SET HLHSR IDENTIFIER(3P) — SUNPHIGS LIBRARY

NAME

SET HLHSR IDENTIFIER − create a structure element to set the current hidden line/hidden surface removal attribute

SYNOPSIS

C Syntax

void
psethlhsrid ( id )
Pintid;HLHSR identifier

FORTRAN Syntax

SUBROUTINE pshrid ( HRID )
INTEGERHRIDHLHSR identifier

Required PHIGS Operating States

(PHOP, ∗, STOP, ∗)

DESCRIPTION

Purpose

SET HLHSR IDENTIFIER creates a structure element containing a value for the Hidden Line and Hidden Surface Removal (HLHSR) primitive attribute. During traversal this attribute replaces the current HLHSR identifier and is applied to all output primitives which follow in the structure network in a workstation-dependent way.

The HLHSR identifier in the structure network is used in conjunction with the HLHSR mode on the workstation during traversal. Presently, both must be one to enable Hidden Surface Removal.

If the current edit mode is INSERT, then a SET HLHSR IDENTIFIER element is inserted into the currently open structure after the element pointed to by the current element pointer. If the edit mode is REPLACE, then the new SET HLHSR IDENTIFIER element replaces the element pointed to by the element pointer. In either case, the element pointer is updated to point to the new element.

C Input Parameter

idThe HLHSR identifier value. Presently supported values are:

0PHIGS_HLHSR_ID_NONERemove Nothing
1PHIGS_HLHSR_ID_ZBUFFRemove Hidden Surfaces and Hidden Lines Using Z-buffer

FORTRAN Input Parameter

HRIDThe HLHSR identifier value. Presently supported values are:

0PHIGSHLHSRIDNONERemove Nothing
1PHIGSHLHSRIDZBUFRemove Hidden Surfaces and Hidden Lines Using Z-buffer

Execution

When the SET HLHSR IDENTIFIER element is traversed, the current HLHSR identifier entry in the PHIGS traversal state list is set to HLHSR identifier. The current HLHSR identifier is applied to output primitives which follow in the structure network. The current HLHSR identifier traversal state from the structure network is compared to the current HLHSR mode on the workstation.

HLHSR is performed using a Z-buffer algorithm.

The Z buffer processing does not work with primitives filled with transparent hatches. When a transparent hatched filled area-defining primitive is to be Z buffered, SunPHIGS will fill it with an opaque hatch.

The HLHSR mode for a workstation is set with the SET HLHSR MODE function. The supported HLHSR modes are workstation-dependent.

For systems without Z-buffered hardware, HLHSR is done in software, but with a significant loss of performance.

ERRORS

005Ignoring function, function requires state (PHOP, ∗, STOP, ∗)

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