I'm working on an iPhone game written in Objective C (which I'm new to). The problem is
that the views which are used to draw the sprites on screen are semi transparent. I have set
the alpha to 1.0 and the opacity to True. I have also used NSLog to confirm that the views' alphas are 1.0. I was using [self.view insertSubview:myView]; to add a view to be drawn but also tried [self.view insertSubview:myView aboveSubview:myOtherView]; just in case they were drawing onto each other.
I have tried searching google but can't seem to articulate a query which helps. I'm using OS 3.0. and I haven't included all the code because there is a lot of it. ANY help would be much appreciated.
Is the view to which you are referring a subview to another view that has an alpha set to a value less than 1.0? Alphas propagate down the the view hierarchy.
I'm not sure why you are getting semi-transparent views, but I would suggest not using UIViews for an iPhone game. Try a more game-oriented system like cocos2d. http://www.cocos2d-iphone.org/
Related
I'm using the standard UIImagePickerController and using a camera overlay view with it, default controls. I've got an external nib file which I load the overlay view from. The problem is that the view seems to be at 460, so doesn't fully encompass the camera view on iphone 5. I'd like to approach this using auto layout, but I'm not sure how to tell the nib to adjust it's size to be either a height for iphone 4 or iphone 5.
I thought about using setFrame, but that's very un-auto layout. I've also thought about having 2 different nib files, one for iphone 4 and one for iphone 5, but that seems to be the wrong approach too. I'm guessing there's some way to tell the nib to fill the current camera view, but I'm not sure what it is. Can someone recommend the "correct" way to handle this?
You can programmatically load a different cameraOverlayView XIB based on the phone dimensions. The camera controls strip is about 54px tall on 480h screens, and about 96px tall on 568h screens.
Alternatively, you can certainly design your XIB with auto resizing masks set appropriately, but will need to then do a setFrame in code to get the right dimensions.
So either way, you're writing some code to detect the screen bounds and either loading a different XIB or doing a setFrame.
I haven't used nibs for a while now (preferred storyboard) but I believe what you have so far is a UIImageView in the nib, right? Make that an outlet. And then in your m file, check for dimension of the device (many people have asked this recently how to check screen dimension), then you set the uiimageview frame based on the found dimensions. It should work ;)
I'm trying to create a crossword app. The game runs in a UIScrollView, because the player should be able to zoom, scroll etc. The largest crossword are 21x21 which means there need to be 441 touchable tiles. What i've tried so far were to create an UIView and added it as a subView to the UIScrollView. Then I call a method that creates 441 custom UIButtons and set the backgroundImage.
Some of the UIButtons need to have a custom label overlay, so i added a UILabel and set it on top of the UIButton.
When I run the app in simulator all works as it should, but when i test it on an iPhone 4 the UIScrollView lags a lot.
I don't know if this the way to do it? Can you maybe try to guide me in the right direction of how to do this so the UIScrollView won't lag on a device.
Thanks in advance.
Big UIScrollViews are difficult to make smooth without some sort of caching mechanism, such as the one provided by UITableView.
One thing you can do, however, to make life easier for your rendering, is to make sure to use opaque backgrounds whenever possible. In stead of making a view transparent you should make it the same color as its underlying view. This is something that does help.
Also, I have experienced better performance using imageWithContentsOfFile: in stead of imageNamed: for initializing images to be used in a UIScrollView.
In order to not keep all those buttons in memory, you should work with reusable table view cells, this will really improve the scroll performance. Here's one component that could make your life easier: DTGridView, there are also others (you can check Cocoa Controls)
there are already some questions on this topic. Unfortunately none of them helped me in anyway. So here is the thing. I am working on an app atm and it has one tabcontroller with two tabs, which contain multiple navigationcontroller on top of each other. Now in one tab at the top level navigation controller, I want to draw some graphics in landscape orientation.
Unfortunately using the shouldAutorotateToInterfaceOrientation method returning YES does not help in anyway.
Now I was wondering whether I could just hide the statusBar and the navigationBar and then draw my graphics so that it looks like it is landscape orientation. But then I also would like to add some labels. I am quite sure I also could turn those around 90 degrees. But this is probably not the right approach here. And I want to submit my app someday...
So now I was hoping someone knows whats the best approach here and how to realize it.
Thanks.
I found a solution somewhere else. The idea is to use the CGAffineTransform method. It allows you to transform the complete coordinate system of a uiview. The piece of code underneath rotatets it to landscape. Now when you draw, the drawing relates to the rotated coordinate systems and everything is drawn in landscape orientation.
CGAffineTransform transform=CGAffineTransformIdentity;
transform=CGAffineTransformRotate(transform, (90.0f*22.0f)/(180.0f*7.0f));
transform=CGAffineTransformTranslate(transform, 80, 80);
This does what I want. But anyway, if there are any other suggestions, please post them!
i have a UIview holding two other UIviews. that two subviews having 15 buttons and images. i have to translate the parent view. but the translation is not smooth in 3g phone. im using UIviewanimation and CGAffineTransformTranslate for translating the view. please help me for making it more smoother.
This is a though question to answer in a general way. I have had views that scrolled smoothly suddenly animating jerkily after just a small change. In short, you need to make sure to have as few subviews as possible and have as few non-opaque views as possible (pngs with alpha values translates to non-opaque UIImageViews).
If all else fails, you can render the whole view into an image, switch out the view for the image just before scrolling, and then re-insert the view again after the animation. That way, you are only moving one big and (hopefully) opaque view.
If you have many images make sure they are small-sized, otherwise theyd take up too much memory and there would be nothing to do. To my experience 4-5 large images(740-480) were too much for the phone to handle.
I'm developing a game. I'm using about 150 UIImageView to hold the graphics. I'm simulating a 3D enviroment, so i would like to change the z-order (how close is an object to the camera).
I know there exists :
[superWindow exchangeSubviewAtIndex:i withSubviewAtIndex:j];
But for some reason it's not working, some of the subviews disappear an re-appear.
Now I just remove all subviews and add it again in the correct z-order, this is ok with 50 subviews (on a 2G iphone) but with 120 it takes half a second so the gameplay sucks (I dont have and 3GS so i didn't try there).
I'm using so many subviews because each one is a square, then i colored it, resize it and move it somewhere in the screen. I'm holding the subviews under a NSMutableArray...
The iPhone documentation often warns about multiple UIViews nested, as it has a large performance hit after a certain point. If you start getting into issues one option is to render your UIViews into an image and using that to lower the number of on-screen views, but if you're simulating 3D that probably isn't going to help much since your composite view would need re-rendering too often.
The iPhone has full support for OpenGL ES, which allows for a real 3D environment. Take a look at some of the samples and/or a good book on the topic and you'll find that it's much easier to simply use OpenGL.
Z-order is an artifact of where your view appears in your superview's list of subviews. The last subview added to the superview is "on top".
So, to move a view to the be "on top", you remove it from its superview, then re-add it -- making it the last one and, therefore, on top.
Here, a view moves himself to the top of the z-order.
// move to the to in the z-order
UIView* superview = [self superview];
[self retain];
[self removeFromSuperview];
[superview addSubview:self];
[self release];
Note the [self retain] to prevent your dealloc if your superview is the only reference to you.
If you don't want to take the plunge to OpenGL ES, as Timothy suggests, you might want to look at replacing the UIViews with CALayers and placing them within a CATransformLayer. CATransformLayer is new in iPhone OS 3.0, and it lets you do a true 3-D layout of the CALayers. You can then set the zPosition property on your CALayers to locate them in the Z plane of the CATransformLayer. For more on 3-D layout of CALayers, I direct you to this article.
You can even add a nice perspective effect on the overall CATransformLayer by setting the m34 element in the CATransform3D applied to that layer.
Changing from UIViews to CALayers is pretty straightforward, because their structures have much in common.
Consider using a 2D game library like Cocos2D. I'm pretty sure that supports Z-ordering, and the performance will be vastly better than using UIViews.
I know this is old, but you can change the z order with bringSubViewToFront.
See this answer: How to set iPhone UI View z index?