I have a iOS app that draws a grid of sprites on screen. I then have another sprite representing a colour which I can drag and drop over the grid. My question is how do I identify which sprite on the grid it was dragged onto?
Ultimately I want to allow a user to drag a colour sprite over another sprite, so I can change the colour, as per the users selection.
The code below only returns the 2nd sprite (the top one) at the location, whereas I need to identify both sprites at that location.
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?)
{
print("tocuhes ended")
for touch in touches
{
let location = touch.locationInNode(self)
let nodeAtLocation = self.nodeAtPoint(location)
let nodeName = nodeAtLocation.name
print("Node Name \(nodeName)")
}
}
override func touchesEnded(touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches
{
let location = touch.locationInNode(self)
let nodesAtLocation = self.nodesAtPoint(location)
for node in nodesAtLocation {
let nodeName = node.name
print("Node Name \(nodeName)")
}
}
}
Related
Essentially, what I want is for when I touch a node, I want to be able to move it across the screen. The problem is that whenever I move my finger too fast, the node just stops following it.
The spriteNodes in particular that I'm trying to do this with have physics bodies and animating textures so I tried to do the same code with a completely plain spriteNode and I've encountered the same problem.
The code that I have here is pretty simple so I'm not sure if this is a problem with what I've written or if it's just a lag problem that I can't fix. It's also basically the same all throughout touchesBegan, touchesMoved and touchesEnded
for touch in touches {
let pos = touch.location(in: self)
let node = self.atPoint(pos)
if node.name == "activeRedBomb"{
node.position = pos
}
if node.name == "activeBlackBomb"{
node.position = pos
}
if node.name == "test"{
node.position.x = pos.x
node.position.y = pos.y
}
}
What's happening is that if you move your finger too fast, then at some point, the touch location will no longer be on the sprite, so you code to move the node won't fire.
What you need to do is set a flag in touchesBegan() to indicate that this sprite is touched, move the sprite to the location of the touch in touchesMoved() if the flag is set and then reset the flag in touchesEnded().
Here's roughly what you need to add for this:
import SpriteKit
class GameScene: SKScene {
var bombIsTouched = false
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
if let touch = touches.first {
if activeRedBomb.contains(touch.location(in: self)) {
bombIsTouched = true
}
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
if bombIsTouched {
activeRedBomb.position = (touches.first?.location(in: self))!
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
if bombIsTouched {
bombIsTouched = false
}
}
So I have these moving sprites with physics bodies that I initially have constrained to one area. Let's say call this area Box1. When the sprites bump the borders of Box1, they bump back and the SKConstraint is just an additional measure to make sure they stay within the box.
What I'm trying to do is make a button that causes all the sprites in Box1 move across the screen to a second box (Box2) that is basically identical to Box1 but right beside it. Box1 and Box2 share a border wall, so essentially the screen is divided in two sections.
My problem is when I call up my button function, the sprites get stuck at the wall and aren't able to go past it to Box2. I've tried setting both the physics bodies and the SKConstraints of the nodes to nil so I don't know what else is preventing them.
func moveSprites(){
if box1Sprites.isEmpty == false {
for sprite in box1Sprites{
sprite.constraints = nil
sprite.physicsBody = nil
let moveAction = SKAction.move(to: CGPoint(x: -300, y: 0), duration: 1) //This is a point within Box2
sprite.run(moveAction)
}
}
}
EDIT:
I also made it so that I could drag and drop the sprites from one box to the other and the code for that is pretty much the same and it works fine.
var currentMovingSprite: SKSpriteNode? = SKSpriteNode()
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let pos = touch.location(in: self)
let node = self.atPoint(pos)
if node.name == "sprite"{
node.constraints = nil
node.physicsBody = nil
currentMovingSprite = node
}
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
let pos = touch.location(in: self)
if let sprite = currentMovingSprite{
sprite.position = pos
}
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
spritePhysics(sprite: currentMovingSprite) // resets the sprite to how it was before
currentMovingSprite = nil
}
I would like to get the location of the touch in the UI, and use that location to determine what direction the sprite runs. For example, if the touch is on the left side of the screen, the user runs left, and if the touch is on the right side of the screen, the user runs right.
Try something like this
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
if let touch = touches.first {
let position = touch.locationInView(view)
print(position)
}
}
#KnightOfDragon's answer is the right one here.
You should use directly
func locationInNode(_ node: SKNode) -> CGPoint
More about Touch events in SpriteKit over here: documentation
As KnightOfDragon mentioned for SpriteKit the correct way would be
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches {
let location = touch.locationInNode(self) // self is the current SKScene
let node = nodeAtPoint(location)
// To get the touched half of the screen I do this
if location.x < CGRectGetMidX(self.frame) {
// left half touched, do something
}
if location.x > CGRectGetMidX(self.frame) {
// right half touched, do something
}
}
}
I have an SKNode on SpriteKit, which I basically want to be able to drag around the screen, but without having to touch it! Imagine I press the screen anywhere. I then want my SKNode to keep its distance to my finger, so that when I drag it I can see it.
I have this working but the object snaps to the touch.
override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches{
let location = touch.locationInNode(self)
circle.position = location
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?) {
for touch in touches{
let location = touch.locationInNode(self)
circle.position = location
}
}
It's a classic basic problem in game engineering.
There are two solutions...
First solution: when finger first goes down, make a note of the "grab" delta, being the delta from the position of the object, to, the finger.
When the finger moves each time to new position P, subtract the "grab" delta from P before setting the position of the object to P.
"It's that easy"
Second solution: each time the finger moves, don't bother at all with the position P of the finger.
Instead, calculate the delta the finger moved from the previous frame.
(So, simply store the previous position each time so you can calculate that - some systems give you the previous position as a property since it's so common, indeed some systems just give you the delta automatically as a property!)
Then just move the object by that delta.
"It's that easy"
Here is precisely the first solution, in iOS/SpriteKit
class FingerFollower: SKSpriteNode {
var grab: CGVector = CGVector.zero
// "grab" is the usual term for the delta from the object
// to where the finger "grabbed" it...
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
let t: UITouch = touches.first! as UITouch
let l = t.location(in: parent!)
grab = (l - position).vector
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
let t: UITouch = touches.first! as UITouch
let loc = t.location(in: parent!)
position = loc - grab
}
// NOTE this code uses the absolutely obvious overrides for
// subtraction etc between vectors, which you will need in 100%
// of spritekit projects (Apple forgot about them)
}
Here is precisely the second solution, in iOS/SpriteKit
class FingerFollower: SKSpriteNode {
func setup() {
// NOTE, you MUST have a "setup" call in your sprite subclasses;
// apple forgot to include a "didAppear" for SKNodes
isUserInteractionEnabled = true
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
// note that Apple do in fact include the "previous location"
// in sprite kit touches. (In systems where they don't do that,
// you just make a note of it each time.)
let prev = t.previousLocation(in: parent!)
let quickDelta = loc - prev
position = position + quickDelta
}
}
override func touchesMoved(touches: Set<UITouch>, withEvent event: UIEvent?){
let touch = touches.anyObject() as UITouch!
let touchLocation = touch.locationInNode(self)
let previousLocation = touch.previousLocationInNode(self)
let distanceX = touchLocation.x - previousLocation.x
let distanceY = touchLocation.y - previousLocation.y
circle.position = CGPointMake(circle.position.x + distanceX, circle.position.y + distanceY)
}
I had a problem with movning some nodes around but I found a way (finally) but then I faced a problem which is : when two nodes gets across the touch will move from one node to the other ! but what I want is when I touch a node I will move it until I move my finger from the screen
here is my code :
override func touchesMoved(touches: Set<NSObject>, withEvent event: UIEvent) {
for touch: AnyObject in touches {
var location = touch.locationInNode(self)
let node = nodeAtPoint(location)
if node == firstCard{
firstCard.position = location
}else if node == secondCard{
secondCard.position = location
println("Second Card Location")
println(secondCard.position)
}else{
println("Test")
}
}
}
You need to keep track of the SKNode the finger touched in touchesBegan
First thing to remember is the the same UITouch object is returned for each finger in touchesMoved with different locations. So we can keep track of the each touch in the node using a touchTracker dictionary.
var touchTracker : [UITouch : SKNode] = [:]
Also give a name to each card, so that we can keep track of the nodes that need to be moved. For example.
card1.name = "card"
card2.name = "card"
In touchesBegan, we will add the node that is under the touch to the touchTracker.
override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
let location = touch.locationInNode(self)
let node = self.nodeAtPoint(location)
if (node.name == "card") {
touchTracker[touch as UITouch] = node
}
}
}
When a touch is moved inside touchesMoved, we will get the node back from the touchTracker and update its position.
override func touchesMoved(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
let location = touch.locationInNode(self)
let node = touchTracker[touch as UITouch]
node?.position = location
}
}
In touchesEnded, we update the final position again, and remove the touch key-value pair from touchTracker.
override func touchesEnded(touches: NSSet, withEvent event: UIEvent) {
for touch in touches {
let location = touch.locationInNode(self)
let node = touchTracker[touch as UITouch]
node?.position = location
touchTracker.removeValueForKey(touch as UITouch)
}
}