VMD-L Mailing List

From: John Stone (johns_at_ks.uiuc.edu)
Date: Sat Apr 29 2006 - 22:50:11 CDT

Hi,
  What you want is to use the new 'mouse mode userpoint' and the
vmd_mouse_pos callback, like this:

proc do_mouse_pos_client { args } {
  global vmd_mouse_pos
  puts "mouse position: $vmd_mouse_pos"
}

trace add variable vmd_mouse_pos write do_mouse_pos_client
mouse mode userpoint

On Sat, Apr 29, 2006 at 10:05:37PM -0400, Chang Hu wrote:
> John,
>
> I went through the user's guide and succeeded in tracing the
> "vmd_pick_mol_silent", resulting in outputing some messae when one
> molecule is picked. However, I tried "vmd_pick_client" hoping it will
> output the same message whenever the cursor is moved, but with no luck.
> In short, I have several problems:
>
> 1. How to obtain the mouse position whenever it's moved?
> 2. How to determine if the mouse is near some atom?
>
> I went through the programmer's guide and got something that returns the
> mouse's x and y position, but that's in source code, I still don't know
> how to get it via the Tcl script.
>
> Thanks,
> Chang
>
> John Stone wrote:
>
> >Chang,
> > That could probably be made to work by disabling the system's mouse
> >cursor while your code is active, and querying the mouse position etc
> >for yourself. You might be able to prototype this for yourself very
> >quickly with VMD 1.8.4 by using the new mouse position callback and
> >writing some simple scripts to test the idea on a tiny molecule.
> >(no need to recompile the code even)
> >You could render the cursor with graphics/draw commands and redraw for
> >every mouse position update. If you like I can give you more suggestions
> >about this tomorrow when I have a bit more time to talk. For now, you
> >might look at the User's Guide section on callbacks, and the Tcl 'trace'
> >command. From there you can user the new position callback and the new
> >userpoint mouse mode. (see mouse command)
> >If you wanted to hack the source code directly rather than prototyping in
> >scripting, then you'll need to pick your favorite display device subclass
> >and disable the mouse cursor and add cursor rendering there,
> >followed by edits to Mouse.C for the new behavior, or something like that.
> >
> > John Stone
> > vmd_at_ks.uiuc.edu
> >
> >On Thu, Apr 27, 2006 at 01:36:23PM -0400, Chang Hu wrote:
> >
> >
> >>Thanks a lot, John,
> >>
> >>In that case I'd want to render a cursor inside VMD display because in
> >>our system the display of a system window and OpenGL rendering are on
> >>seperate screens. Is there any way to do that? I'd imagine getting the
> >>mouse movement from the OS and rendering a cursor for each frame
> >>rendered. I am not sure if I can creat a Displayable object and if it's
> >>the easiest way...
> >>
> >>Chang
> >>
> >>
> >>John Stone wrote:
> >>
> >>
> >>
> >>>Hi,
> >>>VMD doesn't actually directly manipulate the mouse cursor position,
> >>>this is done completely by the host operating system. The farthest VMD
> >>>goes in that direction is to set the active mouse cursor style, among the
> >>>choices available on the host operating system. This is the reason you
> >>>haven't
> >>>found any code of that sort in VMD. All of the important mouse behavior
> >>>code is contained in Mouse.C, with the lowest level mouse I/O calls found
> >>>in each of the DisplayDevice subclasses for OpenGL, Win32 OpenGL, FLTK,
> >>>CAVE, and FreeVR. I'm not even sure there's a means of altering the
> >>>mouse acceleration by application control in most windowing systems.
> >>>There may be a way to do this on some, but I'm sure you'll find that
> >>>to be a difficult thing to write portable code for, if it's even
> >>>possible.
> >>>John Stone
> >>>vmd_at_ks.uiuc.edu
> >>>
> >>>On Thu, Apr 27, 2006 at 12:19:57AM -0400, Chang Hu wrote:
> >>>
> >>>
> >>>
> >>>
> >>>>Hi,
> >>>>
> >>>>I am trying to implement enhanced picking in VMD. To do this, I am
> >>>>planning to decrease the mouse speed whenever it's near an atom,
> >>>>according to the distance between the mouse cursor and the atom. I
> >>>>looked into the Programmer's Guide and had no luck finding related
> >>>>source code. (I guess I need the part where the mouse cursor is
> >>>>rendered.) Could anybody help me out with this?
> >>>>
> >>>>Thanks,
> >>>>Chang
> >>>>
> >>>>
> >>>>
> >>>>
> >>>
> >>>
> >>>
> >
> >
> > 

-- 
NIH Resource for Macromolecular Modeling and Bioinformatics
Beckman Institute for Advanced Science and Technology
University of Illinois, 405 N. Mathews Ave, Urbana, IL 61801
Email: johns_at_ks.uiuc.edu                 Phone: 217-244-3349
  WWW: http://www.ks.uiuc.edu/~johns/      Fax: 217-244-6078