| GPFBM (mask) |
Purpose
Use GPFBM to insert a Set Frame Buffer Protect Mask structure element into the open structure following the element pointer or to replace the element pointed at by the element pointer with a Set Frame Buffer Protect Mask structure element depending on the current edit mode.
This structure specifies a write protect mask. The effect of the mask is to inhibit writing to the masked bit planes in the frame buffer during the rendering of output primitives.
The traversal default for frame buffer protect mask is zero. If a bit is set to a value of one, the corresponding bit plane is protected and cannot be modified.
GPFBM is identified as GSE 1001.
Note:
Not all GSEs are supported on all workstations. Use the Inquire List of Available GSEs (GPQGSE) subroutine to determine the GSEs which are supported by an open workstation. See also the workstation descriptors in The graPHIGS Programming Interface: Technical Reference
Parameters
For an indexed frame buffer workstation, its least significant n bits (where n is the bit depth of the frame buffer) are used for the actual read/write mask. For a component frame buffer workstation, its least significant n1 bits, the next least significant n2 bits, and the next least significant n3 bits are used for each frame buffer component where n1, n2, and n3 are the bit depths of the three frame buffer components.
Error Codes
Related Subroutines
RCP code
201343233 (X'0C004101')