.. role:: blue
   :class: blue

Determining Extrusion or Rotation Parameters
============================================
.. _Determining_Extrusion_or_Rotation_Parameters_:

.. kernel version: 118059

The function

.. code-block:: cpp

   void GetRangeToSurface( const MbSurface &    surface,
                           const MbCurve3D &    curve,
                           const MbVector3D &   direction,
                           const MbAxis3D &     axis,
                           const bool           rotation,
                           const bool           operationDirection,
                           const MbCartPoint &  imagePosition,
                                 double         range, 
                                 MbRect &       rectOnSurface,
                                 MbResultType & resType );

computes the extrusion depths in the forward and backward directions or the revolution angles in the forward and backward directions for subsequent construction of a body by extruding or revolving a generatrix curve up to the given surface, and also determines the bounding box of the curve image.

The input parameters of the function are:

- **surface** – the surface up to which the curve is to be extruded or revolved;
- **curve** – the generatrix curve;
- **direction** – the extrusion direction (used for the extrusion calculation);
- **axis** – the axis of revolution (used for the revolution calculation);
- **rotation** – the flag specifying the calculation type: *true* for revolution and *false* for extrusion;
- **operationDirection** – the direction of the subsequent operation: forward (*true*) or backward (*false*);
- **imagePosition** – the point on the surface where the image of the generatrix curve lies.

The output parameters of the function are:

- **range** – the distances to the surface: range\[0\] is in the backward direction and range\[1\] is in the forward direction; 
- **rectOnSurface** – the bounding rectangle of the curve image on the surface;
- **resType** – the operation result code: if the function succeeds, it returns :blue:`rt_Success`; otherwise it returns an error code from the :blue:`MbResultType` enumeration (see *mb_operation_result.h*).

The function is an auxiliary one for the :blue:`ExtrusionSolid`\(), :blue:`RevolutionSolid`\(), :blue:`ExtrusionResult`\() and :blue:`RevolutionResult`\() functions.