BðP

OpenGL for Win32

*** The contents of this page are obsolete ***

See the new page

• Introduction
• Limitations, bugs
• Download
• Example script
• Links

Introduction

Limitations, bugs

Caveats

• This is a port of the version 0.54 of the module. All the functions supported by the module (and by Windows) works now.
• Of course, the GLX library is not implemented: it's an OpenGL library for the X Window System. So, don't use the glx* functions in your script! Caution: the glpOpenWindow function uses internaly some GLX functions; don't use it.
• The WGL library is not implemented. I'm working on this extension. Be patient!
• I increased the doc but it remains light well: OpenGL.pod

Implementation dependent differences:

• glutInit:
  The following command line options have no meaning (and are ignored) in GLUT for Win32: -display, -indirect, -direct, -sync.
• glutInitWindowPosition, glutPositionWindow:
  Win32 has two different coordinate systems for windows. One is in terms of client space and the other is the whole window space (including the decorations). If you glutPositionWindow(0, 0), GLUT for Win32 will place the window CLIENT area at 0, 0. This will cause the window decorations (title bar and left edge) to be OFF-SCREEN, but it gives the user the most flexibility in positioning. HOWEVER, if the user specifies glutInitWindowPosition(0, 0), the window is placed relative to window space at 0, 0. This will cause the window to be opened in the upper left corner with all the decorations showing. This behaviour is acceptable under the current GLUT specification.
• glutSetIconTitle, glutSetWindowTitle:
  There is no separation between Icon title and Window title in Win32. Therefore, setting an icon title in Win32 has no effect.
• glutSetCursor:
  As indicated in the GLUT specification, cursors may be different on different platforms. This is the case in GLUT for Win32. For the most part, the cursors will match the meaning, but not necessarily the shape. Notable exceptions are the GLUT_CURSOR_INFO & GLUT_CURSOR_SPRAY which use the crosshair cursor and the GLUT_CURSOR_CYCLE which uses the 'no' or 'destroy' cursor in Win32.
• glutVisibilityFunc:
  Win32 seems to be unable to determine if a window is fully obscured. Therefore, the visibility of a GLUT window is only reflected by its Iconic, Hidden or Shown state. That is, even if a window is fully obscured, in GLUT for Win32, it is still "visible".
• glutEntryFunc:
  Window Focus is handled differently in Win32 and X. Specifically, the "window manager" in Win32 uses a "click to focus" policy. That is, in order for a window to receive focus, a mouse button must be clicked in it. Likewise, in order for a window to loose focus, a mouse button must be clicked outside the window (or in another window). Therefore, the Enter and Leave notification provided by GLUT may behave differently in the Win32 and in X11 versions. There is a viable workaround for this. A program called "Tweak UI" is provided by Microsoft which can be used to change the focus policy in Win32 to "focus follows mouse". It is available from the Microsoft Web Pages:
  http://www.microsoft.com/windows/software/PowerToy.htm
• glutCopyColormap:
  GLUT for Win32 always copies the colormap. There is never any sharing of colormaps. This is probably okay, since Win32 merges the logical palette and the physical palette anyway, so even if there are two windows with totally different colors in their colormaps, Win32 will find a (hopefully) good match between them.
• glutIdleFunc + menus: The glut idle function will NOT be called when a menu is active. This causes all animation to stop when a menu is active (in general, this is probably okay). Timer functions will still fire, however. If the timer callback draws into the rendering context, the drawing will not show up until after the menu has finished, though.

Unsupported/Bugs:

• glutAttachMenu:
  Win32 only likes to work with left and right mouse buttons. Especially so with popup menus. Therefore, when attaching the menu to the middle mouse button, the LEFT mouse button must be used to select from the menu.
• glutSpaceball*, glutButtonBox*, glutTablet*, glutDials*:
  None of the special input devices are supported at this time.
• When resizing or moving a GLUT for Win32 window, no updating is performed. This causes the window to leave "tracks" on the screen when getting bigger or when previously obscured parts are being revealed. I put in a bit of a kludgy workaround for those that absolutely can't have the weird lines. The reshape callback is called multiple times for reshapes. Therefore, in the reshape callback, some drawing can be done. It should probably be limited to a color buffer clear.
• The video resizing capabilities of GLUT 3.3+ for X11 is currently unimplemented (this is probably ok, since it really isn't part of the spec until 4.0). I doubt that this will ever be part of GLUT for Win32, since there is no hardware to support it. A hack could simply change the resolution of the desktop.

Download

     ppm install http://www.bribes.org/perl/ppm/OpenGL.ppd

The documentation, in html format, is at its usual location.

You can download the patched source file here: OpenGL-0.54.03.tar.gz
Instructions for compiling the module with MSVC++ are in the README.Win32 file.
You can also use this patch: OpenGL-0.54.patch.

Keep in mind that this module is still in beta stage for Windows.
Report bug (for this version only) to jl_morel@bribes.org. Thanks.

Example script

Links

• OpenGL.org
• Microsoft & OpenGL
• OpenGL Programming Guide (The Red Book)
• OpenGL Reference Manual (The Blue Book)
• OpenGL Programming

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