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#ifndef _SIMPLETEXTURE_KERNEL_H_
#define _SIMPLETEXTURE_KERNEL_H_
#include <cuda.h>

////////////////////////////////////////////////////////////////////////////////
//! Transform an image using texture lookups
//! @param g_odata  output data in global memory
////////////////////////////////////////////////////////////////////////////////
extern "C" __global__ void transformKernel(float *g_odata, int width,
                                           int height, float theta,
                                           CUtexObject tex) {
  // calculate normalized texture coordinates
  unsigned int x = blockIdx.x * blockDim.x + threadIdx.x;
  unsigned int y = blockIdx.y * blockDim.y + threadIdx.y;

  float u = (float)x - (float)width / 2;
  float v = (float)y - (float)height / 2;
  float tu = u * cosf(theta) - v * sinf(theta);
  float tv = v * cosf(theta) + u * sinf(theta);

  tu /= (float)width;
  tv /= (float)height;

  // read from texture and write to global memory
  g_odata[y * width + x] = tex2D<float>(tex, tu + 0.5f, tv + 0.5f);
}

#endif  // #ifndef _SIMPLETEXTURE_KERNEL_H_
