eic-opticks/qudarap/QTex.cu

0001
0002 __global__ void _QTex_uchar4_rotate_kernel(uchar4* output, cudaTextureObject_t texObj, size_t width, size_t height, float theta)
0003 {
0004     unsigned int x = blockIdx.x * blockDim.x + threadIdx.x;
0005     unsigned int y = blockIdx.y * blockDim.y + threadIdx.y;
0006
0007     float u = x / (float) width;  // 0. -> 1.
0008     float v = y / (float) height;
0009
0010     // shift origin to center of image
0011     u -= 0.5f;                   //  -0.5 -> 0.5
0012     v -= 0.5f;
0013
0014     // rotate around the center
0015     float tu = u * cosf(theta) - v * sinf(theta) ;
0016     float tv = v * cosf(theta) + u * sinf(theta) ;
0017
0018     // read from the texture
0019     uchar4 c = tex2D<uchar4>(texObj, tu+0.5f, tv+0.5f);
0020
0021     //if( c.x != 0 ) printf(" c ( %d %d %d %d ) \n",c.x, c.y, c.z, c.w );
0022     //c.x = 255u ;
0023     c.w = 255u ;
0024
0025     output[y * width + x] = c ;
0026 }
0027
0028 extern "C" void QTex_uchar4_rotate_kernel(dim3 dimGrid, dim3 dimBlock, uchar4* d_output, cudaTextureObject_t texObj,  size_t width, size_t height, float theta )
0029 {
0030     _QTex_uchar4_rotate_kernel<<<dimGrid,dimBlock>>>(d_output, texObj, width, height, theta);
0031 }
0032
0033