/**
 * Copyright (c) 2018 mol* contributors, licensed under MIT, See LICENSE file for more info.
 *
 * @author Alexander Rose <alexander.rose@weirdbyte.de>
 */

export function calculateTextureInfo (n: number, itemSize: number) {
    const sqN = Math.sqrt(n * itemSize)
    let width = Math.ceil(sqN)
    width = width + (itemSize - (width % itemSize)) % itemSize
    const height = width > 0 ? Math.ceil(n * itemSize / width) : 0
    return { width, height, length: width * height * itemSize }
}

export interface TextureImage {
    array: Uint8Array
    width: number
    height: number
}

export function createColorTexture (n: number): TextureImage {
    const { length, width, height } = calculateTextureInfo(n, 3)
    return { array: new Uint8Array(length), width, height }
}

export const emptyTexture = { array: new Uint8Array(0), width: 0, height: 0 }

export function fillSerial<T extends Helpers.NumberArray> (array: T) {
    const n = array.length
    for (let i = 0; i < n; ++i) array[ i ] = i
    return array
}