# Synopsis

PDX_MSGT gdx_CompareCurves(long option, MDA_PTR gdx_curv1_ptr, MDA_PTR gdx_curv2_ptr, double toler_geom, double toler_parm, long num_pnts, long max_iters, GDX_ENTITY_COMPARE *gdx_curvcompare)

# Purpose

Compare two curves for conformity.

# Description

Compare two curves for geometric conformity at sample points within a tolerance toler_geom and for parameterization conformity within toler_parm. If the option is GDX_SUB_ENTITY, the first curve could be unbounded, otherwise both curves should be bounded. At every sample point one curve is evaluated and then the evaluated point will be projected on to the other curve. The distance between the original evaluated point and projected point should be less than the toler_geom for all the sample points to indicate geometric conformity of curves at those points.

.nf GDX_ENTITY_COMPARE members .fi .RS 3 .TP 17 max_gdev Maximum geometric deviation between the two entities for sampled points. .TP max_pdev Maximum parameter deviation between original sampled parameters and projected parameters. This value is valid only if the geometric conformity flag mathch_flg is PDX_TRUE .TP match_flg Flag indicating the conformity status. .nf = PDX_TRUE if geometric conformity exists. = PDX_FALSE if geometric conformity does not exists. .fi .TP parm_chg_flg Flag indicating whether or not parameterization has changed. This flag is valid only if geometric conformity flag match_flg, is PDX_TRUE. .nf = PDX_FALSE : parameterization has not changed = PDX_TRUE : parameterization has changed .fi .LP .RE

# Input

## option

### GDX_SUB_ENTITY

Second curve is a sub-curve of the first curve.

### GDX_SAME_ENTITY

Compare the two curves for the same Point set.

### GDX_RANDOM_PNTS

Compare the two curves at random points.

## gdx_curv1_ptr

First curve entity database pointer

## gdx_curv2_ptr

Second curve entity database pointer

## toler_geom

Tolerance within which curves are assumed to conform.

## toler_parm

Tolerance within which parameterization of the curves is assumed to be the same.

## num_pnts

Number of sample points.

## max_iters

Maximum number of iterations when point projection is done numerically.

# Output

## gdx_curvcompare

Comparison results structure.

# Return

          Low level error return
          .fi