var cam = scr_getcam();
if (!surface_exists(mysurf))
    mysurf = surface_create(320, 240);
surface_set_target(mysurf);
draw_sprite_ext(spr_pxwhite, 0, 0, 0, 320, 240, 0, c_black, 1);
if (index >= 0)
{
    var _x = 104;
    var _y = 32;
    draw_sprite(spr_chapter_insert_prompt_letters, 0, _x, _y);
    for (var i = index; i < blocksLength; i++)
    {
        with (blocks[i])
            draw_sprite_ext(spr_pxwhite, 0, x + _x, y + _y, w, h, 0, c_black, 1);
    }
}
surface_reset_target();
if (doshade)
{
    shader_replace_simple_set_hook(shader);
    shader_set_uniform_f(u_time, time);
    shader_set_uniform_f(u_aber, aberration);
}
draw_surface_ext(mysurf, cam.x, cam.y, 1, 1, 0, image_blend, 1);
shader_replace_simple_reset_hook();