shader_type canvas_item;

uniform float tracks : hint_range(1, 200, 1) = 1;
uniform float vshift = 0;
uniform float max_offset = 1;

float random (vec2 uv) {
    return fract(sin(dot(uv.xy,
        vec2(12.9898,78.233))) * 43758.5453123);
}

void vertex() {
}

void fragment() {
	// Called for every pixel the material is visible on.
	vec2 uv = floor(UV * tracks);
	vec2 rv = vec2(0.0, round(UV.y * 4.0) / 4.0 * 2.0);
	rv.y += TIME;
	float r = random(rv);
	float r2 = random(-rv);
	float brightness = .5 + .5 * r * mod(uv.y, 2.0) / 2.0;
	COLOR.rgb = COLOR.rgb * brightness;
}

//void light() {
//	// Called for every pixel for every light affecting the CanvasItem.
//	// Uncomment to replace the default light processing function with this one.
//}