About freeorion's performance

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Geoff the Medio
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Re: About freeorion's performance

#46 Post by Geoff the Medio »

raptor wrote:Could a texture cache be bound only once at application start-up, then just modify the quad coordinates of the glyph when rendering?
If the only texture you ever wanted to render was a font, sure...

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Re: About freeorion's performance

#47 Post by raptor »

Oops. Sorry, I mixed up 'binding' with 'creation', in my head, for some reason... that basically invalidates my line of thought.

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Re: About freeorion's performance

#48 Post by Geoff the Medio »


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Re: About freeorion's performance

#49 Post by raptor »

Performance with the new code is almost identical. With a similar test performed like before, the node cost of GG::Font::RenderCachedText is about 19% of the whole. I looked into getting the debug symbols for my drivers but so far, no luck. I'm looking into other ways to figure out which GL calls are the most expensive; any ideas would be appreciated.

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Re: About freeorion's performance

#50 Post by raptor »

I did some more digging and found other methods that call the same symbol. It looks like the issues is indeed glBindTexture().

Looking at other font caching methods (like this one: https://github.com/akrinke/Font-Stash/b ... ash.c#L414), it looks like that glBindTexture() is only ever called when a new glyph needs to be added to the texture cache or when a new texture is created; however, it looks like freeorion calls it on every glyph render.

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Geoff the Medio
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Re: About freeorion's performance

#51 Post by Geoff the Medio »

raptor wrote:...it looks like freeorion calls [glBindTexture()] on every glyph render.
Why do you say that? RenderCachedText renders (I think) a whole Control's text (many Glyphs), but only binds and unbinds once. PreRenderText similarly binds once (though I'm not sure why that's necessary...)

Edit: commenting out line 855 of Font.cpp,

Code: Select all

    //glBindTexture(GL_TEXTURE_2D, m_texture->OpenGLId());
seems to have no ill-effects for me. Does it still work for you, possibly with an minor speed improvement?

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Re: About freeorion's performance

#52 Post by raptor »

Commenting out that line in PreRenderText() doesn't change the performance; however, commenting out the two calls in RenderCachedText() does give a slight performance boost (with unacceptable visual artifacts), but not much. Maybe I'm mistaken in thinking it was glBindTexture().

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Re: About freeorion's performance

#53 Post by Geoff the Medio »


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Re: About freeorion's performance

#54 Post by raptor »

This was really good!

FPS increased to about 45-50 FPS (from about 30 before) when viewing the tech-tree the same as with previous tests. I did another callgrind analysis and came up with about a 3.7x performance increase of GG:Font::RenderCachedText() as rough guess. See my numbers:
snapshot2.png
snapshot2.png (69.31 KiB) Viewed 2269 times
Note that there is a huge reduction in number of calls per Render() fram of the TechPanel.

The new largest offender is PartlyRoundedRect() at 14% of the whole, with most of that (10%) in CircleArc(), from CUIDrawUtil.cpp.

Great change!

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Geoff the Medio
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Re: About freeorion's performance

#55 Post by Geoff the Medio »

If a few others could test it out, that would be helpful... I'm a bit hesitant to merge without a few other reports.

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Vezzra
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Re: About freeorion's performance

#56 Post by Vezzra »

Geoff the Medio wrote:If a few others could test it out, that would be helpful... I'm a bit hesitant to merge without a few other reports.
I'm still on vacation, will try to get around to it next week.

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MatGB
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Re: About freeorion's performance

#57 Post by MatGB »

I'm having problems getting Git to recognise the branch you've put the code in, I'm sure I'll figure it out.
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Sloth
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Re: About freeorion's performance

#58 Post by Sloth »

I've pulled the PR, compiled and ran a test. The performance is certainly not worse, but i can't really tell whether it's better.

For me the easiest way to crash my framerate is to build the super testers takeover. With a big galaxy (250+) fully visible it even becomes hard to click on a system, because the mouse cursor reacts so badly.
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Re: About freeorion's performance

#59 Post by MatGB »

Builds and runs fine, I perceive an improvement in the tech screen but can't quantify it, then I never noticed a reduction in FPS in that window anyway, I've always had low FPS, even on the new machine.

Edit: on the main map window, it's not just a perception, massive improvement in mouse responsiveness and general control over screen and game.
Last edited by MatGB on Thu Jul 02, 2015 10:05 pm, edited 1 time in total.
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Geoff the Medio
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Re: About freeorion's performance

#60 Post by Geoff the Medio »

Sloth wrote:For me the easiest way to crash my framerate is to build the super testers takeover. With a big galaxy (250+) fully visible it even becomes hard to click on a system, because the mouse cursor reacts so badly.
Have you turned off background starfields and galaxy gas, and tried enabling or disabling optimizing system rendering?
raptor wrote:The new largest offender is PartlyRoundedRect() at 14% of the whole, with most of that (10%) in CircleArc(), from CUIDrawUtil.cpp.
Those functions have a substantial number of immediate glVertex calls, so that's not surprising. This in particular, and most of the UI Wnd-derived classes, would be better re-implementing using buffer objects for rendering instead.

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