sampler tex : register(s0);

struct INPUT
{
    float2 coord : TEXCOORD;
};

struct OUTPUT
{
    vector color : COLOR;
};

const float2 mid=float2(0.5,0.5);

float warp=0;

OUTPUT main(INPUT input)
{
    OUTPUT output;

    float2 t=input.coord;

    float2 a=float2(sin(warp),cos(warp))*(0.25*sin(warp*0.5));

    float2 p=mid+a;

    float2 v=p-t;
    float n=1-(length(v)*2);	

    if(length(t-mid)<=0.5) t+=(normalize(v)*(n*0.05));

    output.color=tex2D(tex,t);
    return output;
}