#2213 Default font hogging FPS

The "pixelated" font used in the default Anthrax theme drops the FPS a lot, unlike "vector" font from Tortola theme. This only seems to affect Intel cards.

How to reproduce. Measure:

1. Without any GUI open and menubar hidden.
2. With a large dialog, such as Rendering Options, or a lot of smaller dialogs.
3. Same as "2", after running "Debug/Cycle GUI Style".

In my case the numbers were 65, 17, 58.

[Anonymous]

Forgot to say, the issue is old and has existed for as long as I remember.

[James Turner]

Thanks for the report. I guess it's some bad interaction of the special textures used for fonts, and the Intel drivers. Can you list the Intel chipset & drivers you're using?

[Anonymous]

lspci -v:

VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) (prog-if 00 [VGA controller])
        Subsystem: Lenovo 2nd Generation Core Processor Family Integrated Graphics Controller

Driver:
xf86-video-intel 1:2.99.917+899+gf66d3954-1

[Anonymous]

Has been the case on FreeBSD Intel driver as well, some other 2 versions.

[James Turner]

@soitanen one thing that would help: can you replace the fonts listed in styles/anthrax.xml one by one, to work out which file is the problem? I see several fonts used:
HELVETICA_12, HELVETICA_14, FIXED_8x13 and SANS_12B

None of these are used in the tortola theme, so I guess any of them could be the cause (hopefully not all of them .. )

[Michael Soitanen]

I'm not sure, that I should be mentioned here :)

[James Turner]

Oh sorry, wrong Michael! My mistake.

[Anonymous]

The offending fonts are most of the fonts used in the Anthrax theme:

HELVETICA_*
FIXED_*
SANS_*
TIMES_*

that is, basically all pixel fonts I know of.

On-screen stats for both themes:
https://imgur.com/a/zrf9Ngp
Please ignore the broken rendering, I just updated my OS, and the antialiased font breaks GUI rendering now (thank you, driver devs, thank you so much for that... -_- ).

[Anonymous]

Update about the broken rendering of GUI with antialiased fonts.

I have just tried with older -next that sure used to render correctly, and the issue is still there, so this is indeed something OS-side.

What dependencies of are responsible for the rendering of antliased fonts, developers of what should I bug about breaking FG's GUI?

[Anonymous]

Another observation: removing <option name="mesa_glthread" value="true"/> from ~/.drirc seems to fix the rendering of GUI with antialiased font.

[James Turner]

I will need to some reaearch into how they're loaded, it will be some special texture options I guess. But, in the screenshot you psoted, what exactly is broken? I don't see something really bad? (At least, I can read the text...)

[Anonymous]

Parts of GUI randomly disappear if antialiased font is used and mesa_glthread is on:
https://gitlab.freedesktop.org/mesa/mesa/-/issues/3213

[James Turner]

Added some comments there to help the driver guys.

[Anonymous]

Thanks, I'm sorry about jumbling 2 or 3 separate issue together, though. I just don't know which one belongs where anymore.

[Anonymous]

Btw, since the pixel fonts are in C++, as opposed to files, could it be that the slowdown is due to them being generated every frame somehow?

[James Turner]

No, the fonts are created just once, as far as I can tell.

[Anonymous]

By the way, why, despite this perf issue and menubar corruption on some AMD drivers, is Anthrax still the default? Tortola has none of these issues and also it looks prettier.

[Megaf]

@jmturner I believe it would be interesting for the community and current users to swap the bitmap fonts to the same font, non bitmap in anthrax.xml if that's the only issue. As I wrote in https://sourceforge.net/p/flightgear/codetickets/2513/#a767/a6e3

Also, @jmturner in the name of the community I want to say thanks for your quick response in the freshly opened tickets, I do really appreciate that!

[Gijs]

Since we're dropping PUI and replacing it by Canvas-based menus/dialogs, this issue is most likely no longer valid.