VMD-L Mailing List

From: Chang Hu (changhu_at_cs.umd.edu)
Date: Sun Apr 30 2006 - 01:03:07 CDT

Thanks John,

You really helped me out of here. I guess I can draw something to
replace the mouse cursor from here. However I have one more problem:

 From mouse position, could one determine which atom it's close to? I
guess it needs an unprojection back to the 3D spece where the molecule
is in.

Chang

John Stone wrote:

>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
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>
>>>
>>>
>
>
>