Method saveToDDS

Source/Falcor/Utils/Image/ImageIO.cpp:622–696

}

void ImageIO::saveToDDS(const std::filesystem::path& path, const Bitmap& bitmap, CompressionMode mode, bool generateMips)
{
    if (!hasExtension(path, "dds"))
    {
        logWarning("Saving DDS image to '{}' which does not have 'dds' file extension.", path);
    }

    try
    {
        ExportData image;
        image.type = nvtt::TextureType::TextureType_2D;
        image.width = bitmap.getWidth();
        image.height = bitmap.getHeight();
        image.depth = 1;
        image.format = bitmap.getFormat();
        image.faceCount = 1;
        image.mipLevels = generateMips ? nvtt::countMipmaps(image.width, image.height, image.depth) : 1;

        if (getFormatChannelCount(image.format) == 2 && mode != CompressionMode::BC5)
        {
            FALCOR_THROW("Only BC5 compression is supported for two channel images.");
        }

        // The DX spec requires the dimensions of BC encoded textures to be a multiple of 4 at the base resolution.
        // If the texture has already been rescaled to meet this requirement, skip clamping.
        if (generateMips && (mode != CompressionMode::None))
        {
            bool clamped = clampIfNeeded(image);
            if (clamped)
            {
                logWarning("Saving DDS image to '{}' with clamped image dimensions to accomodate mipmaps and compression.", path);
            }
        }

        uint32_t srcWidth = bitmap.getWidth();
        uint32_t srcHeight = bitmap.getHeight();

        nvtt::Surface surface;
        FormatType type = getFormatType(image.format);
        if (type == FormatType::Sint || type == FormatType::Snorm)
        {
            setImage<int8_t>(bitmap.getData(), surface, image, srcWidth, srcHeight, image.depth);
        }
        else if (type == FormatType::Uint || type == FormatType::Unorm || type == FormatType::UnormSrgb)
        {
            setImage<uint8_t>(bitmap.getData(), surface, image, srcWidth, srcHeight, image.depth);
        }
        else if (type == FormatType::Float)
        {
            if (getNumChannelBits(image.format, 0) == 16)
            {
                setImage<float16_t>(bitmap.getData(), surface, image, srcWidth, srcHeight, image.depth);
            }
            else if (getNumChannelBits(image.format, 0) == 32)
            {
                setImage<float>(bitmap.getData(), surface, image, srcWidth, srcHeight, image.depth);
            }
        }