// Shadertoy version: https://www.shadertoy.com/view/DdK3z1

uniform shader iChunk;
uniform float2 iChunkSize;
uniform float iFrame;

// Have fun with those values
//
const float LENGTH = 120.0;
const float STRENGTH = 0.01;

vec4 main(vec2 xy) 
{
    vec2 uv = xy / iChunkSize.xy;
    uv.y += sin(xy.x / LENGTH + iFrame) * STRENGTH;
    return iChunk.eval(uv * iChunkSize.xy);
}
