#version 110 uniform sampler2D textures[2]; varying vec2 texcoord; void main() { gl_FragColor = mix( texture2D(textures[0], texcoord), texture2D(textures[1], vec2(texcoord.x, texcoord.y - 1.0/512.0)), sin((texcoord.y * 512.0 - 0.75) * 3.14159265359) / 2.0 + 0.5 ); }