shader_type spatial;
render_mode shadows_disabled, cull_disabled;

uniform vec3 color_bottom : source_color;
uniform vec3 color_top : source_color;
uniform vec3 wind = vec3(0.1, 0.0, 0.1);
uniform vec3 wind_speed = vec3(1.0, 0.0, 1.0);

void vertex() {
	float distance_to_ground = 1.0 - UV.y;

	vec4 sway = vec4(
		sin(NODE_POSITION_WORLD.x + TIME * wind_speed.x) * distance_to_ground * wind.x,
		0.0,
		cos(NODE_POSITION_WORLD.z + TIME * wind_speed.z) * distance_to_ground * wind.z,
		1.0
	);

	VERTEX += (sway * MODEL_MATRIX).xyz;
}

void fragment() {
	ALBEDO = mix(color_top, color_bottom, UV.y);
	
	if (!FRONT_FACING) {
		NORMAL = -NORMAL;
	}
}