overview of OpenGL
OpenGL extensions
GL_HP_supersample extension
This supersample extension defines a mechanism for enabling and disabling a full scene anti-aliasing method. It is supported on Visualize fx-10b, FireGL-UX and FireGL T2/X1/X3 graphics hardware. On the FireGL hardware the X Server must be configured to enable this capability in order for the extension to be present.
On the FireGL-UX graphics hardware, this extension is enabled by using SAM to adjust the Display->X Server Configuration->Screen Options set the "FSAA" option to a supersample resolution (eg. 2.0x2.0) which results in four samples per screen pixel.
On the FireGL T2/X1/X3 this extension is enabled in a similar manner by using SAM to adjust the Display->X Server Configuration->Screen Options set the "FSAAScale" option to a super sample resolution (e.g. 2, 4, or 6) which results in the number of samples per screen pixel. The actual number of samples used will depend on the availability of video memory to implement the supersample function and will vary based on screen resolutions and other functionality that has been also enabled such as stereo display and offscreen pixmaps.
This extension can be enabled either via the OpenGL API using the glEnable(GL_SUPERSAMPLE_HP) call or via the environment variable HPOGL_FORCE_SCENEAA=1 (when in direct rendering mode). The call glDisable(GL_SUPERSAMPLE_HP) can be used to disable this mode. These calls need to be made in the same OpenGL rendering context that is to be supersampled.