shader_type canvas_item;

// Spotlight rect in viewport pixel coordinates
// vec4(x, y, width, height) — set to vec4(0,0,0,0) to dim everything
uniform vec4 spotlight = vec4(0.0, 0.0, 0.0, 0.0);
uniform vec2 viewport_size = vec2(1366.0, 720.0);
uniform float dim_alpha : hint_range(0.0, 1.0) = 0.72;
uniform float padding : hint_range(0.0, 32.0) = 8.0;

void fragment() {
	bool has_spotlight = spotlight.z > 1.0 && spotlight.w > 1.0;

	if (has_spotlight) {
		// Convert spotlight rect to UV space
		float left   = (spotlight.x - padding) / viewport_size.x;
		float top    = (spotlight.y - padding) / viewport_size.y;
		float right  = (spotlight.x + spotlight.z + padding) / viewport_size.x;
		float bottom = (spotlight.y + spotlight.w + padding) / viewport_size.y;

		bool in_hole = (UV.x >= left) && (UV.x <= right)
					&& (UV.y >= top)  && (UV.y <= bottom);

		if (in_hole) {
			COLOR = vec4(0.0, 0.0, 0.0, 0.0); // transparent — element shows through
		} else {
			COLOR = vec4(0.0, 0.0, 0.0, dim_alpha);
		}
	} else {
		COLOR = vec4(0.0, 0.0, 0.0, dim_alpha);
	}
}