Function rgbaToInt

packages/utils/src/index.ts:157–195

(r: number, g: number, b: number, a: number)

 * ```
 */
export function rgbaToInt(r: number, g: number, b: number, a: number) {
  if (
    typeof r !== "number" ||
    typeof g !== "number" ||
    typeof b !== "number" ||
    typeof a !== "number"
  ) {
    throw new Error("r, g, b and a must be numbers");
  }

  if (r < 0 || r > 255) {
    throw new Error("r must be between 0 and 255");
  }

  if (g < 0 || g > 255) {
    throw new Error("g must be between 0 and 255");
  }

  if (b < 0 || b > 255) {
    throw new Error("b must be between 0 and 255");
  }

  if (a < 0 || a > 255) {
    throw new Error("a must be between 0 and 255");
  }

  let i = r & 0xff;
  i <<= 8;
  i |= g & 0xff;
  i <<= 8;
  i |= b & 0xff;
  i <<= 8;
  i |= a & 0xff;

  // Ensure sign is correct
  i >>>= 0;

  return i;
}

/**
 * Compute color difference