graPHIGS Programming Interface: Subroutine Reference

The graPHIGS Programming Interface : Subroutine Reference

GPZBM - Set Z-Buffer Protect Mask

GPZBM (mask)

Purpose

Use GPZBM to insert a Set Z-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 Z-Buffer Protect Mask structure element depending on the current edit mode.

During structure traversal, this structure elements sets the Z-Buffer Protect Mask entry of the graPHIGS API traversal state to the value specified by the parameter.

The mask value specifies a write-protect mask for the z-buffer to inhibit writing into the z-buffer during the rendering of output primitives. If a z-buffer is not present on the workstation, then this attribute is ignored.

The mask is a 32-bit integer. The mask supports two values:

All bits 0 - This value allows updates to the z-buffer.

All bits 1 - This value prohibits updates to the z-buffer.

If the mask value is not all zeros, then it is processed as if a mask value of all ones had been specified.

The traversal default for the z-buffer protect mask is a value of 0 for all 32 bits.

GPZBM is identified as GSE 1009.

Note:

Not all GSEs are supported on all workstations. Use the Inquire List of Generalized Structure Elements (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

mask -- specified by user, fullword integer

z-buffer protect mask. A mask of 0 for all 32 bits allows the application to update the z-buffer. A mask of 1 for all 32 bits prohibits updates to the z-buffer.

Error Codes

5: FUNCTION REQUIRES STATE STOP OR NROP (NOT STCL)

Related Subroutines

None

RCP code

201343243 (X'0C00410B')