Not clear how the plumbing changes but the skia font rendering to canvas seems very "scratchy" on Windows builds. Certainly worse than default GDI, or with OpenGL rendering.
On current build of master on Windows 10 with both nVidia or Intel GPUs (recent drivers so good Vulkan support). In the GUI, note on any of the main menu, or dialog list boxes, the leading round edges of "G", "O", "C" glyphs are not at all smooth. Likewise for the "O" or the "C" on the StartCenter for the Open Filer or Calc Spreadsheet button labels.
Enabling disabling the 'Use anti-alaising' has no effect.
We know it will work, evidenced by Chrome's browsers clear text rendering.
Assume we still have dependencies of bug 103322, but was a lot of grief first with OpenGL then when we brought in HarfBuzz at 5.3; to avoid similar complaints and disruption moving forward with Skia can we address rendering mode--ClearType mode, and antialaising--sooner rather than later?
Created attachment 157472 [details]
Draw file with screenshoot skia<->OpenGL
Hi Stuart, for me looks a bit better with skia (my eyesight is not the best for the test:).
LibreOffice version in the attachment.
DeviceString: Intel(R) HD Graphics 620
Created attachment 157484 [details]
zip of several screen clips Writer document and UI with Skia-Vulkan and OpenGL
Screen clips from 1920x1080 res monitor, Intel HD Graphics 620 (22.214.171.12484) Windows 10 1903, Google Roboto regular (unhinted) installed to system.
Pairs of LO with OpenGL v. Skia/Vulkan rendering of the UI.
One set shows smooth Chrome browser rendering of Roboto regular sample text with LO writer canvas rendering of the same text.
Other set shows LO rendering of document at 250% with the 'Insert' menu showing.
So, while for the Roboto font, rendering to document canvas is not excessively different--both renderings are rough--the Skia/Vulkan rendering has line weight and aliasing issues.
Where differences are quite noticeable is in rendering the LibreOffice user interface (which IIUC is fully hinted Segoe UI). The labeling of LO menu entries with Skia/Vulkan at screen resolution is painful.
Created attachment 157780 [details]
comparison rendering of Help -> About current 7.0.0 alpha0+ master
The attached image shows clips of the Help -> About dialog from a Windows 10 Ent 64-bit with nVidia K2000 GPU (126.96.36.19928)
panels, left to right, are showing rendering by
I know quality is subjective, but the Default GDI rendering seems crispest. The OpenGL DWRITE grayscale antialaising is acceptable. But for both Vulkan renderings, the antialaising seems too heavy--almost smeared--note the O o 0 and ( ), as well as the W and V glyphs.
Created attachment 157783 [details]
Comparison of Help rendering Skia/Vulkan with/without antialaising
Difficult to say which looks better. The black looks more black in the order of the selection.
Attached a comparison Skia/Vulkan with/without antialaising, and on my view if one looks better is without.
(In reply to m.a.riosv from comment #5)
> Attached a comparison Skia/Vulkan with/without antialaising, and on my view
> if one looks better is without.
Hmm, but yes your clip of Skia/Vulkan with VCL "antialaising" enabled renders worse than the clip wihtout antialaising.
But both are painful compared to legacy GDI or OpenGL...
But perhaps depends also on the quality of the screen, and the use case. Being darkness the text can help e.g. editing text or formulas.
Why the hell does an office software need to deal with such a variety of graphic supports? and the hardware largely underutilized, at ridiculous levels.
Created attachment 158398 [details]
screenshot of menu text and document text
I see bad font rendering too, both in menus and in the text.
I have got a "Intel HD Graphics 630" on Windows 10.
Created attachment 158476 [details]
comparisons of default GID, OpenGL, Skia/Vulkan, Skia/raster rendering of text
Attaching rendering samples of the Help -> About dialog for latest 2020-03-07 tb77 Windows build of master. Still noticeably degraded rendering of the Skia Vulcan or Skia raster modes compared to default GDI or OpenGL rendering.
On Windows 10 Home 64-bit en-US (1909) with Intel HD Graphics 620 (drvr 188.8.131.5255) and Version: 184.108.40.206.alpha0+ (x64)
Build ID: 10e20a77ce302a0475a661ad1886f2ca83c55f3f
CPU threads: 4; OS: Windows 10.0 Build 18363; UI render: Skia/Vulkan; VCL: win;
Locale: en-US (en_US); UI-Language: en-US
With Skia/Vulkan now set as the default rendering mode for Windows builds this will become a source of UX complaints.
Is this a Direct2D or GDI/GDI+ issue?
Is Chrome doing well with Skia because they have implemented Freetype? Is that going to be needed along with floating point composition (bug 103322) to get clean font rendering to canvas and the GUI?
AFAIK Skia still uses the same font rendering than with OpenGL - using DirectWrite to a texture atlas, then using Skia to render the texture.
There is work on rendering fonts using Skia directly, so I would wait until that lands and then retest.
"AFAIK Skia still uses the same font rendering..."
I meant "Skia" here as LibreOffice Skia backend.
Current master (1ad3f6b8d9e0ef1e921c3ed5526ea352d67265cf) now uses Skia also for text rendering, and AFAICT the result is the same as with the GDI VCL backend.
Verified! Skia/Vulkan and Skia/Raster both now look as good as Default GDI or OpenGL rendering.
Version: 220.127.116.11.alpha0+ (x64)
Build ID: 6388c578c672690fff662cb04b6a0436cd742f37
CPU threads: 8; OS: Windows 10.0 Build 18362; UI render: Skia/Vulkan; VCL: win;
Locale: en-US (en_US); UI-Language: en-US