[Visualpython-users] gtk2-based beta version for Windows

[Bruce S. <Bru...@nc...>]

VPython 4.beta20 eliminates almost all Windows-specific code in favor of 
gtk2, so that the source code for Visual is nearly universal across all 
platforms (gtk2 was originally developed for creating graphics user 
interfaces on Unix but has been ported to Windows and Macintosh). This 
version works at least as well as 4.beta16 but does not address all 
issues on Windows. The version number was advanced from 4.beta16 to 
4.beta20 as a marker that this represents a significant change.

New to the Windows beta version: At the top of a graphics window is a 
new icon to change right-button dragging to "pan" rather than rotate 
(and another icon to switch back). There are also icons to exit the 
program, switch to or from full-screen mode, and reset to the original 
camera position (this reset option is not yet working).

History: In late spring of 2006 Jonathan Brandmeyer completed the new 
version of VPython, with transparency, surface textures, and 
sophisticated lighting, based on gtk2. However, at that time it became 
evident that it was extraordinarily difficult to assemble all the 
components needed for gtk2-based development on Windows, so he wrote 
some Windows-specific code to substitute for the gtk2 code.

In the intervening time, installers that are much easier to use have 
become available, which made it feasible to return to Brandmeyer's 
original vision of using one code base for all platforms. The necessary 
gtk2 run-time components have been bundled into the VPython 4.beta20 
installer, so the end user doesn't have to install gtk2.

There remain only two small Windows-specific files, wintimer.cpp and 
winrate.cpp, needed due to the absence on Windows of the gettimeofday 
routine found on Unix.

It has always been the case that gtk2 was available on Mac OSX, that 
being a Unix-based operating system, but gtk2 connected to the X11 
windowing system, which necessitated installing X11. There is a new and 
rather raw version of gtk2 for the Mac which connects to the native 
Quartz windowing system, and Steve Spicklemire is trying to build 
VPython on the Mac using this new gtk2 software. If he succeeds, 
installation on the Mac could be vastly simpler than it now is.

Bruce Sherwood