Side scrolling optimization « cocos2d for iPhone

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Side scrolling optimization

(27 posts) (9 voices)

Started 5 months ago by mrdckx
Latest reply from digitalhoax

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mrdckx
Member

The situation: Making a side scrolling game. One main loop calls a function which moves 4 layers. On the different layers there are moving sprites. When different sprites are moving in combination with the 4 moving layers, this causes the game to not move that smooth anymore.

Things you should know:
- I use texture atlas
- There are no memory leaks
- CPU is not fully used
- Only the sprites on the screen are displayed (what I mean is that the problem is not related to to many sprites, I think..)
- Sometimes there is a warning about the capacity but due to some searching I found that this is normal.
- When I move a sprite (for example the player) the sprite is used in other methods to get it's current location
- Because of the moving layers, their x position gets small really fast

Games like Mighty Fin run so smooth, I want to know how to accomplish that.

Are there any tips on optimizing this? Thanks in advance!

Posted 5 months ago #
ShaneT
Member

Thanks for the help.

I think I just figured my issue out because of this question. Even if the map is 4800 wide, you only have to fire bullets if there is a target is within firing range. That will save me heaps off sprite missiles and memory.

There are better coders that will answer you question soon.

Cheers

Shane

Posted 5 months ago #
mrdckx
Member

No tips? Still searching for a solution. Does anyone have a kind of side scrolling example project I could take a look at?

New thing I tried:
- Using .pvr
- Using .ccz
- Using very small images, with worst texture format
- Moving only one layer (with an average of 20 sprites). Stuttering still occurs.
- Move layer by updating the position in a tick-function using dt. Instead of using CCMove action.
- Turning off Retina display

Games like JetPack Joyride do not suffer from this, so it's not the device I guess. I'm using an iPhone 4.

Posted 4 months ago #
alexasha
Member

try not to draw offscreen sprites.

Posted 4 months ago #
itlgames
Moderator

Are you using batchnodes for your sprites? Also why move 4 layers? That would require 4 batch nodes. Why not one single layer and use zordering on your sprites? You could have one single batchnode.

Posted 4 months ago #
itlgames
Moderator

And how big is your map? And how do you scroll your map? Show us some code.

Posted 4 months ago #
mrdckx
Member

@alexasha
Offscreen sprites are removed.

@itlgames
I have 4 layers that I want to move with different speed. But I'm currently testing with only one layer. Using batchnodes isn't making any difference.

Thanks for the answers.

Tomorrow I'm going to start a new project and start over from the beginning..

Posted 4 months ago #
itlgames
Moderator

Are you using a parallax node then?

How big is the map anyway? And how are you actually moving the layer? Without that information we cannot help you. Unless a massive map, you must be doing something wrong, somewhere, you must be looking on the wrong place.

Posted 4 months ago #
Martin
Member

Are you still in debugging mode? Logging often causes stuttering. Are you allocating/deallocating a lot of objects somewhere? Are you frequently recreating actions? Have you disabled sound to see if its a sound problem? Are you testing on device or simulator? Does it happen in both? If testing on device, did you try disconnecting it first? I once had stuttering movements while the device was plugged in.

Posted 4 months ago #
iUridium
Member

Why are you moving complete layers? Would it be enough for you to move just sprites? Not sure would it satisfy completely your needs, but check it anyway: http://www.iuridium.com/?page_id=2.

Posted 4 months ago #
mrdckx
Member
I tried new things the past week and learned a lot. But still my problem exists and I'm starting to think I'm expecting to much.

So I made a new project starting from the cocos2d template. Then I changed the init of the HelloWorldLayer to:
```
-(id) init
{
	if((self=[super init])) {

        CCSprite *s1 = [CCSprite spriteWithFile:@"Icon.png"];
        CCSprite *s2 = [CCSprite spriteWithFile:@"Default.png"];

		CCParallaxNode *pn = [CCParallaxNode node];
        pn.position = ccp(0.0f,50.0f);
        [self addChild:pn];

        [pn addChild:s2 z:1 parallaxRatio:ccp(1.0f, 1.0f) positionOffset:CGPointZero];
        [pn addChild:s1 z:2 parallaxRatio:ccp(3.0f, 3.0f) positionOffset:CGPointZero];

        id move = [CCMoveBy actionWithDuration:1.0f position:ccp(130.0f,0.0f)];
        [pn runAction:[CCRepeatForever actionWithAction:[CCSequence actionOne:[[move copy]autorelease] two:[move reverse]]]];
	}
	return self;
}
```
And changed the scheme so I was in release mode. When the app is running (on my iPhone 4) the icon is not moving smooth. After enabling retina display mode, it's only getting worse. I also tried just moving one sprite without ParallaxNode but it had the same result. Using delta time and updating the sprite manually has the same result to.

What do you guys think? Do you see the stuttering of the icon when running the above code? Can it be something in my Xcode settings?

Thanks for all the info, I sure learned a lot of new techniques to optimize a game!
Posted 4 months ago #
mrdckx
Member

Should I use Box2D? Maybe then the movement will be smooth again..

I found one other project that runs smoothly. It's a side scroller and he just loads 3 different platforms before the game begins. Then the platforms positions are just changed, but no more sprites are created..

Spent a lot of hours searching and trying but without a good result. To bad, now I have to throw away my game idea...

Posted 4 months ago #
DifferentSparks
Member

I ran your code, on iphone 4, and all is perfectly smooth. I think is a your device problem.
try with another one ;)

Posted 4 months ago #
mrdckx
Member

@DifferentSparks Are you serious ? I showed it to someone not involved in coding or such en even he saw it stuttering..

Posted 4 months ago #
DifferentSparks
Member

I'm serious. On my iphone 4 i can't see any stutter.
On the simulator there're some of them.
Did you ever try on others devices?

Posted 4 months ago #
mrdckx
Member

Not yet, I only have one iDevice. But when I'm back home it will be the first thing I try.

In the meantime, is there a possibility that I (or you) can make a binary for the little code above and share it. Just to make sure the problem is not related to Xcode or my MBP?

Strange things are happening.. Thanks for all the help!

EDIT: I have no problem running other games on my iPhone, so I don't think it's the device..

Posted 4 months ago #
DifferentSparks
Member

How should we do that?

Posted 4 months ago #
mrdckx
Member

I created a TestFlight build, which is available here: http://bit.ly/xQ4B7Q

There are 4 sprites moving at different speeds. Can you take a close look at each one of theme for 2 minutes or so, and report if there is any stuttering or not?

Now I also learn to work with TestFlight. :) Hopefully the build is working..

Thanks in advance!

Posted 4 months ago #
DifferentSparks
Member

You have to add my device

Posted 4 months ago #
mrdckx
Member

So sorry but the link is: http://bit.ly/AdAEBu

Posted 4 months ago #
DifferentSparks
Member

If there're, are very small. I saw some stutter sometimes, but really small.
You need more eyes lol

Posted 4 months ago #
mrdckx
Member

So probably I'm expecting to much. There's nothing I can do about the little stutters then.

Thanks for all your help! Now I can finally sleep again :P

Posted 4 months ago #
Duckwit
Member

When you say stutters do you mean a change in the frame rate or a graphic glitch/delay/offset?

Posted 4 months ago #
mrdckx
Member

@Duckwit There is not really a frame rate drop. When moving the sprite sometimes it hangs and then it jumps a little forward. It's like the screen is not updating.

A better explanation: suppose every time the sprite moves 1 pixel to the right, we should have:
- position.x = 0
- position.x = 1
- position.x = 2
- position.x = 3
and so on...

But what I experience:
- position.x = 0
- position.x = 1
- position.x = 1
- position.x = 3

I hope it's clear now?

Posted 4 months ago #
Duckwit
Member

Yeah it seems pretty clear...

I wouldn't dismiss this as unachievable and 'throw away' your game idea. As long as the frame rate is constant then the glitches (as it appears) must be a logic/programming error SOMEWHERE in the code. :/ ?

Maybe the sprites positioning is being affected by the parallax somehow?

Posted 4 months ago #
mrdckx
Member

A few post back I mentioned I started a new project from the template. I only changed the init method of the HelloWorldLayer (code is shown somewhere in this thread).

I tried a lot of things and really spent days of searching and trying, but without the result I had in mind... Found more posts with people having the same problem. But the solution was just to make a release build for the device.

Posted 4 months ago #
digitalhoax
Member

In the example you gave (HelloWorld modification) you were (re)creating a lot of Actions (your [move copy] code) which is something @Martin had asked a couple of posts above. Maybe it is related?

Posted 4 months ago #

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