if (is_finished)
    exit;
if (scroll && !surface_exists(old_screen_surf))
    old_screen_surf = surface_create(camerawidth(), cameraheight());
if (!active || timer <= 0 || strength == 0)
{
    if (scroll)
    {
        surface_set_target(old_screen_surf);
        draw_surface(application_surface, 0, 0);
        surface_reset_target();
    }
    exit;
}
if (!surface_exists(screen_surf))
    screen_surf = surface_create(camerawidth(), cameraheight());
var _ease = scr_ease_in(timer / lifetime, 2);
var _strength = strength * _ease;
var _noisec = 0;
var _num = -1;
var _scany = 0;
if (scroll && !safe_mode)
{
    var _yy = scroll ? scr_wrap_new((1 - (timer / lifetime)) * 500, 0, 480) : i;
    surface_set_target(screen_surf);
    draw_surface_part(old_screen_surf, 0, _yy, camerawidth(), cameraheight() - _yy, 0, 0);
    draw_surface_part(application_surface, 0, 0, camerawidth(), _yy, 0, 0);
    surface_reset_target();
}
else
{
    surface_set_target(screen_surf);
    draw_surface(application_surface, 0, 0);
    surface_reset_target();
}
if (scroll)
    _strength /= 3;
if (safe_mode)
{
    var _xx = camerax();
    var _yy = cameray();
    var _px = 2;
    for (var _i = 0; _i < 480; _i += _px)
    {
        var _sin = (sin(((siner * 20) + _i) / multa) * _strength * 0.75) + ((cos(((siner * -20) + _i) / multb) * _strength) / 4);
        var _absin = ceil(abs(_sin));
        draw_surface_part(screen_surf, 0, _i, 640, _px, _xx + _sin, _yy + _i);
        if (_sin > 0)
            draw_surface_part(screen_surf, 640 - _absin, _i, _absin, _px, (_xx + _sin) - _absin, _yy + _i);
        else if (_sin < 0)
            draw_surface_part(screen_surf, 0, _i, _absin, _px, _xx + _sin + 640, _yy + _i);
    }
}
else
{
    var perlin_texture_page;
    if (use_surface)
    {
        perlin_distort = surface_create(640, 480);
        surface_set_target(perlin_distort);
        draw_sprite_part_ext(noise_sprite, 0, scan_x, 0, scan_x + 1, 480, 0, 0, 640, 2, c_white, 1);
        surface_reset_target();
        perlin_texture_page = surface_get_texture(perlin_distort);
    }
    else
    {
        perlin_texture_page = sprite_get_texture(noise_sprite, 0);
    }
    shader_set(channel_shader);
    texture_set_stage(perlin_stage, perlin_texture_page);
    shader_set_uniform_f(shader_get_uniform(channel_shader, "texel"), 1 / camerawidth(), 1 / cameraheight());
    shader_set_uniform_f(shader_get_uniform(channel_shader, "strength"), _strength);
    if (!use_surface)
    {
        var _UVs = sprite_get_uvs(noise_sprite, 0);
        var _tex = sprite_get_texture(noise_sprite, 0);
        var _texel_x = texture_get_texel_width(_tex);
        var _texel_y = texture_get_texel_height(_tex);
        var _texel_hx = _texel_x * 0.5;
        var _texel_hy = _texel_y * 0.5;
        shader_set_uniform_f(shader_get_uniform(channel_shader, "u_pixelSize"), _texel_x, _texel_y);
        shader_set_uniform_f(shader_get_uniform(channel_shader, "u_UVs"), _UVs[0] + _texel_hx, _UVs[1] + _texel_hy);
        shader_set_uniform_f(shader_get_uniform(channel_shader, "scanx"), floor(scan_x) + 0.5);
    }
    draw_surface(screen_surf, camerax(), cameray());
    shader_reset();
    if (use_surface)
        surface_free(perlin_distort);
}
scan_x = scr_wrap_new(scan_x + (scroll_speed * scroll_dir * (timer / lifetime) * 2), 0, 479);
if (!infinite && timer > 0)
{
    timer--;
    if (timer <= 0)
    {
        if (!silent)
            snd_stop(static_noise);
        multa = random_range(10, 40);
        multb = random_range(5, 10);
    }
}
siner++;
var _alpha = 0;
if (i_ex(obj_tenna_enemy))
{
    _alpha = _ease / 3;
    if (i_ex(obj_actor_tenna) && obj_actor_tenna.changechanneltimermax < 25)
        _alpha = lerp(0, _ease / 3, strength / 200);
}
else
{
    _alpha = _ease / 2;
}
draw_sprite_tiled_ext(spr_static_effect, timer / 2, 0, 0, 2, 2, c_white, _alpha);