#version 450 core

layout (location = 0) in vec2 aPos;
layout (location = 1) in vec2 aTexCoord;

out vec2 TexCoord;

uniform vec2 u_position;   //Position in scrren coordinates (pixel)
uniform vec2 u_size;       //size in pixels (width, height)
uniform vec2 u_resolution; //window resolution

void main(){
	//Covert from screen coordinated to normalized device corrdinates

	//Screen coordinates: origin at top-left , y down

	vec2 screen_pos = aPos * u_size + u_position;

	vec2 ndc;
	ndc.x = (screen_pos.x / u_resolution.x) * 2.0  - 1.0;
	ndc.y = 1.0 - (screen_pos.y / u_resolution.y) * 2.0;

	gl_Position = vec4(ndc, 0.0, 1.0);
	TexCoord = aTexCoord;
}