filled_circle_2d.cpp

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/*
 * This program source code file is part of KiCad, a free EDA CAD application.
 *
 * Copyright (C) 2015-2016 Mario Luzeiro <[email protected]>
 * Copyright (C) 1992-2020 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
 */
 
#include "filled_circle_2d.h"
#include "../ray.h"
#include <wx/debug.h>
 
 
FILLED_CIRCLE_2D::FILLED_CIRCLE_2D( const SFVEC2F& aCenter, float aRadius,
 const BOARD_ITEM& aBoardItem ) :
 OBJECT_2D( OBJECT_2D_TYPE::FILLED_CIRCLE, aBoardItem )
{
 wxASSERT( aRadius > 0.0f ); // If that happens, it should be handled before create this circle
 
 m_center = aCenter;
 m_radius = aRadius;
 m_radius_squared = aRadius * aRadius;
 
 m_bbox.Reset();
 m_bbox.Set( m_center - SFVEC2F( aRadius, aRadius ),
 m_center + SFVEC2F( aRadius, aRadius ) );
 m_bbox.ScaleNextUp();
 m_centroid = m_bbox.GetCenter();
 
 wxASSERT( m_bbox.IsInitialized() );
}
 
 
bool FILLED_CIRCLE_2D::Overlaps( const BBOX_2D& aBBox ) const
{
 // NOT IMPLEMENTED, why?
 return false;
}
 
 
bool FILLED_CIRCLE_2D::Intersects( const BBOX_2D& aBBox ) const
{
 return aBBox.Intersects( m_center, m_radius_squared );
}
 
 
bool FILLED_CIRCLE_2D::Intersect( const RAYSEG2D& aSegRay, float* aOutT, SFVEC2F* aNormalOut ) const
{
 // This code used directly from Steve Marschner's CS667 framework
 // http://cs665pd.googlecode.com/svn/trunk/photon/sphere.cpp
 
 // Compute some factors used in computation
 const float qx = aSegRay.m_Start.x - m_center.x;
 const float qy = aSegRay.m_Start.y - m_center.y;
 
 const float qd = qx * aSegRay.m_Dir.x + qy * aSegRay.m_Dir.y;
 const float qq = qx * qx + qy * qy;
 
 // solving the quadratic equation for t at the pts of intersection
 // dd*t^2 + (2*qd)*t + (qq-r^2) = 0
 const float discriminantsqr = ( qd * qd - ( qq - m_radius_squared ) );
 
 // If the discriminant is less than zero, there is no intersection
 if( discriminantsqr < FLT_EPSILON )
 return false;
 
 // Otherwise check and make sure that the intersections occur on the ray (t > 0) and
 // return the closer one.
 const float discriminant = sqrt( discriminantsqr );
 const float t1 = ( -qd - discriminant );
 const float t2 = ( -qd + discriminant );
 float t;
 
 if( ( t1 > 0.0f ) && ( t1 < aSegRay.m_Length ) )
 {
 t = t1;
 }
 else
 {
 if( ( t2 > 0.0f ) && ( t2 < aSegRay.m_Length ) )
 t = t2;
 else
 return false; // Neither intersection was in the ray's half line.
 }
 
 wxASSERT( ( t > 0.0f ) && ( t <= aSegRay.m_Length ) );
 
 // Convert the intersection to a normalized 0.0 .. 1.0
 if( aOutT )
 *aOutT = t / aSegRay.m_Length;
 
 const SFVEC2F hitPoint = aSegRay.at( t );
 
 if( aNormalOut )
 *aNormalOut = (hitPoint - m_center) / m_radius;
 
 return true;
}
 
 
INTERSECTION_RESULT FILLED_CIRCLE_2D::IsBBoxInside( const BBOX_2D& aBBox ) const
{
 if( !m_bbox.Intersects( aBBox ) )
 return INTERSECTION_RESULT::MISSES;
 
 SFVEC2F v[4];
 
 v[0] = aBBox.Min() - m_center;
 v[1] = aBBox.Max() - m_center;
 v[2] = SFVEC2F( aBBox.Min().x, aBBox.Max().y ) - m_center;
 v[3] = SFVEC2F( aBBox.Max().x, aBBox.Min().y ) - m_center;
 
 float s[4];
 
 s[0] = v[0].x * v[0].x + v[0].y * v[0].y;
 s[1] = v[1].x * v[1].x + v[1].y * v[1].y;
 s[2] = v[2].x * v[2].x + v[2].y * v[2].y;
 s[3] = v[3].x * v[3].x + v[3].y * v[3].y;
 
 bool isInside[4];
 
 isInside[0] = s[0] <= m_radius_squared;
 isInside[1] = s[1] <= m_radius_squared;
 isInside[2] = s[2] <= m_radius_squared;
 isInside[3] = s[3] <= m_radius_squared;
 
 // Check if all points are inside the circle
 if( isInside[0] && isInside[1] && isInside[2] && isInside[3] )
 return INTERSECTION_RESULT::FULL_INSIDE;
 
 // Check if any point is inside the circle
 if( isInside[0] || isInside[1] || isInside[2] || isInside[3] )
 return INTERSECTION_RESULT::INTERSECTS;
 
 return INTERSECTION_RESULT::MISSES;
}
 
 
bool FILLED_CIRCLE_2D::IsPointInside( const SFVEC2F& aPoint ) const
{
 const SFVEC2F v = m_center - aPoint;
 
 if( ( v.x * v.x + v.y * v.y ) <= m_radius_squared )
 return true;
 
 return false;
}