vbooleancmd.cpp

/* This file is part of the KDE project
   Copyright (C) 2001, The Karbon Developers
   Copyright (C) 2002, The Karbon Developers
 
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Library General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.
 
   This library 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
   Library General Public License for more details.
 
   You should have received a copy of the GNU Library General Public License
   along with this library; see the file COPYING.LIB.  If not, write to
   the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
*/
 
 
#include <tqptrlist.h>
#include <tqvaluelist.h>
 
#include <tdelocale.h>
 
#include "vbooleancmd.h"
#include "vpath.h"
#include "vsegment.h"
#include "vselection.h"
#include "vdocument.h"
 
VBooleanCmd::VBooleanCmd( VDocument *doc, VBooleanType type )
    : VCommand( doc, i18n( "Boolean Operation" ) )
{
    m_selection = document()->selection()->clone();
    m_type = type;
}
 
VBooleanCmd::~VBooleanCmd()
{
    delete( m_selection );
}
 
void
VBooleanCmd::execute()
{
    VObjectListIterator itr( m_selection->objects() );
    for ( ; itr.current() ; ++itr )
    {
// TODO: pair wise visiting.
    }
 
//  document()->append(  );
    document()->selection()->clear();
}
 
void
VBooleanCmd::unexecute()
{
}
 
bool
VBooleanCmd::visit( VObject& object1, VObject& object2 )
{
    m_path1 = 0L;
    m_path2 = 0L;
    object1.accept( *this );
    object2.accept( *this );
 
    return success();
}
 
void
VBooleanCmd::visitVSubpath( VSubpath& path )
{
    if( m_path1 == 0L )
        m_path1 = &path;
    else if( m_path2 == 0L )
    {
        m_path2 = &path;
 
        // intersection parameters (t):
        VParamList params1;
        VParamList params2;
        VParamList::iterator pItr;
 
        double prevParam;
 
        m_path1->first();
 
        // ommit "begin" segment:
        while( m_path1->next() )
        {
            params1.clear();
 
            m_path2->first();
 
            // ommit "begin" segment:
            while( m_path2->next() )
            {
                params2.clear();
            
                recursiveSubdivision(
                    *m_path1->current(), 0.0, 1.0,
                    *m_path2->current(), 0.0, 1.0,
                    params1, params2 );
 
                qHeapSort( params2 );
 
                prevParam = 0.0;
 
                // walk down all intersection params and insert knots:
                for( pItr = params2.begin(); pItr != params2.end(); ++pItr )
                {
                    m_path2->insert(
                        m_path2->current()->splitAt(
                            ( *pItr - prevParam )/( 1.0 - prevParam ) ) );
 
                    m_path2->next();
                    prevParam = *pItr;
                }
            }
 
            qHeapSort( params1 );
 
            prevParam = 0.0;
 
            // walk down all intersection params and insert knots:
            for( pItr = params1.begin(); pItr != params1.end(); ++pItr )
            {
                m_path1->insert(
                    m_path1->current()->splitAt(
                        ( *pItr - prevParam )/( 1.0 - prevParam ) ) );
 
                m_path1->next();
                prevParam = *pItr;
            }
        }
    }
}
 
void
VBooleanCmd::recursiveSubdivision(
    const VSegment& segment1, double t0_1, double t1_1,
    const VSegment& segment2, double t0_2, double t1_2,
    VParamList& params1, VParamList& params2 )
{
    if(
        !segment1.boundingBox().intersects(
            segment2.boundingBox() ) )
    {
        return;
    }
 
    if( segment1.isFlat() )
    {
        // calculate intersection of line segments:
        if( segment2.isFlat() )
        {
            KoPoint v1  = segment1.knot() - segment1.prev()->knot();
            KoPoint v2  = segment2.knot() - segment2.prev()->knot();
 
            double det = v2.x() * v1.y() - v2.y() * v1.x();
 
            if( 1.0 + det == 1.0 )
                return;
            else
            {
                KoPoint v = segment2.prev()->knot() - segment1.prev()->knot();
                const double one_det = 1.0 / det;
 
                double t1 = one_det * ( v2.x() * v.y() - v2.y() * v.x() );
                double t2 = one_det * ( v1.x() * v.y() - v1.y() * v.x() );
 
                if ( t1 < 0.0 || t1 > 1.0 || t2 < 0.0 || t2 > 1.0 )
                    return;
 
                params1.append( t0_1 + t1 * ( t1_1 - t0_1 ) );
                params2.append( t0_2 + t2 * ( t1_2 - t0_2 ) );
            }
        }
        else
        {
            // "copy segment" and split it at midpoint:
            VSubpath path2( segment2 );
            path2.insert( path2.current()->splitAt( 0.5 ) );
 
            double mid2 = 0.5 * ( t0_2 + t1_2 );
 
            recursiveSubdivision(
                *path2.current(), t0_2, mid2,
                segment1,         t0_1, t1_1, params2, params1 );
            recursiveSubdivision(
                *path2.next(),    mid2, t1_2,
                segment1,         t0_1, t1_1, params2, params1 );
        }
    }
    else
    {
        // "copy segment" and split it at midpoint:
        VSubpath path1( segment1 );
        path1.insert( path1.current()->splitAt( 0.5 ) );
 
        double mid1 = 0.5 * ( t0_1 + t1_1 );
 
        if( segment2.isFlat() )
        {
            recursiveSubdivision(
                *path1.current(), t0_1, mid1,
                segment2,         t0_2, t1_2, params1, params2 );
            recursiveSubdivision(
                *path1.next(),    mid1, t1_1,
                segment2,         t0_2, t1_2, params1, params2 );
        }
        else
        {
            // "copy segment" and split it at midpoint:
            VSubpath path2( segment2 );
            path2.insert( path2.current()->splitAt( 0.5 ) );
 
            double mid2 = 0.5 * ( t0_2 + t1_2 );
 
            recursiveSubdivision(
                *path1.current(), t0_1, mid1,
                *path2.current(), t0_2, mid2, params1, params2 );
            recursiveSubdivision(
                *path1.next(),    mid1, t1_1,
                *path2.current(), t0_2, mid2, params1, params2 );
 
            recursiveSubdivision(
                *path1.prev(),    t0_1, mid1,
                *path2.next(),    mid2, t1_2, params1, params2 );
            recursiveSubdivision(
                *path1.next(),    mid1, t1_1,
                *path2.current(), mid2, t1_2, params1, params2 );
        }
    }
}