It's too annoying otherwise, especially if padding is involved. Turns
out that if padding is zero, these don't really contribute to the layout
in any way.
The internals are still rather ew, that's for another time, but the goal
here was to make it compile and correctly handle the new variability in
created and passed glyph cache instances. In particular:
- The MagnumFont createGlyphCache() now uploads the texture image
directly, skipping a copy through the CPU-side image which may not
have a size matching the input image. That's kind of nasty (and too
tied to OpenGL), but will be cleaned up once the GlyphCache APIs are
fixed to allow this in a nicer way.
- The MagnumFontConverter will now correctly select a font if the cache
contains more than one, properly deal with glyph caches that either
do or not do image processing, and will fail for array glyph caches
as that's not supported by the current format. It also now has an
early special-case handling for glyph caches with processed images,
where the actual image may have different size (and possibly format),
to match what MagnumFont expects.
The class now supports incremental filling, multiple fonts, texture
arrays, removes all reliance on STL containers and is finally properly
documented.
To avoid complete breakage of every use, as much as possible was kept as
deprecated APIs -- in particular the reserve() with the nasty
std::vectors, the insert() that assumes a 2D cache and a single font
and textureSize() that returns a 2D vector. Those behave the same as
before, but will assert if the cache is an array or contains more than
one font.
On the other hand, begin() / end() access with std::unordered_map iterators
(ew!) was removed as the internals simply aren't a hashmap anymore. The
image() that returned an Image2D is now used to fill the glyph cache
instead of querying its potentially processed contents, and returns a
MutableImageView3D. I considered keeping it and adding sourceImage()
instead, but such naming turned out to be too inconsistent. For querying
processed image data (such as with the distance field cache) there's a
new processedImage() query, guarded by new GlyphCacheFeature bits -- if
both ImageProcessing and ProcessedImageDownload is set, it can be used
to retrieve the processed image (so, similar as ImageDownload was
before), and if neither is set, the cache contents are queryable
directly through image(), without needing any special support from
the GPU API.
Existing code is updated only in the minimal way possible to ensure that
no serious breakage was introduced by reimplementing the deprecated APIs
on top of the new backend. Porting away from deprecated APIs will be
done in next commits. The GlyphCache and DistanceFieldGlyphCache have
their public API kept intact for now, as a similar rework will be needed
for them as well.
Additionally, the MagnumFont and MagnumFontConverter plugins aren't
compiling yet as they require substantial changes to deal with the new
glyph cache features. That is not the case with other plugins in the
magnum-plugins repository tho, for those the backwards compatibility
"just works". On the other hand, since layout of the AbstractGlyphChange
changed, I'm bumping the AbstractFont plugin interface version to
force-trigger a rebuild of dependent projects. Because I ran a stale
magnum-player binary, it worked without crashing or GL errors but just
didn't show ANY text whatsoever due to ABI differences, and I wasted
some precious minutes before realizing that a simple rebuild would fix
it.
Ugh. Was using this to verify that the glyph cache was correctly
populated, only to end up with a GL error that I thought was coming from
the glyph cache itself and not here. Wasted too much time on that.
Need some regression tests for the upcoming glyph cache rework as
otherwise it'll be too miserable. It now fills the glyph cache image
with some non-trivial data and compares to them, and checks the filled
glyphs for the created glyph cache too.
This also fixes a regression introduced when porting away from STL in
47a1295ab8, where UTF-8 layouting was
reporting extra glyphs at the end. Now UTF-8 support is properly tested
both in the MagnumFontConverter plugin and MagnumFont.
Originally GL::hasTextureFormat() returned false on ES2 for
PixelFormat::R8Unorm, RG8Unorm, RGB8Unorm and RGBA8Unorm because
glTexStorage() didn't work with the matching Luminance, LuminanceAlpha,
RGB and RGBA formats. But since the only ES2 platform is nowadays
basically just WebGL 1, which has neither EXT_texture_rg nor
EXT_texture_storage, this implicit failure made no sense and just made
the textureFormat() (and the new genericPixelFormat() API) useless
there.
Now it maps to them, and it's up to the caller to make sure
glTexStorage() doesn't get called with those, only glTexImage does.
Furthermore, if formats from EXT_texture_rg are used, the
genericPixelFormat() now also provides inverse mapping of them back to
the generic PixelFormat. Before it was basically *no* ES2 TextureFormat
that'd work with either of these, now it's all that have a (vaguely)
corresponding PixelFormat.
An ad-hoc solution was already done in DebugTools::screenshot(), now I
need it in another place. While not as fast as the O(1) mapping from
the generic format to the API-specific ones due to the potentially
linear lookup, it definitely could be useful in general.
Only noticed this now when adding inverse mapping. Sigh. OTOH, with the
inverse mapping in place this will no longer be possible to happen, as
it would cause a compile error due to a duplicate switch case.
While it's needed to call basically any useful function in there, its
definition isn't needed to create an instance of the AtlasLandfill
class, and that's what mainly matters.
The overhead of maintaining two classes with only very slight
differences in the API and the internals being basically identical is
not worth it. Too much potential for inconsistencies and doc errors.
Additionally, when I attempted to use it for the reworked Text glyph
cache, I realized I'd need to wrap them both under a common interface,
allowing easy use for both 2D and 2D array textures. And then it's
easier to just have the Atlas class done that way directly instead of
papering over that in a downstream API.
It fails on a linker error otherwise. There's a bit of annoying logic
needed for pre-GLVND systems as there it's not possible to link to GLX
without dragging the whole libGL in as well, causing bad conflicts with
libGLES. Which means I can't test this on the CI yet as there CMake is
forced to version 3.5 and finding GLVND is only in 3.10.
The policy makes it work for all find_package(OpenGL) calls,
possibly even in subprojects, without having to copypaste the same
OpenGL_GL_PREFERENCE override code to each.
Interesting that neither GlxApplication nor XEglApplication was actually
built on the CI. Also test all EGL applications and contexts on GLX
builds as well, as those should work there too. For GLX on EGL builds
it's a different story.
Instead of piling up a mountain if the other end is a ditch. Results in
better packing in most cases, but in one doesn't, so also adding an
option to disable this.
The docs image is now slightly more leveled, one pixel lower.
Not yet the full extent of it including rotations and incremental
packing, as the existing interface is too awful, also patching over
zero-sized glyphs that the new packer doesn't like. Another round of
deprecations needs to happen first.
It takes too long in debug mode, causing timeouts on the Windows CI due
to older MSVC having truly amazing virtually unmatched debug build
performance.
I made the binary data use 16-bit integers instead of 32-bit to make
them occupy less space and forgot to update it here. Also they're in a
different path now.
Just the dumbest possible idea I had, and it compares surprisingly well
in both efficiency (~comparable to stb_rect_pack) and speed
(significantly faster than stb_rect_pack with tons of tiny images,
slower with larger ones -- would probably need to SIMD Math::max() and
such, haha). It's the very first implementation without any additional
improvements I have in mind, so it'll likely improve further.
Includes a benchmark with a bunch of "datasets" extracted from both
fonts and large glTF models. The stb_rect_pack file isn't commited as
it's not useful apart from this single benchmark, put it to
AtlasTestFiles/ and recompile.
I mean, yes, it was already SIGNIFICANTLY better than the atlas() that
took a vector and returned one as well, but still. One of the usual use
cases is that there's an array of structs containing both sizes offsets
and the offsets get written back.
The original versions are deprecated as I really don't see any
convenient use case for these, especially given they return a pair and
not just an array.
Vladimír Vondruš