shader_type canvas_item;

uniform float radius = 0.2;
uniform vec2 center = vec2(0.5, 0.5);
const float feather = 0.01;

float circle(vec2 position) {
	return smoothstep(radius, radius + feather, length(position - center));
}

void fragment() {
	COLOR = vec4(0, 0, 0, circle(UV));
}