lighttroupe/luz

class ActorEffectSaturate < ActorEffect
    title                "Saturate"
    description "Over-saturate or under-saturate image. Amounts above 1.0 multiply color channels, while amounts below 1.0 move colors towards an average of the RGB components."

    categories :color

    setting 'amount', :float, :range => 0.0..100.0, :default => 1.0..2.0, :shader => true

    def render
        if amount < 1.0
            code = "
                output_rgba *= texture2D(texture0, texture_st);

                float average_intensity = (output_rgba.r + output_rgba.g + output_rgba.b) / 3.0;

                float desaturation = (1.0 - amount);

                // move each color channel towards average color
                output_rgba.r = mix(output_rgba.r, average_intensity, desaturation);
                output_rgba.g = mix(output_rgba.g, average_intensity, desaturation);
                output_rgba.b = mix(output_rgba.b, average_intensity, desaturation);
            "
        elsif amount > 1.0
            code = "
                output_rgba *= amount;
            "
        end

        with_fragment_shader_snippet(code, self) {
            yield
        }
    end
end