Painting command executors are defined within the "Painting" namespace,
allowing us to remove this prefix from their names.
This commit performs the following renamings:
- Painting::PaintingCommandExecutor to Painting::CommandExecutor
- Painting::PaintingCommandExecutorCPU to Painting::CommandExecutorCPU
- Painting::PaintingCommandExecutorGPU to Painting::CommandExecutorGPU
BorderRadiusCornerClipper usage to clip border radius is specific to
CPU painter so it should not be stored in painting commands.
Also with this change bitmaps for corner sampling are allocated during
painting commands replaying instead of commands recording.
Given that we have a glyph run where the position of each glyph is
calculated for text fragments during layout, we can reuse it to avoid
this work during painting.
Previously, we determined the positions of glyphs for each text run at
the time of painting, which constituted a significant portion of the
painting process according to profiles. However, since we already go
through each glyph to figure out the width of each fragment during
layout, we can simultaneously gather data about the position of each
glyph in the layout phase and utilize this information in the painting
phase.
I had to update expectations for a couple of reference tests. These
updates are due to the fact that we now measure glyph positions during
layout using a 1x font, and then linearly scale each glyph's position
to device pixels during painting. This approach should be acceptable,
considering we measure a fragment's width and height with an unscaled
font during layout.
If `SkipStackingContext` is returned we also need to restore saved
painter state because corresponding pop_stacking_context command that
is supposed to do that will be skipped.
Fixes https://github.com/SerenityOS/serenity/issues/22092
Before this change, we used Gfx::Bitmap to represent both decoded
images that are not going to be mutated and bitmaps corresponding
to canvases that could be mutated.
This change introduces a wrapper for bitmaps that are not going to be
mutated, so the painter could do caching: texture caching in the case
of GPU painter and potentially scaled bitmap caching in the case of CPU
painter.
Currently, in CPU painter, border painting is implemented by building
a Gfx::Path that is filled by Gfx::AntiAliasingPainter. In the GPU
painter, we will likely want to do something different, and with a
special command, it becomes possible.
Also, by making this change, the CPU executor also benefits because now
we can skip building paths for borders that are out of the viewport.
The current set of stacking context commands do not encode the
information needed to correctly paint the stacking context, instead,
they're based on the limitations of the current CPU renderer.
Stacking contexts should be able to be transformed by an arbitrary
3D transformation matrix, not just scaled from a source to a destination
rect. The `_with_mask()` stacking context also should not be separate
from the regular stacking context.
```c++
push_stacking_context(
bool semitransparent_or_has_non_identity_transform,
float opacity, Gfx::FloatRect const& source_rect,
Gfx::FloatRect const& transformed_destination_rect,
Gfx::IntPoint const& painter_location);
pop_stacking_context(
bool semitransparent_or_has_non_identity_transform,
Gfx::Painter::ScalingMode scaling_mode);
push_stacking_context_with_mask(
Gfx::IntRect const& paint_rect);
pop_stacking_context_with_mask(
Gfx::IntRect const& paint_rect,
RefPtr<Gfx::Bitmap> const& mask_bitmap,
Gfx::Bitmap::MaskKind mask_kind, float opacity);
```
This patch replaces this APIs with just:
```c++
push_stacking_context(
float opacity,
bool is_fixed_position,
Gfx::IntRect const& source_paintable_rect,
Gfx::IntPoint post_transform_translation,
CSS::ImageRendering image_rendering,
StackingContextTransform transform,
Optional<StackingContextMask> mask);
pop_stacking_context()
```
And moves the implementation details into the executor, this should
allow future backends to implement stacking contexts without these
limitations.
Representing a text run panting command as a vector of glyphs, rather
than as a string simplifies collecting of unique glyphs which is a
prerequisite for `prepare_glyphs_texture()` call.
