mapnik/deps/agg/include/agg_conv_clipper.h
artemp 56c0fb6982 + clipper based polygon clipper
(FIXME: avoid leaking memory)
2013-02-12 16:45:13 +00:00

375 lines
14 KiB
C++
Executable file

/*******************************************************************************
* *
* Author : Angus Johnson *
* Version : 1.1 *
* Date : 4 April 2011 *
* Website : http://www.angusj.com *
* Copyright : Angus Johnson 2010-2011 *
* *
* License: *
* Use, modification & distribution is subject to Boost Software License Ver 1. *
* http://www.boost.org/LICENSE_1_0.txt *
* *
*******************************************************************************/
#ifndef AGG_CONV_CLIPPER_INCLUDED
#define AGG_CONV_CLIPPER_INCLUDED
#include <cmath>
#include "agg_basics.h"
#include "agg_array.h"
#include "clipper.hpp"
namespace agg
{
enum clipper_op_e { clipper_or,
clipper_and, clipper_xor, clipper_a_minus_b, clipper_b_minus_a };
enum clipper_PolyFillType {clipper_even_odd, clipper_non_zero, clipper_positive, clipper_negative};
template<class VSA, class VSB> class conv_clipper
{
enum status { status_move_to, status_line_to, status_next };
typedef VSA source_a_type;
typedef VSB source_b_type;
typedef conv_clipper<source_a_type, source_b_type> self_type;
private:
source_a_type* m_src_a;
source_b_type* m_src_b;
status m_status;
int m_vertex;
int m_contour;
int m_expoly;
int m_scaling_factor;
clipper_op_e m_operation;
pod_bvector<ClipperLib::IntPoint, 8> m_vertex_accumulator;
ClipperLib::Polygons m_poly_a;
ClipperLib::Polygons m_poly_b;
ClipperLib::ExPolygons m_result;
ClipperLib::Clipper m_clipper;
clipper_PolyFillType m_subjFillType;
clipper_PolyFillType m_clipFillType;
int Round(double val)
{
if ((val < 0)) return (int)(val - 0.5); else return (int)(val + 0.5);
}
public:
conv_clipper(source_a_type &a, source_b_type &b,
clipper_op_e op = clipper_or,
clipper_PolyFillType subjFillType = clipper_even_odd,
clipper_PolyFillType clipFillType = clipper_even_odd,
int scaling_factor = 2) :
m_src_a(&a),
m_src_b(&b),
m_status(status_next),
m_vertex(-1),
m_contour(-1),
m_expoly(-1),
m_operation(op),
m_subjFillType(subjFillType),
m_clipFillType(clipFillType)
{
m_scaling_factor = std::max(std::min(scaling_factor, 6),0);
m_scaling_factor = Round(std::pow((double)10, m_scaling_factor));
}
conv_clipper(source_a_type &a,
clipper_op_e op = clipper_and,
clipper_PolyFillType subjFillType = clipper_non_zero,
clipper_PolyFillType clipFillType = clipper_non_zero,
int scaling_factor = 6) :
m_src_a(&a),
m_status(status_next),
m_vertex(-1),
m_contour(-1),
m_expoly(-1),
m_operation(op),
m_subjFillType(subjFillType),
m_clipFillType(clipFillType)
{
m_scaling_factor = std::max(std::min(scaling_factor, 6),0);
m_scaling_factor = Round(std::pow((double)10, m_scaling_factor));
}
unsigned type() const { return m_src_a->type(); }
~conv_clipper()
{
}
void attach1(VSA &source, clipper_PolyFillType subjFillType = clipper_even_odd)
{ m_src_a = &source; m_subjFillType = subjFillType; }
void attach2(VSB &source, clipper_PolyFillType clipFillType = clipper_even_odd)
{ m_src_b = &source; m_clipFillType = clipFillType; }
void operation(clipper_op_e v) { m_operation = v; }
void rewind(unsigned path_id);
unsigned vertex(double* x, double* y);
bool next_poly();
bool next_contour();
bool next_vertex(double* x, double* y);
void start_extracting();
void add_vertex_(double &x, double &y);
void end_contour(ClipperLib::Polygons &p);
void reverse(bool reverse);
template<class VS> void add(VS &src, ClipperLib::Polygons &p){
unsigned cmd;
double x; double y; double start_x; double start_y;
bool starting_first_line;
start_x = 0.0;
start_y = 0.0;
starting_first_line = true;
p.resize(0);
cmd = src->vertex( &x , &y );
while(!is_stop(cmd))
{
if(is_vertex(cmd))
{
if(is_move_to(cmd))
{
if(!starting_first_line ) end_contour(p);
start_x = x;
start_y = y;
}
add_vertex_( x, y );
starting_first_line = false;
}
else if(is_end_poly(cmd))
{
if(!starting_first_line && is_closed(cmd))
add_vertex_( start_x, start_y );
}
cmd = src->vertex( &x, &y );
}
end_contour(p);
}
};
//------------------------------------------------------------------------
template<class VSA, class VSB>
void conv_clipper<VSA, VSB>::reverse(bool reverse)
{
m_clipper.ReverseSolution(true);
};
template<class VSA, class VSB>
void conv_clipper<VSA, VSB>::start_extracting()
{
m_status = status_next;
m_expoly = -1;
m_contour = -1;
m_vertex = -1;
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
void conv_clipper<VSA, VSB>::rewind(unsigned path_id)
{
m_src_a->rewind( path_id );
m_src_b->rewind( path_id );
add( m_src_a , m_poly_a );
add( m_src_b , m_poly_b );
m_result.resize(0);
ClipperLib::PolyFillType pftSubj, pftClip;
switch (m_subjFillType)
{
case clipper_even_odd: pftSubj = ClipperLib::pftEvenOdd; break;
case clipper_non_zero: pftSubj = ClipperLib::pftNonZero; break;
case clipper_positive: pftSubj = ClipperLib::pftPositive; break;
default: pftSubj = ClipperLib::pftNegative;
}
switch (m_clipFillType)
{
case clipper_even_odd: pftClip = ClipperLib::pftEvenOdd; break;
case clipper_non_zero: pftClip = ClipperLib::pftNonZero; break;
case clipper_positive: pftClip = ClipperLib::pftPositive; break;
default: pftClip = ClipperLib::pftNegative;
}
m_clipper.Clear();
switch( m_operation ) {
case clipper_or:
{
m_clipper.AddPolygons( m_poly_a , ClipperLib::ptSubject );
m_clipper.AddPolygons( m_poly_b , ClipperLib::ptClip );
m_clipper.Execute( ClipperLib::ctUnion , m_result , pftSubj, pftClip);
break;
}
case clipper_and:
{
m_clipper.AddPolygons( m_poly_a , ClipperLib::ptSubject );
m_clipper.AddPolygons( m_poly_b , ClipperLib::ptClip );
m_clipper.Execute( ClipperLib::ctIntersection , m_result, pftSubj, pftClip );
break;
}
case clipper_xor:
{
m_clipper.AddPolygons( m_poly_a , ClipperLib::ptSubject );
m_clipper.AddPolygons( m_poly_b , ClipperLib::ptClip );
m_clipper.Execute( ClipperLib::ctXor , m_result, pftSubj, pftClip );
break;
}
case clipper_a_minus_b:
{
m_clipper.AddPolygons( m_poly_a , ClipperLib::ptSubject );
m_clipper.AddPolygons( m_poly_b , ClipperLib::ptClip );
m_clipper.Execute( ClipperLib::ctDifference , m_result, pftSubj, pftClip );
break;
}
case clipper_b_minus_a:
{
m_clipper.AddPolygons( m_poly_b , ClipperLib::ptSubject );
m_clipper.AddPolygons( m_poly_a , ClipperLib::ptClip );
m_clipper.Execute( ClipperLib::ctDifference , m_result, pftSubj, pftClip );
break;
}
}
start_extracting();
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
void conv_clipper<VSA, VSB>::end_contour( ClipperLib::Polygons &p)
{
unsigned i, len;
if( m_vertex_accumulator.size() < 3 ) return;
len = p.size();
p.resize(len+1);
p[len].resize(m_vertex_accumulator.size());
for( i = 0 ; i < m_vertex_accumulator.size() ; i++ )
p[len][i] = m_vertex_accumulator[i];
m_vertex_accumulator.remove_all();
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
void conv_clipper<VSA, VSB>::add_vertex_(double &x, double &y)
{
ClipperLib::IntPoint v;
v.X = Round(x * m_scaling_factor);
v.Y = Round(y * m_scaling_factor);
m_vertex_accumulator.add( v );
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
bool conv_clipper<VSA, VSB>::next_poly()
{
m_expoly++;
if (m_expoly >= (int) m_result.size())
return false;
//std::cout << "next poly: " << m_expoly << " " << m_result.size() << " "<< m_result[m_expoly].outer.size() <<"\n";
m_contour = -2;
m_vertex = -1;
return true;
}
template<class VSA, class VSB>
bool conv_clipper<VSA, VSB>::next_contour()
{
m_contour++;
if (m_contour < 0){
// outer ring
//if (!m_result[m_expoly].outer)
// return false;
} else {
// inner rings
if(m_contour >= (int)m_result[m_expoly].holes.size())
return false;
}
// std::cout << "next contour: " << m_contour << "\n";
m_vertex =-1;
return true;
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
bool conv_clipper<VSA, VSB>::next_vertex(double *x, double *y)
{
m_vertex++;
//std::cout << "next vertex: " << m_vertex << "\n";
if (m_contour < 0)
{
if (m_vertex >= (int) m_result[m_expoly].outer.size())
return false;
*x = (double) m_result[m_expoly].outer[m_vertex].X / m_scaling_factor;
*y = (double) m_result[m_expoly].outer[m_vertex].Y / m_scaling_factor;
}
else
{
if (m_vertex >= (int) m_result[m_expoly].holes[m_contour].size())
return false;
*x = (double) m_result[m_expoly].holes[m_contour][m_vertex].X
/ m_scaling_factor;
*y = (double) m_result[m_expoly].holes[m_contour][m_vertex].Y
/ m_scaling_factor;
}
return true;
}
//------------------------------------------------------------------------------
template<class VSA, class VSB>
unsigned conv_clipper<VSA, VSB>::vertex(double *x, double *y)
{
if (m_status == status_next)
{
if (next_poly())
m_status = status_move_to;
else
return path_cmd_stop;
}
if (m_status == status_move_to)
{
if (next_contour())
{
if (next_vertex(x, y))
{
m_status = status_line_to;
return path_cmd_move_to;
}
}
if (next_poly())
{
m_status = status_move_to;
// return two times SEG_CLOSE to indicate
// that all holes of this ExPolygon are finished
return path_cmd_end_poly | path_flags_close;
}
else
return path_cmd_stop;
}
else
{
if (next_vertex(x, y))
{
return path_cmd_line_to;
}
else
{
m_status = status_move_to;
return path_cmd_end_poly | path_flags_close;
}
}
}
//------------------------------------------------------------------------------
} //namespace agg
#endif //AGG_CONV_CLIPPER_INCLUDED