| GPHID (hlhsr) |
Purpose
Use GPHID to insert a Set HLHSR Identifier structure element into the open structure following the element pointer or to replace the element pointed at by the element pointer with a Set HLHSR Identifier structure element depending on the current edit mode.
During structure traversal, this structure element sets the current HLHSR identifier entry of the graPHIGS API traversal state list to the specified parameter. The application uses this value when creating subsequent output primitives in a view with a HLHSR mode other than 1=OFF
If the workstation does not support the specified HLHSR identifier, then the HLHSR identifier defaults to a value of 1=VISUALIZE_IF_NOT_HIDDEN In a view with HLHSR mode set to 1=OFF , this value is completely ignored and has no affect on the visualization of primitives.
HLHSR processing is often implemented by use of a z-buffer and
a frame buffer.
The following table summarizes the effect of the various HLHSR
identifiers on the z-buffer and the frame buffer:
Table 3. HLHSR Processing
| Summary of when the frame buffer and the z-buffer are updated. | ||
| Frame buffer | Z-buffer | |
|---|---|---|
| 1=VISUALIZE_IF_NOT_HIDDEN | Zprim >= Zbuf | Zprim >= Zbuf |
| 2=VISUALIZE_IF_HIDDEN | Zprim < Zbuf | Never |
| 3=VISUALIZE_ALWAYS | Always | Always |
| 4=NOT_VISUALIZE | Never | Zprim >= Zbuf |
| 5=FACE_DEPENDENT_VISUALIZATION | ||
| Front-facing Areas | Zprim >= Zbuf | Zprim >= Zbuf |
| Back-facing Areas | Zprim > Zbuf | Zprim > Zbuf |
| 6=NO_UPDATE | Never | Never |
| 7=GREATER_THAN | Zprim > Zbuf | Zprim > Zbuf |
| 8=EQUAL_TO | Zprim = Zbuf | Zprim = Zbuf |
| 9=LESS_THAN | Zprim < Zbuf | Zprim < Zbuf |
| 10=NOT_EQUAL | Zprim <> Zbuf | Zprim <> Zbuf |
| 11=LESS_THAN_OR_EQUAL_TO | Zprim <= Zbuf | Zprim <= Zbuf |
Note: The actual update of the z-buffer and/or the frame buffer may be prohibited by the use of the z-buffer protect mask and the frame buffer protect mask.
Parameters
Error Codes
Related Subroutines
RCP code
201343240 (X'0C004108')