我正在尝试SKShapeNode
关注UITouch
我的问题是UITouch
的位置是相对于屏幕的左下角而SKShapeNode
的位置是相对于我创建它时给出的位置,屏幕的中心。
例如:ball
以(189.0,335.0)为中心,即视图的中心。我点击球,触摸的位置告诉我触摸事件发生在(189.0,335.0),但ball.position
会告诉我(0.0,0.0)。如何在视图的坐标系中获得ball
的位置?
import SpriteKit
import GameplayKit
class GameScene: SKScene {
var touched = false
var location = CGPoint.zero
var ball: SKShapeNode = SKShapeNode(circleOfRadius: 15)
var background: SKSpriteNode = SKSpriteNode(imageNamed: "background")
override func didMove(to view: SKView) {
background.size = frame.size
background.position = CGPoint(x: view.frame.size.width / 2, y: view.frame.size.height / 2)
addChild(background)
let path = CGMutablePath()
path.addArc(center: CGPoint(x: view.frame.size.width / 2, y: view.frame.size.height / 2),
radius: 15,
startAngle: 0,
endAngle: CGFloat.pi * 2,
clockwise: false)
ball = SKShapeNode(path: path) // Added to center of screen
ball.lineWidth = 1
ball.fillColor = .cyan
ball.strokeColor = .cyan
ball.glowWidth = 0.5
addChild(ball)
print(ball.position)
}
override func update(_ currentTime: TimeInterval) {
// Called before each frame is rendered
moveNode()
}
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
touched = true
for touch in touches {
location = touch.location(in: view)
}
}
override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
for touch in touches {
location = touch.location(in: view)
}
}
override func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) {
touched = false
}
func moveNode() {
if touched {
let speed: CGFloat = 1
if location.x < ball.position.x {
let newLocation = ball.position.x - speed
ball.position = CGPoint(x: newLocation, y: ball.position.y)
} else {
let newLocation = ball.position.x + speed
ball.position = CGPoint(x: newLocation, y: ball.position.y)
}
}
}
}
答案 0 :(得分:1)
你永远不会设置球的位置,因此它是(0,0)。问题是球位于(0,0)但其路径代表球坐标中的(189,335)。 改为:
override func didMove(to view: SKView) {
background.size = frame.size
background.position = CGPoint(x: view.frame.size.width / 2, y: view.frame.size.height / 2)
addChild(background)
let path = CGMutablePath()
// construct a path relative to center of the ball
path.addArc(center: CGPoint(x: 0, y: 0),
radius: 15,
startAngle: 0,
endAngle: CGFloat.pi * 2,
clockwise: false)
ball = SKShapeNode(path: path)
// locate the ball at the center of the screen
ball.position = CGPoint(x: view.frame.size.width / 2, y: view.frame.size.height / 2)
ball.lineWidth = 1
ball.fillColor = .cyan
ball.strokeColor = .cyan
ball.glowWidth = 0.5
addChild(ball)
print(ball.position)
}