shader_type spatial;
render_mode specular_disabled, vertex_lighting;

uniform vec3 color_a : source_color = vec3(1.0);
uniform vec3 color_b : source_color = vec3(0.0);
uniform float stripe_count = 2.0;
uniform float twist_factor = 1.0;
uniform float speed = 0.5;

void vertex() {
	float world_height = (MODEL_MATRIX * vec4(VERTEX, 1.0)).y;
	UV.y = world_height - TIME * speed;
}

void fragment() {
	float twisted_x = UV.x - (UV.y * twist_factor);
	float stripe = step(sin(twisted_x * stripe_count * TAU), 0.0);
	ALBEDO = mix(color_a, color_b, stripe);
}