thi-ng/umbrella

import { canvasPixels } from "@thi.ng/pixel/canvas";
import { ARGB8888 } from "@thi.ng/pixel/format/argb8888";

export interface StripeOpts {
    size: number;
    col1: number;
    col2: number;
    horizontal: boolean;
}

export const stripes = (opts: Partial<StripeOpts>) => {
    opts = {
        size: 16,
        col1: 0xffffffff,
        col2: 0xff000000,
        ...opts,
    };
    const size = opts.size!;
    const col1 = ARGB8888.toABGR(opts.col1!);
    const col2 = ARGB8888.toABGR(opts.col2!);
    const { canvas, ctx, img, data } = opts.horizontal
        ? canvasPixels(1, size)
        : canvasPixels(size, 1);
    for (let x = size; x-- > 0; ) {
        data[x] = x & 1 ? col1 : col2;
    }
    ctx.putImageData(img, 0, 0);
    return canvas;
};