# Synopsis

PDX_MSGT gcr_OffsetSurf(long option, MDA_PTR orig_db_ptr, double cont_toler[4], double off_distance, MDA_PTR surface_ptr, int gdx_model, MDA_PTR *gdx_OS_ptr)

# Purpose

Create a GDX Offset Surface.

# Description

Given the distance, and a GDX base surface create a GDX Offset Surface.

If the cont_tol is NULL, check for the GDX surface continuity will not occur.

The orig_db_ptr argument should contain the database pointer of the entity that the new entity was created from (usually this should be obtained by the calling routine via mda_GetOrigDbptr) or MDA_NULL_PTR. See the mda_intro man page for more information about predecessor entities.

\fBRules\fR .IP • 3 The surface continuity must be greater than 1. .LP

# Input

## option

### GCR_NOVALIDATE

No validation will occur on the input data.

## orig_db_ptr

The original entities orig_db_ptr as obtained from the mda_GetOrigDbptr call, or MDA_NULL_PTR

## cont_toler

The continuity tolerance. The distance between the derivatives must be less then or equal this value to have derivative continuity .nf [0] = Model Space Distance (G0) [1] = Radian angular difference (G1) [2] = Curvature difference (G2) [3] = Normalized derivative difference .fi

## off_distance

The distance to offset the surface, +,- or 0.0.

## surface_ptr

The GDX base surface to offset. The GDX base surface must have a continuity >= G1 and a minimum radius of curvature (1.0/G2) >= offset distance. (Currently this module does not check for minimum radius conditions.)

## gdx_model

The GDX model for entity creation

# Output

## gdx_OS_ptr

Entity database pointer of the GDX Offset Surface

# Tolerances

          .fi

# Return

          GCR_NOERR
          GCR_INVALID_MODEL
          GCR_OFF_SURF_CONT
          Low level error return
          .fi