# Synopsis

PDX_MSGT gdx_ECGetParmCurve(long option, MDA_PTR gdx_surf_ptr, PDX_BOOL usage, MDA_PTR gdx_ec_ptr, MDA_PTR *gdx_pcurve_ptr, int *index)

# Purpose

Get the correct Parameter space curve from the given EC.

# Description

Get the correct Parameter space curve from the given EC, parent entity being an Edge. Search the faces array in the EC for the given surface. If not found, index will be set to -1. If the surface is found, then the index value will correspond to the surface in the faces array of the edge curve. If the surface is found multiple times, the parm curves will be compared against the model curve using the usage flag. The index to the parm curve that corresponds best will be returned.

usage is the combined sense from the senses used in Loop and Edge.

# Input

## option

Options (not used)

## gdx_surf_ptr

db_ptr of the surface to locate in the edge.

## usage

### PDX_TRUE

model and parm in the same direction

### PDX_FALSE

model and parm in opposite direction

## gdx_ec_ptr

db_ptr of the gdx_edge_curve for this edge

# Output

## gdx_pcurve_ptr

db_ptr of the correct parameter space curve in the desired direction. MDA_NULL_PTR indicates that parm curve does not exist.

## index

location in faces array that paramerter curve is from. -1 indicates that the surface was not found in the faces array.

# Return

          GDX_NOERR
          Low level error return
          .fi