NAME

SET REFLECTANCE EQUATION −  create a structure element to set the current interior reflectance equation

SYNOPSIS

C Syntax

void
pset_refl_eqn ( equation )
Pintequation;reflectance equation

Required PHIGS Operating States

(PHOP, ∗, STOP, ∗)

DESCRIPTION

Purpose

SET REFLECTANCE EQUATION creates a structure element to set the current interior reflectance equation. 

When the current interior reflectance equation Aspect Source Flag (ASF) is set to INDIVIDUAL, the current value of this attribute defines the interior reflectance equation to be applied to the following output primitives:

• FILL AREA

• FILL AREA 3

• FILL AREA SET

• FILL AREA SET 3

• FILL AREA SET 3 WITH DATA

• SET OF FILL AREA SET 3 WITH DATA

• NON-UNIFORM B-SPLINE SURFACE

• QUADRILATERAL MESH 3 WITH DATA

• TRIANGLE STRIP 3 WITH DATA

C Input Parameters

equation
The reflectance equation.  The possible values defined in phigs.h are:

1PREFL_NONENo Reflectance Calculation Performed
2PREFL_AMBIENTUse Ambient Term
3PREFL_AMB_DIFFUse Ambient and Diffuse Terms
4PREFL_AMB_DIFF_SPECUse Ambient, Diffuse, and Specular Terms

Execution

Depending on the edit mode, a SET REFLECTANCE EQUATION element is inserted into the open structure after the element pointer or replaces the element pointed at by the element pointer. The element pointer is then updated to point to this SET REFLECTANCE EQUATION element. 

At traversal time, if the specified reflectance equation is not defined, then the default is used. 

When the current interior reflectance equation ASF is set to INDIVIDUAL, area-defining output primitives which follow in the structure network are filled using the current interior reflectance equation. 

When the current interior reflectance equation ASF is set to BUNDLED, the interior reflectance equation is taken from the workstation extended representation indicated by the current interior index.  In this case, the interior reflectance equation set with SET REFLECTANCE EQUATION has no effect. 

ERRORS

002Ignoring function, function requires state (PHOP, ∗, STOP, ∗)

SEE ALSO

SET INDIVIDUAL ASF (3P)
SET INTERIOR REPRESENTATION (3P)
SET FACE DISTINGUISHING MODE (3P+)
SET INDIVIDUAL ASF (3P)
SET INTERIOR REPRESENTATION PLUS (3P+)
SET REFLECTANCE EQUATION (3P+)
FILL AREA (3P)
FILL AREA 3 (3P)
FILL AREA SET (3P)
FILL AREA SET 3 (3P)
FILL AREA SET 3 WITH DATA (3P+)
SET OF FILL AREA SET 3 WITH DATA (3P+)
NON-UNIFORM B-SPLINE SURFACE (3P+)
QUADRILATERAL MESH 3 WITH DATA (3P+)
TRIANGLE STRIP 3 WITH DATA (3P+)

September 02, 1992