Table of Contents
Advertisement
4.3.2.2.2 Overlay Planes
The PowerStorm 300 provides hardware support for 2-bit double-buffered overlay planes.
Note that for performance reasons, not all pixel formats support overlay planes. If you do
not require overlay planes, selecting a pixel format without overlay support will ensure
maximum performance. The availability of pixel formats with overlay planes can be
disabled by using the Display Application.
4.3.2.2.3 Stencil Planes
The PowerStorm 300 device driver provides hardware support for a 4-bit stencil buffer.
Note that for performance reasons, not all pixel formats support stencil planes. If you do
not require stencil planes, selecting a pixel format without stencil planes will ensure
maximum performance. The availability of pixel formats with stencil planes can be
disabled by using the Display Application.
4.3.2.2.4 SoftImage Customizations
When using the PowerStorm 300 with Microsoft's SoftImage®, you should enable
SoftImage Customizations using the Display Application. In addition, you also need to
enable 4-bit overlay using the Display Application. Before starting Softimage, you need to
make sure that the following environment variable is set:
SI_OVERLAY = USE_ONE_BIT
When SoftImage Customizations are enabled, other OpenGL applications may not behave
correctly. Therefore it is recommended that SoftImage Customizations be disabled before
running other OpenGL applications.
4.3.3 Developing OpenGL Applications on Alpha Platforms
This section provides information for developing OpenGL applications that optimize the
PowerStorm 300 graphics device on Alpha platforms.
4.3.3.1 Pixel Format Support
The PowerStorm 300 driver and device, in combination with Windows NT OpenGL,
support a fully compliant implementation of OpenGL. Color index mode support is
provided by the Windows NT generic OpenGL implementation, and thus is not hardware-
accelerated.
On the PowerStorm 300 device, the display driver supports the pixel formats listed in
Table 4-2.
PowerStorm 300 Graphics Options Windows NT and Hardware Installation 4–7
Operation
Advertisement
Table of Contents
