kicad/include/geometry/geometry_utils.h

59 lines
2.3 KiB
C

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2018 Jean-Pierre Charras, jp.charras at wanadoo.fr
* Copyright (C) 1992-2018 KiCad Developers, see AUTHORS.txt for contributors.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, you may find one here:
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.html
* or you may search the http://www.gnu.org website for the version 2 license,
* or you may write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
*/
/**
* @file geometry_utils.h
* @brief a few functions useful in geometry calculations.
*/
#ifndef GEOMETRY_UTILS_H
#define GEOMETRY_UTILS_H
/**
* @return the number of segments to approximate a arc by segments
* with a given max error (this number is >= 1)
* @param aRadius is the radius od the circle or arc
* @param aErrorMax is the max error
* This is the max distance between the middle of a segment and the circle.
* @param aArcAngleDegree is the arc angle in degrees
*/
int GetArcToSegmentCount( int aRadius, int aErrorMax, double aArcAngleDegree );
/**
* @return the correction factor to approximate a circle by segùments
* @param aSegCountforCircle is the number of segments to approximate the circle
*
* When creating a polygon from a circle, the polygon is inside the circle.
* Only corners are on the circle.
* This is incorrect when building clearance areas of circles, that need to build
* the equivalent polygon outside the circle
* The correction factor is a scaling factor to apply to the radius to build a
* polygon outside the circle (only the middle of each segment is on the circle
*/
double GetCircletoPolyCorrectionFactor( int aSegCountforCircle );
#endif // #ifndef GEOMETRY_UTILS_H