shader_type spatial;
render_mode cull_front, unshaded;

// Controls the width of the outline
uniform float outline_thickness : hint_range(0.0, 0.5) = 0.03;

// Controls the color of the outline
uniform vec4 outline_color : source_color = vec4(0.0, 0.0, 0.0, 1.0);

void vertex() {
	// The core of the inverted hull method:
	// We push the vertices outward along their normal vectors.
	// Since front faces are culled, this creates the outline border.
	VERTEX += NORMAL * outline_thickness;
}

void fragment() {
	// Apply the solid outline color
	ALBEDO = outline_color.rgb;
	ALPHA = outline_color.a;
}