From: Chang Hu (
Date: Thu Apr 27 2006 - 12:36:23 CDT

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...


John Stone wrote:

> 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
>On Thu, Apr 27, 2006 at 12:19:57AM -0400, Chang Hu wrote:
>>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?