root/FalconView/trunk/public/fvw_core/GeodataDataSources/KMLImageDataResource.cpp @ 2279

// KMLImageDataResource.cpp
//

#include "stdafx.h"
#include "KMLImageDataResource.h"
#include "UtilityMethods.h"
#include "ComErrorObject.h"
#include "LibkmlDataSource.h"

void CKMLImageDataResource::Load()
{  
   try
   {
      static ULONG s_nextMemFile = 0;

      // fetch the image data
      std::string file_contents;
      m_pParentDataSource->FetchDataRelativeToDataSource(m_imageIdentifier.c_str(), file_contents);
      char mem_file_name[MEM_FILE_NAME_MAX_LENGTH];
      sprintf_s(mem_file_name, MEM_FILE_NAME_MAX_LENGTH, "/vsimem/LibkmlDSMemFile%u", s_nextMemFile++);
      VSIFCloseL(VSIFileFromMemBuffer(mem_file_name, (GByte*)file_contents.c_str(), file_contents.length(), FALSE));

      // use GDAL to interpret the raw data
      IFvGDALDataSetPtr GDALDataset(CLSID_FvGDALDataSet);
      GDALDataset->Open(_bstr_t(mem_file_name));
      IRasterDataSetPtr raster = GDALDataset;
      m_imageData = raster->InterpretAsImage().Detach();
      VSIUnlink(mem_file_name);
   }
   catch(_com_error& )
   {
      WriteToLogFile(L"Unable to load image");
   }

   __super::Load();
}

void CKMLImageDataResource::GetImageData(VARIANT* imageData)
{
   if (State() != Resource_Loaded)
   {
      static _variant_t defaultImageData;
      if (defaultImageData.vt == VT_EMPTY)
      {
         const int imgWidth = 16;
         const int imgHeight = 16;

         CUtilityMethods::Create32BppBitmap(&defaultImageData, imgWidth, imgHeight);

         UCHAR* img = NULL;
         SafeArrayAccessData(defaultImageData.parray, reinterpret_cast<void **>(&img));

         // use an opaque white canvas
         memset(img + 40, 0xff, 4*imgWidth*imgHeight);

         SafeArrayUnaccessData(defaultImageData.parray);
      }
      *imageData =  _variant_t(defaultImageData).Detach();

      return;
   }

   *imageData = _variant_t(m_imageData).Detach(); // copies buffer to imageData 
}