Understanding and Overcoming the Jerky Effect in Object Movement

Understanding the Jerky Effect in Object Movement

When creating games that involve multiple objects moving across the screen, a jerky effect can be frustrating and affect the overall gaming experience. In this article, we will explore the causes of this jerky effect and how to resolve it.

What is the Jerky Effect?

The jerky effect refers to the unpredictable movement or stuttering of objects on the screen when they are moving rapidly. This effect can be caused by various factors, including:

  • Frame rate: If the frame rate is too low, it can lead to a jerky effect.
  • Timing issues: Inaccurate timing can cause objects to jump or stutter.
  • Resource-intensive operations: Performing complex calculations or loading large assets can slow down the game.

Understanding Object Generation and Movement

When generating objects at an interval of 1 to 0.45 seconds, it’s essential to consider the timing of their movement. The goal is to create a smooth transition between object movements.

Here’s an example of how this could be implemented in code using Swift:

import UIKit

class ViewController: UIViewController {

    var objects = [UIImageView]() {
        didSet {
            // Update the positions of all objects
            for obj in objects {
                if obj != nil {
                    updateObjectPosition(obj)
                }
            }
        }
    }

    func generateObjects() {
        // Generate new object at a random interval between 1 and 0.45 seconds
        let duration = TimeInterval.random(in: TimeInterval(1...0.45))
        DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
            self.generateNewObject()
        }
    }

    func generateNewObject() {
        // Create a new image view for the object
        let obj = UIImageView(image: UIImage(named: "object"))
        objects.append(obj)
        obj.frame = CGRect(x: CGFloat.random(in: 0...UIScreen.main.bounds.width), y: CGFloat.random(in: 0...UIScreen.main.bounds.height), width: 100, height: 100)

        // Animate the object to move across the screen
        UIView.animate(withDuration: TimeInterval(1), animations: {
            self.objects[objects.count - 1].center = CGPoint(x: UIScreen.main.bounds.width, y: UIScreen.main.bounds.height / 2)
        })
    }

    func updateObjectPosition(_ obj: UIImageView) {
        // Animate the object to move across the screen
        UIView.animate(withDuration: TimeInterval(0.45), animations: {
            self.objects[objects.firstIndex(of: obj)!].center = CGPoint(x: CGFloat.random(in: 0...UIScreen.main.bounds.width), y: CGFloat.random(in: 0...UIScreen.main.bounds.height))
        })
    }

}

Creating Separate Threads for Object Generation and Movement

By creating separate threads for object generation and movement, we can better control the timing of these operations.

Here’s an example of how this could be implemented in code using Swift:

import UIKit
import Foundation

class ViewController: UIViewController {

    var objects = [UIImageView]() {
        didSet {
            // Update the positions of all objects
            for obj in objects {
                if obj != nil {
                    updateObjectPosition(obj)
                }
            }
        }
    }

    func generateObjects() {
        // Create a new thread for generating objects
        let objectThread = Thread(target: self, selector: #selector(objectGeneration), arguments: [])
        objectThread.start()
    }

    @objc func objectGeneration() {
        // Generate new object at an interval of 1 to 0.45 seconds
        while true {
            let duration = TimeInterval.random(in: TimeInterval(1...0.45))
            DispatchQueue.main.asyncAfter(deadline: .now() + duration) {
                self.generateNewObject()
            }
            usleep_forTimeInterval(duration)
        }
    }

    func generateNewObject() {
        // Create a new image view for the object
        let obj = UIImageView(image: UIImage(named: "object"))
        objects.append(obj)
        obj.frame = CGRect(x: CGFloat.random(in: 0...UIScreen.main.bounds.width), y: CGFloat.random(in: 0...UIScreen.main.bounds.height), width: 100, height: 100)

        // Animate the object to move across the screen
        UIView.animate(withDuration: TimeInterval(1), animations: {
            self.objects[objects.count - 1].center = CGPoint(x: UIScreen.main.bounds.width, y: UIScreen.main.bounds.height / 2)
        })
    }

    func updateObjectPosition(_ obj: UIImageView) {
        // Animate the object to move across the screen
        UIView.animate(withDuration: TimeInterval(0.45), animations: {
            self.objects[objects.firstIndex(of: obj)!].center = CGPoint(x: CGFloat.random(in: 0...UIScreen.main.bounds.width), y: CGFloat.random(in: 0...UIScreen.main.bounds.height))
        })
    }

}

Handling Touches Moved Event

When handling the touches moved event, we need to update the position of the objects accordingly.

Here’s an example of how this could be implemented in code using Swift:

import UIKit

class ViewController: UIViewController {

    var objects = [UIImageView]() {
        didSet {
            // Update the positions of all objects
            for obj in objects {
                if obj != nil {
                    updateObjectPosition(obj)
                }
            }
        }
    }

    func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
        // Update the position of the object at the touch location
        for (idx, touch) in touches.enumerated() {
            if let location = touch.location(in: self.view), let obj = objects[idx] {
                UIView.animate(withDuration: TimeInterval(0.01), animations: {
                    obj.center = CGPoint(x: location.x, y: location.y)
                })
            }
        }
    }

}

Conclusion

In this article, we explored the jerky effect in object movement and its causes. We also discussed ways to resolve this issue by creating separate threads for object generation and movement.

By using these techniques, you can create a smoother gaming experience with fewer jerk effects.


Last modified on 2023-11-03