gdalalg_raster_nodata_to_alpha.h

/******************************************************************************
 *
 * Project:  GDAL
 * Purpose:  "nodata-to-alpha" step of "raster pipeline"
 * Author:   Even Rouault <even dot rouault at spatialys.com>
 *
 ******************************************************************************
 * Copyright (c) 2025, Even Rouault <even dot rouault at spatialys.com>
 *
 * SPDX-License-Identifier: MIT
 ****************************************************************************/
 
#ifndef GDALALG_RASTER_NODATA_TO_ALPHA_INCLUDED
#define GDALALG_RASTER_NODATA_TO_ALPHA_INCLUDED
 
#include "gdalalg_raster_pipeline.h"

 
/************************************************************************/
/*                  GDALRasterNoDataToAlphaAlgorithm                    */
/************************************************************************/
 
class GDALRasterNoDataToAlphaAlgorithm /* non final */
    : public GDALRasterPipelineStepAlgorithm
{
  public:
    static constexpr const char *NAME = "nodata-to-alpha";
    static constexpr const char *DESCRIPTION =
        "Replace nodata value(s) with an alpha band.";
    static constexpr const char *HELP_URL =
        "/programs/gdal_raster_nodata_to_alpha.html";
 
    explicit GDALRasterNoDataToAlphaAlgorithm(bool standaloneStep = false);
 
  private:
    bool RunStep(GDALPipelineStepRunContext &ctxt) override;
 
    std::vector<double> m_nodata{};
 
    // Work variables
    std::unique_ptr<GDALDataset> m_tempDS{};
};
 
/************************************************************************/
/*              GDALRasterNoDataToAlphaAlgorithmStandalone              */
/************************************************************************/
 
class GDALRasterNoDataToAlphaAlgorithmStandalone final
    : public GDALRasterNoDataToAlphaAlgorithm
{
  public:
    GDALRasterNoDataToAlphaAlgorithmStandalone()
        : GDALRasterNoDataToAlphaAlgorithm(/* standaloneStep = */ true)
    {
    }
 
    ~GDALRasterNoDataToAlphaAlgorithmStandalone() override;
};

 
#endif /* GDALALG_RASTER_NODATA_TO_ALPHA_INCLUDED */