I have a game where you have "specks" and "connectors".
I make a UIImageView that connects two "specks"… but as you can see (if the picture works), when the specks are almost on top of each other, like on the left, it doesn't work. This is my code… and I was wondering how you would make the rotation more accurate in that sort of situation.
UIImageView *connector = [[UIImageView alloc] initWithImage:[UIImage imageNamed:#"RedConnector.png"]];
connector.contentMode = UIViewContentModeScaleToFill;
connector.hidden = NO;
connector.alpha = 1;
connector.frame = CGRectMake(0, 0, [self DistanceBetweenPoints:speck1.center :speck2.center], 7);
connector.center = CGPointMake((speck1.center.x + speck2.center.x)/2, (speck1.center.y + speck2.center.y)/2);
//This is where the prob is:
connector.transform = CGAffineTransformMakeRotation(tanh((speck2.center.y - speck1.center.y)/(speck2.center.x - speck1.center.x)) );
[Connectors addObject:connector];
[self.view addSubview:connector];
"DistanceBetweenPoints" is not the problem. That works fine. Also, I know the center AND the frame is sort of redundant-- I'll work that out later. Third of all, I have made sure that two specks are never directly on top of each other (to never divide by zero). Last of all, I STILL WANT THESE TO BE UIIMAGEVIEWS!! So I can change the image and animate them so it looks like electricity flowing from speck to speck.
If anybody could show me how to make the rotation more accurate, it would be greatly appreciated. Thanks!
You should use atan2(y,x), not tanh(y/x). That is, you want the arctangent, not the hyperbolic tangent.
Related
I am working on a game where my hero will be able to jump. I can do that with applyImpulse easy enough. The problem I'm having is I want him to be able to double jump and sometimes triple jump. When he does a double jump, sometimes he goes REALLY high. Way higher than the first jump. I want his jump to be equal each time he does it and I want him to go down at the same speed that he went up.
I am using this for the jump:
[hero.physicsBody applyImpulse:CGVectorMake(0, 120)];
I don't have a lot of physicsWorld defined which might be my issue. I have the following set:
self.physicsWorld.contactDelegate = self;
self.physicsWorld.gravity = CGVectorMake(0, -10.0);
I've tried different gravity's but it comes out the same.
My hero has the following properties:
hero.physicsBody.friction = 1.0f;
hero.physicsBody.restitution = 0.0f;
hero.physicsBody.linearDamping = 0.1f;
hero.physicsBody.allowsRotation = NO;
hero.physicsBody.mass = 0.2f;
Is there something here that would be causing my issue? Something I'm missing or I should try?
That's how physics works. A way around it is to reset hero's velocity right before you apply the second impulse.
hero.physicsBody.velocity = CGVectorMake(0, 0);
[hero.physicsBody applyImpulse:CGVectorMake(0, 120)];
I supplied slider graphic for my slider.
This is the result:
Then on the right
So you see, the edge become a "box" rather than rounded. What I really want is something that's closer with what apple provide. This is the code I used to switch back and forth between using custom slider image and nil:
- (IBAction)groupPinButton:(id)sender {
self.groupPinButton.selected = ! self.groupPinButton.selected;
UIImage *minImage = [[UIImage imageNamed:#"minimum_slider.png"]resizableImageWithCapInsets2:UIEdgeInsetsMake(0, 5, 0, 0)];
UIImage *maxImage = [[UIImage imageNamed:#"maximum_slider.png"]resizableImageWithCapInsets2:UIEdgeInsetsMake(0, 0, 0, 5)];
if (self.groupPinButton.selected)
{
[self.distanceSlider setMaximumTrackImage:maxImage forState:UIControlStateNormal];
[self.distanceSlider setMinimumTrackImage:minImage forState:UIControlStateNormal];
}
else{
[self.distanceSlider setMaximumTrackImage:nil forState:UIControlStateNormal];
[self.distanceSlider setMinimumTrackImage:nil forState:UIControlStateNormal];
}
}
If I set the maximumTrackImage as nil, this is the screenshot:
Which looks lot nicer. But I want to customize.
The pictures that I use for minimum_slider.png and maximum_slider.png is the following:
and you can get there at
http://i.stack.imgur.com/n30aw.png
and
http://i.stack.imgur.com/sF9SQ.png
Note the other edge is fine though. So when slider is anywhere except the maximum and minimum things work fine. If the slider is at maximum then the far right corner is messed up. The far left corner is fine.
Ah! The same problem I was having. As you get to the end of the program, and the slider is at maximum, the entire track image is now the left side, the "minimum_slider.png" in your example. Thus there is no part of the "maximum_slider" image showing (which would have given you the rounded right edge), only the square right side of the "minimum_slider".
I suspect the answer is to give your two images rounded sides on both ends, and make the expandable parts (the edge insets) in the middle of the graphic.
I haven't done this yet, as I'm still confused as to the workings of UIEdgeInsets (I find the documentation terrible!) and the default track is sufficient for me now. So let us all know when you solve this.
I am using the Leaves project to move from one pdf page to another it is working fine. Now the page curl is from left to right and from right to left like a note book. I need to curl it from top to bottom and bottom to top. Does anyone know the methods to do it, or any other templates to do this?
Just use the UIPageViewController from Apple instead of Leaves http://developer.apple.com/library/ios/#DOCUMENTATION/UIKit/Reference/UIPageViewControllerClassReferenceClassRef/UIPageViewControllerClassReference.html
This gives you exactly the curl they use in iBooks for example, so a lot more beautiful (more realistic) matrix of the curled view.
Just make all your note sheets a View and give the views the UIPageViewController
It also has various options where the spine is located and other stuff
To make a curl up you could either use
[UIView setAnimationTransition:UIViewAnimationTransitionCurlUp forView:self.view cache:YES];
[UIView setAnimationTransition:UIViewAnimationTransitionCurlDown forView:self.view cache:YES]; like bala mentioned or instantiate another UIPageViewController that is responsible for up and downwards transitions.
If you want to really go into the view and maybe switch with this through multiple items i would just use 2 uipageviewcontrollers so one horizontal and one vertical
this method
SampleViewController *sampleView = [[[SampleViewController alloc] init] autorelease];
[sampleView setModalTransitionStyle:UIModalTransitionStylePartialCurl];
[self presentModalViewController:sampleView animated:YES];
as in this tutorial may be helpful
The existing leaves view is hard-coded to be left-to-right. You can create a hard-coded top-to-bottom version easily enough, but there may well be more robust generic solutions.
However, if you definitely must use leaves, you can rewrite its source to suit. The solution below hard-codes for vertical motion. If you need horizontal and vertical options, you will have more work do do.
Display
setUpLayers
Reverse the axes in every call to CGPointMake. This fixes up the gradients that display the shadows.
Also change topPage.contentsGravity = kCAGravityLeft; to topPage.contentsGravity = kCAGravityBottom; and topPageReverseImage.contentsGravity = kCAGravityRight; to topPageReverseImage.contentsGravity = kCAGravityTop;. This is a subtle change that makes sure incoming pages are displayed with the correct edges.
setLayerFrames
Most of the geometry changes happen here. The original code oddly uses view bounds in some places and layer bounds in others. I duplicated those, but it would be good to understand if the distinction is meaningful before using this code in production.
- (void) setLayerFrames {
topPage.frame = CGRectMake(self.layer.bounds.origin.x,
self.layer.bounds.origin.y,
self.bounds.size.width,
leafEdge * self.layer.bounds.size.height);
topPageReverse.frame = CGRectMake(self.layer.bounds.origin.x,
self.layer.bounds.origin.y + (2*leafEdge-1) * self.layer.bounds.size.height,
self.bounds.size.width,
(1-leafEdge) * self.layer.bounds.size.height);
bottomPage.frame = self.layer.bounds;
topPageShadow.frame = CGRectMake(0,
topPageReverse.frame.origin.y - 40,
bottomPage.bounds.size.width,
40);
topPageReverseImage.frame = topPageReverse.bounds;
topPageReverseImage.transform = CATransform3DMakeScale(1, -1, 1);
topPageReverseOverlay.frame = topPageReverse.bounds;
topPageReverseShading.frame = CGRectMake(0,
topPageReverse.bounds.size.height - 50,
topPageReverse.bounds.size.width,
50 + 1);
bottomPageShadow.frame = CGRectMake(0,
leafEdge * self.bounds.size.height,
bottomPage.bounds.size.width,
40);
topPageOverlay.frame = topPage.bounds;
}
Interaction
updateTargetRects
Where this calculates nextPageRect and prevPageRect, put them on the bottom and top instead of the right and left.
touchesMoved:withEvent:
Change self.leafEdge = touchPoint.x / self.bounds.size.width; to self.leafEdge = touchPoint.y / self.bounds.size.height;.
This question has been asked before but in a slightly different way and I was unable to get any of the answers to work the way I wanted, so I am hoping somebody with great Core Animation skills can help me out.
I have a set of cards on a table. As the user swipes up or down the set of cards move up and down the table. There are 4 cards visible on the screen at any given time, but only the second card is showing its face. As the user swipes the second card flips back onto its face and the next card (depending on the swipe direction) lands in it's place showing its face.
I have set up my card view class like this:
#interface WLCard : UIView {
UIView *_frontView;
UIView *_backView;
BOOL flipped;
}
And I have tried flipping the card using this piece of code:
- (void) flipCard {
[self.flipTimer invalidate];
if (flipped){
return;
}
id animationsBlock = ^{
self.backView.alpha = 1.0f;
self.frontView.alpha = 0.0f;
[self bringSubviewToFront:self.frontView];
flipped = YES;
CALayer *layer = self.layer;
CATransform3D rotationAndPerspectiveTransform = CATransform3DIdentity;
rotationAndPerspectiveTransform.m34 = 1.0 / 500;
rotationAndPerspectiveTransform = CATransform3DRotate(rotationAndPerspectiveTransform, M_PI, 1.0f, 0.0f, 0.0f);
layer.transform = rotationAndPerspectiveTransform;
};
[UIView animateWithDuration:0.25
delay:0.0
options: UIViewAnimationCurveEaseInOut
animations:animationsBlock
completion:nil];
}
This code works but it has the following problems with it that I can't seem to figure out:
Only half of the card across the x-axis is animated.
Once flipped, the face of the card is upside down and mirrored.
Once I've flipped the card I cannot get the animation to ever run again. In other words, I can run the animation block as many times as I want, but only the first time will animate. The subsequent times I try to animate lead to just a fade in and out between the subviews.
Also, bear in mind that I need to be able to interact with the face of the card. i.e. it has buttons on it.
If anybody has run into these issues it would be great to see your solutions. Even better would be to add a perspective transform to the animation to give it that extra bit of realism.
This turned out to be way simpler than I thought and I didn't have to use any CoreAnimation libraries to achieve the effect. Thanks to #Aaron Hayman for the clue. I used transitionWithView:duration:options:animations:completion
My implementation inside the container view:
[UIView transitionWithView:self
duration:0.2
options:UIViewAnimationOptionTransitionFlipFromBottom
animations: ^{
[self.backView removeFromSuperview];
[self addSubview:self.frontView];
}
completion:NULL];
The trick was the UIViewAnimationOptionTransitionFlipFromBottom option. Incidentally, Apple has this exact bit of code in their documentation. You can also add other animations to the block like resizing and moving.
Ok, this won't be a complete solution but I'll point out some things that might be helpful. I'm not a Core-Animation guru but I have done a few 3D rotations in my program.
First, there is no 'back' to a view. So if you rotate something by M_PI (180 degrees) you're going to be looking at that view as though from the back (which is why it's upside down/mirrored).
I'm not sure what you mean by:
Only half of the card across the x-axis is animated.
But, it it might help to consider your anchor point (the point at which the rotation occurs). It's usually in the center, but often you need it to be otherwise. Note that anchor points are expressed as a proportion (percentage / 100)...so the values are 0 - 1.0f. You only need to set it once (unless you need it to change). Here's how you access the anchor point:
layer.anchorPoint = CGPointMake(0.5f, 0.5f) //This is center
The reason the animation only ever runs once is because transforms are absolute, not cumulative. Consider that you're always starting with the identity transform and then modifying that, and it'll make sense...but basically, no animation occurs because there's nothing to animate the second time (the view is already in the state you're requesting it to be in).
If you're animating from one view to another (and you can't use [UIView transitionWithView:duration:options:animations:completion:];) you'l have to use a two-stage animation. In the first stage of the animation, for the 'card' that is being flipped to backside, you'll rotate the view-to-disappear 'up/down/whatever' to M_PI_2 (at which point it will be 'gone', or not visible, because of it's rotation). And in the second stage, you're rotate the backside-of-view-to-disappear to 0 (which should be the identity transform...aka, the view's normal state). In addition, you'll have to do the exact opposite for the 'card' that is appearing (to frontside). You can do this by implementing another [UIView animateWithDuration:...] in the completion block of the first one. I'll warn you though, doing this can get a little bit complicated. Especially since you're wanting views to have a 'backside', which will basically require animating 4 views (the view-to-disappear, the view-to-appear, backside-of-view-to-disappear, and the backside-of-view-to-appear). Finally, in the completion block of the second animation you can do some cleanup (reset view that are rotated and make their alpha 0.0f, etc...).
I know this is complicated, so you might want read some tutorial on Core-Animation.
#Aaron has some good info that you should read.
The simplest solution is to use a CATransformLayer that will allow you to place other CALayer's inside and maintain their 3D hierarchy.
For example to create a "Card" that has a front and back you could do something like this:
CATransformLayer *cardContainer = [CATransformLayer layer];
cardContainer.frame = // some frame;
CALayer *cardFront = [CALayer layer];
cardFront.frame = cardContainer.bounds;
cardFront.zPosition = 2; // Higher than the zPosition of the back of the card
cardFront.contents = (id)[UIImage imageNamed:#"cardFront"].CGImage;
[cardContainer addSublayer:cardFront];
CALayer *cardBack = [CALayer layer];
cardBack.frame = cardContainer.bounds;
cardBack.zPosition = 1;
cardBack.contents = (id)[UIImage imageNamed:#"cardBack"].CGImage; // You may need to mirror this image
[cardContainer addSublayer:cardBack];
With this you can now apply your transform to cardContainer and have a flipping card.
#Paul.s
I followed your approach with card container but when i applt the rotation animation on card container only one half of the first card rotates around itself and finally the whole view appears.Each time one side is missing in the animation
Based on Paul.s this is updated for Swift 3 and will flip a card diagonally:
func createLayers(){
transformationLayer = CATransformLayer(layer: CALayer())
transformationLayer.frame = CGRect(x: 15, y: 100, width: view.frame.width - 30, height: view.frame.width - 30)
let black = CALayer()
black.zPosition = 2
black.frame = transformationLayer.bounds
black.backgroundColor = UIColor.black.cgColor
transformationLayer.addSublayer(black)
let blue = CALayer()
blue.frame = transformationLayer.bounds
blue.zPosition = 1
blue.backgroundColor = UIColor.blue.cgColor
transformationLayer.addSublayer(blue)
let tgr = UITapGestureRecognizer(target: self, action: #selector(recTap))
view.addGestureRecognizer(tgr)
view.layer.addSublayer(transformationLayer)
}
Animate a full 360 but since the layers have different zPositions the different 'sides' of the layers will show
func recTap(){
let animation = CABasicAnimation(keyPath: "transform")
animation.delegate = self
animation.duration = 2.0
animation.fillMode = kCAFillModeForwards
animation.isRemovedOnCompletion = false
animation.toValue = NSValue(caTransform3D: CATransform3DMakeRotation(CGFloat(Float.pi), 1, -1, 0))
transformationLayer.add(animation, forKey: "arbitrarykey")
}
In viewWillAppear I want to adjust some of my views using the following transformation (Monotouch code):
CATransform3D oTransform3D = CATransform3D.Identity;
oTransform3D.m34 = 1.0f / -400;
oTransform3D = oTransform3D.Translate( 110, 0, 0);
oTransform3D = oTransform3D.Rotate( (-70f) * (float)Math.PI / 180f, 0, 1, 0);
However, this causes the view to be rendered far left of the screen.
If I put the very same code in viewDidAppear, it is working.
I have already checked that all views have valid sizes.
Did you ever figure this out? I've run into a similar situation where a 3D transform refuses to behave when applied to an immediate subview of a UIViewController's root view. A workaround for me was to wrap the subview in another container UIView.
Something along these lines:
- (void)viewDidLoad {
[super viewDidLoad];
UIView *container = [[UIView alloc] initWithFrame:CGRectMake(0,0,self.view.frame.size.width,self.view.frame.size.height)];
container.autoresizingMask = UIViewAutoresizingFlexibleWidth | UIViewAutoResizingFlexibleHeight;
[self.view addSubview:container];
self.myCrazyFlippingSpinningView = [[CrazyFlippingSpinningView alloc] init];
[container addSubview:self.myCrazyFlippingSpinningView];
}
Of course, I'd prefer to not have to do that. It's such a hack. If anyone's encountered this and has a better solution, I'd love to see it.
Thanks!
Not sure I fully understand the question but I am going to take a swag.
CATransform3D has a vanishing point that transforms refer to. The vanishing point is always the x,y center point of whatever view you place the transformed view onto. When I was struggling through the 3D transform issues and getting unexpected results, it was always solved by simply making sure I knew the size and center point of the container view.
You say your code works in ViewDidLoad...does that mean you are adding a transformed view to the base view? like: this.View.AddSubview(yourTransformedView); ??
I mean, I don't think your problem is a matter of ViewWillAppear vs. ViewDidLoad; I am going to guess that if I saw the code where you apply your transform to the views and then add your views to a base view or some other superview, I would be able to quickly tell you what is happening.