​

uniform vec2 resolution;

uniform float time;

uniform vec2 mouse;

uniform sampler2D backbuffer;

​

void main(void) {

    vec2 uv = (gl_FragCoord.xy * 2.0 - resolution.xy) / min(resolution.x, resolution.y);

​

    gl_FragColor = vec4(uv, 1.0, 1.0);

}