UIPanGestureRecognizer sometimes doesn't get into End State - ios

I'm developing a card view like in Tinder. When cards X origin is bigger than a value which I declare, It moves out the screen. Otherwise, It sticks to center again. I'm doing all of these things inside UIPanGestureRecognizer function. I can move the view in Change state. However, It sometimes doesn't get into end state so card is neither moves out of the screen or stick to center again. It just stays in some weird place.
So My problem is that card should go out of the screen like in below screenshot or stick into center.
I tried solutions in below post but nothing worked:
UIPanGestureRecognizer not calling End state
UIPanGestureRecognizer does not switch to state "End" or "Cancel" if user panned x and y in negative direction
/// This method handles the swiping gesture on each card and shows the appropriate emoji based on the card's center.
#objc func handleCardPan(sender: UIPanGestureRecognizer) {
// Ensure it's a horizontal drag
let velocity = sender.velocity(in: self.view)
if abs(velocity.y) > abs(velocity.x) {
return
}
// if we're in the process of hiding a card, don't let the user interace with the cards yet
if cardIsHiding { return }
// change this to your discretion - it represents how far the user must pan up or down to change the option
// distance user must pan right or left to trigger an option
let requiredOffsetFromCenter: CGFloat = 80
let panLocationInView = sender.location(in: view)
let panLocationInCard = sender.location(in: cards[0])
switch sender.state {
case .began:
dynamicAnimator.removeAllBehaviors()
let offset = UIOffsetMake(cards[0].bounds.midX, panLocationInCard.y)
// card is attached to center
cardAttachmentBehavior = UIAttachmentBehavior(item: cards[0], offsetFromCenter: offset, attachedToAnchor: panLocationInView)
//dynamicAnimator.addBehavior(cardAttachmentBehavior)
let translation = sender.translation(in: self.view)
print(sender.view!.center.x)
sender.view!.center = CGPoint(x: sender.view!.center.x + translation.x, y: sender.view!.center.y)
sender.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
case .changed:
//cardAttachmentBehavior.anchorPoint = panLocationInView
let translation = sender.translation(in: self.view)
print(sender.view!.center.x)
sender.view!.center = CGPoint(x: sender.view!.center.x + translation.x, y: sender.view!.center.y)
sender.setTranslation(CGPoint(x: 0, y: 0), in: self.view)
case .ended:
dynamicAnimator.removeAllBehaviors()
if !(cards[0].center.x > (self.view.center.x + requiredOffsetFromCenter) || cards[0].center.x < (self.view.center.x - requiredOffsetFromCenter)) {
// snap to center
let snapBehavior = UISnapBehavior(item: cards[0], snapTo: CGPoint(x: self.view.frame.midX, y: self.view.frame.midY + 23))
dynamicAnimator.addBehavior(snapBehavior)
} else {
let velocity = sender.velocity(in: self.view)
let pushBehavior = UIPushBehavior(items: [cards[0]], mode: .instantaneous)
pushBehavior.pushDirection = CGVector(dx: velocity.x/10, dy: velocity.y/10)
pushBehavior.magnitude = 175
dynamicAnimator.addBehavior(pushBehavior)
// spin after throwing
var angular = CGFloat.pi / 2 // angular velocity of spin
let currentAngle: Double = atan2(Double(cards[0].transform.b), Double(cards[0].transform.a))
if currentAngle > 0 {
angular = angular * 1
} else {
angular = angular * -1
}
let itemBehavior = UIDynamicItemBehavior(items: [cards[0]])
itemBehavior.friction = 0.2
itemBehavior.allowsRotation = true
itemBehavior.addAngularVelocity(CGFloat(angular), for: cards[0])
dynamicAnimator.addBehavior(itemBehavior)
showNextCard()
hideFrontCard()
}
default:
break
}
}

I was checking If I'm swiping in horizontal with:
let velocity = sender.velocity(in: self.view)
if abs(velocity.y) > abs(velocity.x) {
return
}
For some reason, It was getting in to return while I'm swiping horizontal. When I comment this block of code, everything started to work :)

Related

I need to move and rotate view around point in the screen with pan gesture

I want to make the view rotate and move around the center of the screen.
Here is visual representation of what I want to achieve. Image
And my current solution:
#objc func circleMoved(_ gesture: UIPanGestureRecognizer) {
switch gesture.state {
case .changed:
let translation = gesture.translation(in: view)
circle.layer.zPosition = 200
let spread = view.width
let angle: CGFloat = 100
let angleMoveX = angle * translation.x / spread
let angleMoveY = angle * translation.y / spread
let angleMoveXRadians = angleMoveX * CGFloat.pi/180
let angleMoveYRadians = angleMoveY * CGFloat.pi/180
var move = CATransform3DIdentity
move = CATransform3DRotate(move, angleMoveXRadians, 0, 1, 0)
move = CATransform3DRotate(move, -angleMoveYRadians, 1, 0, 0)
move = CATransform3DTranslate(move, translation.x, translation.y, 0)
circle.layer.transform = CATransform3DConcat(circle.layer.transform, move)
gesture.setTranslation(.zero, in: view) } }
But the problem is that it rotates more than I wanted. (60 degrees max)

Pan Gesture making view jump away from finger on drag

I'm having a problem when trying to drag a view using a pan gesture recognizer. The view is a collectionViewCell and the dragging code is working, except when the drag starts the view jumps up and to the left. My code is below.
In the collectionViewCell:
override func awakeFromNib() {
super.awakeFromNib()
let panRecognizer = UIPanGestureRecognizer(target:self, action:#selector(detectPan))
self.gestureRecognizers = [panRecognizer]
}
var firstLocation = CGPoint(x: 0, y: 0)
var lastLocation = CGPoint(x: 0, y: 0)
#objc func detectPan(_ recognizer:UIPanGestureRecognizer) {
switch recognizer.state {
case .began:
firstLocation = recognizer.translation(in: self.superview)
lastLocation = recognizer.translation(in: self.superview)
case .changed:
let translation = recognizer.translation(in: self.superview)
self.center = CGPoint(x: lastLocation.x + translation.x, y: lastLocation.y + translation.y)
default:
UIView.animate(withDuration: 0.1) {
self.center = self.firstLocation
}
}
}
The first image is before the drag starts, the second is what happens when dragging up.
You're using self.center instead of using self.frame.origin.x and self.frame.origin.y then later you're setting your translation and adding it to the lastLocation.
Effectively what's happening is that your view is calculating the position changed from the center of the view, as if you were perfectly dragging from that location and then translating + lastLocation. I'm sure just by reading that you're aware of the issue.
The fix is simple.
self.frame.origin.x = translation.x
self.frame.origin.y = translation.y
The difference is the starting calculation with the translation. Origin will grab the x/y position based on where the touch event begins. Whereas the .center always goes from the center.

SceneKit: Using pan gesture to move a node that's not at origin

I have a SCNNode that I've set at a position of SCNVector3(0,0,-1). The following code moves the node forward or backward along the Z-axis, however, the initial pan gesture moves the node to (0,0,0) and then moves the node in line with the pan gesture.
let currentPositionDepth = CGPoint()
#objc func handlePan(sender: UIPanGestureRecognizer) {
let translation = sender.translation(in: sceneView)
var newPos = CGPoint(x: CGFloat(translation.x), y: CGFloat(translation.y))
newPos.x += currentPositionDepth.x
newPos.y += currentPositionDepth.y
node.position.x = Float(newPos.x)
node.position.z = Float(newPos.y)
if(sender.state == .ended) { currentPositionDepth = newPos }
}
I'd like the node to move from it's set position of (0,0,-1). I've tried setting currentPositionDepth.y to -1, however it does not achieve the desired effect. How can I achieve this?
Try something like this:
var previousLoc = CGPoint.init(x: 0, y: 0)
#objc func panAirShip(sender: UIPanGestureRecognizer){
var delta = sender.translation(in: self.view)
let loc = sender.location(in: self.view)
if sender.state == .changed {
delta = CGPoint.init(x: 2 * (loc.x - previousLoc.x), y: 2 * (loc.y - previousLoc.y))
airshipNode.position = SCNVector3.init(airshipNode.position.x + Float(delta.x * 0.02), airshipNode.position.y + Float(-delta.y * (0.02)), 0)
previousLoc = loc
}
previousLoc = loc
}
I have multiplied the 0.02 factor to make the translation smoother and in turn easier for the end user. You may change that factor to anything else you like.

SceneKit: move camera towards direction its facing with pan gesture

I have set up some custom camera controls in my SceneKit game. I am having a problem with my pan gesture auto-adapting based on the cameras y euler angle. The pan gesture I have works by panning the camera on the x and z axis (by using the gestures translation) The problem is, despite the cameras rotation, the camera will continue to pan on the x and z axis. I want it so that the camera pans on the axis its facing.
here are my gestures I am using to pan/rotate:
panning:
var previousTranslation = SCNVector3(x: 0.0,y: 15,z: 0.0)
var lastWidthRatio:Float = 0
var angle:Float = 0
#objc func pan(gesture: UIPanGestureRecognizer) {
gesture.minimumNumberOfTouches = 1
gesture.maximumNumberOfTouches = 1
if gesture.numberOfTouches == 1 {
let view = self.view as! SCNView
let node = view.scene!.rootNode.childNode(withName: "Node", recursively: false)
let secondNode = view.scene!.rootNode.childNode(withName: "CameraHandler", recursively: false)
let translation = gesture.translation(in: view)
let constant: Float = 30.0
angle = secondNode!.eulerAngles.y
//these were the previous values I was using to handle panning, they worked but provided really jittery movement. You can change the direction they rotate by multiplying the sine/cosine .pi values by any integer.
//var translateX = Float(translation.y) * sin(.pi) / cos(.pi) - Float(translation.x) * cos(.pi)
//var translateY = Float(translation.y) * cos(.pi) / cos(.pi) + Float(translation.x) * sin(.pi)
//these ones work a lot smoother
var translateX = Float(translation.x) * Float(Double.pi / 180)
var translateY = Float(translation.y) * Float(Double.pi / 180)
translateX = translateX * constant
translateY = translateY * constant
switch gesture.state {
case .began:
previousTranslation = node!.position
break;
case .changed:
node!.position = SCNVector3Make((previousTranslation.x + translateX), previousTranslation.y, (previousTranslation.z + translateY))
break
default: break
}
}
}
rotation:
#objc func rotate(gesture: UIPanGestureRecognizer) {
gesture.minimumNumberOfTouches = 2
gesture.maximumNumberOfTouches = 2
if gesture.numberOfTouches == 2 {
let view = self.view as! SCNView
let node = view.scene!.rootNode.childNode(withName: "CameraHandler", recursively: false)
let translate = gesture.translation(in: view)
var widthRatio:Float = 0
widthRatio = Float(translate.x / 10) * Float(Double.pi / 180)
switch gesture.state {
case .began:
lastWidthRatio = node!.eulerAngles.y
break
case .changed:
node!.eulerAngles.y = lastWidthRatio + widthRatio
print(node!.eulerAngles.y)
break
default: break
}
}
}
the CameraHandler Node is the parent node of the Camera Node. It all works, it just doesnt work like I want it to. Hopefully this is clear enough for you guys to understand.
In Objective C. The key part is the last three lines and specifically the order of multiplication of the matrices in the last line (causing the movement to happen in local space). If the transmat and cammat are switched it would behave again like you have now (moving in world space). The refactor part is just something that works for my specific situation where both perspective and orthographic camera is possible.
-(void)panCamera :(CGPoint)location {
CGFloat dx = _prevlocation.x - location.x;
CGFloat dy = location.y - _prevlocation.y;
_prevlocation = location;
//refactor dx and dy based on camera distance or orthoscale
if (cameraNode.camera.usesOrthographicProjection) {
dx = dx / 416 * cameraNode.camera.orthographicScale;
dy = dy / 416 * cameraNode.camera.orthographicScale;
} else {
dx = dx / 720 * cameraNode.position.z;
dy = dy / 720 * cameraNode.position.z;
}
SCNMatrix4 cammat = self.cameraNode.transform;
SCNMatrix4 transmat = SCNMatrix4MakeTranslation(dx, 0, dy);
self.cameraNode.transform = SCNMatrix4Mult(transmat, cammat);
}
I figured it out, based off of what Xartec answered. I translated it into swift and retro-fitted it to work with what I needed. I'm not truly happy with it because the movement is not smooth. I will work on smoothing it out later today.
pan gesture: This gesture pans the cameras parent node around the scene in the direction that the camera is rotated. It works exactly like I wanted.
#objc func pan(gesture: UIPanGestureRecognizer) {
gesture.minimumNumberOfTouches = 1
gesture.maximumNumberOfTouches = 1
if gesture.numberOfTouches == 1 {
let view = self.view as! SCNView
let node = view.scene!.rootNode.childNode(withName: "CameraHandler", recursively: false)
let translation = gesture.translation(in: view)
var dx = previousTranslation.x - translation.x
var dy = previousTranslation.y - translation.y
dx = dx / 100
dy = dy / 100
print(dx,dy)
let cammat = node!.transform
let transmat = SCNMatrix4MakeTranslation(Float(dx), 0, Float(dy))
switch gesture.state {
case .began:
previousTranslation = translation
break;
case .changed:
node!.transform = SCNMatrix4Mult(transmat, cammat)
break
default: break
}
}
}
rotation gesture: This gesture rotates the camera with two fingers.
#objc func rotate(gesture: UIPanGestureRecognizer) {
gesture.minimumNumberOfTouches = 2
gesture.maximumNumberOfTouches = 2
if gesture.numberOfTouches == 2 {
let view = self.view as! SCNView
let node = view.scene!.rootNode.childNode(withName: "CameraHandler", recursively: false)
let translate = gesture.translation(in: view)
var widthRatio:Float = 0
widthRatio = Float(translate.x / 10) * Float(Double.pi / 180)
switch gesture.state {
case .began:
lastWidthRatio = node!.eulerAngles.y
break
case .changed:
node!.eulerAngles.y = lastWidthRatio + widthRatio
break
default: break
}
}
}
To get the same functionality that I have, you need to attach the cameraNode to a parent node. Like so:
//create and add a camera to the scene
let cameraNode = SCNNode()
//cameraHandler is declared outside viewDidLoad.
let cameraHandler = SCNNode()
cameraNode.camera = SCNCamera()
cameraNode.name = "Camera"
cameraNode.position = SCNVector3(x: 0.0,y: 10.0,z: 20.0)
//This euler angle only rotates the camera downward a little bit. It is not neccessary
cameraNode.eulerAngles = SCNVector3(x: -0.6, y: 0, z: 0)
cameraHandler.addChildNode(cameraNode)
cameraHandler.name = "CameraHandler"
scene.rootNode.addChildNode(cameraHandler)

Spritekit bounce effect from spritenode dragged by finger

I have a demo app for testing physics in SpriteKit. I was able to simulate inertia after throwing sprite with pan gesture. When I release finger bouncing works great.
Problem is: How to simulate bouncing during dragging? I would like to red SKSpriteNode bounce off when I hit it with dragging SKSpriteNode.
I tried to set self.selectedNode?.physicsBody?.isDynamic = true but then sprite moves away under finger even when I set correct position.
Here is my repo. Feel free to copy or experiment.
Crucial code:
func handlePan(panGestureRecognizer recognizer:UIPanGestureRecognizer) {
let touchLocationView = recognizer.location(in: recognizer.view)
let touchLocationScene = self.convertPoint(fromView: touchLocationView)
switch recognizer.state {
case .began:
self.showMoved = false
let canditateNode = self.touchedNode(touchLocationScene)
if let name = canditateNode.name, name.contains(kMovableNode) {
self.selectedNode = canditateNode
self.selectedNode?.physicsBody?.isDynamic = false;
}
case .changed:
let translation = recognizer.translation(in: recognizer.view)
if let position = self.selectedNode?.position {
self.selectedNode?.position = CGPoint(x: position.x + translation.x, y: position.y - translation.y)
recognizer.setTranslation(CGPoint.zero, in: recognizer.view)
}
case .ended:
self.selectedNode?.physicsBody?.isDynamic = true;
let velocity = recognizer.velocity(in: recognizer.view)
self.selectedNode?.physicsBody?.applyImpulse(CGVector(dx: velocity.x, dy: -velocity.y))
self.selectedNode = nil
self.showMoved = true
default:
break
}
}

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