Method calculateImageSize

source/game/StarImageMetadataDatabase.cpp:158–269

}

Vec2U ImageMetadataDatabase::calculateImageSize(AssetPath const& path) const {
  // Carefully calculate an image's size while trying not to actually load it.
  // In error cases, this will fall back to calling Assets::image, so that image
  // can possibly produce a missing image asset or properly report the error.

  auto assets = Root::singleton().assets();

  auto fallback = [&assets, &path]() {
    return assets->image(path)->size();
  };

  if (!assets->assetExists(path.basePath)) {
    return fallback();
  }

  Vec2U imageSize;
  if (path.subPath) {
    auto frames = assets->imageFrames(path.basePath);
    if (!frames)
      return fallback();

    if (auto rect = frames->getRect(*path.subPath))
      imageSize = rect->size();
    else
      return fallback();
  } else {
    // We ensure that the base image size is cached even when given directives,
    // so we don't have to call Image::readPngMetadata on the same file more
    // than once.
    MutexLocker locker(m_mutex);
    if (auto size = m_sizeCache.ptr(path.basePath)) {
      imageSize = *size;
    } else {
      locker.unlock();
      auto file = assets->openFile(path.basePath);
      if (Image::isPng(file))
        imageSize = get<0>(Image::readPngMetadata(file));
      else
        imageSize = fallback();
      locker.lock();
      m_sizeCache.set(path.basePath, imageSize);
    }
  }

  struct OperationSizeAdjust {
    Vec2U& imageSize;
    bool hasError;

    OperationSizeAdjust(Vec2U& size) : imageSize(size), hasError(false) {};

    void operator()(NullImageOperation const&) {}

    void operator()(ErrorImageOperation const&) {}

    void operator()(HueShiftImageOperation const&) {}

    void operator()(SaturationShiftImageOperation const&) {}