kicad/common/geometry/seg.cpp

158 lines
4.2 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2013 CERN
* @author Tomasz Wlostowski <tomasz.wlostowski@cern.ch>
*
* 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
*/
#include <geometry/seg.h>
template <typename T>
int sgn( T aVal )
{
return ( T( 0 ) < aVal ) - ( aVal < T( 0 ) );
}
bool SEG::PointCloserThan( const VECTOR2I& aP, int aDist ) const
{
VECTOR2I d = B - A;
ecoord dist_sq = (ecoord) aDist * aDist;
SEG::ecoord l_squared = d.Dot( d );
SEG::ecoord t = d.Dot( aP - A );
if( t <= 0 || !l_squared )
return ( aP - A ).SquaredEuclideanNorm() < dist_sq;
else if( t >= l_squared )
return ( aP - B ).SquaredEuclideanNorm() < dist_sq;
int dxdy = abs( d.x ) - abs( d.y );
if( ( dxdy >= -1 && dxdy <= 1 ) || abs( d.x ) <= 1 || abs( d.y ) <= 1 )
{
int ca = -sgn( d.y );
int cb = sgn( d.x );
int cc = -ca * A.x - cb * A.y;
ecoord num = ca * aP.x + cb * aP.y + cc;
num *= num;
if( ca && cb )
num >>= 1;
if( num > ( dist_sq + 100 ) )
return false;
else if( num < ( dist_sq - 100 ) )
return true;
}
VECTOR2I nearest;
nearest.x = A.x + rescale( t, (ecoord) d.x, l_squared );
nearest.y = A.y + rescale( t, (ecoord) d.y, l_squared );
return ( nearest - aP ).SquaredEuclideanNorm() <= dist_sq;
}
SEG::ecoord SEG::SquaredDistance( const SEG& aSeg ) const
{
// fixme: rather inefficient....
if( Intersect( aSeg ) )
return 0;
const VECTOR2I pts[4] =
{
aSeg.NearestPoint( A ) - A,
aSeg.NearestPoint( B ) - B,
NearestPoint( aSeg.A ) - aSeg.A,
NearestPoint( aSeg.B ) - aSeg.B
};
ecoord m = VECTOR2I::ECOORD_MAX;
for( int i = 0; i < 4; i++ )
m = std::min( m, pts[i].SquaredEuclideanNorm() );
return m;
}
OPT_VECTOR2I SEG::Intersect( const SEG& aSeg, bool aIgnoreEndpoints, bool aLines ) const
{
const VECTOR2I e( B - A );
const VECTOR2I f( aSeg.B - aSeg.A );
const VECTOR2I ac( aSeg.A - A );
ecoord d = f.Cross( e );
ecoord p = f.Cross( ac );
ecoord q = e.Cross( ac );
if( d == 0 )
return OPT_VECTOR2I();
if( !aLines && d > 0 && ( q < 0 || q > d || p < 0 || p > d ) )
return OPT_VECTOR2I();
if( !aLines && d < 0 && ( q < d || p < d || p > 0 || q > 0 ) )
return OPT_VECTOR2I();
if( !aLines && aIgnoreEndpoints && ( q == 0 || q == d ) && ( p == 0 || p == d ) )
return OPT_VECTOR2I();
VECTOR2I ip( aSeg.A.x + rescale( q, (ecoord) f.x, d ),
aSeg.A.y + rescale( q, (ecoord) f.y, d ) );
return ip;
}
bool SEG::ccw( const VECTOR2I& aA, const VECTOR2I& aB, const VECTOR2I& aC ) const
{
return (ecoord) ( aC.y - aA.y ) * ( aB.x - aA.x ) > (ecoord) ( aB.y - aA.y ) * ( aC.x - aA.x );
}
bool SEG::Collide( const SEG& aSeg, int aClearance ) const
{
// check for intersection
// fixme: move to a method
if( ccw( A, aSeg.A, aSeg.B ) != ccw( B, aSeg.A, aSeg.B ) &&
ccw( A, B, aSeg.A ) != ccw( A, B, aSeg.B ) )
return true;
#define CHK( _seg, _pt ) \
if( (_seg).PointCloserThan( _pt, aClearance ) ) return true;
CHK( *this, aSeg.A );
CHK( *this, aSeg.B );
CHK( aSeg, A );
CHK( aSeg, B );
#undef CHK
return false;
}
bool SEG::Contains( const VECTOR2I& aP ) const
{
return PointCloserThan( aP, 1 );
}