I am trying to design another app and am struggling to think of the best way to do it. I'm after some advice please!
If you imaging a bicycle wheel in the middle of the ipad (and iPhone)... I want the user to be able to click on the tyre and spin it to the left or right. Depending on the speed of the swish will drive the speed of the wheel rotation.
It should rotate around the centre of the wheel and not move any other direction.
Do I need to use some graphics code, or simply listen for the touch, check the area they touched, then rotate the image around it's centre left or right?
Really I'm after some pointers around the methods to use - I'm not being lazy and asking for code, but if anyone knows of tutorials - that would help immensely!!
Thanks for any info.
Your best bet is to use one of the UIGestureRecognizer subclasses, probably UIPanGestureRecognizer as it includes velocity.
Apple's SimpleGestureRecognizers project will help you get started.
Related
i'm new to game developing so i might be a little confusing on defining what i need.
Assume i have a wide background picture, much bigger than the screen(e.g.4000*3000px), how should i approach if i want to navigate it with the input from the gyroscopes?
i mean handling the device up, down, left, right and so on.
If you remember the old Mosquitoes game on Symbian i would like to do something similar but without the camera.
However any suggestion is appreciated.
Thanks in advance.
Use UIScrollView - put your pic inside the scroll view and try to navigate with fingers.
When scroll will be working nice, use this or this or any other tutorial to find out how to use accelerometer.
Finally, when you will be able to collect data from accelerometer, give it to UIScrollView using [myScrollView scrollRectToVisible:myRect animated:YES];
All needed math and physics must be done by you.
I want to create a 360 degree turntable showing lots of pictures (12, 24 or 36) by controlling that rotation with touch events (like that example but coded for an iOS app natively).
The simplest idea depending on the touch position is to load that specific uiimage.
Any ideas what's the best practice for that? Is there a chance to create that image-turntable with the help of coreanimation faster? Any other hints on that? Any other projects known where I can get some help on that?
Thanks for your time and hints in the right direction.
Here's another example for an ipad-app from the "audi a8".
From the first example it becomes obvious that the objects have actually been photographed for each angle of rotation. This is the really tricky part. You will need a tripod and a camera with remote control, and if possible also a rotational platter to keep angles consistent.
Implementation is relatively straightforward. As you guessed, you just track the touch positions and, depending on delta to the last touch position, show the appropriate image.
well, you can just use the HTML/CSS/JS used in the same example... just load that in an UIWebView in your app and load your site embedded as a resource...
Subclass UIImageView, load array of your frames, handle tap movement over the screen y-axis and change active image accordingly. Don't forget to loop your images. :)
Is there a way to capture the amount of screen that is making contact with the users? I assume there is since this finger painting app shows the ipad responding to only the pixels that the user makes contact with.
Thanks so much in advance for your help!
The size of the touch is abstracted away by the framework, and UITouches only contain calculated (“best estimated”) points instead of the raw, actual areas that were touched. I would guess that the “pressure” was calculated from the duration and the direction of the touch.
In a nutshell, there is no public API to get the contact area.
I don't think Apple provides APIs for the size of the touch, or as #nickthedude said (I think) any kind of way to measure pressure. Basically, you need to implement your own algorithm/policy for determining line thickness/opacity/other effects. I believe a common way to do this is to measure the amount of time spent for the stroke, and work from there. For instance, if the user moved more quickly, you might want a thinner line segment. Apple really should just provide a canvas view of some kind. Best of luck!
to get the exact area you may have to roll your own but you can get uievents pretty easily and then do some magic from there. Basically impliment/override touchesBegan, touchesEnded, touchesMoved on the UIView in question and put in your custom code there.
Looking at the video maybe the amount of touches in the UIEvent set might correspond to the "pressure" of the touch, then again maybe not.
What if you laid down a series of successively smaller square uiviews wherever the user touched then if the touches "spilled" into the larger uiviews behind the smaller front ones than you could conjecture that the touch pressure was harder. Something to try I guess. Good luck.
Why not just describe what you want to do and foxus on asking about that instead - it may not have anything at all to do with the example that has you so otherwise enthralled - I can use a camera to monitor your hand from across the table and paint pixels on the screen via BT, completely ignoring any contact between your fingers and the screen.
I need to rotate an image when the user do a two finger twist on it.
do you have an idea on how i can code this or if you've done this before.
I think it would be a good idea to write a class that detect all the main gesture and provide iif.
I found this example on the internet. It's very nicely written...
http://www.skylarcantu.com/blog/2009/08/08/multitouchsingletouchtap-handling/
When you rotate your thumb and index clockwise what really happens is that:
the thumb starts on the right
descrives a u shape underneath the index
finishes on the left
If you look at the full gesture it is .) rotated clockwise. In some cases, the index will move slightly south-east so you get /).
I suggest looking into SDK 3.2 - it has extended support for gesture detection.
i am quit new at iphone development and trying to make a photo collage software while learning it. Right now i have a lil problem and hope you can help me out.
I have an UiviewController with a view in it, in this view i have 7 scrollviews with uiimagevies in them for zooming and scollign images within these scrollviews.
All that works well but now i want to make these 7 scrollviews dragable and maybe if possible zoomable (so that the image within the given scroolview zoom together with the scrollview).
It should be possible to drag them all around the screen and if possible even overlap them
and by the way rotating would be great ;-) hope that is not to much asked for.
Would be great if someone can help me out with this..
Well you've got to decide on some other choice here because the functionality you are asking for overlaps, and you can't ask the app to magically know which the user wants to do. What I mean by this is that when you touch and drag within a scroll view, it's going to try to scroll itself, rather than drag the entire scroll view around.
As for rotation and zooming - that gets more complicated, because you start dealing with vector math and the like. You can check out my question on rotation here. The link I gave you has the code to get both rotation and zooming to work.