Bitmap based pictures doesn't need the viewbox,
LoaderModule should delegate the viewbox to the derived classes which
having vector-based image loaders such as svg, tvg.
In that case, paint resizing can be performed by the loaders by own
policy.
replace from Scene to Paint at the internal interface.
Picture doesn't need to know the returned Node type.
base class, Paint is enough to in the data passing.
This patch introduces tvg loader module for loading .tvg binary files.
This allows to load and reuse pregenerated scene.
tvg file format:
.tvg is a binary file format designed for saving/restoring the scene content.
It allows to save scenes and reuse them in other apps or to restore state of
the application.
@Example:
auto picture = tvg::Picture::gen();
picture->load(EXAMPLE_DIR"/tvg_file.tvg");
canvas->push(move(picture));
@API Additions:
Result paint(std::unique_ptr<Paint> paint) noexcept;
@Issue: Issue ticket is #375.
