Synopsis

PDX_MSGT igeo_EvalCurveDerivs(long option, MDA_PTR db_ptr, IMTH_MATRIX matrix, double tval, int max_deriv, double (*derivs)[3])

Purpose

Evaluate a derivatives on an IGES curve entity

Description

At a given parameter value between 0.0 and 1.0 inclusive, evaluate derivatives on the IGES curve entity. The IGES curve entity must be a valid IGES definition. A max_deriv > the degree the curve will return zero derivative values in the derivs array. The IGES spline, composite and NURBS curve entities can be evaluated from the left or right (default).

Input

option

IGES_NOMATRIX

Do not apply the IGES entities matrix to the data

IGEO_FROMLEFT

Evaluate the derivates from the left

db_ptr

The IGES curve entity database pointer

matrix

The matrix to apply to the derivatives

tval

The parameter value to evaluate (0.0 - 1.0)

max_deriv

The maximum derivative required

Output

derivs

The 3D evaluted derivates

Return

      IGEO_NOERR
      IGEO_ENTITYNOTCURVE
      Low level error return
      .fi