Cannot move my avatar at my own defined speed

问题

I am unable to move my avatar in my gameScene at my defined speed(set at 40). It looks as if the avatar and the enemy is free floating in space. Here is my code- import SpriteKit

public class GameScene: SKScene, SKPhysicsContactDelegate {

let playerSpeed: CGFloat = 40.0
let coronaSpeed: CGFloat = 10.0

var mask: SKSpriteNode?
var player: SKSpriteNode?
var mcorona: [SKSpriteNode] = []

var lastTouch: CGPoint? = nil

override public func didMove(to view: SKView) {
    physicsWorld.contactDelegate = self

    // Animations
    player = childNode(withName: "player") as? SKSpriteNode

    mask = childNode(withName: "mask") as? SKSpriteNode
    mask!.run(SKAction.repeatForever(
        SKAction.sequence([
            SKAction.moveBy(x: 0, y: 10, duration: 0.45),
            SKAction.moveBy(x: 0, y: -10, duration: 0.45)
            ]
    )))

    for child in self.children {
        if child.name == "corona" {
            if let child = child as? SKSpriteNode {
                mcorona.append(child)
            }
        }
    }
    // </> Animations
}

override public func touchesBegan(_ touches: Set<UITouch>,with event: UIEvent?) { handleTouches(touches) }

override public func touchesMoved(_ touches: Set<UITouch>,with event: UIEvent?) { handleTouches(touches) }

override public func touchesEnded(_ touches: Set<UITouch>, with event: UIEvent?) { handleTouches(touches) }

fileprivate func handleTouches(_ touches: Set<UITouch>) { lastTouch = touches.first?.location(in: self) }

override public func didSimulatePhysics() {
    if player != nil {
        updatePlayer()
        updateZombies()
    }
}


fileprivate func shouldMove(currentPosition: CGPoint,
                            touchPosition: CGPoint) -> Bool {
    guard let player = player else { return false }
    return abs(currentPosition.x - touchPosition.x) > player.frame.width / 2 ||
        abs(currentPosition.y - touchPosition.y) > player.frame.height / 2
}

fileprivate func updatePlayer() {
    guard let player = player,
        let touch = lastTouch
        else { return }
    let currentPosition = player.position
    if shouldMove(currentPosition: currentPosition,
                  touchPosition: touch) {
        updatePosition(for: player, to: touch, speed: playerSpeed)


    } else {
        player.physicsBody?.isResting = true
    }
}


func updateZombies() {
    guard let player = player else { return }
    let targetPosition = player.position

    for corona in mcorona {
        updatePosition(for: corona, to: targetPosition, speed: coronaSpeed)
    }
}
fileprivate func updatePosition(for sprite: SKSpriteNode, to target: CGPoint, speed: CGFloat) {

    let currentPosition = sprite.position
    let angle = CGFloat.pi + atan2(currentPosition.y - target.y, currentPosition.x - target.x)
    let rotateAction = SKAction.rotate(toAngle: angle + (CGFloat.pi*0.5), duration: 0)
    sprite.run(rotateAction)
    //sprite.physicsBody?.isDynamic = true

    let velocityX = speed * cos(angle)
    let velocityY = speed * sin(angle)

    let newVelocity = CGVector(dx: velocityX, dy: velocityY)
    sprite.physicsBody?.velocity = newVelocity
    let moveToTouch = SKAction.move(to: CGPoint(x: target.x, y: target.y), duration: TimeInterval(speed))
    sprite.run(moveToTouch)
    sprite.physicsBody?.affectedByGravity = false

}

public func didBegin(_ contact: SKPhysicsContact) {

    var firstBody: SKPhysicsBody
    var secondBody: SKPhysicsBody

    if contact.bodyA.categoryBitMask < contact.bodyB.categoryBitMask {
        firstBody = contact.bodyA
        secondBody = contact.bodyB
    } else {
        firstBody = contact.bodyB
        secondBody = contact.bodyA
    }

    // Check contact
    if firstBody.categoryBitMask == player?.physicsBody?.categoryBitMask &&
        secondBody.categoryBitMask == mcorona[0].physicsBody?.categoryBitMask {
        // Player & corona
        gameOver(false)
    } else if firstBody.categoryBitMask == player?.physicsBody?.categoryBitMask &&
        secondBody.categoryBitMask == mask?.physicsBody?.categoryBitMask {
        // Player & mask
        gameOver(true)
    }


}
fileprivate func gameOver(_ didWin: Bool) {
    let resultScene = MenuScene(size: size, didWin: didWin, levelToSend: 2)
    let transition = SKTransition.flipVertical(withDuration: 1.0)
    view?.presentScene(resultScene, transition: transition)
}

}

Here is a GIF representing the situation- https://media.giphy.com/media/TLNx0x3HUtpdPJ9KIK/giphy.gif PLS HELP! . Thanks in advance!

回答1:

func getDuration(pointA:CGPoint,pointB:CGPoint,speed:CGFloat)->TimeInterval{
        let xDist = (pointB.x - pointA.x)
        let yDist = (pointB.y - pointA.y)
        let distance = sqrt((xDist * xDist) + (yDist * yDist));
        let duration : TimeInterval = TimeInterval(distance/speed)
        return duration
    }

changed the moveToTouch file as shown below

let moveToTouch = SKAction.move(to: CGPoint(x: target.x, y: target.y),duration: getDuration(pointA:currentPosition,pointB:target,speed:speed))
sprite.run(moveToTouch)

来源：https://stackoverflow.com/questions/61744489/cannot-move-my-avatar-at-my-own-defined-speed