draw_primitive_begin(pr_trianglestrip);
var _in_foreground = false;
var _arraysize = array_length(points);
var i = _arraysize - 1;
while (i >= 0)
{
    if (i == (_arraysize - 1))
    {
        with (points[i])
        {
            if (foreground)
                _in_foreground = true;
            else
                draw_vertex_color(x, y, other.end_color, clamp01(other.end_alpha + min(0, other.lifetime / 10)));
        }
    }
    else if (!_in_foreground || !foreground)
    {
        var _prog = i / (_arraysize - 1);
        var _size = sin(_prog * pi) * (_arraysize / child_lifetime) * 4;
        if (lifetime < 14)
            _size *= max(0, lifetime / 14);
        var _col = merge_color(start_color, end_color, _prog);
        var _alpha = clamp01(lerp(start_alpha, end_alpha, _prog) + min(0, lifetime / 10));
        with (points[i])
        {
            var _yy = lerp(y, other.ystart, other.owner.ys[0]);
            draw_vertex_color(x - (sidex * _size), _yy - (sidey * _size), _col, _alpha);
            draw_vertex_color(x + (sidex * _size), _yy + (sidey * _size), _col, _alpha);
        }
    }
    i--;
}
draw_vertex_color(x, y, start_color, clamp01(start_alpha + min(0, lifetime / 10)));
draw_primitive_end();