There is an issue where gifs with many frames cannot be loaded, as each
bitmap is sent over IPC using a separate file descriptor, and there is
limit on the maximum number of descriptors per IPC message. Thus, trying
to load gifs with more than 64 frames (the current limit) causes the
image decoder process to die.
This commit introduces the BitmapSequence class, which is a thin wrapper
around the type Vector<Optional<NonnullRefPtr<Gfx::Bitmap>>> and
provides an IPC encode/decode routine that collates all bitmap data into
a single buffer so that only a single file descriptor is required per
IPC transfer, even if multiple frames are being sent.
Typeface is a more widely used name for the data represented by
class previously named VectorFont.
Now:
- Typeface represents decoded font that is not ready for rendering
- ScaledFont represents the combination of typeface and size for
rendering
No behavior change. No measurable performance different either.
(I tried `hyperfine 'Build/lagom/bin/image --no-output foo.webp'`
for a few input images before and after this change, and I didn't
see a difference. I also tried if moving both
Gfx::CanonicalCode::read_symbol() and
Compress::CanonicalCode::read_symbol() inline, and that didn't
help either.)
* Matches how the loader is organized
* `compress_VP8L_image_data()` will grow longer when we add actual
compression
* Maybe someone wants to write a lossy compressor one day
No behavior change.
JPEG2000 is the last image format used in PDF filters that we
don't have a loader for. Let's change that.
This adds all the scaffolding, but no actual implementation yet.
IFF was a generic container fileformat that was popular on the Amiga
since it was the only file format supported by Deluxe Paint.
ILBM is an image format popular in the late eighties/nineties
that uses the IFF container.
This is a very first version of the decoder that only supports
(byterun) compressed files with bpp <= 8.
Only the minimal chunks are decoded: CMAP, BODY, BMHD.
I am planning to add support for the following variants:
- EHB (32 colours + lighter 32 colours)
- HAM6 / HAM8 (special mode that allowed to display the whole Amiga
4096 colours / 262 144 colours palette)
- TrueColor (24bit)
Things that could be fun to do:
- Still images could be animated using color cycle information
