OPEN STRUCTURE(3P) — SUNPHIGS LIBRARY

NAME

OPEN STRUCTURE − create a new structure or begin editing an existing structure

SYNOPSIS

C Syntax

void
popenstruct ( struct_id )
Pintstruct_id;structure identifier

FORTRAN Syntax

SUBROUTINE popst ( STRID )
INTEGERSTRIDstructure identifier

Required PHIGS Operating States

(PHOP, ∗, STCL, ∗)

DESCRIPTION

Purpose

Use OPEN STRUCTURE to create a new structure or to begin editing an existing structure. Some structure inquiry functions can only be performed on an open structure.

C Input Parameter

struct_id
An integer specifying the identifier to be assigned to a new structure or the identifier of an existing structure in the Central Structure Store to be opened.

FORTRAN Input Parameter

STRID
An integer specifying the identifier to be assigned to a new structure or the identifier of an existing structure in the Central Structure Store to be opened.

Execution

If structure identifier does not exist, a new empty structure is created and opened, and the element pointer is set to 0.

If the structure specified in OPEN STRUCTURE already exists, the structure is opened for editing and the element pointer is set to the last element in the structure.

A structure consists of a sequence of numbered structure elements. A structure element may contain

• the specification for an output primitive • attribute selection • view selection • a modelling transformation • a reference to another structure • a name set or label • a generalized structure element, or • application data.

An element pointer in the open structure is used to reference specific structure elements. When a PHIGS function creates a new element, the current edit mode determines whether the new element is inserted after, or replaces the element pointed to by the current element pointer. You can perform the following operations on the open structure:

• add or delete structure elements • copy all elements from another structure • inquire about the current element type and size or the current element content • change the position of the element pointer • inquire the current position of the element pointer.

The PHIGS state list stores the identifier for the currently open structure, the position of the current element pointer, the current edit mode, and a list of all structure identifiers in use.

ERRORS

006Ignoring function, function requires state (PHOP, ∗, STCL, ∗)

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