move xxxInternal extendable

[yomotsu]

this PR could solve the issue: #187

Currently rotateInternal() and so are scoped and cannot modify by users. this change allows users to modify them.

based on @farfromrefug's PR https://github.com/yomotsu/camera-controls/pulls

use case:

class MyCameraControls extends CameraControls {
	constructor() {
		super();
	}

	private _rotateInternal( deltaX: number, deltaY: number ): void => {
		// what ever
	}
}

[yomotsu]

@farfromrefug
Sorry, I made another PR that I mentioned...
I know you have spent your time on the PR but I thought this is the best way to show my thought...
Hope this change would be some hints for your next PR, which is to make event handlers to be extendable.

Could you take a look at the change and does this solve the part of your problem?

[farfromrefug]

@yomotsu thanks and really dont worry, just glad we are getting it.
Yes it solves my issue about handling zoom while dragging!
i ll try and create the other PR. Thanks

[yomotsu]

Thanks for understanding and taking a look.
I'll merge this.

[PlopTheReal]

Hey,
Thanks for that feature. I'm trying to animate the dolly by I'm getting the following within the constructor:
TypeError: Cannot read properties of undefined (reading 'up')
Any idea on such error?
Thanks