IOS 4.2 -> iPad, Strange behavior

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IOS 4.2 -> iPad, Strange behavior

(21 posts) (6 voices)

Started 1 year ago by asebist
Latest reply from Daniel

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asebist
Member

Hi,

I updated my iPad to the glorious IOS 4.2 Version yesterday and also updated XCode etc. Everything works fine except of 1 strange, strange thing.
If I "force" Sparrow to load @2x images, it is ignored with IOS 4.2, the same code runs perfectly under iOS 3.2.2

That means, I have 2 .pngs:

head.png (16x16 px), and
head@2x.png (32x32 px).

When I load it with
[[[SPTexture alloc] initWithContentsOfFile: @"head@2x.png"] retain];

under 3.2.3 it loads the 32x32px
under 4.2 it loads the 16x16px

maybe that's some important infos for upgrading Sparrow to 4.2

PS: if i load a 32x32px png that does not end with @2x.png it works.

greets&thanks
asebist

Posted 1 year ago #
freerunnering
Moderator

I think 4.2 might use @2x graphics by default so forcing it to breaks it's auto detection?

Posted 1 year ago #
asebist
Member

no it's not default

Posted 1 year ago #
Daniel
Primary Feather

I will have a look at this, thanks for pointing it out!

So you say that when you display e.g. "image@2x.png" (explicitly adding the '@2x'-suffix), it now displays "image.png" instead, and before (iOS 3.2) it displayed the HD texture, right?

Posted 1 year ago #
asebist
Member

yes Daniel, that's right, it's complete reproducable.
But maybe this is the best time to create a flag useHDRessourcesOnIPad ...

tx
asebist

Posted 1 year ago #
Daniel
Primary Feather

Yes, you're right - now that iOS 4.2 is finally available for the iPad, this is the plan =)

Posted 1 year ago #
asebist
Member

Hi Daniel,

any estimation of a "fix" or an update for HD iPad resources?

tx
Michael

Posted 1 year ago #
Daniel
Primary Feather

Hi Michael,

sorry that it's taking so long -- I'm extremely busy at the moment

However, at least I have downloaded the 3.5 GB package with iOS 4.2 today *g* -- so I will have a look at it in the next days!

Posted 1 year ago #
Daniel
Primary Feather

I had a look at that issue! Now, there's no more need to append "@2x" manually for HD graphics on the iPad. Here's what I came up with.

Posted 1 year ago #
asebist
Member

Hi Daniel,

i have a universial application, and that for it does not work for me. So maybe this was a misunderstanding, but loading @2x directly with iOS < 4.x did work on the iPad, now it does not, also not with the newest build.

I do understand that it is best to have a different design/layout for the iPad, because of the not matching aspect ratios, but in my opinion it would make perfect sense to have the higher rsolution assets automatically on the ipad, and the @2x assets will nearly always fit for an universal app.
I just do not want to have all my assets 2 times (with 2 names) with exactly the same content, isn't there anything I can do? Did you find out why it did work with iOS < 4.x?

sorry to bother you with this, but I can imagine that this is not an uncommon desire, to have the already created HD assets easily accessible for the iPad in universal apps, although you have to care about small memory and different Stage sizes,

thanks in advance
asebist

Posted 1 year ago #
Daniel
Primary Feather

Hi asebist,

mhm, I understand that issue of course. What I proposed above is just a simple way to have iPhone-targeted apps looking good on the iPad, not universal apps.

I have not tried it yet, but perhaps the following would work:

- I guess you started development on the iPhone, with a stage size of 480x320 and two sets of textures (normal and @2x). That should work already, I guess.
- You should have it already, but make sure to set:

[SPStage supportHighResolutions:YES];

Now, if you find out that you're on an iPad, do the following:

- Make the stage size: 512x384 (!) (that's exactly half of the iPad resolution). That's the stage size, NOT the size of the SPView (which is still 1024x768)! The stage content will ALWAYS fill up the SPView.
- Set [SPStage setContentScaleFactor:2.0f];
- Load your textures WITHOUT (!) the "@2x". The big textures should be loaded automatically.

*** UPDATE ***
- Make sure that the content scale factor of the native view (SPView) is set to 1.0. Currently, Sparrow sets it to 2.0 automatically, which will lead to a huge performance loss!!
*** *** ***

Think about it as if there had been another iPhone version with a 512x384 screen, and now there had been a system upgrade with a retina display, creating a 1024x768 resolution. It's just like developing for the old 512x384 screen and adding HD textures for the retina version of the hardware.

In theory, that should work -- though it will require iOS 4. But that's a price I would pay if I were in your position, I'm sure almost everybody will have switched soon on the iPad.

Please try that out! I'll see if I find the time to write a blog article about this with a little more detail.

Posted 1 year ago #
evilliam
Member

Aha! That's great Daniel, thanks so much, it works much better than scaling sprites at a class level.
Works like a charm for me -

Posted 1 year ago #
Daniel
Primary Feather

Very good, I'm glad to hear that!

Posted 1 year ago #
asebist
Member

Hi all,

i tried it and it works fine. I don't know why, but it also is loading @2x resources even if I do not change the resolution of the SPStage.
Looks like the new Sparrow Version and [SPStage setContentScaleFactor:2.0f]; work fine for my need of a universal app with the same assets for retina and iPad.

Thanks for all the efforts Daniel, you are great.

PS: I guess we'll be having a lot of fun with the next iPad (retina + 512 MB???)

cheers
asebist

Posted 1 year ago #
Daniel
Primary Feather

Good to hear that it works!

BTW, if HD textures are loaded is simply decided by the scale-factor of SPStage. The reason I proposed changing the stage size is just to have a simpler coordinate system at hand when you're placing the objects on the screen. With a stage size of 512x384, a texture that is 20 pixels wide in normal resolution and 40 pixels wide in HD resolution would then be displayed with a width of exactly 40 pixels on the screen.

However, it's not required to do so - I guess it depends on what you find easier to handle =)
Good luck with your project!

Posted 1 year ago #
Dan
Member

I've been having this same problem with a Universal app we're building at the moment.
The problem seems to stem from UIImage having a "scale" property which is only really used post iOS4.0. In SPTexture.m glTexture.scale is set to the scale property of the UIImage being loaded, on iPads running 3.x this property was just 1.0 or didn't return at all which meant the images displayed fine. However on iPads running 4.x the property is 2.0 which results in the image being scaled down by half.

Hope that makes sense!

For now I'm adding a nasty hack to SPTexture to set glTexture.scale to 1.0 if the device is an iPad.

So I've changed this:

'if ([image respondsToSelector:@selector(scale)])'

To this:

'if (![SPTexture isPad] && [image respondsToSelector:@selector(scale)])'

(Where 'isPad' is just a function returning TRUE if the device is an iPad)

Posted 1 year ago #
Daniel
Primary Feather

Hm, you're right: the problem is that if you load a texture with the "@2x" suffix on iOS 3.2, the UIImage will return a scale factor of 1, while it will return 2 on a 4.2 device.

That's because the whole retina stuff was only added to iOS in Version 4.0. I think your small hack is an easy solution. The other options would be either to request iOS 4 for your app, or to use another prefix for the HD textures -- which is problematic, because then you'd have to add your textures twice, once for the iPhone4 and once for the iPad.

Personally, I'd opt for requesting iOS 4. The update enhances the functionality of the iPad very much (without making it slower) and is free to download -- thus, I'm sure almost all users will have upgraded soon. (Though I must admit that I have no hard numbers for that assumption ;-)). However, if that's not a choice for you, I think your small little hack is, as I said, a nice work-around =)

Posted 1 year ago #
asebist
Member

I have to note, that this only works, if you have a projekt created from the sparrow 1.0 scaffold Version and update to Sparrow 1.x (latest) afterwords. At least for me, it did not work, with a project I created from the 1.x (latest) scaffold Version.

asebist

Posted 1 year ago #
Anonymous
Unregistered

yes i agree

Posted 1 year ago #
Daniel
Primary Feather

All who have used this method, have a look at the UPDATE I inserted above!

Posted 6 months ago #
Ron
Moderator

Hi Daniel,

I am trying this 512x384 solution for my Universal app, and it seems to be working correctly. But I don't understand the UPDATE section that you reference.

"Make sure that the content scale factor of the native view (SPView) is set to 1.0. Currently, Sparrow sets it to 2.0 automatically, which will lead to a huge performance loss!!"

I checked my SPView's contentScaleFactor, and it is 1.0. I can't find where it is set to 2.0 automatically.

Also, since you are editing old posts, should you also update:
- Set [SPStage setScaleFactor:2.0f];
to
- Set [SPStage setContentScaleFactor:2.0f];

Thanks,
Ron

Posted 5 months ago #
Daniel
Primary Feather

Hi Ron,

thanks for bringing this up -- I'll try to have another look at this issue. I've been informed about the problem by another user and have looked at the code only briefly -- I'll give it another go! Perhaps the problem does not pop up in all situations. If your 'scaleFactor' is correct and the game is running fast on the iPad, then it has to be OK in your project.

Posted 5 months ago #

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