I make a game on iOS, but on iPhone 4/4S, crash due to memory pression.
The Image is a map that the retina size its 4MB. I have it in two small parts (For design proposes), of 3MB and the other of 1MB.
I know they are kind-of big images but not enough to crash, the weird part its that when it loads on a UIImageView that loads on a UISCROLLVIEW it expands to 50MB (I check it with instruments).
on those phones, that its killing me, because if I consume more than 100MB apple kill the app, and its just the map, then I load the gameplay.
How can I handle this, why 4MB expands to 50MB. All my assets are 70MB (iPad, iPad Retina, iPhone & iPhone Retina)
Edit:
I have 2 posible solutions:
1-. Disable #2x on iPhone 4/4S (I don't know how to do this)
2-. Tiled the map in like 1000 small pieces of about 100px x 480px. and load it while the user it's scrolling?
What do you think?
Thanks
Related
I am trying to figure out how to use the xcassets folder in Xcode 6 and I have to say Apple could have done a way better job. I'm a big fan of Xcode but their images storage per type of screen / phone is a nightmare.
First, in my application I am using images which will have a height of half their width. From what I understood, taking pictures of around 1200x600px should do for all types of iphones (full width minus small margin). So I put them in 3x universal, right? If I gave the maximum size why would apple need 1x and 2x ...? Just resize it yourself, no? Is it compulsory for me to give something or will it work by itself? Images are not vector but simple PNGs. In the simulator nothing is complaining and it works well for all types of iphones. Is it okay to leave the other two empty? From I see from the simulator iphone 6 will use downsized #3x images so what is the point of having two images? Only ratio is important and they have the same ...
Secondly, I just added today a launch screen for retina hd 5.5 / 4.7 and now when I run the app in the simulator my uitableviews only take around 4/5 of the full width instead of full width .... can't figure out why adding a launch screen would modify layout of my uitableviews ....? Navigation bar and other screens seem untouched though ...
Any help appreciated.
you need to add the images for the 2x & 3x because when you add large size image then at the run time this image get resize as per the actual width of the image it utilize memory lots of memory to do this & some time if your application have too many images then you will get memory issues
if you want to test this then run your application in iPhone 5 then see the memory utilisation by first keeping the high resolution image now take image which will be of appropriate size to iPhone 5 & then run again you will see the difference
so the best practice is to use different image for different size & not images in this fashion.
The answer to your second Question
if you are not adding the splash screen for iPhone 6/6+ then iOS stretches your UI of iphone 5 to fit into the size of the iPhone 6/6+.
But when you add splash screen it stops doing that.
late to the party but yes you need to manage all this resolution by yourself. Otherwise it will consume more memory.
but yes there is one tool which will make your work less by generating all assets for you
AVXCassets Generator
To support iOS 7 to 8 on universal devices, I have to make 4 copies of the same image in different size.
For the iPhones
image#2x.png (iphone 4s,5,5s,6)
image#3x.png (iphone 6+)
For the iPads
image.png (ipad 2, ipad mini 1)
image#2x.png (ipad 3, 4, ipad mini 2, ipad Air)
The images are really bloating the app size.
Is it ok to just use 1 image size, the largest one of the set and scale to fit in the uiimageview and use the image view to scale down the image on the smaller screens?
imageView.contentMode = UIViewContentModeScaleAspectFit;
or is it absolutely necessary to have all 4 copies at different sizes?
It works on all the devices on the simulator and on a retina iPad 3, but I have no way of actual testing on other devices and am afraid that the images may not display.
Has anyone tried using 1 large image instead of the set of copies?
Yes, you can theoretically use the largest resolution image and have the UIImageView scale the image down using mode Aspect Fit.
The only drawback is the older phones that don't support retina also are less performant. For example, when using images on cells of a UITableView and scrolling, the device has to load the large image, then scale the image down, and scroll it at the same time, and it will stutter on old, slower devices.
So, perhaps just use multiple images in list views (should just be thumbnails and are tiny anyway, or just use the smaller images here), but don't worry about larger images that stay on the screen and don't scroll.
Make sure you load images in list views using methods that allow caching like imageNamed:.
As long as you take into consideration the performance penalties involved in scaling down the images, you can use just the largest image and scale it down to fit.
By the way, yes I've used this technique in real live apps in the App Store.
Another technique I've seen is to include lower quality images (1x or 2x) and if you run it on a higher resolution device (2x or 3x), automatically download high resolution images from the web. Maybe be nice about it and only download them on wifi.
I have been developing an app for iPad and was testing i on iPad 3 and iPad air with no problems at all. When i tried same app on iPad 2 the images were blur and some of them were not displaying properly even some were half visible half not visible.
As per my knowing the iOS7 only apps do not need non-retina graphics so i am using only Retina Graphics. So i tried using Asset Catalog too but same was the result.
Strangely when i use image#2x.png in xib it displays fine but do not show image in xib and when i use image.png it is displayed in xib but same issue when run on the device.
What i need to do to show images in xib too and would run fine on device?
Fisrt You MUST provide non-retina graphics in the asset catalog. You should understand that bigger images on old devices provides bigger memory and performance impacts.
You must pay attention also on odd measure, because if some geometric frames calculation results in decimal point such as 23.5 1.5 you are going to have antialiased elements in your interfaces.
You can avoid that wrapping frames into CGRectIntegral.
If you have an app that works fine on non retina devices, and then you deploy it on a retina device, without providing the requisite #2x images, what side effects could occur?
high memory usage? crashing of the application?
No, the events you mentioned will not occur. However, obviously your images will look terrible as they will not scale properly (therefore they will be pixelated and incorrect sizes etc.).
There isn't any point in not using retina images - all you have to do is add #2x to the images and double the image size, and they will scale correctly for both non-retina and retina display.
If you do not include #2x images, then the device will automatically stretch the image on a retina device to take up the same room (enlarge the image).
The scaling method that UIKit uses does not do any interpolation. Instead, it merely doubles the size of every pixel ("nearest neighbor" scaling). For images of squares with hard edges, that works fine. However, for photos or most artwork, the image ends up looking very pixelated (has artifacts).
Scaling the images up on a retina device is not performance intensive because of the simple scaling method that is employed. It is not likely to affect performance, only image quality.
If you include only high resolution images, they are not automatically scaled down for the non-retina device. Instead, for an UIImageView, for instance, you would set the view mode to Scale to Fill, so that the image scales down to fit the frame. However, again, UIKit uses the nearest neighbor, but when scaling down, artifacts are less noticeable.
The newer, retina devices are more performant, so they are able to handle high resolution images at the same speed as non-retina devices can handle the low resolution images, and scaling images up is trivial for them. However, older non-retina devices will simply be slower with high-resolution images which require more memory and more graphics power, especially since it has to scale them down as well.
This is very noticeable if you have high resolution images in a UITableView. Your retina device will scroll the table very smoothly, whereas you will notice some jitter on the non-retina device. It will not crash, it just won't be smooth. If the user experience is too bad, your app could be rejected. For static, non-moving images, there is unlikely to be much noticeable performance difference.
If you have room in your bundle, you should include both retina and non-retina images. Even if you simply double the image size in a nice photo editor like Photoshop to create your #2x images, the images will be of much nicer quality than what UIKit produces.
Remember that if your zipped app bundle is over 50 MB, it can only be downloaded via WiFi from the App Store. PNGs and JPEGs do not compress much since they are already compressed. That is one reason why you might choose to only include high resolution images (to keep the size of your app bundle down, especially for a universal app, where you might end up having 4 sets of images).
Of course you can provide only retina or even only non-retina images.
We did some testing on this matter a few month ago.
Only non-retina images resulted - as expected - in poor graphics. Even an non-trained eye could notice the blurrines.
Only retina images: it works. But memory footprint is bigger (for non-retina devices that would otherwise load non-retina images) and some lag could be noticed. Though we had to measure it to be sure.
To answer your question: zenith provided the answer. If you only provide non-retina images the graphics on retina devices will be blurry, but no low-memory condition could emerge because of this.
EDIT:
Unless you are doing some kind of research on graphics capabilities of different iOS devices i'd strongly suggest to provide both types of images: retina and non-retina.
If your designer is giving you hard time because of this you can do few things:
get a new designer
provide him some kind of tool to make his job easier: Unretiner for example
I have an app that works on iPad 1st gen. This is a game, made using cocos2d framework.
The first iPad does have 256mb ram and using instruments(the memory monitor tool) i was able to determine that the app works at around ~90-110mb ram on the device (well lets just trust "Physical Memory Used" chart though the "Physical Memory Free" at the very beginning shows it is ~128mb free and then gets to ~3-4mb free after playing several levels and never gets higher)
So while it does have enough memory it caches the assets and when it runs out of ram the cached assets get released.
What i did is added the high res graphics to it. Almost all of the assets are loaded as 4bit assets so say if i have an asset 100x100 pix it will consume 100x100x4 = 40000 bytes ram; the same hd image will be 200x200 pix and will consume 200x200x4 = 16000 bytes ram; which is 4 times bigger!
So the question is - will it work fine on iPad 2 hd screen which has 512mb ram?
See if i multiply ~110mb*4 it will be ~440mb, what means it will be 512 - ~440 = ~72mb left for system. So i do not know if that is enough for system and it won't close the app. I am not sure but i think the 1st gen iPad may give around ~120-130mb ram for the app and then will close it. So that makes me think this won't work on the iPad2. Am i likely correct?
ps: i've tested the app on the 3d gen iPad which has 1gb ram and it runs just fine
The iPad 2 has the same screen resolution as the original iPad, so it will not use the new retina artwork that you are adding to the app. This means it should run fine on the iPad 2 if its already running original iPad.
The iPad 2 does not have a retina screen, so the physical resolution of the iPad 2 is the same as on the iPad 1. Only do the retina style images on a device that supports it, this way you keep memory low on device that can't handle the retina resolution.