Function LoadData

libs/drape/static_texture.cpp:37–92

using TLoadingFailure = std::function<void(std::string const &)>;

bool LoadData(std::string const & textureName, std::string const & skinPathName, uint8_t bytesPerPixel,
              TLoadingCompletion const & completionHandler, TLoadingFailure const & failureHandler)
{
  ASSERT(completionHandler != nullptr, ());
  ASSERT(failureHandler != nullptr, ());

  std::vector<unsigned char> rawData;
  try
  {
    ReaderPtr<Reader> reader = !skinPathName.empty() ? skinPathName == StaticTexture::kDefaultResource
                                                         ? GetStyleReader().GetDefaultResourceReader(textureName)
                                                         : GetStyleReader().GetResourceReader(textureName, skinPathName)
                                                     : GetPlatform().GetReader(textureName);

    CHECK_LESS(reader.Size(), static_cast<uint64_t>(std::numeric_limits<size_t>::max()), ());
    size_t const size = static_cast<size_t>(reader.Size());
    rawData.resize(size);
    reader.Read(0, &rawData[0], size);
  }
  catch (RootException & e)
  {
    failureHandler(e.what());
    return false;
  }

  int w, h, bpp;
  if (!stbi_info_from_memory(&rawData[0], static_cast<int>(rawData.size()), &w, &h, &bpp))
  {
    failureHandler(std::string("Failed to get image file info from ") + textureName);
    return false;
  }

  ASSERT(glm::isPowerOfTwo(w), (w));
  ASSERT(glm::isPowerOfTwo(h), (h));

  unsigned char * data = stbi_load_from_memory(&rawData[0], static_cast<int>(rawData.size()), &w, &h, &bpp, 0);

  if (bytesPerPixel != bpp)
  {
    std::vector<unsigned char> convertedData(static_cast<size_t>(w * h * bytesPerPixel));
    auto const pixelsCount = static_cast<uint32_t>(w * h);
    for (uint32_t i = 0; i < pixelsCount; ++i)
    {
      unsigned char const * p = data + i * bpp;
      for (uint8_t b = 0; b < bytesPerPixel; ++b)
        convertedData[i * bytesPerPixel + b] = (b < bpp) ? p[b] : 255;
    }
    stbi_image_free(data);
    completionHandler(convertedData.data(), static_cast<uint32_t>(w), static_cast<uint32_t>(h));
    return true;
  }

  completionHandler(data, static_cast<uint32_t>(w), static_cast<uint32_t>(h));
  stbi_image_free(data);
  return true;
}

class StaticResourceInfo : public Texture::ResourceInfo