# Synopsis

PDX_MSGT gdx_ConvertOffsetToNurbCurve(long option, MDA_PTR gdx_offset_db_ptr, int model, double tolerance, int max_iters, void *gdx_nurb_curve)

# Purpose

Convert a GDX offset curve to a GDX NURB Curve

# Description

Converts a GDX offset curve entity to a GDX NURB Curve entity

If a conversion error occurs any data created during the conversion is deleted and no GDX NURB Curve is created.

The tolerance value is a measure of the distance that the offset can vary from the true offset. The max_iters is the maximium number of iterations that a span in the original base curve converted to a NURBS curve is subdivided for offsetting to approximate the true offset. Typically only several iterations are required for convergence to the tolerance, but a discontinuous base curve may never converge to the requested tolerance. A max_iters value of around ten(10) is recommended.

The GDX offset curve entity must be a valid GDX definition.

The conversion is an approximate conversion to within the specified tolerance unless the base entity is a GDX line or a GDX arc entity in which case the conversion is exact.

# Input

## option

### GDX_COMMIT

Commit the GDX NURB Curve to the database

## gdx_offset_db_ptr

The valid GDX offset curve entity database pointer

## model

The model to create the GDX NURB Curve in

## tolerance

The offset approximation tolerance

## max_iters

The maximium number of iterations to test for tolerance convergence.

# Output

## gdx_nurb_curve

The GDX NURB Curve entity database pointer or structure pointer

# Return

          GDX_NOERR
          GDX_INVALIDMODEL
          GDX_INVALIDENTITYTYPE
          Low level error return
          .fi