@Neurofuzzy, performance issues?

oztune

Hey,

I saw you mentioned Pixelwave having some performance issues on Twitter. I'd really appreciate it if you gave me some details so I can look into it. We've put a lot of effort into optimizing it so if something is running slowly I'd really like to fix it.

Thanks,

Oz

neurofuzzy

Well, first of all let me say that PixelWave is pretty darn fast. I may just be doing something wrong.

1. You saw my thread about touch response and high frame rates. This only occurs under high graphic load at 60fps. I'm dragging a sprite for use on a Joypad control. If there's high load, there seems to be a delay and a latency in touch events. They kind of chug along.

2. I am using colored rectangles to draw my background and all moving sprites (for testing) using the graphics API. This may be slower than the SPQuad I'm using with Sparrow. Also, In Sparrow, I'm using an SPRenderTexture to "collapse" the background to a single texture, whereby in PixelWave I just did multiple graphics.drawRect calls in a single sprite. I'm thinking this is slower, because the more rects I draw in the single sprite, the slower it gets. It appears the PixelWave must be redrawing the graphics on every frame instead of treating it as a texture. Is there a way to do the equivalent of cacheAsBitmap?

Bekenn

Use PXTextureData:

PXTextureData* cachedData = [[[PXTextureData alloc] initWithWidth: w height: h transparency: YES fillColor: 0] autorelease];
[cachedData drawDisplayObject: obj];
PXTexture* cachedImage = [PXTexture textureWithTextureData: cachedData];

drawRect is really intended for objects whose contents are expected to change often (perhaps even every frame).

neurofuzzy

Okay, If replaced everything in my game with textures.

Moving Sprites are Textures with 32x32 initted TextureDatas with color.

Background is a single Texture as well.

It's actually slower. I think it's because I'm creating a lot of separate textures for the moving sprites as opposed to a single texture atlas. Mind you I've got no 'real' graphics now.. just boxes moving around the screen.

I'm curious to know if there's an equivalent of Sparrow's SPQuad? It's simply a couple of triangles with color assigned to the vertices. If there was an equivalent in PixelWave, I could test apples to apples. :)

neurofuzzy

Did a quick time profile, and yes, I think I must be zigging when I should be zagging. Almost all the time is spent on rendering.

Running (Self) Symbol Name

17886.0ms 94.9% PXEngineRenderDisplayObject

17877.0ms 94.8% -[PXTexture _renderGL]

17862.0ms 94.7% PXGLBindTexture

17862.0ms 94.7% PXGLFlushBuffer

17862.0ms 94.7% PXGLFlushBufferToGL

17861.0ms 94.7% glDrawArrays

17861.0ms 94.7% glDrawArrays_IMM_Exec

17843.0ms 94.6% gleDrawArraysOrElements_ExecCore

13176.0ms 69.9% gleFlushTriQuadStripFunc

13158.0ms 69.8% 0xb980612

13158.0ms 69.8% gldRenderFillPolygonPtr

12798.0ms 67.9% 0xb9815b8

Here's my display list:

-(PXSprite *)root

|

-(PXsprite *)container

-(PXsprite *)background

-(PXTexture *)background image (640 x 480)

-(PXsprite *)objects (container for moving sprites)

-(PXTexture *)game object (32x32)

... more game objects (30 of them)

|

-(PXsprite *)controls (child of root!)

-(PXsprite *)joypad

-(PXsprite *)buttonA

-(PXsprite *)buttonB

I hope that gives a better idea of what is going on.

oztune

Hmm, are you creating a different PXTextureData for each object on screen? That could cost you the performance. You could instead have all the PXTexture objects share a single PXTextureData

To draw a simple quad you can use PXShape. Here's how you can make a colored rectangle:

PXShape *shape = [[PXShape alloc] init];
[shape.graphics beginFill:0x00FF00 alpha:1.0f];
[shape.graphics drawRectWithX:0 y:0 width:100.0f height:100.0f];

neurofuzzy

Well, actually, I was using PXSprites with the same code you have there using [sprite.graphics drawRectWithX:y:width:height:] and it was chugging. So, I just switched to PXTexture to test and it was slower.

I just switched to using PXShape for everything except the background, which is a PXTexture. It's about the same speed as using PXSprite.. maybe a tiny bit faster.

I may post a video showing the difference in speed I'm getting between Sparrow and PixelWave. Still fiddling with it.

neurofuzzy

Here's a couple of videos demonstrating the differences in performance I'm seeing between PixelWave and Sparrow using the same game code. It may be a little hard to see on a 30fps video.

Notice the annotation when I drag my finger on the left side around 50 seconds into the PixelWave video.

oztune

Yeah, I definitely see the difference. Seems really odd. The touch performance is so laggy (I've done more complex things with it and haven't seen it go this slow) that I have to assume something is really wrong. Just not sure what.

I tried replicating the issue and I can't seem to do it. Check out this project: http://www.pixelwave.org/temp/TouchResp.zip

It renders 1000 quads on the screen at around 70fps on my iPhone 4, and the dragging seems smooth when the quads are visible or not.

Let me know if that code helps at all. If not John or I would be glad to look at the actual code and debug it that way (not sure how you feel about sending the code over, but you can email it to me at oz at pixelwave.org).

neurofuzzy

Thanks for putting together this example!

On my iPod Touch 2G, I get around 9 fps with the quads visible. The dragging is just as laggy as mine.

Without the quads, I get 100fps and the dragging is smooth.

Maybe the iPod 2g is just too wimpy to handle it. :(

oztune

Well that kind of makes sense if the total framerate is 9 the dragging would lag.

In your project, what kind of framerate are you getting with Pixelwave? If you're getting a good total framerate there's really no good reason for the touch to lag...

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