NAME

SET DEPTH CUE INDEX − create a structure element containing the value depth cue index

SYNOPSIS

C Syntax

void
pset_dcue_ind ( index )
Pintindex;depth cue index

Required PHIGS Operating States

(PHOP, ∗, STOP, ∗)

DESCRIPTION

Purpose

SET DEPTH CUE INDEX creates an element in the currently open structure containing a depth cue index number. The index number corresponds to an entry in the table of defined depth cue operations in the workstation state list. 

C Input Parameter

indexThis is an index to the workstation depth cue bundle table. 

The index number corresponds to an entry in the table of defined depth cue operations in the workstation state list. Up to 20 depth cue table entries may be defined. Entry zero is predefined to a depth cue mode of SUPPRESSED and cannot be changed. Entries other than zero can be changed with the SET DEPTH CUE REPRESENTATION subroutine. 

Execution

Depending on the edit mode, a SET DEPTH CUE INDEX element with a value depth cue index is inserted into the open structure after the element pointer or replaces the element pointed to by the element pointer. The element pointer is then updated to point to this SET DEPTH CUE INDEX element. 

When a SET DEPTH CUE INDEX structure element is traversed, the current depth cue index value in the PHIGS Extension traversal state list is set to index. This value indexes a depth cue representation in the table of defined depth cue operations stored in the workstation state list.  If the entry corresponding to the specified index is not defined, then an entry of zero is substituted in the index. 

The current depth cue index determines the depth cue operation that will be applied to all primitives in the display. Each entry in the workstation table of defined depth cue operations contains the following information:

•  depth cue index number •  depth cue mode (SUPPRESSED or ALLOWED) •  depth cue reference planes •  depth cue scale factors •  depth cue color

If the depth cue mode is SUPPRESSED, depth cueing is not applied to subsequent primitives in the display.  If the depth cue mode is ALLOWED, depth cueing is applied to all subsequent primitives using the operation defined by the reference planes, scale factors, and depth cue color. 

When a workstation is opened, entries zero and one are initialized with the following representation:

Entry 0Entry 1
depth cue modeSUPPRESSED ALLOWED
depth cue reference planes0.0, 1.00.0, 1.0
depth cue scaling1.0, 1.0 0.0, 1.0
depth cue colour(INDIRECT, 0) (INDIRECT, 0)

For depth cue reference planes and depth cue scaling, the first value is the back reference plane and scaling. 

ERRORS

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

063Ignoring function, the depth cue index value is less than zero

SEE ALSO

SET DEPTH CUE REPRESENTATION (3P+)
INQUIRE LIST OF DEPTH CUE INDICES (3P+)

September 02, 1992