kicad/libs/kimath/src/geometry/shape_arc.cpp

457 lines
12 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2017 CERN
* Copyright (C) 2019-2020 KiCad Developers, see AUTHORS.txt for contributors.
* @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/geometry_utils.h>
#include <geometry/seg.h> // for SEG
#include <geometry/shape_arc.h>
#include <geometry/shape_line_chain.h>
#include <trigo.h>
SHAPE_ARC::SHAPE_ARC( const VECTOR2I& aArcCenter, const VECTOR2I& aArcStartPoint,
double aCenterAngle, int aWidth ) :
SHAPE( SH_ARC ), m_width( aWidth )
{
m_start = aArcStartPoint;
m_mid = aArcStartPoint;
m_end = aArcStartPoint;
RotatePoint( m_mid, aArcCenter, -aCenterAngle * 10.0 / 2.0 );
RotatePoint( m_end, aArcCenter, -aCenterAngle * 10.0 );
update_bbox();
}
SHAPE_ARC::SHAPE_ARC( const VECTOR2I& aArcStart, const VECTOR2I& aArcMid,
const VECTOR2I& aArcEnd, int aWidth ) :
SHAPE( SH_ARC ), m_start( aArcStart ), m_mid( aArcMid ), m_end( aArcEnd ),
m_width( aWidth )
{
update_bbox();
}
SHAPE_ARC::SHAPE_ARC( const SEG& aSegmentA, const SEG& aSegmentB, int aRadius, int aWidth )
: SHAPE( SH_ARC )
{
m_width = aWidth;
/*
* Construct an arc that is tangent to two segments with a given radius.
*
* p
* A
* A \
* / \
* / , * , \ segB
* /* *\
* segA / c \
* / B
* /
* /
* B
*
*
* segA is the fist segment (with its points A and B)
* segB is the second segment (with its points A and B)
* p is the point at which segA and segB would intersect if they were projected
* c is the centre of the arc to be constructed
* rad is the radius of the arc to be constructed
*
* We can create two vectors, betweeen point p and segA /segB
* pToA = p - segA.B //< note that segA.A would also be valid as it is colinear
* pToB = p - segB.B //< note that segB.A would also be valid as it is colinear
*
* Let the angle formed by segA and segB be called 'alpha':
* alpha = angle( pToA ) - angle( pToB )
*
* The distance PC can be computed as
* distPC = rad / abs( sin( alpha / 2 ) )
*
* The polar angle of the vector PC can be computed as:
* anglePC = angle( pToA ) + alpha / 2
*
* Therefore:
* C.x = P.x + distPC*cos( anglePC )
* C.y = P.y + distPC*sin( anglePC )
*/
OPT_VECTOR2I p = aSegmentA.Intersect( aSegmentB, true, true );
if( !p || aSegmentA.Length() == 0 || aSegmentB.Length() == 0 )
{
// Catch bugs in debug
wxASSERT_MSG( false, "The input segments do not intersect or one is zero length." );
// Make a 180 degree arc around aSegmentA in case we end up here in release
m_start = aSegmentA.A;
m_end = aSegmentA.B;
m_mid = m_start;
VECTOR2I arcCenter = aSegmentA.Center();
RotatePoint( m_mid, arcCenter, 900.0 ); // mid point at 90 degrees
}
else
{
VECTOR2I pToA = aSegmentA.B - p.get();
VECTOR2I pToB = aSegmentB.B - p.get();
if( pToA.EuclideanNorm() == 0 )
pToA = aSegmentA.A - p.get();
if( pToB.EuclideanNorm() == 0 )
pToB = aSegmentB.A - p.get();
double pToAangle = ArcTangente( pToA.y, pToA.x );
double pToBangle = ArcTangente( pToB.y, pToB.x );
double alpha = NormalizeAngle180( pToAangle - pToBangle );
double distPC = (double) aRadius / abs( sin( DECIDEG2RAD( alpha / 2 ) ) );
double angPC = pToAangle - alpha / 2;
VECTOR2I arcCenter;
arcCenter.x = p.get().x + KiROUND( distPC * cos( DECIDEG2RAD( angPC ) ) );
arcCenter.y = p.get().y + KiROUND( distPC * sin( DECIDEG2RAD( angPC ) ) );
// The end points of the arc are the orthogonal projected lines from the line segments
// to the center of the arc
m_start = aSegmentA.LineProject( arcCenter );
m_end = aSegmentB.LineProject( arcCenter );
//The mid point is rotated start point around center, half the angle of the arc.
VECTOR2I startVector = m_start - arcCenter;
VECTOR2I endVector = m_end - arcCenter;
double startAngle = ArcTangente( startVector.y, startVector.x );
double endAngle = ArcTangente( endVector.y, endVector.x );
double midPointRotAngle = NormalizeAngle180( startAngle - endAngle ) / 2;
m_mid = m_start;
RotatePoint( m_mid, arcCenter, midPointRotAngle );
}
update_bbox();
}
SHAPE_ARC::SHAPE_ARC( const SHAPE_ARC& aOther )
: SHAPE( SH_ARC )
{
m_start = aOther.m_start;
m_end = aOther.m_end;
m_mid = aOther.m_mid;
m_width = aOther.m_width;
m_bbox = aOther.m_bbox;
}
bool SHAPE_ARC::Collide( const SEG& aSeg, int aClearance, int* aActual, VECTOR2I* aLocation ) const
{
int minDist = aClearance + m_width / 2;
VECTOR2I center = GetCenter();
ecoord dist_sq;
ecoord closest_dist_sq = VECTOR2I::ECOORD_MAX;
VECTOR2I nearest;
VECTOR2I ab = ( aSeg.B - aSeg.A );
VECTOR2I ac = ( center - aSeg.A );
ecoord lenAbSq = ab.SquaredEuclideanNorm();
double lambda = (double) ac.Dot( ab ) / (double) lenAbSq;
if( lambda >= 0.0 && lambda <= 1.0 )
{
VECTOR2I p;
p.x = (double) aSeg.A.x * lambda + (double) aSeg.B.x * (1.0 - lambda);
p.y = (double) aSeg.A.y * lambda + (double) aSeg.B.y * (1.0 - lambda);
dist_sq = ( m_start - p ).SquaredEuclideanNorm();
if( dist_sq < closest_dist_sq )
{
closest_dist_sq = dist_sq;
nearest = p;
}
dist_sq = ( m_end - p ).SquaredEuclideanNorm();
if( dist_sq < closest_dist_sq )
{
closest_dist_sq = dist_sq;
nearest = p;
}
}
dist_sq = aSeg.SquaredDistance( m_start );
if( dist_sq < closest_dist_sq )
{
closest_dist_sq = dist_sq;
nearest = m_start;
}
dist_sq = aSeg.SquaredDistance( m_end );
if( dist_sq < closest_dist_sq )
{
closest_dist_sq = dist_sq;
nearest = m_end;
}
if( closest_dist_sq == 0 || closest_dist_sq < SEG::Square( minDist ) )
{
if( aLocation )
*aLocation = nearest;
if( aActual )
*aActual = std::max( 0, (int) sqrt( closest_dist_sq ) - m_width / 2 );
return true;
}
return false;
}
void SHAPE_ARC::update_bbox()
{
std::vector<VECTOR2I> points;
// Put start and end points in the point list
points.push_back( m_start );
points.push_back( m_end );
double start_angle = GetStartAngle();
double end_angle = start_angle + GetCentralAngle();
// we always count quadrants clockwise (increasing angle)
if( start_angle > end_angle )
std::swap( start_angle, end_angle );
int quad_angle_start = std::ceil( start_angle / 90.0 );
int quad_angle_end = std::floor( end_angle / 90.0 );
// count through quadrants included in arc
for( int quad_angle = quad_angle_start; quad_angle <= quad_angle_end; ++quad_angle )
{
const int radius = KiROUND( GetRadius() );
VECTOR2I quad_pt = GetCenter();
switch( quad_angle % 4 )
{
case 0: quad_pt += { radius, 0 }; break;
case 1:
case -3: quad_pt += { 0, radius }; break;
case 2:
case -2: quad_pt += { -radius, 0 }; break;
case 3:
case -1: quad_pt += { 0, -radius }; break;
default: assert( false );
}
points.push_back( quad_pt );
}
m_bbox.Compute( points );
}
const BOX2I SHAPE_ARC::BBox( int aClearance ) const
{
BOX2I bbox( m_bbox );
if( aClearance != 0 )
bbox.Inflate( aClearance );
return bbox;
}
bool SHAPE_ARC::Collide( const VECTOR2I& aP, int aClearance, int* aActual,
VECTOR2I* aLocation ) const
{
int minDist = aClearance + m_width / 2;
auto bbox = BBox( minDist );
if( !bbox.Contains( aP ) )
return false;
ecoord min_dist_sq = SEG::Square( minDist );
ecoord r_sq = SEG::Square( GetRadius() );
ecoord dist_sq = ( aP - GetCenter() ).SquaredEuclideanNorm();
ecoord dist_to_edge_sq = abs( dist_sq - r_sq );
if( dist_to_edge_sq == 0 || dist_to_edge_sq < min_dist_sq )
{
if( aLocation )
*aLocation = ( aP + GetCenter() ) / 2;
if( aActual )
*aActual = std::max( 0, (int) sqrt( dist_to_edge_sq ) - m_width / 2 );
return true;
}
return false;
}
double SHAPE_ARC::GetStartAngle() const
{
VECTOR2D d( m_start - GetCenter() );
auto ang = 180.0 / M_PI * atan2( d.y, d.x );
return NormalizeAngleDegrees( ang, 0.0, 360.0 );
}
double SHAPE_ARC::GetEndAngle() const
{
VECTOR2D d( m_end - GetCenter() );
auto ang = 180.0 / M_PI * atan2( d.y, d.x );
return NormalizeAngleDegrees( ang, 0.0, 360.0 );
}
VECTOR2I SHAPE_ARC::GetCenter() const
{
return GetArcCenter( m_start, m_mid, m_end );
}
double SHAPE_ARC::GetCentralAngle() const
{
VECTOR2I center = GetCenter();
VECTOR2I p0 = m_start - center;
VECTOR2I p1 = m_mid - center;
VECTOR2I p2 = m_end - center;
double angle1 = ArcTangente( p1.y, p1.x ) - ArcTangente( p0.y, p0.x );
double angle2 = ArcTangente( p2.y, p2.x ) - ArcTangente( p1.y, p1.x );
return ( NormalizeAngle180( angle1 ) + NormalizeAngle180( angle2 ) ) / 10.0;
}
double SHAPE_ARC::GetRadius() const
{
return ( m_start - GetCenter() ).EuclideanNorm();
}
const SHAPE_LINE_CHAIN SHAPE_ARC::ConvertToPolyline( double aAccuracy ) const
{
SHAPE_LINE_CHAIN rv;
double r = GetRadius();
double sa = GetStartAngle();
auto c = GetCenter();
double ca = GetCentralAngle();
int n;
if( r < aAccuracy )
n = 0;
else
n = GetArcToSegmentCount( r, aAccuracy, ca );
// Split the error on either side of the arc. Since we want the start and end points
// to be exactly on the arc, the first and last segments need to be shorter to stay within
// the error band (since segments normally start 1/2 the error band outside the arc).
r += aAccuracy / 2;
n = n * 2;
rv.Append( m_start );
for( int i = 1; i < n ; i += 2 )
{
double a = sa;
if( n != 0 )
a += ( ca * i ) / n;
double x = c.x + r * cos( a * M_PI / 180.0 );
double y = c.y + r * sin( a * M_PI / 180.0 );
rv.Append( KiROUND( x ), KiROUND( y ) );
}
rv.Append( m_end );
return rv;
}
void SHAPE_ARC::Move( const VECTOR2I& aVector )
{
m_start += aVector;
m_end += aVector;
m_mid += aVector;
update_bbox();
}
void SHAPE_ARC::Rotate( double aAngle, const VECTOR2I& aCenter )
{
m_start -= aCenter;
m_end -= aCenter;
m_mid -= aCenter;
m_start = m_start.Rotate( aAngle );
m_end = m_end.Rotate( aAngle );
m_mid = m_mid.Rotate( aAngle );
m_start += aCenter;
m_end += aCenter;
m_mid += aCenter;
update_bbox();
}
void SHAPE_ARC::Mirror( bool aX, bool aY, const VECTOR2I& aVector )
{
if( aX )
{
m_start.x = -m_start.x + 2 * aVector.x;
m_end.x = -m_end.x + 2 * aVector.x;
m_mid.x = -m_mid.x + 2 * aVector.x;
}
if( aY )
{
m_start.y = -m_start.y + 2 * aVector.y;
m_end.y = -m_end.y + 2 * aVector.y;
m_mid.y = -m_mid.y + 2 * aVector.y;
}
update_bbox();
}