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Multitouch Gesture Option in User Preferences
Closed, ResolvedPublicPATCH


This proposed patch has been discussed on the mailing list a bit and adds an "Enable Multitouch Gestures" toggle to the User Preferences. The gestures include magnify, rotate and pan. When turned off, magnify and rotate get discarded, while pan gets turned back into a scroll event for zooming.

Edit: link to mail thread:

Event Timeline

Uploaded V2, adding a wm_event directly rather than going through wm_event_add_ghostevent() again when GHOST_kEventTrackpad needs to be turned into a GHOST_kEventWheel.

Made a small boo-boo and moved some code around; trackpad-specific code now only gets executed when needed, including the update_tablet_data() call.

this batch is old and doesn't apply to 2.74, any chance of updating, i tried to do by my self but there are missing places in blender now, thank you.

Woah, this *is* old! This is actually one of the reasons I still use a modified 2.67 build myself (I have a physical handicap and the current behaviour of pinching and rotating is extremely hard for me to do). At some point the patch stopped working though and I couldn't be bothered to fix it.

Knowing that there is at least some interest in this however, I'll see if I can give it a whirl the coming days. =)

@Patrick Boelens (senshi), yes there is definitely an interest in better multitouch support, the issue is that we used to have a quite poor review support. I'd be happy to see an updated patch (but better use our differential tool now which makes review a bit easier), you can assign me as a reviewer.

Alright, so I'm looking at the current state of Blender and what this patch was meant to accomplish. The goal of this patch was simply to allow "classic" scene navigation using a multi-touch trackpad. For me this only meant having a two-finger scroll to zoom.

To me, it now seems like this patch would be redundant, as we already have remappable input. The problem there, however, is that two-finger scroll isn't being picked up by Blender when reassigning an operation (at least on OSX 10.9, on a 2009 MacBook Pro).

Would others agree that fixing this might be a better course of action? I feel like adding a toggle just for this switch would now be very much overkill. If so, I would also propose to rename Trackpad Zoom to Trackpad Pinch or Trackpad Magnify in an effort to decouple this gesture name from it's original function a bit.

Please let me know what you think, thanks.

@Aaron Carlisle (Blendify) The original patch was made with multi-touch trackpads in mind. I don't think it would have affected tablets, especially when going the input route I described above.

And just after posting this I remembered what the original problem was: Two-finger scroll gets picked up as a pan event, not a scroll one. I would love some input on how to best tackle this, or even how to look at it. I feel like adding a toggle just for this switch would now be overkill, but I'm also not sure how else this could be handled nicely. Perhaps some kind of modifier toggle or secondary Value to treat Pan as either 2D Pan, Horizontal Scroll or Vertical Scroll?

I think if you could work this patch so that it will pick up input from tablets will be much more helpful to users since the majority of people most likely have a desktop system

Two-finger scroll gets picked up as a pan event

strange! this works ok with me, when:

  • two-finger scroll it zooms in and out on the trackpad
  • two-finger scroll does nothing on the touch screen
  • pinch in it pan to left and pinch out it pan to right with multitouch and trackpad.

also i'm ready to help test anything you make man, hope this continues, thank you.

@Aaron Carlisle (Blendify) I'm sorry, but I'm afraid tablet input is really beyond the scope of this patch (and my abilities; I'm not very familiar with the Blender source).

@Yousef Harfoush (bat3a) This is beginning to sound like a bigger problem/ bug than I had originally anticipated. Definitely seems like a bug that your trackpad and touch screen provide different results though. Is this on the same machine?

I just removed all trackpad events from my input list and found something odd as well. Adding a new Zoom View event did absolutely nothing, but by modfiying an existing (Keyboard) one I could get a two-finger scroll to be picked up as a pan event, causing the view to zoom in regardless of my scroll direction.

With that said, I'm beginning to think there may be an underlying issue to all of this. I haven't looked at the source yet, but I'm guessing GHOST may be failing to "translate" certain events properly? I'll see if I can give it a look tomorrow, but if anyone knows more or can point me to a specific block of code that would be much appreciated.

Is this on the same machine?

yes, it is a surface pro 3 with 10 finger touch, and type cover trackpad.

also deleting the view pan with Ctrl + Wheel Up and Ctrl + Wheel Down shortcuts stop's the pan left and right when pinching.

other info that may help: windows 8.1 pro x64, 2.74 tag compiled with mingw x64.

Patrick Boelens (senshi) changed the task status from Unknown Status to Resolved.Mar 1 2016, 4:09 AM
Patrick Boelens (senshi) claimed this task.

I just realized I still had this task open. I'm pretty sure everything works as intended and has been for a while now. Seperate bug reports may still follow if I ever encounter similar weirdness again in the future, but I don't believe this patch serves any public purpose anymore. Closing for now.