go to the source code of this file.

Functions
uint32_t	EHSVtoHEXhelper (uint8_t hue, uint8_t sat, uint8_t val, bool applyGamma)
	This converts a hue, saturation, and value (HSV) into 32 bit RGB (0xBBGGRR).
led_t	LedEHSVtoHEXhelper (uint8_t hue, uint8_t sat, uint8_t val, bool applyGamma)
	This converts a hue, saturation, and value (HSV) into led_t color.
paletteColor_t	paletteHsvToHex (uint8_t hue, uint8_t sat, uint8_t val)
	This converts a hue, saturation, and value (HSV) into paletteColor_t color.
paletteColor_t	RGBtoPalette (uint32_t rgb)
	Find the palette color closest to the given 32 bit RGB color.
uint32_t	paletteToRGB (paletteColor_t pal)
	Find the 32 bit RGB color for the given palette color.

Variables
const uint32_t	gamma_correction_table [256]
	A LUT which maps perceived brightness to LED brightness.

Function Documentation

EHSVtoHEXhelper()

uint32_t EHSVtoHEXhelper	(	uint8_t	hue,
		uint8_t	sat,
		uint8_t	val,
		bool	applyGamma )

This converts a hue, saturation, and value (HSV) into 32 bit RGB (0xBBGGRR).

Parameters

hue	Hue, the color, 0..255
sat	Saturation, how intense the color is, 0..255
val	Value, how bright the color is, 0..255
applyGamma	Whether or not to apply gamma to the output

Returns

An RGB color (0xBBGGRR)

LedEHSVtoHEXhelper()

led_t LedEHSVtoHEXhelper	(	uint8_t	hue,
		uint8_t	sat,
		uint8_t	val,
		bool	applyGamma )

This converts a hue, saturation, and value (HSV) into led_t color.

Parameters

hue	Hue, the color, 0..255
sat	Saturation, how intense the color is, 0..255
val	Value, how bright the color is, 0..255
applyGamma	Whether or not to apply gamma to the output

Returns

An led_t set to the RGB color

paletteHsvToHex()

paletteColor_t paletteHsvToHex	(	uint8_t	hue,
		uint8_t	sat,
		uint8_t	val )

This converts a hue, saturation, and value (HSV) into paletteColor_t color.

Parameters

hue	Hue, the color, 0..255
sat	Saturation, how intense the color is, 0..255
val	Value, how bright the color is, 0..255

Returns

The paletteColor_t closest to the HSV color

RGBtoPalette()

paletteColor_t RGBtoPalette

(

uint32_t

rgb

)

Find the palette color closest to the given 32 bit RGB color.

Parameters

rgb	A 32 bit RGB color (0xBBGGRR)

Returns

The closest palette color to the given RGB color

paletteToRGB()

uint32_t paletteToRGB

(

paletteColor_t

pal

)

Find the 32 bit RGB color for the given palette color.

Parameters

pal	A palette color

Returns

The 32 bit RGB representation of the palette color (0xBBGGRR)

Variable Documentation

gamma_correction_table

const uint32_t gamma_correction_table[256]

extern

A LUT which maps perceived brightness to LED brightness.

A table that can be used for gamma correction.

A LUT which maps perceived brightness to LED brightness.

Maps a uint8_t value to a gamma-corrected uint8_t.