I'm new to computer coding and have just finished coding an app and tested it on both 3G and 3GS. On 3GS, it worked as normal as on the simulator. However, when I tried to run it on 3G, the app becomes extremely slow. I'm not sure what's the reason and I hope someone could shed some light on me.
Generally, my app has a couple of view controller classes, with one of them being the title page, one being the main page, one is setting, etc. I used a dissolve to transition from the title page to the main page. But even this simple transition shows un-smooth performance on a 3G! My other part of the app involves zooming in to some images by scaling up the images, switching images by push or dissolve upon receiving touch events, saving photos into photo library and storing and retrieving some photos in a folder and some data in a SQlite database, each showing un-smooth actions.
Compared with some heavy graphic or heavy maths app, I think mine is pretty simple. I totally have no clue why the app would behave so slow and un-smooth that it is barely useful on a 3G. Any help/ direction would be much appreciated. Thanks for helping out.
You might want to try profiling your application with Shark to find out where the performance bottlenecks are.
I don't know how relevant it is to your case, but my game (shameless plug) MultiMaze is quite undemanding graphically, and worked beautifully on my 3GS. But when I tried it on a 3G, the frame rate dropped to a glacial 10-20 fps. I ported the whole code base from CoreGraphics to OpenGL ES, and that made a world of difference. It now runs at the limit (60 fps) on my 3GS and very close to it on the 3G.
Are you using a lot of memory? 3G has 128MB while the 3GS has 256MB RAM.
Are you getting memory warnings? In my debug builds I have an NSLog in didReceiveMemoryWarning so I can see if/when I get warnings.
EDIT: Check the size of your photos, are they resized for the iPhone screen or are they original sized?
OK, finally found the problem and got the solution. The problem was that I have about a dozens of transparent images laying on each other to form my main view. So when in any animation, the system needs to redraw on every single layer and calculate their transparent effect and so on. (actually I'm not quite sure, but that's what I think)
The solution I have is to make a temporary composite view containing of them all, and placing the composite as an image in a full screen view before starting any animation. It delays starting the fade a moment, but the fade itself is a lot smoother now.
Related
I am fairly new to OpenGL development on iOS. I'm working on software that will create 3D reconstructions of objects in the form of *.ply files. I'm trying to make an iOS app to visualize these simple vertex-only *.ply files. Everything works as intended on the iPhone and iPad Simulator, but when I run it on my iPhone, the points rendered in the view are glitchy and covered with large squares. Here's the comparison: iPhone and simulator. Has anyone run into similar issues with OpenGL?
It's important to understand that when running OpenGL ES code on the simulator, you're actually running it on the simulator's software implementation and not on the GPU.
The simulator's implementation is close to, but not identical to the implementation on the device GPU. This means that faulty code may render fine on the simulator. I've experienced it myself on a couple of occasions, like when using glbuffers and not allocating enough storage.
It's obviously hard to say where your code goes wrong, but I'd suggest you to go through your code and look for subtle errors.
I'm using some animated gifs on our mobile-site. It's a clock-animation and since the iOS 5 update it sometimes happens that the clock gets blue instead of red, as planned. Happens on iPhone4 and iPhone5 with the new os.
Any ideas what could cause the problems? It's hard to reconstruct this failure but it happens from time to time.
Any help would be appreciated.
Sometimes ios devices may not be able to process all the images because of its relatively low graphics ability compared to that of a computer. Instead of using a GIF I would suggest using an animated PNG. This has been more popular among the ios devices as using GIFs has become obsolete when working with ios devices. I am not sure how fast this would be, but I would say it can apply less stress then that of a gif. Another idea, because it is a clock gif is to analyze the gif in a program and determine any problems. Also use imgoptim (for mac) or pngcrush for windows to reduce the size of the gif to reduce the stress on the processor.
use GIF 128 Dither and Please make sure that images size has to be base on the resolution it happen some time if your images size is not depend on retina or normal resolutions. And if I am not wrong you facing problem only in retina device, may be below details will help
iPhone Retina Display
~~~~~~~~~~~~~~~~~~~~~~~
Width - 640px
Height - 960px : including 40px status bar
DPI - 326
You can use Cocos2D framework, Cocos2d and UIKIT both work great with out any graphic related errors... Sprite sheets reduces the memory usage and also support all transparant images , you can run animation ,stop and repeat them. Good luck..
Hey, I got kind of a weird issue here.
I have an iPhone-only OpenGL ES app which runs fine on all iPhone and iPod touch models supported.
When running on the iPad, it runs on an iPhone-sized window as expected, and pressing the "2x" button once scales up the window to twice the size, as expected, and the app continues to run without problems.
But if the user taps the "2x" button 3 or 4 times quickly, the app is killed with the Program received signal: "0" message (which, from what I understand, means the OS killed my app for using too much memory, is that right?)
What I really do not understand is what in my app could possibly be using up more memory when the iPad scales the window up and down? As far as I know there's not even any way for my app to tell if and when the iPad is doing that. I don't know if the fact I'm using OpenGL ES is related or not, but that issue doesn't happen on any of the Cocoa Touch apps I have - though it also doesn't happen on the other two OpenGL ES apps I have. And this app does use more memory than any of the other ones.
Anyone ever had or even heard of this problem? Googling gave me nothing.
Since no one has posted with a direct answer (your situation might be a little vague), I have a suggestion for how to move forward and gather more information on what might be causing your problem.
Check out the Instruments in Xcode which can identify memory leaks:
Instruments User Guide
Or for an even friendlier introduction, here's a video that address performance issues, including memory leaks (and how to find them). iOS Performance Optimization Video
Just adding this so there's some kind of an answer here...
I never figured out what the hell was going on with the 2x button.
The way I fixed it back then was to optimize memory usage as much as I could, lazy-load all that I could and unload again when not in use.
Weird that it never complains about memory when running on any of the supported iPhone or iPod touch models, even the older ones, but it got killed on the iPad ONLY when pressing the 2x button repeatedly and quickly... I guess that's always gonna be a mystery to me.
Images that I add to the layer in Cocos2d look pixelated around the edges of the image (i.e. a hillside, the rounded part of the hill, where the sky and the hill meet). I don't know if it's the image quality, or just because the graphics processor on my 'older' MacBook Pro is not as advanced as the iPhone 4 or iPod Touch 4 or iPad 2. Is it because of that?
I have ran into an instance where a large resolution image was being used in the context of a locally packaged HTML file in a UIWebView. The image looked fine in the simulator, but when ran on a hardware device, a bug was exposed in the rendering engine where it would invert the colors. Here's a bug report as an example of this. The solution was to scale the image down a bit in photo editing application.
While an extreme corner case, this is an example of the simulator not quite living up to how things will work on a hardware device.
The simulator usually does a pretty good job representing what the final image will look like. For the image quality on a normal computer to be worse than that of an iPhone for it to make a large enough difference, your MacBook Pro has to be really bad. So I doubt it.
However, if you really want to make sure, the best way to check would be to transfer the image you are using to another machine to see if it still looks pixelated. If it does, its a problem with your image.
Hope this helps and good luck!
I am writing an application which contains some graphs drawn in OpenGL ES. each of these graphs are in a table cell, when I press some of those graphs, it is being opened in full screen mode.
Everything worked perfectly since I upgraded to iOS4.2. Now the problem is in simulator, I can't see the drawn graph in cells, but in full screen mode I do see the chart. There are no changes no the device, it is only on the simulator and only in a case.
The behavior is the same for other Mac's here.
Does anyone have a clue?
As explained in this answer to this similar question, there has been a change in the way that 4.2 handles renderbuffers in Core Animation layers. From the OpenGL ES Programming Guide:
In iOS 4.2 and later, the performance
of Core Animation rotations of
renderbuffers have been significantly
improved, and are now the preferred
way to rotate content between
landscape and portrait mode. For best
performance, ensure the renderbuffer’s
height and width are each a multiple
of 32 pixels.
It appears that if your renderbuffer isn't an even multiple of 32 pixels, it doesn't display in the Simulator. This is a bug in the Simulator, but you should probably make your renderbuffer a multiple of 32 in either dimension in any case to improve performance.
Same things with my App. My textures are broken sporadically on the simulator (4.2). On the hardware everything looks fine.
I don't know if this helps much, but I've seen all manner of strange behaviour on the simulator implementation of OpenGL ES: spurious images appearing; strange lighting on the first render pass; broken rendering to bitmaps, depending on when I call it. I'm no expert in OpenGL programming, so I could just be writing crap code, but there is definitely a noticeable difference in the behaviour of the simulator vs the real hardware.
Your experience suggests that maybe my problems aren't entirely my fault. :-)