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#include "precomp.hpp"

#ifndef HAVE_CUDA

cv::gpu::VIBE_GPU::VIBE_GPU(unsigned long) { throw_nogpu(); }
void cv::gpu::VIBE_GPU::initialize(const GpuMat&, Stream&) { throw_nogpu(); }
void cv::gpu::VIBE_GPU::operator()(const GpuMat&, GpuMat&, Stream&) { throw_nogpu(); }
void cv::gpu::VIBE_GPU::release() {}

#else

namespace cv { namespace gpu { namespace device
{
    namespace vibe
    {
        void loadConstants(int nbSamples, int reqMatches, int radius, int subsamplingFactor);

        void init_gpu(DevMem2Db frame, int cn, DevMem2Db samples, DevMem2D_<unsigned int> randStates, cudaStream_t stream);

        void update_gpu(DevMem2Db frame, int cn, DevMem2Db fgmask, DevMem2Db samples, DevMem2D_<unsigned int> randStates, cudaStream_t stream);
    }
}}}

namespace
{
    const int defaultNbSamples = 20;
    const int defaultReqMatches = 2;
    const int defaultRadius = 20;
    const int defaultSubsamplingFactor = 16;
}

cv::gpu::VIBE_GPU::VIBE_GPU(unsigned long rngSeed) :
    frameSize_(0, 0), rngSeed_(rngSeed)
{
    nbSamples = defaultNbSamples;
    reqMatches = defaultReqMatches;
    radius = defaultRadius;
    subsamplingFactor = defaultSubsamplingFactor;
}

void cv::gpu::VIBE_GPU::initialize(const GpuMat& firstFrame, Stream& s)
{
    using namespace cv::gpu::device::vibe;

    CV_Assert(firstFrame.type() == CV_8UC1 || firstFrame.type() == CV_8UC3 || firstFrame.type() == CV_8UC4);

    cudaStream_t stream = StreamAccessor::getStream(s);

    loadConstants(nbSamples, reqMatches, radius, subsamplingFactor);

    frameSize_ = firstFrame.size();

    if (randStates_.size() != frameSize_)
    {
        cv::RNG rng(rngSeed_);
        cv::Mat h_randStates(frameSize_, CV_8UC4);
        rng.fill(h_randStates, cv::RNG::UNIFORM, 0, 255);
        randStates_.upload(h_randStates);
    }

    int ch = firstFrame.channels();
    int sample_ch = ch == 1 ? 1 : 4;

    samples_.create(nbSamples * frameSize_.height, frameSize_.width, CV_8UC(sample_ch));

    init_gpu(firstFrame, ch, samples_, randStates_, stream);
}

void cv::gpu::VIBE_GPU::operator()(const GpuMat& frame, GpuMat& fgmask, Stream& s)
{
    using namespace cv::gpu::device::vibe;

    CV_Assert(frame.depth() == CV_8U);

    int ch = frame.channels();
    int sample_ch = ch == 1 ? 1 : 4;

    if (frame.size() != frameSize_ || sample_ch != samples_.channels())
        initialize(frame);

    fgmask.create(frameSize_, CV_8UC1);

    update_gpu(frame, ch, fgmask, samples_, randStates_, StreamAccessor::getStream(s));
}

void cv::gpu::VIBE_GPU::release()
{
    frameSize_ = Size(0, 0);

    randStates_.release();

    samples_.release();
}

#endif
