# Synopsis

PDX_MSGT gcr_PolyShell(long option, MDA_PTR orig_db_ptr, MDA_COUNT num_points, double (*points)[3], double (*parms)[2], MDA_COUNT num_boundary_points, long *boundary_points, MDA_COUNT num_polygons, struct t_gdx_poly_shell_polygons *polygons, int gdx_model, MDA_PTR *gdx_ps_ptr)

# Purpose

Create a GDX Polygon Shell.

# Description

A GDX Polygon Shell entity is created for the given number of model space points and number of polygons. The polygons constitute the surface of the polygon shell. The parameter values define the parameter space points of the polygon shell surface.

The orig_db_ptr argument should contain the database pointer of the entity that the new entity was created from (usually this should be obtained by the calling routine via mda_GetOrigDbptr) or MDA_NULL_PTR. See the mda_intro man page for more information about predecessor entities.

# Input

## option

### GCR_NOVALIDATE

No validation will occur on the input data.

## orig_db_ptr

The original entities orig_db_ptr as obtained from the mda_GetOrigDbptr call, or MDA_NULL_PTR

## num_points

Number of points

## points

MDA memory containing model space points. Always consumed by this function even on error.

## parms

MDA memory containing parameter space points. Always consumed by this function even on error.

## num_boundary_points

Number of points that define the loop boundarys of each tessalated face.

## boundary_points

Array of indices of each point that lays on the boundary

## num_polygons

Number of polygons representing the surface

## polygons

MDA memory containing polygon structures each containing the number of polygon points and indices of each point that make up the facet polygons. Always consumed by this function even on error.

## gdx_model

The GDX model for entity creation

# Output

## gdx_ps_ptr

Entity database pointer of the GDX Poly Shell

# Tolerances

          .fi

# Return

          GCR_NOERR
          GCR_INVALID_MODEL
          Low level error return
          .fi