kicad/common/bezier_curves.cpp

94 lines
3.2 KiB
C++

/*
* This program source code file is part of KiCad, a free EDA CAD application.
*
* Copyright (C) 2014-2019 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
*/
/************************************/
/* routines to handle bezier curves */
/************************************/
#include <bezier_curves.h>
BEZIER_POLY::BEZIER_POLY( const std::vector<wxPoint>& aControlPoints )
{
for( unsigned ii = 0; ii < aControlPoints.size(); ++ii )
m_ctrlPts.emplace_back( VECTOR2D( aControlPoints[ii] ) );
m_minSegLen = 0.0;
}
void BEZIER_POLY::GetPoly( std::vector<wxPoint>& aOutput, int aMinSegLen )
{
aOutput.clear();
std::vector<VECTOR2D> buffer;
GetPoly( buffer, double( aMinSegLen ) );
for( unsigned ii = 0; ii < buffer.size(); ++ii )
aOutput.emplace_back( wxPoint( int( buffer[ii].x ), int( buffer[ii].y ) ) );
}
void BEZIER_POLY::GetPoly( std::vector<VECTOR2D>& aOutput, double aMinSegLen )
{
wxASSERT( m_ctrlPts.size() == 4 );
// FIXME Brute force method, use a better (recursive?) algorithm
// with a max error value.
// to optimize the number of segments
#define CURVE_POINTS 32
double dt = 1.0 / CURVE_POINTS;
aOutput.clear();
aOutput.push_back( m_ctrlPts[0] );
// If the Bezier curve is degenerated (straight line), skip intermediate points:
bool degenerated = m_ctrlPts[0] == m_ctrlPts[1] && m_ctrlPts[2] == m_ctrlPts[3];
if( !degenerated )
{
for( int ii = 1; ii < CURVE_POINTS; ii++ )
{
double t = dt * ii;
double omt = 1.0 - t;
double omt2 = omt * omt;
double omt3 = omt * omt2;
double t2 = t * t;
double t3 = t * t2;
VECTOR2D vertex = omt3 * m_ctrlPts[0]
+ 3.0 * t * omt2 * m_ctrlPts[1]
+ 3.0 * t2 * omt * m_ctrlPts[2]
+ t3 * m_ctrlPts[3];
// a minimal filter on the lenght of the segment being created:
// The offset from last point:
VECTOR2D delta = vertex - aOutput.back();
double dist = delta.EuclideanNorm();
if( dist > aMinSegLen )
aOutput.push_back( vertex );
}
}
if( aOutput.back() != m_ctrlPts[3] )
aOutput.push_back( m_ctrlPts[3] );
}