# Synopsis

PDX_MSGT gcr_RevSurf2(long option, MDA_PTR orig_db_ptr, MTH_3DPNT center, MTH_3DVEC axis_vec, MTH_3DVEC ref_vec, double maj_radius, double min_radius, int keep_flg, int gdx_model, MDA_PTR *gdx_rs_ptr)

# Purpose

Create a GDX Revolve Surface from a torus definition.

# Description

Given a point on the torus axis, a torus axis vector, the maj_radius of the torus, the min_radius of the torus, create a GDX Revolve Surface. The torus may be degenerate (maj_radius less than min_radius). If it is, the keep_flg should be used to indicate which portion of the torus the revolved surface will represent.

The maj_radius must be > the current GDX ZERO_TOL

The min_radius must be > the current GDX ZERO_TOL.

If ref_vec is not NULL, the corresponding magnitude of the given vector must be > the current GDX NORMAL_MAG_TOL. If the given vector is not perpendicular to the torus axis vector within the current GDX ANGLE_TOL, the closest perpendicular vector is used.

If the ref_vec is NULL, an arbitrary ref_vec (perpendicular to the given axis_vec) will be determined and stored in the entity.

If the magnitude of the axis_vec torus axis vector is less than the current GDX NORMAL_MAG_TOL, the Z torus axis vector is assumed. if the torus definition is not degenerate, then the keep_flg will be ignored The GCR_REVERSE_NORMAL option will make the resulting surface point toward the interior of the surface.

\fBRules\fR .IP • 3 maj_radius must be > 0.0 .IP • 3 min_radius must be > 0.0 .IP • 3 ref_vec magnitude > 0.0 (if ref_vec not NULL) .LP

# Input

## option

### GCR_NOVALIDATE

No validation will occur on the input data.

### GCR_REVERSE_NORMAL

Normal of resulting GDX_REV_SURF will point inward

## orig_db_ptr

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

## center

The torus point

## axis_vec

The center axis of the torus

## ref_vec

The U parametric axis reference vector (Must be > 0.0), or NULL to create an unparametrized Torus.

## maj_radius

The maj_radius of the torus at the torus point (Must be > 0.0)

## min_radius

The min_radius of the torus at the torus point (Must be > 0.0)

## keep_flg

### GCR_TORUS_ALL

Keep the whole torus, should not be used on degenerative torus entites

### GCR_TORUS_INTERIOR

The interior of degenerate torus, tear drop.

### GCR_TORUS_EXTERIOR

The exterior of degenerate torus, apple shape.

## gdx_model

The GDX model for entity creation

# Output

## gdx_rs_ptr

Entity database pointer of the GDX Torus

# Tolerances

          NORMAL_MAG_TOL
          ANGLE_TOL
          ZERO_TOL
          .fi

# Return

          GCR_NOERR
          GCR_INVALID_MODEL
          GCR_TORUS_MIN_RADIUS
          GCR_TORUS_MAJ_RADIUS
          GCR_TORUS_U_REF_VECTOR
          Low level error return
          .fi