An extension to LibGGI handling auxiliary buffers

Name

libggibuf : An extension to LibGGI handling auxiliary buffers

Description

LibGGIBuf is an extension to LibGGI which adds functionality pertaining to ancilary buffers, e.g. Alpha and Z buffers. LibGGI is a graphics library developed by the GGI Project.

In addition to providing some internal support infrastructurefor other extensions which use ancilary buffers, LibBuf can overload a normal LibGGI visual such that normal LibGGI drawing operations can do things like perform Alpha blends and Z clipping.

LibGGIBuf supports acceleration of graphics primitives where possible, but also provides a fallback mechanism which provides emulation on all supported LibGGI visuals.

Environment variables

The following outlines the environment variables, intended for the user, which affect the behaviour of LibGGIBuf:

BUF_DEBUG

The debugging level for LibGGIBuf:

  • 0 or unset : debug output is off; debugging is off
  • 255 : all debug output is on

You may also bitwise-or any of the following together:

  • 2 : debug core
  • 4 : debug mode setting
  • 8 : debug color handling
  • 16 : debug drawing
  • 32 : misc debugging output
  • 64 : debug dynamic library handling

The debugging output can be quite verbose and in most cases you should redirect stderr so that it does not interfere with your program's output.

BUF_DEBUGSYNC

Turn on synchronous debugging output, flushing the output buffers before returning from DPRINT calls.

GGI_CONFDIR

Override compiled-in path to global config files (Win32 only, but not Cygwin).

Note that the last environment variable really begin with GGI, and not BUF.