[help] Camera control

All,
I am making a Camera class for my games and I am having an issue with one of my pan modes.

I have a QuickPan which uses the 'divide the distance' method an works fine.

Code:

---

//the deltas
var camDX = camx-x;
var camDY = camy-y;
//delta divided by QuickPan speed
cameraTargetX -= camDX/qpan_time;
cameraTargetY -= camDY/qpan_time;
//set the position
clip._x = -cameraTargetX;
clip._y = -cameraTargetY;

---

I am trying to create a mode that is panning by a specified speed (i.e. always move 5 pixels per tick to the target) I cannot figure out the math. I can get it going forward fine, but I cannot get it going backwards.

For example.
cam.panTo(150,100); // this works fine
now do:
cam.panTo(225,100); // this also works fine
now do:
cam.panTo(150,100); // now it pans forward, when it should pan BACK to 150

My speed is always a positive integer (cam.setPanSpeed(5)) and my xVel and yVel always resolve to positive integers as a result.

Maybe I am just going about this the totally wrong way. Can anyone offer any ideas?

thanks,
brad

bump

Post your panTo function and I'll see what I can do.

Logically it sounds like you are not taking into account the direction of the speed.

cam.panTo(150,100); // no speed
cam.panTo(225,100); // x has positive speed
cam.panTo(150,100); // x has negative speed

That's the only way I can explain that it continues to increase.

Try tracing the camera's actual x values to see what's happening.

What you need is something like this:

if( newPosition < currentPosition )
currentPosition -= speed;
else
currentPosition += speed;