terravisor/shaders/quad_fragment.glsl

#version 330 core
out vec4 FragColor;

in vec2 TexCoord;

uniform sampler2D screenTexture;

void main()
{
    FragColor = texture(screenTexture, TexCoord);
    //FragColor = vec4(vec3(1.0 - texture(screenTexture, TexCoord)), 1.0);
}