int SHAPE_LINE_CHAIN::Intersect( const SHAPE_LINE_CHAIN& aChain, INTERSECTIONS& aIp ) const
{
BOX2I bb_other = aChain.BBox();
for( int s1 = 0; s1 < SegmentCount(); s1++ )
{
const SEG& a = CSegment( s1 );
const BOX2I bb_cur( a.A, a.B - a.A );
if( !bb_other.Intersects( bb_cur ) )
continue;
for( int s2 = 0; s2 < aChain.SegmentCount(); s2++ )
{
const SEG& b = aChain.CSegment( s2 );
INTERSECTION is;
if( a.Collinear( b ) )
{
is.our = a;
is.their = b;
if( a.Contains( b.A ) ) { is.p = b.A; aIp.push_back( is ); }
if( a.Contains( b.B ) ) { is.p = b.B; aIp.push_back( is ); }
if( b.Contains( a.A ) ) { is.p = a.A; aIp.push_back( is ); }
if( b.Contains( a.B ) ) { is.p = a.B; aIp.push_back( is ); }
}
else
{
OPT_VECTOR2I p = a.Intersect( b );
if( p )
{
is.p = *p;
is.our = a;
is.their = b;
aIp.push_back( is );
}
}
}
}
return aIp.size();
}
bool SHAPE_POLY_SET::pointInPolygon( const VECTOR2I& aP, const SHAPE_LINE_CHAIN& aPath ) const
{
int result = 0;
int cnt = aPath.PointCount();
if ( !aPath.BBox().Contains( aP ) ) // test with bounding box first
return false;
if( cnt < 3 )
return false;
VECTOR2I ip = aPath.CPoint( 0 );
for( int i = 1; i <= cnt; ++i )
{
VECTOR2I ipNext = ( i == cnt ? aPath.CPoint( 0 ) : aPath.CPoint( i ) );
if( ipNext.y == aP.y )
{
if( ( ipNext.x == aP.x ) || ( ip.y == aP.y &&
( ( ipNext.x > aP.x ) == ( ip.x < aP.x ) ) ) )
return true;
}
if( ( ip.y < aP.y ) != ( ipNext.y < aP.y ) )
{
if( ip.x >= aP.x )
{
if( ipNext.x > aP.x )
result = 1 - result;
else
{
int64_t d = (int64_t)( ip.x - aP.x ) * (int64_t)( ipNext.y - aP.y ) -
(int64_t)( ipNext.x - aP.x ) * (int64_t)( ip.y - aP.y );
if( !d )
return true;
if( ( d > 0 ) == ( ipNext.y > ip.y ) )
result = 1 - result;
}
}
else
{
if( ipNext.x > aP.x )
{
int64_t d = (int64_t)( ip.x - aP.x ) * (int64_t)( ipNext.y - aP.y ) -
(int64_t)( ipNext.x - aP.x ) * (int64_t)( ip.y - aP.y );
if( !d )
return true;
if( ( d > 0 ) == ( ipNext.y > ip.y ) )
result = 1 - result;
}
}
}
ip = ipNext;
}
return result ? true : false;
}