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)
}
}
Related
I would like to animate the appearance of a NSSplitViewItem using .setPosition() using Swift, Cocoa and storyboards. My app allows a student to enter a natural deduction proof. When it is not correct, an 'advice view' appears on the right. When it is correct, this advice view will disappear.
The code I'm using is the below, where the first function makes the 'advice' appear, and the second makes it disappear:
func showAdviceView() {
// Our window
let windowSize = view.window?.frame.size.width
// A CGFloat proportion currently held as a constant
let adviceViewProportion = BKPrefConstants.adviceWindowSize
// Position is window size minus the proportion, since
// origin is top left
let newPosition = windowSize! - (windowSize! * adviceViewProportion)
NSAnimationContext.runAnimationGroup { context in
context.allowsImplicitAnimation = true
context.duration = 0.75
splitView.animator().setPosition(newPosition, ofDividerAt: 1)
}
}
func hideAdviceView() {
let windowSize = view.window?.frame.size.width
let newPosition = windowSize!
NSAnimationContext.runAnimationGroup{ context in
context.allowsImplicitAnimation = true
context.duration = 0.75
splitView.animator().setPosition(newPosition, ofDividerAt: 1)
}
}
My problem is that the animation action itself is causing the text in the views to stretch, as you can see in this example: Current behaviour
What I really want is the text itself to maintain all proportions and slide gracefully in the same manner that we see when the user themselves moves the separator: Ideal behaviour (but to be achieved programmatically, not manually)
Thus far in my troubleshooting process, I've tried to animate this outside of NSAnimationContext; played with concurrent drawing and autoresizing of subviews in XCode; and looked generally into Cocoa's animation system (though much of what I've read doesn't seem to have direct application here, but I might well be misunderstanding it). I suspect what's going on is that the .animator() proxy object allows only alpha changes and stretches---redrawing so that text alignment is honoured during the animation might be too non-standard. My feeling is that I need to 'trick' the app into treating the animation as though it's being performed by the user, but I'm not sure how to go about that.
Any tips greatly appreciated...
Cheers
I'm doing some death animations for a game, and wanted to ask for some help. I want my monster to disappear in a puff of smoke, but not before it animates a slash effect going across his body.
I have 3 animations that I want to use:
weaponSlash - a line that draws across the monster. Looks like you slashed him with a sword.
smoke - a puff of smoke that slowly expands out
monsterFalling - the monster falls back, startled
What I want to do is play it in this order:
Simultaneously, the slash appears & the monster starts to fall back
About 0.25s into the above animation, I want the cloud to start to appear
When the cloud is about to end (so maybe after 1s) I want the monster to disappear
Remove the smoke, the monster, the sword, etc, and drop some coins on the ground
I started like this, as a test that works somewhat: (ignore the above times for now)
//Cancel any current actions, like a monster attacking
monster.removeAllActions()
//since you can't play 3 animations on one node at the same time, you have to create 3 separate nodes for everything
let slash = SKSpriteNode()
let cloud = SKSpriteNode()
cloud.size = monster.size
slash.size = monster.size
monster.addChild(cloud)
monster.addChild(slash)
//Start the slash animation
slash.run(self.player.currentlyEquippedWeapon.attackAnimation())
//Start the cloud animation (how I get it is elsewhere and not relevant)
cloud.run(cloudAnimation)
//Run the monster death animation, followed by the cleanup/coin dropping
monster.run(SKAction.sequence([monster.deathAnimation(), SKAction.wait(forDuration: 1), postDeathActions]))
The variable PostDeathActions above simply removes the monster node and animates some coins falling.
WHERE I NEED SOME HELP
So the above code doesn't work so great in that the animations all run independently of each other. Based on this, you can see how regardless of whether the slash/cloud finish, the monster will run two actions: him falling back, followed by cleanup, which just removes the monster and spawns the coins. As you can see I tried to delay this by adding a 1s delay but this is all somewhat of a hack since I may have different monsters or attacks, etc, that are faster/slower. I'd rather guarantee that everything finishes before I despawn the monster.
I tried to group this into an SKAction.Run like so:
let preDeath = SKAction.run {
[unowned self] in
monster.run(monster.deathAnimation()
slash.run(self.player.currentlyEquippedWeapon.attackAnimation())
cloud.run(cloudAnimation)
}
but this runs everything at the same time again.
What I want to do is sequence it like this (pseudo code):
let preDeathAnimations = SKAction.Group([slash, cloud, monsterDeathAnimation])
])
SKAction.sequence([preDeathAnimations, postDeathActions])
So this way it'll run all 3 before running cleanup.
Is there a way to do something like this? I know Sequnce/Group need to be run against an SKNode, but I don't have 3 separate ones.
Thanks for your time reading this and any advice you can offer!
This is one idea that I had, but you could use threading + state + onCompletion blocks to take the math out of it. I didn't test it out fully but this general concept should work:
let slash = SKAction.fadeIn(withDuration: 0.5)
let fall = SKAction.fadeOut(withDuration: 0.25)
let puff = SKAction.fadeIn(withDuration: 0.1)
// Put in ALL of the actions from ALL parties that you want to happen prior to puff:
func findLongestTime(from actions: [SKAction]) -> TimeInterval {
var longestTime = TimeInterval(0)
for action in actions {
if action.duration > longestTime { longestTime = action.duration }
}
// Note, if you put a sequence into this function I don't know if it will work right..
// Might need another func like `findDurationOfSequence(_ sequence: SKAction) -> TimeInterval
return longestTime
}
// Note, if you have the monster doing more than falling prior to puff, then you will
// need to subtract those as well:
let monsterActionsPriorToPuff = [fall]
// Add the duration of all monster animations prior to puff:
var MAPTP_duration = TimeInterval(0)
for action in monsterActionsPriorToPuff {
MAPTP_duration += action.duration
}
// Calculate our final wait time, with no negative numbers:
var waitTime = findLongestTime(from: [slash, fall]) - MAPTP_duration
if waitTime < 0 { waitTime = 0 }
let wait = SKAction.wait(forDuration: waitTime)
// Our monster sequence (I forgot to add the disappear, just add after puff)
let monsterSequence = SKAction.sequence([fall, wait, puff])
// Player slashes:
SKSpriteNode().run(slash)
// Monster will wait 0.25 seconds after falling,
// for slash to finish before puffing:
SKSpriteNode().run(monsterSequence)
et me know if this idea isn't working I can try updating it.
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.
I have a (moving) sprite node.
I'd like to detect other (moving) sprite nodes within a certain range of this node. Once one is detected, it should execute an action.
The playing an action part is no problem for me but I can't seem to figure out the within-range detection. Does have any ideas how to go about this?
A simple, but effective way to do this is comparing the position's in your scene's didEvaluateActions method. didEvaluateActions gets called once a frame (after actions have been evaluated but before physics simulation calculations are run). Any new actions you trigger will start evaluating on the next frame.
Since calculating the true distance requires a square root operation (this can be costly), we can write our own squaredDistance and skip that step. As long as our range/radius of detect is also squared, our comparisons will work out as expected. This example shows detect with a "true range" of 25.
// calculated the squared distance to avoid costly sqrt operation
func squaredDistance(p1: CGPoint, p2: CGPoint) -> CGFloat {
return pow(p2.x - p1.x, 2) + pow(p2.x - p1.x, 2)
}
// override the didEvaluateActions function of your scene
public override func didEvaluateActions() {
// assumes main node is called nodeToTest and
// all the nodes to check are in the array nodesToDetect
let squaredRadius: CGFloat = 25 * 25
for node in nodesToDetect {
if squareDistance(nodeToTest.position, p2: node.position) < squaredRadius {
// trigger action
}
}
}
If the action should only trigger once, you'll need to break out of the loop after the first detection and add some sort of check so it does not get triggered again on the next update without the proper cool down period. You may also need to convert the positions to the correct coordinate system.
Also, take a look at the documentation for SKScene. Depending on your setup, didEvaluateActions might not be the best choice for you. For example, if your game also relies on physics to move your nodes, it might be best to move this logic to didFinishUpdate (final callback before scene is rendered, called after all actions, physics simulations and constraints are applied for the frame).
Easiest way I can think of without killing performance is to add a child SKNode with an SKPhysicsBody for the range you want to hit, and use this new nodes contactBitMask to determine if they are in the range.
Something like this (pseudo code):
//Somewhere inside of setup of node
let node = SKNode()
node.physicsBody = SKPhysicsBody(circleOfRadius: 100)
node.categoryBitMask = DistanceCategory
node.contactBitMask = EnemyCategory
sprite.addNode(node)
//GameScene
func didBeginContact(...)
{
if body1 contactacted body2
{
do something with body1.node.parent
//we want parent because the contact is going to test the bigger node
}
}
What would be the best way to make a Swift SKSpriteNode auto correct its orientation after it has had a couple of physicsBody knocks and is now not in the default orientation?
For example I have have a 2D stick-man who gets knocked to the side by another object and would like the stick-man to tilt and reorient itself to the default standing position.
The way I have done this in the past is to wait until the physics body comes to rest, turn off the physics engine for the stickman, reorient the stickman, turn the physics engine back on again.
Write yourself an action called standupAction which animates the stickman's reorientation, maybe just a rotate or a jump up. Then do something like the following.
Sorry this Objective-C not Swift, don't know swift, but should be easy to translate.
if (stickman.physicsBody.resting) {
stickman.physicsBody.dynamic = NO;
[stickman runAction:[SKAction sequence:#[
standupAction,
[SKAction runBlock:^{ stickman.physicsBody.dynamic = YES;}]
]]];
}
The only downside of this approach is that sometimes it can take a full second until the stickman comes comes to rest. Box2d takes quite a long time to settle down. But it looks very realistic if you wait.
Alternatively, you could just check the orientation of stickman and if he is >45degrees off balance then reorient him with impulses. I find impulses to be very difficult to know how much force to apply when you need precise movement like this.
Just to update, I couldn't afford to set the physicsBody to not be dynamic.
My scene updates each node, similarly to Apple's Adventure game, as such I implemented the rotation in the subclassed SKSpriteNode's update method as such:
if (isTouchingGround) {
if self.zRotation != 0 && !rotating {
let actions = [
SKAction.runBlock {
self.rotating = true
},
SKAction.rotateToAngle(0, duration: 1.0),
SKAction.runBlock {
self.rotating = false
}]
runAction(SKAction.sequence(actions))
}
}