haiku/headers/libs/agg/agg_vertex_sequence.h

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//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.4
// Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
//
// Permission to copy, use, modify, sell and distribute this software
// is granted provided this copyright notice appears in all copies.
// This software is provided "as is" without express or implied
// warranty, and with no claim as to its suitability for any purpose.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
// mcseemagg@yahoo.com
// http://www.antigrain.com
//----------------------------------------------------------------------------
//
// vertex_sequence container and vertex_dist struct
//
//----------------------------------------------------------------------------
#ifndef AGG_VERTEX_SEQUENCE_INCLUDED
#define AGG_VERTEX_SEQUENCE_INCLUDED
#include "agg_basics.h"
#include "agg_array.h"
#include "agg_math.h"
namespace agg
{
//----------------------------------------------------------vertex_sequence
// Modified agg::pod_bvector. The data is interpreted as a sequence
// of vertices. It means that the type T must expose:
//
// bool T::operator() (const T& val)
//
// that is called every time new vertex is being added. The main purpose
// of this operator is the possibility to calculate some values during
// adding and to return true if the vertex fits some criteria or false if
// it doesn't. In the last case the new vertex is not added.
//
// The simple example is filtering coinciding vertices with calculation
// of the distance between the current and previous ones:
//
// struct vertex_dist
// {
// double x;
// double y;
// double dist;
//
// vertex_dist() {}
// vertex_dist(double x_, double y_) :
// x(x_),
// y(y_),
// dist(0.0)
// {
// }
//
// bool operator () (const vertex_dist& val)
// {
// return (dist = calc_distance(x, y, val.x, val.y)) > EPSILON;
// }
// };
//
// Function close() calls this operator and removes the last vertex if
// necessary.
//------------------------------------------------------------------------
template<class T, unsigned S=6>
class vertex_sequence : public pod_bvector<T, S>
{
public:
typedef pod_bvector<T, S> base_type;
void add(const T& val);
void modify_last(const T& val);
void close(bool remove_flag);
};
//------------------------------------------------------------------------
template<class T, unsigned S>
void vertex_sequence<T, S>::add(const T& val)
{
if(base_type::size() > 1)
{
if(!(*this)[base_type::size() - 2]((*this)[base_type::size() - 1]))
{
base_type::remove_last();
}
}
base_type::add(val);
}
//------------------------------------------------------------------------
template<class T, unsigned S>
void vertex_sequence<T, S>::modify_last(const T& val)
{
base_type::remove_last();
add(val);
}
//------------------------------------------------------------------------
template<class T, unsigned S>
void vertex_sequence<T, S>::close(bool closed)
{
while(base_type::size() > 1)
{
if((*this)[base_type::size() - 2]((*this)[base_type::size() - 1])) break;
T t = (*this)[base_type::size() - 1];
base_type::remove_last();
modify_last(t);
}
if(closed)
{
while(base_type::size() > 1)
{
if((*this)[base_type::size() - 1]((*this)[0])) break;
base_type::remove_last();
}
}
}
//-------------------------------------------------------------vertex_dist
// Vertex (x, y) with the distance to the next one. The last vertex has
// distance between the last and the first points if the polygon is closed
// and 0.0 if it's a polyline.
struct vertex_dist
{
double x;
double y;
double dist;
vertex_dist() {}
vertex_dist(double x_, double y_) :
x(x_),
y(y_),
dist(0.0)
{
}
bool operator () (const vertex_dist& val)
{
bool ret = (dist = calc_distance(x, y, val.x, val.y)) > vertex_dist_epsilon;
if(!ret) dist = 1.0 / vertex_dist_epsilon;
return ret;
}
};
//--------------------------------------------------------vertex_dist_cmd
// Save as the above but with additional "command" value
struct vertex_dist_cmd : public vertex_dist
{
unsigned cmd;
vertex_dist_cmd() {}
vertex_dist_cmd(double x_, double y_, unsigned cmd_) :
vertex_dist(x_, y_),
cmd(cmd_)
{
}
};
}
#endif