When I run my program. The code I put into "override func sceneDidLoad()" runs two times.
E.g.
Note: I have no idea why this picture is not uploading, but it shows "spawn" happening twice.
This code should only run once when "sceneDidLoad()" is called.
Here is the code for the "sceneDidLoad" function, and for the "testSpawn()" function (which is the specific one that gave the duplicated printout).
class GameScene: SKScene {
var mapTerrain: SKTileMapNode!
override func sceneDidLoad() {
cam = SKCameraNode()
cam.xScale = 1
cam.yScale = 1
//do zoom by change in scale in pinch. (E.g. if they start out 5 units apart and end up 15 units apart, zoom by a factor of 3
self.camera = cam
self.addChild(cam)
cam.position = CGPoint(x: 100, y: 100)
setupLayers()
loadSceneNodes()
setUpUI()
testSpawn()
//print("\(self.frame.width), \(self.frame.height)")
}
func testSpawn(){
let RedLegion = legion(texture: textureRedLegion, moveTo: nil, tag: 1, health: 2)
RedLegion.position = mapTerrain.centerOfTile(atColumn: 0, row: 0)
RedLegion.team = "Red"
unitsLayer.addChild(RedLegion)
legionList.append(RedLegion)
print("spawn")
}
}
Note: Not all of the code is here (like "setUpLayers()"), if needed I can supply it, I just do not think it is neccessary.
Search your whole document for "print("spawn")" just to make sure that is the only time you call the function. Also check for "testSpawn()" to make sure it is only called once. Additionally, instead of relying on this print to count how many times the sceneDidLoad runs, place a print directly within your sceneDidLoad. Finally, check to make sure you are not creating the scene twice.
I've also seen this and submitted a bug report but apple responded saying that it is intended behavior. Apple said that it creates a dummy scene and then creates the actual scene. Before it runs the second time it gets rid of anything done the first time so you shouldn't get any errors from it. The bug is really hard to reproduce, one of my friends working off the same repository that I was but did not experience the bug.
I changed sceneDidLoad to didMoveToView:(SKView *)view if you are looking for a solution to this. Make sure you xcode is up to date.
Related
I have a method that manage constraints, while some conditions are met. That method is placed inside scrollViewDidScroll methood:
func scrollViewDidScroll(_ scrollView: UIScrollView) {
partiallyHideOverallViewOnScrolling(scrollView)
scrollToNewRowsIfNeeded()
}
Recently I discover freezes and weird behaviour while scrolling table, is there are possibility to call method inside scrollViewDidScroll no more then, for example, every 0.1 second?
It appears that method called 111 times on single drag down, when there is not much items in a tableView, that's quite a lot
even though Dogan Altinbas's comment suggesting to use scrollViewWillBeginDragging and scrollViewWillEndDragging sounds like the right approach to me I'd like to answer your question.
Just a quick example I created in a playground:
import UIKit
var date = Date()
while (true) {
if Date().timeIntervalSince(date) > 1 {
print("foo")
date = Date()
}
}
You'll see it'll only print once per second. I just remember the last time I fired the event I wanted to fire and go from there.
Cheers,
Dominic
I am compositing an array of UIImages via an MTKView, and I am seeing refresh issues that only manifest themselves during the composite phase, but which go away as soon as I interact with the app. In other words, the composites are working as expected, but their appearance on-screen looks glitchy until I force a refresh by zooming in/translating, etc.
I posted two videos that show the problem in action: Glitch1, Glitch2
The composite approach I've chosen is that I convert each UIImage into an MTLTexture which I submit to a render buffer set to ".load" which renders a poly with this texture on it, and I repeat the process for each image in the UIImage array.
The composites work, but the screen feedback, as you can see from the videos is very glitchy.
Any ideas as to what might be happening? Any suggestions would be appreciated
Some pertinent code:
for strokeDataCurrent in strokeDataArray {
let strokeImage = UIImage(data: strokeDataCurrent.image)
let strokeBbox = strokeDataCurrent.bbox
let strokeType = strokeDataCurrent.strokeType
self.brushStrokeMetal.drawStrokeImage(paintingViewMetal: self.canvasMetalViewPainting, strokeImage: strokeImage!, strokeBbox: strokeBbox, strokeType: strokeType)
} // end of for strokeDataCurrent in strokeDataArray
...
func drawStrokeUIImage (strokeUIImage: UIImage, strokeBbox: CGRect, strokeType: brushTypeMode) {
// set up proper compositing mode fragmentFunction
self.updateRenderPipeline(stampCompStyle: drawStampCompMode)
let stampTexture = UIImageToMTLTexture(strokeUIImage: strokeUIImage)
let stampColor = UIColor.white
let stampCorners = self.stampSetVerticesFromBbox(bbox: strokeBbox)
self.stampAppendToVertexBuffer(stampUse: stampUseMode.strokeBezier, stampCorners: stampCorners, stampColor: stampColor)
self.renderStampSingle(stampTexture: stampTexture)
} // end of func drawStrokeUIImage (strokeUIImage: UIImage, strokeBbox: CGRect)
func renderStampSingle(stampTexture: MTLTexture) {
// this routine is designed to update metalDrawableTextureComposite one stroke at a time, taking into account
// whatever compMode the stroke requires. Note that we copy the contents of metalDrawableTextureComposite to
// self.currentDrawable!.texture because the goal will be to eventually display a resulting composite
let renderPassDescriptorSingleStamp: MTLRenderPassDescriptor? = self.currentRenderPassDescriptor
renderPassDescriptorSingleStamp?.colorAttachments[0].loadAction = .load
renderPassDescriptorSingleStamp?.colorAttachments[0].clearColor = MTLClearColorMake(0, 0, 0, 0)
renderPassDescriptorSingleStamp?.colorAttachments[0].texture = metalDrawableTextureComposite
// Create a new command buffer for each tessellation pass
let commandBuffer: MTLCommandBuffer? = commandQueue.makeCommandBuffer()
let renderCommandEncoder: MTLRenderCommandEncoder? = commandBuffer?.makeRenderCommandEncoder(descriptor: renderPassDescriptorSingleStamp!)
renderCommandEncoder?.label = "Render Command Encoder"
renderCommandEncoder?.setTriangleFillMode(.fill)
defineCommandEncoder(
renderCommandEncoder: renderCommandEncoder,
vertexArrayStamps: vertexArrayStrokeStamps,
metalTexture: stampTexture) // foreground sub-curve chunk
renderCommandEncoder?.endEncoding() // finalize renderEncoder set up
//begin presentsWithTransaction approach (needed to better synchronize with Core Image scheduling
copyTexture(buffer: commandBuffer!, from: metalDrawableTextureComposite, to: self.currentDrawable!.texture)
commandBuffer?.commit() // commit and send task to gpu
commandBuffer?.waitUntilScheduled()
self.currentDrawable!.present()
// end presentsWithTransaction approach
self.initializeStampArray(stampUse: stampUseMode.strokeBezier) // clears out the stamp array in preparation of next draw call
} // end of func renderStampSingle(stampTexture: MTLTexture)
First of all, the domain Metal is very deep, and it's use within the MTKView construct is sparsely documented, especially for any applications that fall outside the more traditional gaming paradigm. This is where I have found myself in the limited experience I have accumulated with Metal with the help from folks like #warrenm, #ken-thomases, and #modj, whose contributions have been so valuable to me, and to the Swift/Metal community at large. So a deep thank you to all of you.
Secondly, to anyone troubleshooting metal, please take note of the following: If you are getting the message:
[CAMetalLayerDrawable present] should not be called after already presenting this drawable. Get a nextDrawable instead
please don't ignore it. It mays seem harmless enough, especially if it only gets reported once. But beware that this is a sign that a part of your implementation is flawed, and must be addressed before you can troubleshoot any other Metal-related aspect of your app. At least this was the case for me. As you can see from the video posts, the symptoms of having this problem were pretty severe and caused unpredictable behavior that I was having a difficult time pinpointing the source of. The thing that was especially difficult for me to see was that I only got this message ONCE early on in the app cycle, but that single instance was enough to throw everything else graphically out of whack in ways that I thought were attributable to CoreImage and/or other totally unrelated design choices I had made.
So, how did I get rid of this warning? Well, in my case, I assumed that having the settings:
self.enableSetNeedsDisplay = true // needed so we can call setNeedsDisplay() to force a display update as soon as metal deems possible
self.isPaused = true // needed so the draw() loop does not get called once/fps
self.presentsWithTransaction = true // for better synchronization with CoreImage (such as simultaneously turning on a layer while also clearing MTKView)
meant that I could pretty much call currentDrawable!.present() or commandBuffer.presentDrawable(view.currentDrawable) directly whenever I wanted to refresh the screen. Well, this is not the case AT ALL. It turns out these calls should only be made within the draw() loop and only accessed via a setNeedsDisplay() call. Once I made this change, I was well on my way to solving my refresh riddle.
Furthermore, I found that the MTKView setting self.isPaused = true (so that I could make setNeedsDisplay() calls directly) still resulted in some unexpected behavior. So, instead, I settled for:
self.enableSetNeedsDisplay = false // needed so we can call setNeedsDisplay() to force a display update as soon as metal deems possible
self.isPaused = false // draw() loop gets called once/fps
self.presentsWithTransaction = true // for better synchronization with CoreImage
as well as modifying my draw() loop to drive what kind of update to carry out once I set a metalDrawableDriver flag AND call setNeedsDisplay():
override func draw(_ rect: CGRect) {
autoreleasepool(invoking: { () -> () in
switch metalDrawableDriver {
case stampRenderMode.canvasRenderNoVisualUpdates:
return
case stampRenderMode.canvasRenderClearAll:
renderClearCanvas()
case stampRenderMode.canvasRenderPreComputedComposite:
renderPreComputedComposite()
case stampRenderMode.canvasRenderStampArraySubCurve:
renderSubCurveArray()
} // end of switch metalDrawableDriver
}) // end of autoreleasepool
} // end of draw()
This may seem round-about, but it was the only mechanism I found to get consistent user-driven display updates.
It is my hope that this post describes an error-free and viable solution that Metal developers may find useful in the future.
At the minute I'm using the SKConstraint.positionX(rangex, y: rangey) to confine my SKCameraNode within the game board I've created. This is nice because when you hit the boundary there's no stuttering. But my current way to cap the scale of the camera creates a stutter as it hits the bound as it goes past and pings back.
#objc func zoomedView(_ sender:UIPinchGestureRecognizer) {
if newCamera.xScale > 0.148{
let pinch = SKAction.scale(by: 1/sender.scale, duration: 0.0)
newCamera.run(pinch)
sender.scale = 1.0
} else {newCamera.setScale(0.148)}
}
Is there an SKConstraint for scale (or equivalent) which is a better way to stop this stutter? Thanks :)
There is no direct SKConstraint equivalent for scale, however the reason you're experiencing the stuttering is as you go over the bound it snaps back the next time the function is called, rather before a frame is rendered, so theoretically you could zoom in massively instantaneously, and stay there until you activate the zoom function again.
A way to create an equivalent is to put the code checking whether the scale is greater than x in the rendering loop as outlined here.
So if you were to check at the last possible moment:
override func didFinishUpdate() {
if newCamera.xScale < 0.148{
newCamera.setScale(0.148)
} else if newCamera.xScale > 10{
newCamera.setScale(10)
}
}
I found some other questions about node removal in swift, but none of them seemed to be quite relevant to my issue.
I just want to do a basic node removal, for example:
override func touchesBegan(touches: NSSet, withEvent event: UIEvent){
let covernode1 = SKSpriteNode(imageNamed: "tester")
covernode1.position = CGPointMake(100.0, 600.0)
for touch: AnyObject in touches {
if self.nodeAtPoint(location) == self.fake {
button1++
button2++
}
if(button1 == 1 && button2 == 1){
addChild(covernode1)
}
if(button1 == 2 && button2 == 2){
//THIS IS WHERE I WANT TO REMOVE THE NODE
}
I have tried
covernode1.removeFromParent()
but to no avail.
The code runs the addChild part fine, but removal seems to be a problem. I even tried just changing the position of the node so it's off screen, with something like
covernode1.position = CGPointMake(-100.0, -600.0)
This did not work either.
Thank you.
Unfortunately I don't have enough reputation to comment on your original question, so this may not be an "answer" per se, but I'll try and diagnose what I think is going on, and hopefully you can clear up some points for me.
The covernode1 that you are trying to remove from the parent view in your if statement may be a different node than the one you added to the view when you called addChild(covernode1)
I think this is the case because when you say you are using covernode1.position = CGPointMake(-100.0, -600.0) and it still does not work, that makes me think that is a completely different SKNode object.
Instead, try declaring covernode1 outside of the function as a class variable. That way, when you actually instantiate it and refer to it in the function, it is grabbing the correct node you are looking for. Let me know if any of this helps. I'll edit the answer when I know a bit more from your response.
Also, are your button1 and button2 vars originally set to 1?
EDIT: Another question: Are you receiving any error when calling .removeFromParent() or is just "not doing anything"?
One simple thing you could do (kind of cheating but it will work) is to hide the node using
covernode1.hidden = true
Note
Also make sure the if statement actually runs because I don't know why the things you tried should not work. To test that, place a println("log") in the if block.
Hope that helps :)
From button1 and button2, I think you are trying to do this: On the first click, you add a SKNode. On the second click, you want to remove the SKNode.
Thus on the second click your let covernode1 = SKSpriteNode(imageNamed: "tester") is a different instance although it has the same variable name ! Thus the instance on the second click is not removable since it was not added to anything.
Try this,
if(button1 == 1 && button2 == 1){
addChild(covernode1)
self.tempChildCount = count(self.children) //tempChildCount is an integer
}
if(button1 == 2 && button2 == 2){
let childNode = self.children[self.tempChildCount - 1 ] as! SKNode
self.removeChildrenInArray([childNode])
}
I'm new to objective c and swift and I created a small app where small circles are rendered and once the player collides with a circle, the game ends. I managed to get everything to work, but how do I remove the nodes after they collide. I tried removeAllChildren(), but none of them disappear. When I use removeFromParent(), only 1 disappears. I want a way to remove all 3 nodes that will be rendered in the code below
//addEvilGuys() is called first
func addEvilGuys()
{
addEvilGuy(named: "paul", speed: 1.3, xPos: CGFloat(self.size.height/3))
addEvilGuy(named: "boris", speed: 1.7, xPos: frame.size.width/4 + 50)
addEvilGuy(named: "natasha", speed: 1.5, xPos: frame.size.width/4 + 150)
}
func addEvilGuy(#named:String, speed:Float, xPos: CGFloat)
{
evilGuyNode = SKSpriteNode(imageNamed: named)
evilGuyNode.zPosition = 10
evilGuyNode.physicsBody = SKPhysicsBody(circleOfRadius: 16)
evilGuyNode.physicsBody!.affectedByGravity = false
evilGuyNode.physicsBody!.categoryBitMask = ColliderType.BadGuy.rawValue
evilGuyNode.physicsBody!.contactTestBitMask = ColliderType.Hero.rawValue
evilGuyNode.physicsBody!.collisionBitMask = ColliderType.Hero.rawValue
evilGuyNodeCount++
var evilGuy = EvilGuy(speed: speed, eGuy: evilGuyNode)
evilGuys.append(evilGuy)
resetEvilGuy(evilGuyNode, xPos: xPos)
evilGuy.xPos = evilGuyNode.position.x
addChild(evilGuyNode)
}
func resetEvilGuy(evilGuyNode:SKSpriteNode, xPos:CGFloat)
{
evilGuyNode.position.y = endOfScreenBottom
evilGuyNode.position.x = xPos
}
It looks like in addEvilGuy you are recreating a stored property (i.e. that is visible for the entire class + whatever the access level allows) to create the SKSpriteNode that you're adding. This means that you are orphaning the previously created EvilGuy.
In addEvilGuy, replace
evilGuyNode = SKSpriteNode(imageNamed: named)
with
let evilGuyNode = SKSpriteNode(imageNamed: named)
and remove the property from your class (it doesn't seem like you have a need for in in a larger scope).
It also looks like you're creating EvilGuys and storing them in an array, which is good. So when you can remove all of them from the screen with a function like:
func removeAllEvilGuys(evilGuys: [EvilGuy]) {
for evilGuy in evilGuys {
evilGuy.eGuy.removeFromParent()
}
}
As a best practice advice, since you mentioned you're a beginner:
I'd recommend defining the characteristics of the evil guys in a .plist and then use the file to create an array of evil guys. This way you can easily make changes to the evil guys in that file without having to change anything in your code.
The code that creates an EvilGuy object should be separated from the one that adds the evil guy to the screen. As long as you are storing the SKNode of each one, you'll be able to add/remove without unnecessarily recreating the entire object.