# version 450

layout(location = 0) in vec4 in_border_color;
layout(location = 1) in vec4 in_background_color;
layout(location = 2) in vec2 in_px_scale;
layout(location = 3) in vec3 in_uv;

layout(location = 0) out vec4 out_color;

const float border_px = 1.f;

bool is_in_border() {
  return (in_uv.x <=     ((in_px_scale.x*border_px)))
    ||   (in_uv.x >= 1.0-((in_px_scale.x*border_px)))
    ||   (in_uv.y <=      (in_px_scale.y*border_px))
    ||   (in_uv.y >= 1.0- (in_px_scale.y*border_px));
}

void main() {
	out_color = in_background_color;
	if (is_in_border()) {
		out_color = in_border_color;
	}
}