I'm working on a project in swift and I am able to make a sprite. I am trying to make a sprite at a number of different locations. As a test I replaced the code in the game scene to be:
class GameScene: SKScene {
override func didMoveToView(view: SKView){
let wall = SKSpriteNode(imageNamed: "Wall")
wall.position = CGPoint(x: 289, y: 0)
}
}
What I do not understand is this code makes a sprite in the lower left corner. As expected in the y direction only half of the sprite shows, but the x direction seems completely off. If I try to set the x value to any number below 289 it will not appear. Is the 0,0 point really 289,0 or am I missing something? I am programming for iphone 6 if that makes a difference.
Thank you!
Your scene it is not necessarily the same size of your view. You can check the size of your scene as follow:
view.scene!.frame.size
view.scene!.frame.width
view.scene!.frame.height
view.scene!.frame.midX
view.scene!.frame.midY
Related
Im trying to pin the game pad controller to the bottom left on my camera node but when i add the node as a child of my camera it doesnt show up?
let gameCamera = SKCameraNode()
var joypadBackground : SKSpriteNode = SKSpriteNode(imageNamed: "a")
override func didMove(to view: SKView) {
//Set game camera
self.camera = gameCamera
joypadBackground.position = convert(CGPoint(x: 0, y: 0), to: gameCamera)
joypadBackground.size = CGSize(width: 50, height: 50)
joypadBackground.zPosition = 1000
gameCamera.addChild(joypadBackground)
}
I had a hard time with this same problem the first time I was working with SKCameraNode and creating a heads up display.
Basically you have to remember that there are two parts to the camera. Running its functionality and rendering its children. By setting the scene's camera to gameCamera you've setup the functionality, but your camera isn't in the node tree for rendering. So, if you ever have a camera that needs to render its children don't forget to add it to the scene as a child, then the camera's children will be displayed.
self.camera = gameCamera
self.addChild(gameCamera)
Hope that helps someone avoid a very common error with a very simple solution.
You don't need
convert(CGPoint(x: 0, y: 0), to: gameCamera)
You can just set the CGPoint position to (0,0) and it should be at that point relative to the camera's space.
Not sure if this helps, at all, but what I do is (generally) position a child node AFTER I've added it to its parent. This is mainly a mental reminder, to me, that the child's position is within the coordinate space of the parent. So I'd do something like this:
gameCamera.addChild(joypadBackground)
joypadBackground.position = CGPoint(x: 0, y: 0)
If you're using a mid screen origin in your SKScene, this should be in the middle of the screen.
Bottom left will be a negative x and negative y value, size of which is relative to your frame size.
I am trying to add two SKSpriteNodes with their respective textures in swift, however the "Blade" does not show up on screen during the simulation. I am having no trouble getting the "Handle" to appear though. So my question is, what is the proper way to add a child of a child of self in swift so that everything works as intended?
var Handle = SKSpriteNode(imageNamed: "Handle.png")
var Blade = SKSpriteNode(imageNamed: "Blade.png")
override func didMoveToView(view: SKView) {
Handle.position = CGPointMake(self.size.width / 2, self.size.height / 14)
Blade.position = CGPointMake(Handle.position.x, Handle.position.y + 124)
self.addChild(Handle)
Handle.addChild(Blade)
}
This should get you close to where you expected it.
Blade.position = CGPointMake(0, 124)
Keep in mind when you add a sprite to another sprite the position is the position "within" that sprite. If you don't change the anchor that starts at the center of its parent. So you were starting in the center of Handle and adding half the width of the scene. Because Handle was already centered in the scene blade was off the scene.
Hopefully that makes sense and is helpful.
Also as lchamp mentioned you should lowerCamelCase
var Blade = SKSpriteNode(imageNamed: "Blade.png")
This will help you in the future identifying Classes vs Variables.
I am creating a Terraria-style game in Swift. I want to have it so the player node is always in the center of the screen, and when you move right the blocks go left like in Terraria.
I am currently trying to figure out how to keep the view centered on the character. Does anyone know of a good way of accomplishing this?
Since iOS 9 / OS X 10.11 / tvOS, SpriteKit includes SKCameraNode, which makes a lot of this easier:
positioning the camera node automatically adjusts the viewport
you can easily rotate/zoom the camera by transform in the camera node
you can fix HUD elements relative to the screen by making them children of the camera node
the scene's position stays fixed, so things like physics joints don't break the way they do when you emulate a camera by moving the world
It gets even better when you combine camera nodes with another new feature, SKConstraint. You can use a constraint to specify that the camera's position is always centered on a character... or add extra constraints to say, for example, that the camera's position must stay within some margin of the edge of the world.
The below will center the camera on a specific node. It can also smoothly transition to the new position over a set time frame.
class CameraScene : SKScene {
// Flag indicating whether we've setup the camera system yet.
var isCreated: Bool = false
// The root node of your game world. Attach game entities
// (player, enemies, &c.) to here.
var world: SKNode?
// The root node of our UI. Attach control buttons & state
// indicators here.
var overlay: SKNode?
// The camera. Move this node to change what parts of the world are visible.
var camera: SKNode?
override func didMoveToView(view: SKView) {
if !isCreated {
isCreated = true
// Camera setup
self.anchorPoint = CGPoint(x: 0.5, y: 0.5)
self.world = SKNode()
self.world?.name = "world"
addChild(self.world)
self.camera = SKNode()
self.camera?.name = "camera"
self.world?.addChild(self.camera)
// UI setup
self.overlay = SKNode()
self.overlay?.zPosition = 10
self.overlay?.name = "overlay"
addChild(self.overlay)
}
}
override func didSimulatePhysics() {
if self.camera != nil {
self.centerOnNode(self.camera!)
}
}
func centerOnNode(node: SKNode) {
let cameraPositionInScene: CGPoint = node.scene.convertPoint(node.position, fromNode: node.parent)
node.parent.position = CGPoint(x:node.parent.position.x - cameraPositionInScene.x, y:node.parent.position.y - cameraPositionInScene.y)
}
}
Change what’s visible in the world by moving the camera:
// Lerp the camera to 100, 50 over the next half-second.
self.camera?.runAction(SKAction.moveTo(CGPointMake(100, 50), duration: 0.5))
Source: swiftalicio - 2D Camera in SpriteKit
For additional information, look at Apple's SpriteKit Programming Guide (Example: Centering the Scene on a Node).
You have to create World node that contains nodes. And you should put anchorPoint for example (0.5,0.5). Center on your player. And then you should move your player.
func centerOnNode(node:SKNode){
let cameraPositionInScene:CGPoint = self.convertPoint(node.position, fromNode: world!)
world!.position = CGPoint(x:world!.position.x - cameraPositionInScene.x, y: world!.position.y - cameraPositionInScene.y)
}
override func didSimulatePhysics() {
self.centerOnNode(player!)
}
I'm working in a side-scolling game and I need to know what nodes are in an area to implement something like "line of sight". Right now I'm trying using enumerateBodyiesInRect() however it's detecting bodies that are 20px or more from the evaluated rect and I cannot figure out why it's so imprecise.
This is what I'm trying now:
import SpriteKit
import CoreMotion
class GameScene: SKScene, SKPhysicsContactDelegate
{
var player = SKShapeNode()
var world = SKShapeNode()
var rShape = SKShapeNode()
override func didMoveToView(view: SKView) {
self.physicsWorld.contactDelegate = self
self.scaleMode = SKSceneScaleMode.AspectFit
self.size = view.bounds.size
// Add world
world = SKShapeNode(rectOfSize: view.bounds.size)
world.physicsBody = SKPhysicsBody(edgeLoopFromPath: world.path)
world.position = CGPointMake(self.frame.size.width/2, self.frame.size.height/2) // Move camera
self.addChild(world)
// Add player
player = SKShapeNode(rectOfSize: CGSize(width: 25, height: 25))
player.physicsBody = SKPhysicsBody(rectangleOfSize: player.frame.size)
player.physicsBody.dynamic = false
player.strokeColor = SKColor.blueColor()
player.fillColor = SKColor.blueColor()
player.position = CGPointMake(90, -50)
world.addChild(player)
}
override func update(currentTime: CFTimeInterval) {
// Define rect position and size (area that will be evaluated for bodies)
var r : CGRect = CGRect(x: 200, y: 200, width: 25, height: 25)
// Show rect for debug
rShape.removeFromParent()
rShape = SKShapeNode(rect: r)
rShape.strokeColor = SKColor.redColor()
self.addChild(rShape)
// Evaluate rect
rShape.fillColor = SKColor.clearColor()
self.physicsWorld.enumerateBodiesInRect(r) {
(body: SKPhysicsBody!, stop: UnsafePointer<ObjCBool>) in
self.rShape.fillColor = SKColor.redColor() // Paint the area blue if it detects a node
}
}
}
This code should show the evaluated rect and ray on the screen (for debugging purposes) and paint them red if they contact the player node. However you can see in the screenshot how it turns red when the player is 25px or more away from it, it's like if the drawing is a little bit off, or smaller than the actual area being evaluated. You can copy paste it to a project to duplicate the problem.
Could this be because this is just beta or am I doing something wrong?
You are creating a physical world where there is a specific rectangle that has 'special properties' - this is the rectangle that you use in enumerateBodiesInRect(). Why not create an invisible, inert physical body with the required rectangular dimension and then use SKPhysicsBody to check for collisions and/or contacts? You could then use allContactedBodies() or some delegate callbacks to learn what other bodies are inside your special rectangle.
Think of it like a 'tractor beam' or a 'warp rectangle'.
I believe you want SKPhysicsWorld's enumerateBodyiesInRect() instance method, which will iterate over all nodes in a given rectangle. If you're looking to get at the physics world through your scene, usage could look like this:
self.physicsWorld.enumerateBodiesInRect(CGRect(x: 0, y: 0, width: 50, height: 50)) {(body: SKPhysicsBody!, stop: UnsafePointer<ObjCBool>) in
// enumerates all nodes in given frame
}
I've experimented quite a bit with enumerateBodiesInRect now, and I've found it to be incredibly inaccurate. It seems to not have any of the claimed functionality, and instead produces random results. I honestly cannot even determine any pattern from its products.
enumerateBodiesAlongRay seems better, but still very buggy. The problem with that function seems to be the conversion between Screen and PhysicsWorld coordinates. I would avoid that one, as well.
I think your solution should simply be to use the existing contact detection system. All of your desired functionality can be written in the didBeginContact() and didEndContact() functions. This has the added benefit of allowing you to specify distinct functionality for both entering and leaving the area. You can also add particle effects, animations, and similar, as well as intentionally ignoring specific types of nodes.
The only thing to ensure success with this method is to clarify that the contact area has a unique category, that the contactTestBitMask contains all desired nodes and the collisionBitMask is set to 0.
The enumerateBodiesInRect method of SKPhysicsWorld expects the rect parameter to be in scene coordinates. This is important. If you have a scene hierarchy of nodes, you need to convert the rect you calculate from a reference node to the scene coordinates.
I faced a lot of issues with this method returning bodies that were off by values like 30px to the left etc. and finally realized the issue was because of the rect parameter not defined in scene coordinate space.
In my case, I had a worldNode inside my scene, and all objects were created in the worldNode. My camera was moving the worldNode about, and applying scaling to it for zooming out and in.
In order to use enumerateBodiesInRect correctly, I had to do something as follows:
// get your world rect based on game logic
let worldRect = getWorldRect()
// calculate the scene rect
let sceneRectOrigin = scene.convertPoint(worldRect.origin, fromNode:scene.worldNode)
let worldScale = scene.worldNode.xScale // assert this is not 0
// now to get the scene rect relative to the world rect, in scene coordinates
let sceneRect = CGRectMake( sceneRectOrigin.x, sceneRectOrigin.y, worldRect.width / worldScale, worldRect.height / worldScale)
world.physicsWorld.enumerateBodiesInRect(sceneRect) {
// your code here
}
Hope this helps.
I am not sure if this is a good practice. Correct me if not. But I am using
let shapeNode = SKShapeNode()
shapeNode.intersects(playerNode)
I checked selected nodes with simple loop if they intersect the player. Additionally I created SKShapeNodes which are drawn in front of nodes representing view sight of other actors in the game. They are moved along those actors.
There is only nodesAtPoint: method.
To achieve what you want you'd better to store all enemies in an array and have an int variable, something like nextEnemyIndex. This approach lets you to easily return the next enemy node, it's much more efficient than trying to find a node on the scene.
yes problem may occur because of your player's image, for example try to use 10px smaller body size:
player.physicsBody = SKPhysicsBody(rectangleOfSize: CGRectMake(self.frame.origin.x, self.frame.origin.y, self.size.width-10, self.size.height-10)));
How can I constrain manual movement of an SKSpriteNode to a fixed rectangular area within a scene? This fixed rectangular area a also a SKSpriteNode which is fixed within the scene. In other words, I want to constrain manual movement of an object (SKSpriteNode) to be completely contained within another SKSpriteNode or at least in the same space that it occupies. I have tried several different approaches (e.g. using an SKShapeNode that has an edged-based physics body), but nothing seems to work. This seems like it should be a fairly simple task to accomplish. Thanks for any help or hints you can offer.
Put an if statement around your moving code - so don't carry out the movement if it will take the object past your boundary. e.g.
//check that a positive movement won't take your node past the right boundary
if(node.position.x + yourXMovementValue < boundaryXRight){
//move your node
}
//same for y
let rangeX = SKRange(lowerLimit: CGFloat, upperLimit: CGFloat)
let contraintX = SKConstraint.positionX(rangeX)
let rangeY = SKRange(lowerLimit: CGFloat, upperLimit: CGFloat)
let contraintY = SKConstraint.positionY(rangeY)
yourObject.constraints = [contraintX, contraintY]