// rotated texture
// a bit based on Dizzy from Ati Render Monkey
// Holger Grahn hg . snafu.de 
float time=0;
float sampleDist = 1.0f/512.0f;  // distance one pixel in u/v


float rings: register(c1) = 2;
float speed: register(c2)=5;
float exponent: register(c3)=1.5;

float2 center = { 0.5, 0.5 };
float2 scale =  { 2, 2 };

// input
sampler2D image : register(s0);




float4 main(
	float4 Pos : POSITION,
	float2 texCoord: TEXCOORD0) : COLOR 
{

	texCoord = scale* (texCoord-center);
	
	float radius = length(texCoord);
	
   	float ang = atan2(texCoord.x, texCoord.y);
   	float rad = pow(dot(texCoord, texCoord), exponent);
   	
   	ang = ang + rings * sin(time*6.28) * rad + speed * time;
   	
   	float2 newTexCoord = float2(0.5 * (1 + radius*sin(ang)),0.5 * (1 + radius*cos(ang)));
   	


	float4 img = tex2D(image, newTexCoord);
	return img;

}