Add save() API that takes tvg::Animation as a parameter.
This API uses gif.h to create each animation frame as a gif frame.
Gif creation do not support threads because they must be added sequentially.
Please see example/GifSaver.cpp
ex)
auto animation = tvg::Animation::gen();
auto picture = animation->picture();
picture->load(EXAMPLE_DIR"/walker.json");
auto saver = tvg::Saver::gen();
saver->save(std::move(animation), EXAMPLE_DIR"/test.gif");
saver->sync();
New API:
Result Saver::save(std::unique_ptr<Animation> animation, const std::string& path, uint32_t quality = 100, uint32_t fps = 0);
Issue: https://github.com/thorvg/thorvg/issues/1712
