A better way to scroll items using mouse / finger.

Hi, I'm new to unity but love it.. I'll never program for mobile natively again...

I am scrolling items down the screen using the following code I came up with..

Code (CSharp):

1. void Update () {
2.  
3.         //If running game in editor
4.         #if UNITY_EDITOR
5.  
6.         //If mouse button 0 is down
7.         if(Input.GetMouseButton(0))
8.         {
9.             //Cache mouse position
10.             Vector2 mouseCache = Input.mousePosition;
11.             if (mouseCache.x <= Screen.width) {
12.                 if (Input.GetAxis("Mouse Y") > 0f) {
13.                     transform.position = new Vector3(transform.position.x, transform.position.y + mouseCache.y * .000009f, 0);
14.                 }
15.                 if (Input.GetAxis("Mouse Y") < 0f) {
16.                     transform.position = new Vector3(transform.position.x, transform.position.y - mouseCache.y * .000009f, 0);
17.                 }
18.             }
19.         }
20.  
21.         #endif
22. }

This seems a bit crude.. having to multiply by .00009f to slow things down seems a bit odd.. There must be an easier way.. I'm also still trying to figure out how to make this work using a finger on mobile.

Is this is best utilization? Can I easily convert to finger tap and drag on iOS and Android? Thanks a ton. This platform rocks.

 

You probably have to use that very small multiplicator because you use the 'mouse position' (the touch position) for the translation of the objects. The mousePosition/touch position is in screen coordinates though.
Which means, you'd be moving the objects by XXX units(per frame!) when your current y position is XXX (let's say 500).
Short: don't use the touch position directly for the translation.

 

Well, the other thing is that you're moving by a fixed amount per frame... possibly forgetting that Update() is called anywhere from 3 to 60 frames per second. So you never want to move a fixed amount per frame, both because it will probably be too fast, and because the speed will vary with the frame rate.

Instead, pretty much any sort of movement you do in Update, FixedUpdate, or OnGUI should be multiplied by Time.deltaTime.

HTH,
- Joe

 

Update and FixedUpdate, but not OnGui

 

Well, this is where I'm stuck.