This modification introduces a new layer to the painting process. The
stacking context traversal no longer immediately calls the
Gfx::Painter methods. Instead, it writes serialized painting commands
into newly introduced RecordingPainter. Created list of commands is
executed later to produce resulting bitmap.
Producing painting command list will make it easier to add new
optimizations:
- It's simpler to check if the painting result is not visible in the
viewport at the command level rather than during stacking context
traversal.
- Run painting in a separate thread. The painting thread can process
serialized painting commands, while the main thread can work on the
next paintable tree and safely invalidate the previous one.
- As we consider GPU-accelerated painting support, it would be easier
to back each painting command rather than constructing an alternative
for the entire Gfx::Painter API.
This allows applying SVG <mask>s to elements. It is only implemented for
the simplest (and default) case:
- mask-type = luminance
- maskContentUnits = maskContentUnits
- maskUnits = objectBoundingBox
- Default masking area
It should be possible to extend to cover more cases. Though the layout
for maskContentUnits = objectBoundingBox will be tricky to figure out.
The SVGContext is a leftover from when SVG properties were more ad-hoc.
All properties are now (for better or worse) treated as CSS properties
(or handled elsewhere). This makes the SVGContext's fill/stroke
inheritance handling unnecessary.
This fixes a plethora of rounding problems on many websites.
In the future, we may want to replace this with fixed-point arithmetic
(bug #18566) for performance (and consistency with other engines),
but in the meantime this makes the web look a bit better. :^)
There's a lot more things that could be converted to doubles, which
would reduce the amount of casting necessary in this patch.
We can do that incrementally, however.
This avoids a ton of work when painting large documents. Even though it
would eventually get clipped by the painter anyway, by bailing out
earlier, we avoid a lot more work (UTF-8 iteration, OpenType lookups,
etc).
It would be even nicer if we could skip entire line boxes, but we don't
have a fast way to get the bounding rect of a line box at the moment.
Store the ratio between device and CSS pixels on the PaintContext, so
that it can convert between the two.
Co-authored-by: MacDue <macdue@dueutil.tech>
When cloning the PaintContext we should be using the painter backed by
the bitmap created for this stacking context layer.
Fixes: 54c3053bc3 ("LibWeb: Preserve paint state when painting...")
For layers that require indirect painting (due to opacity, transform,
etc.) we create a nested PaintContext. Until now, that PaintContext
was created fresh without transferring all the state from the parent
PaintContext.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
A C++ source file containing just
#include <LibFoo/Bar.h>
should always compile cleanly.
This patch adds missing header inclusions that could have caused weird error
messages if they were used in a different context. Also, this confused QtCreator.
