NAME

SET PATTERN REFERENCE POINT − create structure element to set the current pattern reference point

SYNOPSIS

C Syntax

void
pset_pat_ref_point ( ref_pt )
Ppoint∗ref_pt;pattern reference point

Required PHIGS Operating States

(PHOP, ∗, STOP, ∗)

DESCRIPTION

Purpose

SET PATTERN REFERENCE POINT creates a structure element containing a value for the current pattern reference point attribute.  The structure implicitly resets the current pattern reference vectors attribute as well.  When the interior style is PATTERN, these attributes apply to the following output primitives:

•  FILL AREA•  NON-UNIFORM B-SPLINE SURFACE
•  FILL AREA 3•  SET OF FILL AREA SET 3 WITH DATA
•  FILL AREA SET•  TRIANGLE STRIP 3 WITH DATA
•  FILL AREA SET 3•  QUADRILATERAL MESH 3 WITH DATA
•  FILL AREA SET 3 WITH DATA

Note: This function places the appropriate data in the Central Structure Store and in PEX-SI archives, but the structure element is currently ignored during traversal. 

If the current edit mode is INSERT, a SET PATTERN REFERENCE POINT element is inserted into the currently open structure after the element pointed to by the current element pointer. If the edit mode is REPLACE, the new 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

ref_ptThe pattern reference point is given in Modelling Coordinates (MC), using a 2D shorthand; 0 is used as the z coordinate.  The Ppoint type is defined in phigs.h as:

typedef struct {
Pfloatx; /∗ x coordinate ∗/
Pfloaty; /∗ y coordinate ∗/
} Ppoint;

Execution

When the SET PATTERN REFERENCE POINT element is traversed, the current pattern reference point entry in the traversal state list is set to the x and y values contained in this element, and the z value 0.  The current pattern reference vectors are set to (1,0,0) and (0,1,0).  When the interior style (either individual or bundled, as selected by the current interior style ASF) is set to PATTERN, these attributes are used in conjunction with the current pattern size for the area-defining primitives that follow in the structure network. 

ERRORS

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

SEE ALSO

INQUIRE PATTERN FACILITIES (3P)
SET PATTERN SIZE (3P)
SET PATTERN REPRESENTATION (3P)
SET PATTERN REFERENCE POINT AND VECTORS (3P)

September 02, 1992