precision highp float;

uniform mat4 matrix_image;
uniform mat4 matrix_background;
attribute vec2 position;
varying vec2 position_background;
varying vec2 uv;

void main() {
    vec4 p = vec4(position, 0.0, 1.0);
    gl_Position = matrix_image * p;
    position_background = (matrix_background * p).xy;
    uv = position;
}