#version 430

in vec2 uv;

out vec4 final_color;

uniform sampler2D tex;
uniform bool depth;


float LinearizeDepth(in vec2 uv)
{
    float zNear = 0.1f;    //  zNear of your perspective projection
    float zFar  = 2000.0f; // zFar of your perspective projection
    float depth = texture(tex, uv).x;	
    return (2.0 * zNear) / (zFar + zNear - depth * (zFar - zNear));
}

void main()
{
	//rrra because depth textures are not usual textures, they have only one channel
	final_color = (depth) ? texture(tex, uv).rrra : texture(tex, uv).rgba;
	
	if (depth) {
	   float d;
	   d = LinearizeDepth(uv);
	   final_color = vec4(d,d,d,1.0);	   	   
	}	
}