For the MCU port, we need to proccess the image to save them in the binary
in a convenient format.
This patch start this work by trying to anaylyze what format should an image
be using, and saving it as a texture in the binary.
The current graphical backend and the C++ frontend are not yet supported
* Change SharedVector::as_mut_slice() to SharedVector::make_mut_slice()
* SharedPixelBuffer::as_mut_slice and SharedPixelBuffer::make_mut_slice()
* SharedPixelBuffer::as_bytes_mut() to SharedPixelBuffer::make_mut_bytes()
This is consistent with Rc::make_mut() and is supposed to emphasize
that, unlike the usual as_* operations, it is not a free operation but
may involve work (detaching the data by cloning it).
Amends commit 7384ebdc32
There's only one place where we need this ourselves and that's also
easily done by hand. Otherwise the `as_bytes(_mut)()` accessor provides the
functionality along with `width()` and `height()`.
Other than that the API is mostly consuming, given that `sixtyfps::Image`
has no way of extracting the data again.
This adds an ImageBuffer and PixelBuffer type for SharedVector
backed images. The documentation explains how to use this
with low-level rendering functions and the popular image crate.
Fixes#387
This requires the image size query to be window independent and go
through the backend instead.
This implies minor changes for the Qt backend and bigger ones for the GL
backend:
* There exists now a thread-local IMAGE_CACHE, which is used by the
backend's image_size() function as well as by the renderer for
loading CPU side images.
* The image remain as decoded images in there (including SVG tree)
and the window now has a texture_cache, which holds CachedImage
with ImageData::Texture.
* Rendering an image item therefore fetches the CPU side image,
calls upload_to_gpu() on it, which creates a new Rc<CachedImage>
and that's stored in the texture_cache.
* The texture cache continues to be pruned when hiding the window.
