Like the piggybacking in CSS, this is also totally ad-hoc, since there's
no spec to follow.
The code here is weird and definitely sub-optimal as we do a second load
if it turns out the loaded resource is an image, but given that object
elements are rarely used nowadays, I doubt we'll even notice.
That said, we should of course improve this code as we move forward.
This is all ad-hoc since no spec currently exists for this behavior.
Basically, ImageStyleValue now uses ImageRequest for fetching and
decoding of images.
This already leads to visible improvements on many websites.
This forces us to diverge from the spec, but it's for a good cause:
by moving it into ImageRequest, we'll be able to reuse fetching and
decoding logic from CSS and other places.
This patch also makes ImageRequests shareable, currently keyed by
the URL (this part needs improvement!)
Previously, we did an evenodd fill for everything which while for most
SVGs works, it is not correct default (it should be nonzero), and broke
some SVGs. This fixes a few of the icons on https://shopify.com/.
Before this change we always returned the font's point size as the
x-height which was basically never correct.
We now get it from the OS/2 table (if one with version >= 2 is available
in the file). Otherwise we fall back to using the ascent of the 'x'
glyph. Most fonts appear to have a sufficiently modern OS/2 table.
Some of these functions can be called millions of times even for images
of moderate size. Inlining these functions really helps the compiler and
gives performance improvements up to 10%.
Inside each scan, raw data is read with the following rules:
- Each `0x00` that is preceded by `0xFF` should be discarded
- If multiple `0xFF` are following, only consider one.
That, plus the fact that we don't know the size of the scan beforehand
made us put a prepared stream in a vector for an easy, later on, usage.
This patch remove this duplication by realizing these operations in a
stream-friendly way.
This class is similar to some extent to an implementation of `Stream`,
but specialized for JPEG reading.
Technically, it is composed of a `Vector` to bufferize the input and
provides a simple interface to read bytes.
This patch aims for a future better and specialized control over the
input data. The encapsulation already allows us to get rid of the last
`seek` in the decoder, thus the ability to use the decoder with a raw
`Stream`.
As it provides faster `read` routines, this patch already reduces time
spend on reading.
Previously we were unable to parse code like `yield/2` because `/2`
was parsed as a regex. At the same time `for (a in / b/)` was parsed
as a division.
This is solved by defaulting to division in the lexer, but calling
`force_slash_as_regex()` from the parser whenever an IdentifierName
is parsed as a ReservedWord.
We need to add another pair of parenthesizes when propagating an
initialization of ItemListModel, because a comma in a template argument
would work as a separator of macro arguments, leading to a compile
error.
Bionic warns on this, but not passing the mode argument is technically
undefined behaviour (depending on the libc implementation of open), as
our LibC reads `mode` unconditionally (yolo!), just pass a zero to avoid
the UB.
Errors are now deferred until `finish_decode()` is finished, meaning
branches to return errors only need to occur at the end of a ranged
decode. If VPX_DEBUG is enabled, a debug message will be printed
immediately when an overread occurs.
Average decoding times for `Tests/LibGfx/test-inputs/4.webp` improve
by about 4.7% with this change, absolute decode times changing from
27.4ms±1.1ms down to 26.1ms±1.0ms.
This does a few things:
- The decoder uses a 32- or 64-bit integer as a reservoir of the data
being decoded, rather than one single byte as it was previously.
- `read_bool()` only refills the reservoir (value) when the size drops
below one byte. Previously, it would read out a bit-sized range from
the data to completely refill the 8-bit value, doing much more work
than necessary for each individual read.
- VP9-specific code for reading the marker bit was moved to its own
function in Context.h.
- A debug flag `VPX_DEBUG` was added to optionally enable checking of
the final bits in a VPX ranged arithmetic decode and ensure that it
contains all zeroes. These zeroes are a bitstream requirement for
VP9, and are also present for all our lossy WebP test inputs
currently. This can be useful to test whether all the data present in
the range has been consumed.
A lot of the size of this diff comes from the removal of error handling
from all the range decoder reads in LibVideo/VP9 and LibGfx/WebP (VP8),
since it is now checked only at the end of the range.
In a benchmark decoding `Tests/LibGfx/test-inputs/4.webp`, decode times
are improved by about 22.8%, reducing average runtime from 35.5ms±1.1ms
down to 27.4±1.1ms.
This should cause no behavioral changes.
