As mentioned in F.2.1.5 - Inverse DCT (IDCT), the decoder needs to
perform a level shift by adding 128. This used to be done in
`ycbcr_to_rgb` after the conversion. Now, we do it in `inverse_dct` in
order to ensure that the task is done unconditionally.
Consequences of this are that we are no longer required to explicitly
do it for RGB images and also, the `ycbcr_to_rgb` function is exactly
like the specification.
When reading the stream, interpreted as a normal value 0xF0 means skip
15 values and assign the 16th to 0. On the other hand, the marker ZRL
- which has the value 0xF0, means skip 16 values. For baseline JPEGs,
ZRL doesn't need to be interpreted differently as writing the 16th value
has no consequence. This is no longer the case with refining scans.
That's why this patch implement correctly ZRL.
We used to skip over zero coefficient by modifying the loop counter. It
is unfortunately impossible to perform this with SOF2 images as only
coefficients with a zero-history should be skipped.
This induces no behavior change for the user of the function.
This commit is nonsense for anything else than SOF2 images with spectral
approximation. For this particular case, skips like EOB or ZRL only
apply to coefficients with a zero-history. This commit prepares the code
to handle this behavior.
Rather than the very C-like API we currently have, accepting a void* and
a length, let's take a Bytes object instead. In almost all existing
cases, the compiler figures out the length.
This function has probably been added when we weren't as good with error
propagations as we are now. We can safely remove it and let future
calls to `read` fail if the file is corrupted.
This can be tested with the following bytes (already used in 9191829a):
ffd8ffc000000800080ef701101200ffda00030100
This parses the new background-position-x/y longhands and properly
hooks up them up. This requires converting PositionStyleValue to
just contain two EdgeStyleValues so that it can be easily expanded
into the longhands.
This is very similar to the LittleEndianInputBitStream bit buffer change
from 8e834d4bb2.
We currently buffer one byte of data for the underlying stream. And when
we put bits onto that buffer, we do so 1 bit at a time.
This replaces the u8 buffer with a u64. And instead of looping at all,
we perform bitwise operations to write the desired number of bits.
Using the "enwik8" file as a test (100MB uncompressed, commonly used in
benchmarks: https://www.mattmahoney.net/dc/enwik8.zip), compression time
decreases from:
13.62s to 10.9s on Serenity (cold)
13.62s to 9.22s on Serenity (warm)
2.93s to 2.32s on Linux
One caveat is that this requires explicitly flushing any leftover bits
when the caller is done with the stream. The byte buffer implementation
implicitly flushed its data every time the buffer was byte-aligned, as
doing so would always fill the byte. This is no longer the case. But for
now, this should be fine as the one user of this class, DEFLATE, already
has a "flush everything now that we're done" finalizer.
This is something we're supposed to do according to the HTML spec.
Note that image loading is currently completely ad-hoc, and this just
adds a simple DocumentLoadEventDelayer to the existing implementation.
This will allow us to use images in layout tests, which rely on the
document load event firing at a predictable time.
Instead of passing the continuously merged initial forbidden token set
(with the new additional forbidden tokens from each parsed secondary
expression) to the next call of parse_secondary_expression(), keep a
copy of the original set and use it as the base for parsing the next
secondary expression.
This bug prevented us from properly parsing the following expression:
```js
0 ?? 0 ? 0 : 0 || 0
```
...due to LogicalExpression with LogicalOp::NullishCoalescing returning
both DoubleAmpersand and DoublePipe in its forbidden token set.
The following correct AST is now generated:
Program
(Children)
ExpressionStatement
ConditionalExpression
(Test)
LogicalExpression
NumericLiteral 0
??
NumericLiteral 0
(Consequent)
NumericLiteral 0
(Alternate)
LogicalExpression
NumericLiteral 0
||
NumericLiteral 0
An alternate solution I explored was only merging the original forbidden
token set with the one of the last parsed secondary expression which is
then passed to match_secondary_expression(); however that led to an
incorrect AST (note the alternate expression):
Program
(Children)
ExpressionStatement
LogicalExpression
ConditionalExpression
(Test)
LogicalExpression
NumericLiteral 0
??
NumericLiteral 0
(Consequent)
NumericLiteral 0
(Alternate)
NumericLiteral 0
||
NumericLiteral 0
Truth be told, I don't know enough about the inner workings of the
parser to fully explain the difference. AFAICT this patch has no
unintended side effects in its current form though.
Fixes#18087.
This now uses the current font (rather than the painter's default)
and scales it correctly. This is not perfect though as just naviely
doing .draw_text() here does not follow the proper text layout logic
so this is misaligned (by a pixel or two) with the text in the <li>.
At the end of HTML::EventLoop::process(), the loop reschedules itself if
there are more runnable tasks available.
However, the condition was flawed: we would reschedule if there were any
microtasks queued, but those tasks will not be processed if we're
currently within the scope of a microtask checkpoint.
To fix this, we now only reschedule the HTML event loop for microtask
processing *if* we're not already in a microtask checkpoint.
This fixes the 100% CPU churn seen when looking at PRs on GitHub. :^)
This is copy-pasted from the gzip utility, along with its existing TODO.
This is currently only needed by that utility, but this gives us API
symmetry with GzipDecompressor, and helps ensure we won't end up in a
situation where only one utility receives optimizations that should be
received by all interested parties.
HackStudio's Editor has displayed indicators in its gutter for a long
time, but each required manual code to paint them in the right place
and respond to click events. All indicators on a line would be painted
in the same location. If any other applications wanted to have gutter
indicators, they would also need to manually implement the same code.
This commit adds an API to GUI::TextEditor so it deals with these
indicators. It makes sure that multiple indicators on the same line
each have their own area to paint in, and provides a callback for when
one is clicked.
- `register_gutter_indicator()` should be called early on. It returns a
`GutterIndicatorID` that is then used by the other methods.
Indicators on a line are painted from right to left, in the order
they were registered.
- `add_gutter_indicator()` and `remove_gutter_indicator()` add the
indicator to the given line.
- `clear_gutter_indicators()` removes a given indicator from every line.
- The `on_gutter_click` callback is called whenever the user clicks on
the gutter, but *not* on an indicator.
Instead of reading bytes from the output stream into a buffer, just to
immediately write them back out, we can skip the middle-man and copy the
bytes directly into the output buffer.
