Instead of fetching a generic set of metrics for each glyph, only fetch
the advance when that's all we need.
This is extremely hot in LibWeb text layout, where it makes a nice dent.
Rather than make path segments virtual and refcounted let's store
`Gfx::Path`s as a list of `FloatPoints` and a separate list of commands.
This reduces the size of paths, for example, a `MoveTo` goes from 24
bytes to 9 bytes (one point + a single byte command), and removes a
layer of indirection when accessing segments. A nice little bonus is
transforming a path can now be done by applying the transform to all
points in the path (without looking at the commands).
Alongside this there's been a few minor API changes:
- `path.segments()` has been removed
* All current uses could be replaced by a new `path.is_empty()` API
* There's also now an iterator for looping over `Gfx::Path` segments
- `path.add_path(other_path)` has been removed
* This was a duplicate of `path.append_path(other_path)`
- `path.ensure_subpath(point)` has been removed
* Had one use and is equivalent to an `is_empty()` check + `move_to()`
- `path.close()` and `path.close_all_subpaths()` assume an implicit
`moveto 0,0` if there's no `moveto` at the start of a path (for
consistency with `path.segmentize_path()`).
Only the last point could change behaviour (though in LibWeb/SVGs all
paths start with a `moveto` as per the spec, it's only possible to
construct a path without a starting `moveto` via LibGfx APIs).
Before this change, we would only cache and reuse Gfx::ScaledFont
instances for downloaded CSS fonts.
By moving it into Gfx::VectorFont, we get caching for all vector fonts,
including local system TTFs etc.
This avoids a *lot* of style invalidations in LibWeb, since we now vend
the same Gfx::Font pointer for the same font when used repeatedly.
This updates fonts so rather than rastering directly to a bitmap, you
can extract paths for glyphs. This is then used to implement a
Gfx::Path::text("some text", font) API, that if given a vector font
appends the path of the text to your Gfx::Path. This then allows
arbitrary manipulation of the text (rotation, skewing, etc), paving the
way for Word Art in Serenity.
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.
This patch does three things:
- Font::has_color_bitmaps() (true if CBLC and CBDT are present)
- Glyph now knows when its bitmap comes from a color bitmap font
- Painter draws color bitmap glyphs with the appropriate scaling etc
This adds the option to pass a subpixel offset when fetching a glyph
from a font, this offset is currently snapped to thirds of a pixel
(i.e. 0, 0.33, 0.66). This is then used when rasterizing the glyph,
which is then cached like usual.
Note that when using subpixel offsets you're trading a bit of space
for accuracy. With the current third of a pixel offsets you can end
up with up to 9 bitmaps per glyph.
We have a new, improved string type coming up in AK (OOM aware, no null
state), and while it's going to use UTF-8, the name UTF8String is a
mouthful - so let's free up the String name by renaming the existing
class.
Making the old one have an annoying name will hopefully also help with
quick adoption :^)
This remained undetected for a long time as HeaderCheck is disabled by
default. This commit makes the following file compile again:
// file: compile_me.cpp
#include <LibDNS/Question.h>
// That's it, this was enough to cause a compilation error.
Likewise for most other files touched by this commit.
