Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Enable color Temperatures from 1000°K to 2000°K #5

Open
wants to merge 1 commit into
base: typescript
Choose a base branch
from
Open

Enable color Temperatures from 1000°K to 2000°K #5

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
41 changes: 27 additions & 14 deletions src/color.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -31,7 +31,7 @@ const REGEX_HEX_6 = new RegExp(HEX_START + HEX_INT_DOUBLE + HEX_INT_DOUBLE + HEX
const REGEX_HEX_8 = new RegExp(HEX_START + HEX_INT_DOUBLE + HEX_INT_DOUBLE + HEX_INT_DOUBLE + HEX_INT_DOUBLE + '$');

// Kelvin temperature bounds
const KELVIN_MIN = 2000;
const KELVIN_MIN = 1000;
const KELVIN_MAX = 40000;

// Math shorthands
Expand Down Expand Up @@ -295,8 +295,9 @@ export class IroColor {
/**
* @desc Convert a kelvin temperature to an approx, RGB value
* @param kelvin - kelvin temperature
* @param realValues - flag to issue real values instead integers
*/
public static kelvinToRgb(kelvin: number): RgbColor {
public static kelvinToRgb(kelvin: number, realValues = false): RgbColor {
const temp = kelvin / 100;
let r, g, b;
if (temp < 66) {
Expand All @@ -309,9 +310,9 @@ export class IroColor {
b = 255
}
return {
r: clamp(floor(r), 0, 255),
g: clamp(floor(g), 0, 255),
b: clamp(floor(b), 0, 255)
r: clamp(realValues ? r : floor(r), 0, 255),
g: clamp(realValues ? g : floor(g), 0, 255),
b: clamp(realValues ? b : floor(b), 0, 255)
};
}

Expand All @@ -322,16 +323,28 @@ export class IroColor {
public static rgbToKelvin(rgb: RgbColor): number {
const { r, g, b } = rgb;
const eps = 0.4;
let minTemp = KELVIN_MIN;
let maxTemp = KELVIN_MAX;
let minTemp = (b>0) ? 2000 : KELVIN_MIN;
let maxTemp = (b>0) ? KELVIN_MAX : 2000;
let temp;
while (maxTemp - minTemp > eps) {
temp = (maxTemp + minTemp) * 0.5;
const rgb = IroColor.kelvinToRgb(temp);
if ((rgb.b / rgb.r) >= (b / r)) {
maxTemp = temp;
} else {
minTemp = temp;
if (b>0) { // temperatures expected to be over 2000k
while (maxTemp - minTemp > eps) {
temp = (maxTemp + minTemp) * 0.5;
const rgb = IroColor.kelvinToRgb(temp, true); // get results in real values
if (rgb.b / rgb.r >= b / r) {
maxTemp = temp;
} else {
minTemp = temp;
}
}
} else { // below 2000k where blue is 0 and red is 255 only green is relevant;
while (maxTemp - minTemp > eps) {
temp = (maxTemp + minTemp) * 0.5;
const rgb = IroColor.kelvinToRgb(temp, true); // get results in real values
if (rgb.g >= g) {
maxTemp = temp;
} else {
minTemp = temp;
}
}
}
return temp;
Expand Down