#include "wled.h"
/*
* Color conversion & utility methods
*/
/*
* color blend function
*/
uint32_t color_blend(uint32_t color1, uint32_t color2, uint16_t blend, bool b16) {
if(blend == 0) return color1;
uint16_t blendmax = b16 ? 0xFFFF : 0xFF;
if(blend == blendmax) return color2;
uint8_t shift = b16 ? 16 : 8;
uint32_t w1 = W(color1);
uint32_t r1 = R(color1);
uint32_t g1 = G(color1);
uint32_t b1 = B(color1);
uint32_t w2 = W(color2);
uint32_t r2 = R(color2);
uint32_t g2 = G(color2);
uint32_t b2 = B(color2);
uint32_t w3 = ((w2 * blend) + (w1 * (blendmax - blend))) >> shift;
uint32_t r3 = ((r2 * blend) + (r1 * (blendmax - blend))) >> shift;
uint32_t g3 = ((g2 * blend) + (g1 * (blendmax - blend))) >> shift;
uint32_t b3 = ((b2 * blend) + (b1 * (blendmax - blend))) >> shift;
return RGBW32(r3, g3, b3, w3);
}
/*
* color add function that preserves ratio
* idea: https://github.com/Aircoookie/WLED/pull/2465 by https://github.com/Proto-molecule
*/
uint32_t color_add(uint32_t c1, uint32_t c2, bool fast)
{
if (fast) {
uint8_t r = R(c1);
uint8_t g = G(c1);
uint8_t b = B(c1);
uint8_t w = W(c1);
r = qadd8(r, R(c2));
g = qadd8(g, G(c2));
b = qadd8(b, B(c2));
w = qadd8(w, W(c2));
return RGBW32(r,g,b,w);
} else {
uint32_t r = R(c1) + R(c2);
uint32_t g = G(c1) + G(c2);
uint32_t b = B(c1) + B(c2);
uint32_t w = W(c1) + W(c2);
uint16_t max = r;
if (g > max) max = g;
if (b > max) max = b;
if (w > max) max = w;
if (max < 256) return RGBW32(r, g, b, w);
else return RGBW32(r * 255 / max, g * 255 / max, b * 255 / max, w * 255 / max);
}
}
/*
* fades color toward black
* if using "video" method the resulting color will never become black unless it is already black
*/
uint32_t color_fade(uint32_t c1, uint8_t amount, bool video)
{
uint8_t r = R(c1);
uint8_t g = G(c1);
uint8_t b = B(c1);
uint8_t w = W(c1);
if (video) {
r = scale8_video(r, amount);
g = scale8_video(g, amount);
b = scale8_video(b, amount);
w = scale8_video(w, amount);
} else {
r = scale8(r, amount);
g = scale8(g, amount);
b = scale8(b, amount);
w = scale8(w, amount);
}
return RGBW32(r, g, b, w);
}
void setRandomColor(byte* rgb)
{
lastRandomIndex = get_random_wheel_index(lastRandomIndex);
colorHStoRGB(lastRandomIndex*256,255,rgb);
}
void colorHStoRGB(uint16_t hue, byte sat, byte* rgb) //hue, sat to rgb
{
float h = ((float)hue)/65535.0f;
float s = ((float)sat)/255.0f;
int i = floorf(h*6);
float f = h * 6.0f - i;
int p = int(255.0f * (1.0f-s));
int q = int(255.0f * (1.0f-f*s));
int t = int(255.0f * (1.0f-(1.0f-f)*s));
p = constrain(p, 0, 255);
q = constrain(q, 0, 255);
t = constrain(t, 0, 255);
switch (i%6) {
case 0: rgb[0]=255,rgb[1]=t, rgb[2]=p; break;
case 1: rgb[0]=q, rgb[1]=255,rgb[2]=p; break;
case 2: rgb[0]=p, rgb[1]=255,rgb[2]=t; break;
case 3: rgb[0]=p, rgb[1]=q, rgb[2]=255;break;
case 4: rgb[0]=t, rgb[1]=p, rgb[2]=255;break;
case 5: rgb[0]=255,rgb[1]=p, rgb[2]=q; break;
}
}
//get RGB values from color temperature in K (https://tannerhelland.com/2012/09/18/convert-temperature-rgb-algorithm-code.html)
void colorKtoRGB(uint16_t kelvin, byte* rgb) //white spectrum to rgb, calc
{
int r = 0, g = 0, b = 0;
float temp = kelvin / 100.0f;
if (temp <= 66.0f) {
r = 255;
g = roundf(99.4708025861f * logf(temp) - 161.1195681661f);
if (temp <= 19.0f) {
b = 0;
} else {
b = roundf(138.5177312231f * logf((temp - 10.0f)) - 305.0447927307f);
}
} else {
r = roundf(329.698727446f * powf((temp - 60.0f), -0.1332047592f));
g = roundf(288.1221695283f * powf((temp - 60.0f), -0.0755148492f));
b = 255;
}
//g += 12; //mod by Aircoookie, a bit less accurate but visibly less pinkish
rgb[0] = (uint8_t) constrain(r, 0, 255);
rgb[1] = (uint8_t) constrain(g, 0, 255);
rgb[2] = (uint8_t) constrain(b, 0, 255);
rgb[3] = 0;
}
void colorCTtoRGB(uint16_t mired, byte* rgb) //white spectrum to rgb, bins
{
//this is only an approximation using WS2812B with gamma correction enabled
if (mired > 475) {
rgb[0]=255;rgb[1]=199;rgb[2]=92;//500
} else if (mired > 425) {
rgb[0]=255;rgb[1]=213;rgb[2]=118;//450
} else if (mired > 375) {
rgb[0]=255;rgb[1]=216;rgb[2]=118;//400
} else if (mired > 325) {
rgb[0]=255;rgb[1]=234;rgb[2]=140;//350
} else if (mired > 275) {
rgb[0]=255;rgb[1]=243;rgb[2]=160;//300
} else if (mired > 225) {
rgb[0]=250;rgb[1]=255;rgb[2]=188;//250
} else if (mired > 175) {
rgb[0]=247;rgb[1]=255;rgb[2]=215;//200
} else {
rgb[0]=237;rgb[1]=255;rgb[2]=239;//150
}
}
#ifndef WLED_DISABLE_HUESYNC
void colorXYtoRGB(float x, float y, byte* rgb) //coordinates to rgb (https://www.developers.meethue.com/documentation/color-conversions-rgb-xy)
{
float z = 1.0f - x - y;
float X = (1.0f / y) * x;
float Z = (1.0f / y) * z;
float r = (int)255*(X * 1.656492f - 0.354851f - Z * 0.255038f);
float g = (int)255*(-X * 0.707196f + 1.655397f + Z * 0.036152f);
float b = (int)255*(X * 0.051713f - 0.121364f + Z * 1.011530f);
if (r > b && r > g && r > 1.0f) {
// red is too big
g = g / r;
b = b / r;
r = 1.0f;
} else if (g > b && g > r && g > 1.0f) {
// green is too big
r = r / g;
b = b / g;
g = 1.0f;
} else if (b > r && b > g && b > 1.0f) {
// blue is too big
r = r / b;
g = g / b;
b = 1.0f;
}
// Apply gamma correction
r = r <= 0.0031308f ? 12.92f * r : (1.0f + 0.055f) * powf(r, (1.0f / 2.4f)) - 0.055f;
g = g <= 0.0031308f ? 12.92f * g : (1.0f + 0.055f) * powf(g, (1.0f / 2.4f)) - 0.055f;
b = b <= 0.0031308f ? 12.92f * b : (1.0f + 0.055f) * powf(b, (1.0f / 2.4f)) - 0.055f;
if (r > b && r > g) {
// red is biggest
if (r > 1.0f) {
g = g / r;
b = b / r;
r = 1.0f;
}
} else if (g > b && g > r) {
// green is biggest
if (g > 1.0f) {
r = r / g;
b = b / g;
g = 1.0f;
}
} else if (b > r && b > g) {
// blue is biggest
if (b > 1.0f) {
r = r / b;
g = g / b;
b = 1.0f;
}
}
rgb[0] = byte(255.0f*r);
rgb[1] = byte(255.0f*g);
rgb[2] = byte(255.0f*b);
}
void colorRGBtoXY(byte* rgb, float* xy) //rgb to coordinates (https://www.developers.meethue.com/documentation/color-conversions-rgb-xy)
{
float X = rgb[0] * 0.664511f + rgb[1] * 0.154324f + rgb[2] * 0.162028f;
float Y = rgb[0] * 0.283881f + rgb[1] * 0.668433f + rgb[2] * 0.047685f;
float Z = rgb[0] * 0.000088f + rgb[1] * 0.072310f + rgb[2] * 0.986039f;
xy[0] = X / (X + Y + Z);
xy[1] = Y / (X + Y + Z);
}
#endif // WLED_DISABLE_HUESYNC
//RRGGBB / WWRRGGBB order for hex
void colorFromDecOrHexString(byte* rgb, char* in)
{
if (in[0] == 0) return;
char first = in[0];
uint32_t c = 0;
if (first == '#' || first == 'h' || first == 'H') //is HEX encoded
{
c = strtoul(in +1, NULL, 16);
} else
{
c = strtoul(in, NULL, 10);
}
rgb[0] = R(c);
rgb[1] = G(c);
rgb[2] = B(c);
rgb[3] = W(c);
}
//contrary to the colorFromDecOrHexString() function, this uses the more standard RRGGBB / RRGGBBWW order
bool colorFromHexString(byte* rgb, const char* in) {
if (in == nullptr) return false;
size_t inputSize = strnlen(in, 9);
if (inputSize != 6 && inputSize != 8) return false;
uint32_t c = strtoul(in, NULL, 16);
if (inputSize == 6) {
rgb[0] = (c >> 16);
rgb[1] = (c >> 8);
rgb[2] = c ;
} else {
rgb[0] = (c >> 24);
rgb[1] = (c >> 16);
rgb[2] = (c >> 8);
rgb[3] = c ;
}
return true;
}
float minf (float v, float w)
{
if (w > v) return v;
return w;
}
float maxf (float v, float w)
{
if (w > v) return w;
return v;
}
// adjust RGB values based on color temperature in K (range [2800-10200]) (https://en.wikipedia.org/wiki/Color_balance)
// called from bus manager when color correction is enabled!
uint32_t colorBalanceFromKelvin(uint16_t kelvin, uint32_t rgb)
{
//remember so that slow colorKtoRGB() doesn't have to run for every setPixelColor()
static byte correctionRGB[4] = {0,0,0,0};
static uint16_t lastKelvin = 0;
if (lastKelvin != kelvin) colorKtoRGB(kelvin, correctionRGB); // convert Kelvin to RGB
lastKelvin = kelvin;
byte rgbw[4];
rgbw[0] = ((uint16_t) correctionRGB[0] * R(rgb)) /255; // correct R
rgbw[1] = ((uint16_t) correctionRGB[1] * G(rgb)) /255; // correct G
rgbw[2] = ((uint16_t) correctionRGB[2] * B(rgb)) /255; // correct B
rgbw[3] = W(rgb);
return RGBW32(rgbw[0],rgbw[1],rgbw[2],rgbw[3]);
}
//approximates a Kelvin color temperature from an RGB color.
//this does no check for the "whiteness" of the color,
//so should be used combined with a saturation check (as done by auto-white)
//values from http://www.vendian.org/mncharity/dir3/blackbody/UnstableURLs/bbr_color.html (10deg)
//equation spreadsheet at https://bit.ly/30RkHaN
//accuracy +-50K from 1900K up to 8000K
//minimum returned: 1900K, maximum returned: 10091K (range of 8192)
uint16_t approximateKelvinFromRGB(uint32_t rgb) {
//if not either red or blue is 255, color is dimmed. Scale up
uint8_t r = R(rgb), b = B(rgb);
if (r == b) return 6550; //red == blue at about 6600K (also can't go further if both R and B are 0)
if (r > b) {
//scale blue up as if red was at 255
uint16_t scale = 0xFFFF / r; //get scale factor (range 257-65535)
b = ((uint16_t)b * scale) >> 8;
//For all temps K<6600 R is bigger than B (for full bri colors R=255)
//-> Use 9 linear approximations for blackbody radiation blue values from 2000-6600K (blue is always 0 below 2000K)
if (b < 33) return 1900 + b *6;
if (b < 72) return 2100 + (b-33) *10;
if (b < 101) return 2492 + (b-72) *14;
if (b < 132) return 2900 + (b-101) *16;
if (b < 159) return 3398 + (b-132) *19;
if (b < 186) return 3906 + (b-159) *22;
if (b < 210) return 4500 + (b-186) *25;
if (b < 230) return 5100 + (b-210) *30;
return 5700 + (b-230) *34;
} else {
//scale red up as if blue was at 255
uint16_t scale = 0xFFFF / b; //get scale factor (range 257-65535)
r = ((uint16_t)r * scale) >> 8;
//For all temps K>6600 B is bigger than R (for full bri colors B=255)
//-> Use 2 linear approximations for blackbody radiation red values from 6600-10091K (blue is always 0 below 2000K)
if (r > 225) return 6600 + (254-r) *50;
uint16_t k = 8080 + (225-r) *86;
return (k > 10091) ? 10091 : k;
}
}
//gamma 2.8 lookup table used for color correction
uint8_t NeoGammaWLEDMethod::gammaT[256] = {
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1,
1, 1, 1, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 2, 2,
2, 3, 3, 3, 3, 3, 3, 3, 4, 4, 4, 4, 4, 5, 5, 5,
5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8, 8, 9, 9, 9, 10,
10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 14, 14, 15, 15, 16, 16,
17, 17, 18, 18, 19, 19, 20, 20, 21, 21, 22, 22, 23, 24, 24, 25,
25, 26, 27, 27, 28, 29, 29, 30, 31, 32, 32, 33, 34, 35, 35, 36,
37, 38, 39, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 50,
51, 52, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 66, 67, 68,
69, 70, 72, 73, 74, 75, 77, 78, 79, 81, 82, 83, 85, 86, 87, 89,
90, 92, 93, 95, 96, 98, 99,101,102,104,105,107,109,110,112,114,
115,117,119,120,122,124,126,127,129,131,133,135,137,138,140,142,
144,146,148,150,152,154,156,158,160,162,164,167,169,171,173,175,
177,180,182,184,186,189,191,193,196,198,200,203,205,208,210,213,
215,218,220,223,225,228,231,233,236,239,241,244,247,249,252,255 };
// re-calculates & fills gamma table
void NeoGammaWLEDMethod::calcGammaTable(float gamma)
{
for (size_t i = 0; i < 256; i++) {
gammaT[i] = (int)(powf((float)i / 255.0f, gamma) * 255.0f + 0.5f);
}
}
uint8_t NeoGammaWLEDMethod::Correct(uint8_t value)
{
if (!gammaCorrectCol) return value;
return gammaT[value];
}
// used for color gamma correction
uint32_t NeoGammaWLEDMethod::Correct32(uint32_t color)
{
if (!gammaCorrectCol) return color;
uint8_t w = W(color);
uint8_t r = R(color);
uint8_t g = G(color);
uint8_t b = B(color);
w = gammaT[w];
r = gammaT[r];
g = gammaT[g];
b = gammaT[b];
return RGBW32(r, g, b, w);
}