Method createFromFile

Source/Falcor/Utils/Image/Bitmap.cpp:291–449

}

Bitmap::UniqueConstPtr Bitmap::createFromFile(const std::filesystem::path& path, bool isTopDown, ImportFlags importFlags)
{
    if (!std::filesystem::exists(path))
    {
        logWarning("Error when loading image file. File '{}' does not exist.", path);
        return nullptr;
    }

    FREE_IMAGE_FORMAT fifFormat = FIF_UNKNOWN;

    fifFormat = FreeImage_GetFileType(path.string().c_str(), 0);
    if (fifFormat == FIF_UNKNOWN)
    {
        // Can't get the format from the file. Use file extension
        fifFormat = FreeImage_GetFIFFromFilename(path.string().c_str());

        if (fifFormat == FIF_UNKNOWN)
        {
            genWarning("Image type unknown", path);
            return nullptr;
        }
    }

    // Check the library supports loading this image type
    if (FreeImage_FIFSupportsReading(fifFormat) == false)
    {
        genWarning("Library doesn't support the file format", path);
        return nullptr;
    }

    // Read file using memory mapped access which is much faster than regular file IO.
    MemoryMappedFile file(path, MemoryMappedFile::kWholeFile, MemoryMappedFile::AccessHint::SequentialScan);
    if (!file.isOpen())
    {
        genWarning("Can't open image file {}", path);
        return nullptr;
    }

    if (fifFormat == FIF_EXR)
    {
        if (isFloat16Exr(file))
            importFlags |= ImportFlags::ConvertToFloat16;
    }

    FIMEMORY* memory = FreeImage_OpenMemory((BYTE*)file.getData(), file.getSize());
    FIBITMAP* pDib = FreeImage_LoadFromMemory(fifFormat, memory);
    FreeImage_CloseMemory(memory);
    file.close();

    if (pDib == nullptr)
    {
        genWarning("Can't read image file", path);
        return nullptr;
    }

    // Create the bitmap
    const uint32_t height = FreeImage_GetHeight(pDib);
    const uint32_t width = FreeImage_GetWidth(pDib);