# Synopsis

PDX_BOOL igeo_TestSurfContinuity(long option, double *cont_toler, int test_deriv, double deriv_rght[][GDX_MAX_DEG + 1][3], double deriv_left[][GDX_MAX_DEG + 1][3])

# Purpose

Test the surface derivative for continuity

# Description

Compares the surface derivatives for continuity. The derivatives are assumed to have been evaluated from the left and the right or from above and below. For the IGEO_GTEST option and test_deriv == 2, the first and second derivatives must be set for the right and left derivative values.

# Input

## option

### IGEO_GTEST

Test for G continuity up to test_deriv of 2

## cont_toler

The surface 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

## test_deriv

The surface degree of the derivatives being tested

## deriv_rght

The derivative(s) calculated from the right or above

## deriv_left

The derivative(s) calculated from the left or below

# Tolerances

ZERO_TOL NORMAL_MAG_TOL

# Return

          PDX_TRUE - The derivatives are continuous within cont_toler
          PDX_FALSE - The derivatives are not continuous within cont_toler
          .fi