Multi touch gestures on trackpad?

Discussion in 'MacBook Pro' started by macaddict34, Nov 1, 2007.

  1. macaddict34 macrumors newbie

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    Nov 1, 2007
    #1
    Does anyone know of a program that would give the trackpad iphone-like, multitouch gestures, like pinching to zoom in and out? The flick-scroll thing would be pretty cool (not sure how accurate a trackpad really is though). I've tried to get this effect with quicksilver, but without much luck.
     
  2. ab2650 macrumors 6502a

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    Jun 21, 2007
    #2
    AFAIK, no such program exists. Here's something you can do with the trackpad and OS X that is pretty cool though, and without installing anything:

    If you have two-finger scrolling turned on, holding down control and moving two fingers up will zoom in your entire display (and follow your pointer). Down zooms back out.

    Sorry if that seems obvious, but since you asked about "zooming" I thought I should mention it.
     
  3. macaddict34 thread starter macrumors newbie

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    #3
    How about setting hot corners on the trackpad, say for like spaces?
     
  4. ab2650 macrumors 6502a

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    #4
    I'm not on Leopard yet, so no comment here.. Aren't the key combos pretty easy though? Like Cmd-Arrow?
     
  5. macaddict34 thread starter macrumors newbie

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    #5
    The key commands aren't bad, but I just thought it would be cool. I was just thinking about how you can use two fingers to scroll, so there must be more that the trackpad can do with multiple fingers.
     
  6. g-ram macrumors newbie

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    #6
    Wanted to let you know that the 'flick scrolling' does work. That is, if you're talking about using it for coverflow. Just hover the mouse over the nice big icons and use two finger scrolling. Slide your fingers left and right and it works like a charm. I don't think the decel is the same as the iPhone, as it seems a bit more abrupt... but it works very nicely indeed.

    Also I'd like to note this post in another thread (about MBP 2008):
    I think that sounds about right, the trackpad recognizes two fingers... so it seems only a matter of an update or some kind of applescript to take advantage of pinching and zooming.
     
  7. cmaier macrumors G3

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    #7
    I don't think it works that way. I think it senses one large point, not two individual points (and certainly not three like the iphone can sense).
     
  8. tracetritt macrumors member

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    #8
    i know if I have one finger on the track pad on one end and if i go kitty corner to that end and place a finger and start scrolling with another, it'll do it. so, it's really not one large point that it is sensing now is it? or is what I'm saying not relating to this conversation at all?

    Trace
     
  9. cmaier macrumors G3

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    #9
    Doesn't prove anything. When you put one finger on the top left, for example, it returns a rectangle (0,0) (assuming top left is 0,0).

    When you put your other finger on the bottom right, you get (0,0)->(100,100) (as an example).

    Say it averages that to (50,50).

    Then you drag your right finger up. As you raise it, the "average" raises to (50,0) so it looks to the computer like you are dragging up. When you drag back down, it goes in reverse.

    Anyway, I'm just using my engineering judgment to guess - I haven't actually investigated it. I just know it's much more complicated to return multiple coordinates rather than averaging them based on rasterizing which parts of the pad are touched.
     
  10. g-ram macrumors newbie

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    #10
    I still think it can distinguish two separate points...

    What do you mean the iPhone can sense three separate points? What could you possibly need three fingers at once for and HOW would you do it? A family member owns an iPhone and I have never until now, heard of using three fingers.

    Please, elaborate.
     
  11. cmaier macrumors G3

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    #11
    The iphone doesn't currently use three points, but it's in the spec. (This was discussed in some detail quite awhile ago). Nothing uses three fingers yet because it's awkward, particularly on a small phone.

    The trackpad used by most laptops (can't speak to apple's) seems to only be physically capable of spitting out, at best, rectangles. Go take a look at the technical specs or linux driver for synaptics touchpads.

    Think about how it would have to work. In a normal touchpad, you press at x,y, and you are intersecting two lines (one running vertically at x, one running horizontally at y). At the edges of the pad, amplifiers detect this and send the x/y as the result.

    Since your finger isn't a point, you are actually intersecting x1->x2 and y1->y2. So a finger intersects a range of x and a range of y. Again, at the edge of the pad, amplifiers detect this, and send off the appropriate ranges.

    If you have two vertically stacked fingers, it increases the range of y, but the range of x stays the same. So it sends off an increased range of y, that software can interpret as a "double touch." And if it's only two fingers, it can sort of guess at where they are. But it's only a guess, not multitouch sensing in which each x,y can generate its own signal.
     
  12. TheStu macrumors 65816

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    #12
    I think I can see where you are going with that, but at the same time, it is also ok with you having the fingers as far apart as the pad allows and yet still registers a click or a drag (secondary clicking/scrolling). However, if one were to lay two fingers across the pad, or place a third finger on the pad nothing happens, not even cursor movement.

    So, to a certain degree, the pad is sensitive enough to distinguish between 1 finger tip, 2 finger tips, and anything larger than that (tips being any amount of skin from the nail to the first knuckle it seems). I think that if the trackpad driver could be found, it could be conceivably edited to allow the 2 points to operate independently, allowing for iphone like usage. Inertia scrolling, pinch/spread zooming, all that jazz.
     
  13. cmaier macrumors G3

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    #13
    Well, maybe, but, again, I just don't think it's physically capable of tracking multiple points, driver or no driver, unless the mac touchpads are different than synaptics. (i was an electrical engineer for a long time, and i know how these things work generally, but i don't have specific knowledge of what's in apple's notebooks).

    I wouldn't get my hopes up. Some things, like pinch/zoom are possible, though, since all you need for that is a rectangle.
     
  14. TheStu macrumors 65816

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    #14
    Well, I think that Apple used to use Synaptics in their machines, just like how they used to use them in their iPods, but have since switched to an in-house design IIRC.
     
  15. g-ram macrumors newbie

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    #15
    I understand the geometric and algebraic ideas here. That makes perfect sense, and as you stated in the last post... it seems quite possible to achieve the pinching, since all you would be doing is resizing your rectangle (moving points from (1,1)(100,100) to (30,30)(70,70) for example).

    However...
    I still think this is incorrect. I had a chance to play with a MBP again yesterday, and I tried something else. By your concept here of increasing the y range but leaving x the same, I can place one finger flat on the pad vertically and should be able to scroll. This did not work, no matter how I tried it, it sensed only one 'point' and moved the cursor. I even tried what TheStu mentioned with three fingers and absolutely nothing happened.
     

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