Synopsis

PDX_MSGT gdx_RevSurfAngleParmPoint(long option, double parm, MDA_PTR gdx_surf_ptr, MTH_3DPNT center_pnt, MTH_3DVEC vec_axis, PDX_BOOL v_revolve, double *angle)

Purpose

Find the angle of a parm point on a revolving surface

Description

The angle of a point in parameter space on a revolving surface is computed. The angle is measured about the revolving axis from the seam of the surface with right hand rule.

The surface must be of revolution and the parameter must not be normalized.

Input

option

Options (not used)

parm

The parameter in revolving direction

gdx_surf_ptr

The valid GDX surface database pointer

center_pnt

A point on the revolve axis

vec_axis

The vector of the revolve axis

v_revolve

Flag indicating if the revolve direction is the surface's v-direction.

Output

angle

The angle of a point in parameter space on a revolving surface

Return

      GDX_NOERR
      Low level error return
      .fi