light_mode unshaded;

uniform sampler2D SCREEN_TEXTURE;
uniform highp float strength;

void fragment()
{
    highp vec2 uv = UV;
    highp vec4 color = texture(SCREEN_TEXTURE, uv);

    highp float x = (uv.x + 4.0 ) * (uv.y + 4.0 ) * (TIME * 10.0);

    highp vec4 grain = vec4(mod((mod(x, 13.0) + 1.0) * (mod(x, 123.0) + 1.0), 0.01) - 0.005) * strength;

    grain = color * (1.0 - grain);

    COLOR = grain;
}