function createRadialGradient(ctx, obj, rect) {
    var width = rect.width;
    var height = rect.height;
    var min = Math.min(width, height);

    var x = obj.x == null ? 0.5 : obj.x;
    var y = obj.y == null ? 0.5 : obj.y;
    var r = obj.r == null ? 0.5 : obj.r;
    if (!obj.global) {
        x = x * width + rect.x;
        y = y * height + rect.y;
        r = r * min;
    }

    var canvasGradient = ctx.createRadialGradient(x, y, 0, x, y, r);

    return canvasGradient;
}
It helps merging respectively, rather than parsing an entire font string.
@type {string}