aseprite-atlas/src/utils/NumberUtil.ts

Aseprite sprite atlas parser and animator for browser and Node.js.

/** @internal */
export namespace NumberUtil {
  /** @arg min An integer < max
      @arg max An integer > min
      @return A value wrapped to the domain [min, max). */
  export function wrap(val: number, min: number, max: number): number {
    const range = max - min // range ∈ [0, +∞).
    const x = (val - min) % range // Subtract min and wrap to x ∈ (-range, range).
    const y = x + range // Translate to y ∈ (0, 2 * range).
    const z = y % range // Wrap to z ∈ [0, range).
    return z + min // Add min to return ∈ [min, max).
  }
}