Multi-touch suggestion

[AndyH]

A common way to control something on the iphone is to drag with your finger. I'm using the multitouch object to do this with some events, but it would make it even easier if you could incorporate extra properties to this object that return the number of pixels on the X and Y since you started dragging with your finger on the screen.

So what I'd like the multitouch object to have are four new properties and one new condition:

• =XTouchOrigin( "iPhone Multiple Touch", 0) - returns the X position where you first touched the screen when the "a new touch has occurred" condition became true
• =YTouchOrigin( "iPhone Multiple Touch", 0) - returns the Y position where you first touched the screen when the "a new touch has occurred" condition became true
• =XTouchDelta( "iPhone Multiple Touch", 0) - returns XTouch-XTouchOrigin (the difference between the start touch position and the current touch position)
• =YTouchDelta( "iPhone Multiple Touch", 0) - returns YTouch-YTouchOrigin (the difference between the start touch position and the current touch position)
• (new condition) Is touch (x) occurring? - returns true if the touch is still alive (the current conditions only return true when a touch is first registered or when it ends)

*note: I have achieved the above with events in MMF, but it would make things even easier if this was built in.

If you were making your own analogue joystick control you could display the base point of it at XTouchOrigin and YTouchOrigin. The XTouchDelta and YTouchDelta would give you the amount of movement which you could act on. (i've seen several iphone games where the joystick position is dynamic in this way)

The XTouchDelta and YTouchDelta also work for short dragging of your finger on the screen. This is useful for either moving an active object or for dragging the screen for scrolling.

I guess it would make sense to add something similar to the joystick Control object as well, which at present only returns a direction. It would be useful if you could also return the amount you have moved the joystick from it's origin just like the XTouchDelta would do.

I don't think any of this functionality is currently built in (apologies if any of it is, in which case I've not seen it!).

[AndyH]

As we have the origin and the delta, you could also return the angle and distance which would be very useful.

• =TouchAngle( "iPhone Multiple Touch", 0)
• =TouchDistance( "iPhone Multiple Touch", 0)

[Anders]

Very good suggestions

[AndyH]

so we might see these in the next beta?

[AndyH]

Oh, could we have two actions as well -

• SetXTouchOrigin
• SetYTouchOrigin

[netninja]

Those are good suggestions. I've done the same as AndyH in incorporating the Deltas with my own code, but having it built into the extension would make a lot of things much easier.

[AndyH]

Yes, I think it will make life easier for the mutlitouch and joystick objects.

For drag scrolling (where you can keep the momentum going) you have to adjust the X and Y origin value hence the two set actions above.

[AndyH]

I see Beta 15 has a new touch object. Will you be adding the above to one of the upcoming betas?

[Francois]

Yes, the beta was created a little on the rush, I did not implemented all that I wanted. It will be for the next version.

[AndyH]

Thanks for putting these in. Will do some testing.