/******************************************************************************

 * (c) 2024 info@hobu.co

 *

 * SPDX-License-Identifier: MIT

 ****************************************************************************/

#include "combiner.h"

#include "util.h"

namespace gdal

{

namespace viewshed

{

/// Read viewshed executor output and sum it up in our owned memory raster.

void Combiner::run()

{

    DatasetPtr pTempDataset;

    while (m_inputQueue.pop(pTempDataset))

    {

        if (!m_dataset)

            m_dataset = std::move(pTempDataset);

        else

            sum(std::move(pTempDataset));

    }

    // Queue remaining summed rasters.

    queueOutputBuffer();

}

/// Add the values of the source dataset to those of the owned dataset.

/// @param src  Source dataset.

void Combiner::sum(DatasetPtr src)

{

    if (!m_dataset)

    {

        m_dataset = std::move(src);

        return;

    }

    size_t size = bandSize(*m_dataset->GetRasterBand(1));

    uint8_t *dstP =

        static_cast<uint8_t *>(m_dataset->GetInternalHandle("MEMORY1"));

    uint8_t *srcP = static_cast<uint8_t *>(src->GetInternalHandle("MEMORY1"));

    for (size_t i = 0; i < size; ++i)

        *dstP++ += *srcP++;

    // If we've seen 255 inputs, queue our raster for output and rollup since we might overflow

    // otherwise.

    if (++m_count == 255)

        queueOutputBuffer();

}

/// Queue the owned buffer as for output.

void Combiner::queueOutputBuffer()

{

    if (m_dataset)

        m_outputQueue.push(std::move(m_dataset));

    m_count = 0;

}

}  // namespace viewshed

}  // namespace gdal