Very strange behavior with tiles and fps (Ashley, David)

I can't reproduce any performance difference by changing the layout size. The layout size is pretty much just used to enforce scrolling limits - it doesn't have much to do with rendering, so I'm not sure why you'd see a difference there.

Ok, it seems to really show itself when the layout size is changed, but not the application size. Here are some samples:

Default 1024x1024 application and layout:

<img src="http://i244.photobucket.com/albums/gg36/some9000/32x32DX9runtime725FPS000mbVRAM.png">

Now only the layout is set to 1024x768:

<img src="http://i244.photobucket.com/albums/gg36/some9000/32x32DX9runtime471FPS400mbVRAM.png">

And now both application and layout are 1024x768:

<img src="http://i244.photobucket.com/albums/gg36/some9000/32x32DX9runtime968FPS000mbVRAM.png">

Some visible difference right there. And the fps shown is pretty much an average, I waited a moment for it to stabilize.

Edit: Also just noticed that it suddenly starts to need 4 Megs of VRAM in the second sample - why is that? Sort-of drawing the application "background" and the layout as different things or something like that?

Well I'm willing to concede that I screwed up and made it 16x18 and not 16x16. BECAUSE, it perfectly shows why pow2 should ALWAYS be used! Oh yeah, I came out of this smelling like roses, lol.

But seriously though, it does clearly demonstrate how very easy it can be to be off by just a few pixels, and what a big negative effect that can have on a game.

So if/when I do do a pow2 tutorial, I'll be references this thread as a perfect example of why pow2 should always be used. See cause like.. I made this thread as part of a tutorial.. you believe that, right? RIGHT??

> Your 16x16 .cap actually uses a 16x18 texture

>

Nice. I think maybe you should look at a tutorial before you make your tutorial LMK

Hehe, I kid!

Haha, it was intentional, I swear *hides*

Oh right, it shows black bars when the layout is smaller than the window. Those black bars are drawn as well, and each weighs up to about the same performance impact as the tiled background (a four vertex quad). In such an intensive test, they're bound to show up as making a difference. Always keep the layout bigger than the window if you want to keep it a fair test.

Edit:

[quote:7mikr2h8]Edit: Also just noticed that it suddenly starts to need 4 Megs of VRAM in the second sample - why is that? Sort-of drawing the application "background" and the layout as different things or something like that?

When the layout is smaller than the window, it draws to an offscreen surface first, to ensure nothing is drawn outside the viewable area. It's this offscreen surface you're seeing VRAM usage for. It's also going to further reduce performance copying this offscreen surface to the main window, which also explains the FPS dip.

In short, these performance/VRAM usages probably won't make much sense unless you know how the engine works.

Oh right, it shows black bars when the layout is smaller than the window. Those black bars are drawn as well, and each weighs up to about the same performance impact as the tiled background (a four vertex quad). In such an intensive test, they're bound to show up as making a difference. Always keep the layout bigger than the window if you want to keep it a fair test.

Ok, but what exactly eats up the 4 Megs of VRAM in this case?

This is some good stuff to know, to be careful of when trying for max performance, hence all the questions, Ashley

Edit: Got it, buffering of sorts.

I edited my post to include an answer about VRAM.

What if the tiles are power of two, but different heigh and width? Like 16x16 is better than 16x18, but is 16x32 good?

Just discussed this in the chat, seems to be graphics card dependant. Some may support it, some may not.