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 *    notice, this list of conditions and the following disclaimer in the
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 *    contributors may be used to endorse or promote products derived
 *    from this software without specific prior written permission.
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 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS ``AS IS'' AND ANY
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 */

// Utilities and system includes

#include <helper_cuda.h>

// clamp x to range [a, b]
__device__ float clamp(float x, float a, float b) { return max(a, min(b, x)); }

__device__ int clamp(int x, int a, int b) { return max(a, min(b, x)); }

// convert floating point rgb color to 8-bit integer
__device__ int rgbToInt(float r, float g, float b)
{
    r = clamp(r, 0.0f, 255.0f);
    g = clamp(g, 0.0f, 255.0f);
    b = clamp(b, 0.0f, 255.0f);
    return (int(b) << 16) | (int(g) << 8) | int(r);
}

__global__ void cudaProcess(unsigned int *g_odata, int imgw)
{
    extern __shared__ uchar4 sdata[];

    int tx = threadIdx.x;
    int ty = threadIdx.y;
    int bw = blockDim.x;
    int bh = blockDim.y;
    int x  = blockIdx.x * bw + tx;
    int y  = blockIdx.y * bh + ty;

    uchar4 c4             = make_uchar4((x & 0x20) ? 100 : 0, 0, (y & 0x20) ? 100 : 0, 0);
    g_odata[y * imgw + x] = rgbToInt(c4.z, c4.y, c4.x);
}

extern "C" void launch_cudaProcess(dim3 grid, dim3 block, int sbytes, unsigned int *g_odata, int imgw)
{
    cudaProcess<<<grid, block, sbytes>>>(g_odata, imgw);
}
