crop.ts

export function sleep(ms:number):Promise<void> {
    return new Promise<void>((resolve:any) => setTimeout(resolve, ms));
}
export async function crop(image:HTMLImageElement, x:number, y:number, width:number, height:number, image_type:string = "image/png", recurs_depth:number = 0):Promise<HTMLImageElement>
{
    const canvas = document.createElement("canvas");
    if(image && image.height && image.width)
    {
        canvas.width = image.width;
        canvas.height = image.height;
        const ctx = canvas.getContext("2d")!;
        ctx.drawImage(image, x, y, width, height, 0, 0, width, height);
        const res:HTMLImageElement = new Image();
        res.src = canvas.toDataURL(image_type, 1);
        return res;
    }
    else if(recurs_depth < 100)
    {
        await sleep(5);
        return await crop(image, x, y, width, height, image_type, recurs_depth + 1);
    }
    else
    {
        throw "Exception: timeout waiting to parse image data in render";
    }
}