Color Class — react Architecture

Source Code

compiler/packages/react-forgive/client/src/colors.ts lines 12–60

export class Color {
  constructor(
    private r: number,
    private g: number,
    private b: number,
  ) {}

  toAlphaString(a: number) {
    return this.toCssString(a);
  }
  toString() {
    return this.toCssString(1);
  }

  /**
   * Adjust the color by a multiplier to lighten (`> 1.0`) or darken (`< 1.0`) the color. Returns a new
   * instance.
   */
  adjusted(mult: number) {
    const adjusted = Color.redistribute([
      this.r * mult,
      this.g * mult,
      this.b * mult,
    ]);
    return new Color(...adjusted);
  }

  private toCssString(a: number) {
    return `rgba(${this.r},${this.g},${this.b},${a})`;
  }
  /**
   * Redistributes rgb, maintaing hue until its clamped.
   * https://stackoverflow.com/a/141943
   */
  private static redistribute([r, g, b]: RGB): RGB {
    const threshold = 255.999;
    const max = Math.max(r, g, b);
    if (max <= threshold) {
      return [int(r), int(g), int(b)];
    }
    const total = r + g + b;
    if (total >= 3 * threshold) {
      return [int(threshold), int(threshold), int(threshold)];
    }
    const x = (3 * threshold - total) / (3 * max - total);
    const gray = threshold - x * max;
    return [int(gray + x * r), int(gray + x * g), int(gray + x * b)];
  }
}