scroll screen view with the mouse

2D
1

Hi everyone,

I am really a beginner, need my view to scroll when the mouse reaches the border of the screen. Here is how my script looks like . It works but I would like that the scrolling stops whn the mouses reached the border of the screen. how do I do that? thanks a lot for your help!

#pragma strict

public var Boundary : int = 50;
public var speed : int = 5;
public var scrollingAllowed: boolean = false;

private var theScreenWidth : int;
private var theScreenHeight : int;

function Start()
{
     theScreenWidth = Screen.width;
     theScreenHeight = Screen.height;
}
public function Update()

{if (scrollingAllowed == true)

     {if (Input.mousePosition.x > theScreenWidth - Boundary)
     {
        transform.position.x += speed * Time.deltaTime; // move on +X axis
     }
     if (Input.mousePosition.x < 0 + Boundary)
     {
        transform.position.x -= speed * Time.deltaTime; // move on -X axis
     }

     }
     }


  public function allowScrolling()

{
     scrollingAllowed = true;
}
2

You’re contradicting yourself in your explanation. Could you explain in more detail the behavior you’re trying to make?

Also please use Code Tags when pasting code.

3

Ah yeah sorry,
I meant that I would like the scrolling to stop when I have reached the end of my background.
I will be careful now with pasting the code,

thank you!

4

One simple way to do this would be to add a new SpriteRenderer variable, to act as your “scrollable area” or something.

Then you can use SpriteRenderer.bounds.max and min to clamp your camera’s position inside of it.

I would use LateUpdate to clamp it. I don’t write Unity Javascript so forgive me if this has errors or something.

I did some conversion to get the world-unit size of the camera. I have not tested this.

public var backgroundSprite : SpriteRenderer; // the sprite renderer to use for boundaries
private var maxScrollPosition : Vector2; // the maximum position for the camera
private var minScrollPosition : Vector2; // the minimum position for the camera
private var cameraSize : Vector2; // the world-space size of the camera (not pixels)

public function Start() {
    // viewport space goes from (0,0) to (1,1)
    // position of the bottom left corner of the camera
    Vector3 min = Camera.main.ViewportToWorldPoint(Vector3.zero);
    // position of the top right corner of the camera
    Vector3 max = Camera.main.ViewportToWorldPoint(Vector3.one);

    // get the distances between max and min on the x and y axes
    // to find how big the camera is in the world
    cameraSize.x = max.x - min.x;
    cameraSize.y = max.y - min.y;

    // for the maximum position, start with the top right corner of the background
    maxScrollPosition = backgroundSprite.bounds.max;

    // subtract half of the camera size in both directions
    // this gives you the position where the camera is perfectly in the upper right corner of the sprite
    maxScrollPosition.x -= cameraSize.x * 0.5f;
    maxScrollPosition.y -= cameraSize.y * 0.5f;

    // for minimum position, start with the bottom left corner of the background
    minScrollPosition = backgroundSprite.bounds.min;

    // add half the camera size in both directions
    // this gives you the position where the camera is perfectly in the bottom left corner of the sprite
    minScrollPosition.x += cameraSize.x * 0.5f;
    minScrollPosition.y += cameraSize.y * 0.5f;
}

// called after Update, before rendering (so adjustments will not be visible to the player)
public function LateUpdate() {
    // keep this object's position within the min and max for both axes
    transform.position.x = Mathf.Clamp(transform.position.x, minScrollPosition.x, maxScrollPosition.x);
    transform.position.y = Mathf.Clamp(transform.position.y, minScrollPosition.y, maxScrollPosition.y);
}

Another method would be to check before actually moving the camera, and then only move the camera to the min or max if it would otherwise over-shoot the edge.

5

Thank you! I am not sure I understood everything because I am really a beginner but I will try that tonight! Thank you again!

6

You’re welcome, feel free to ask questions, and let me know if you managed to apply this to your existing code. I’ll add some more comments to the code to explain it.