shader_type canvas_item;
 
uniform vec4 shadowColor : hint_color = vec4(0.0, 0.0, 0.0, 0.8);
 
//将贴图渲染为阴影
 
void fragment() {
	float a = texture(TEXTURE, UV).a;
	
	COLOR = mix(vec4(0.0, 0.0, 0.0, 0.0), shadowColor, a);
}