# Synopsis

(macro) PDX_MSGT gdx_EvalCurvePnt(long option, MDA_PTR db_ptr, double tval, MTH_3DPNT point)

# Purpose

Evaluate a point on a GDX curve entity

# Description

At a given parameter value in the domain of the GDX curve by default, evaluate a point on the GDX curve entity. The GDX curves supported for evaluation are:

.RS 4 GDX_ARC .RE .RS 4 GDX_COMP_CURVE .RE .RS 4 GDX_CONIC .RE .RS 4 GDX_NURB_CURVE .RE .RS 4 GDX_OFFSET_CURVE .RE .RS 4 GDX_POLYLINE .RE .RS 4 GDX_SPLINE_CURVE .RE .RS 4 GDX_TRIM_CURVE .RE

# Input

## option

### GDX_UNNORM

Unnormalize the parameter value

### GDX_FROMLEFT

Evaluate the curve point from the left

## db_ptr

The GDX curve entity database pointer

## tval

The parameter value to evaluate in the parametric domain of the GDX curve

# Output

## point

The XYZ 3D evaluated point location

# Return

          GDX_NOERR
          GDX_ENTITYNOTCURVE
          Low level error return
          .fi