#define iChannel0 inputImageTexture
#define texture(a,b) texture2D(a,fract(b))

precision highp float;

varying highp vec2 textureCoordinate;

uniform sampler2D inputImageTexture;
 
uniform float iTime;
 
 void main()
{

    vec2 uv = textureCoordinate;
    vec2 pv = vec2(uv.x, uv.y);
    if(uv.y < 0.5){
        pv.y += 0.25;
    } else if(uv.y > 0.5){
        pv.y -= 0.25;
    }
    // Output to screen
    gl_FragColor = texture(iChannel0,pv);
}