third_party/agg23/agg_conv_adaptor_vcgen.h

//----------------------------------------------------------------------------
// Anti-Grain Geometry - Version 2.3
// 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
//----------------------------------------------------------------------------
#ifndef AGG_CONV_ADAPTOR_VCGEN_INCLUDED
#define AGG_CONV_ADAPTOR_VCGEN_INCLUDED
#include "agg_basics.h"
namespace agg
{
struct null_markers  {
    void remove_all() {}
    void add_vertex(FX_FLOAT, FX_FLOAT, unsigned) {}
    void prepare_src() {}
    void rewind(unsigned) {}
    unsigned vertex(FX_FLOAT*, FX_FLOAT*)
    {
        return path_cmd_stop;
    }
};
template<class VertexSource,
         class Generator,
         class Markers = null_markers> class conv_adaptor_vcgen 
{
    enum status {
        initial,
        accumulate,
        generate
    };
public:
    conv_adaptor_vcgen(VertexSource& source) :
        m_source(&source),
        m_status(initial)
    {}
    void set_source(VertexSource& source)
    {
        m_source = &source;
    }
    Generator& generator()
    {
        return m_generator;
    }
    const Generator& generator() const
    {
        return m_generator;
    }
    Markers& markers()
    {
        return m_markers;
    }
    const Markers& markers() const
    {
        return m_markers;
    }
    void rewind(unsigned path_id)
    {
        m_source->rewind(path_id);
        m_status = initial;
    }
    unsigned vertex(FX_FLOAT* x, FX_FLOAT* y);
private:
    conv_adaptor_vcgen(const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
    const conv_adaptor_vcgen<VertexSource, Generator, Markers>&
    operator = (const conv_adaptor_vcgen<VertexSource, Generator, Markers>&);
    VertexSource* m_source;
    Generator     m_generator;
    Markers       m_markers;
    status        m_status;
    unsigned      m_last_cmd;
    FX_FLOAT        m_start_x;
    FX_FLOAT        m_start_y;
};
template<class VertexSource, class Generator, class Markers>
unsigned conv_adaptor_vcgen<VertexSource, Generator, Markers>::vertex(FX_FLOAT* x, FX_FLOAT* y)
{
    unsigned cmd = path_cmd_stop;
    bool done = false;
    while(!done) {
        switch(m_status) {
            case initial:
                m_markers.remove_all();
                m_last_cmd = m_source->vertex(&m_start_x, &m_start_y);
                m_status = accumulate;
            case accumulate:
                if(is_stop(m_last_cmd)) {
                    return path_cmd_stop;
                }
                m_generator.remove_all();
                m_generator.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
                m_markers.add_vertex(m_start_x, m_start_y, path_cmd_move_to);
                for(;;) {
                    cmd = m_source->vertex(x, y);
                    if(is_vertex(cmd)) {
                        m_last_cmd = cmd;
                        if(is_move_to(cmd)) {
                            m_start_x = *x;
                            m_start_y = *y;
                            break;
                        }
                        m_generator.add_vertex(*x, *y, cmd);
                        m_markers.add_vertex(*x, *y, path_cmd_line_to);
                    } else {
                        if(is_stop(cmd)) {
                            m_last_cmd = path_cmd_stop;
                            break;
                        }
                        if(is_end_poly(cmd)) {
                            m_generator.add_vertex(*x, *y, cmd);
                            break;
                        }
                    }
                }
                m_generator.rewind(0);
                m_status = generate;
            case generate:
                cmd = m_generator.vertex(x, y);
                if(is_stop(cmd)) {
                    m_status = accumulate;
                    break;
                }
                done = true;
                break;
        }
    }
    return cmd;
}
}
#endif