Anti-Grain Geometry Tutorial
agg_span_subdiv_adaptor.h
1 //----------------------------------------------------------------------------
2 // Anti-Grain Geometry - Version 2.4
3 // Copyright (C) 2002-2005 Maxim Shemanarev (http://www.antigrain.com)
4 //
5 // Permission to copy, use, modify, sell and distribute this software
6 // is granted provided this copyright notice appears in all copies.
7 // This software is provided "as is" without express or implied
8 // warranty, and with no claim as to its suitability for any purpose.
9 //
10 //----------------------------------------------------------------------------
11 // Contact: mcseem@antigrain.com
12 // mcseemagg@yahoo.com
13 // http://www.antigrain.com
14 //----------------------------------------------------------------------------
15 #ifndef AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
16 #define AGG_SPAN_SUBDIV_ADAPTOR_INCLUDED
17 
18 #include "agg_basics.h"
19 
20 namespace agg
21 {
22 
23  //=================================================span_subdiv_adaptor
24  template<class Interpolator, unsigned SubpixelShift = 8>
26  {
27  public:
28  typedef Interpolator interpolator_type;
29  typedef typename interpolator_type::trans_type trans_type;
30 
31  enum sublixel_scale_e
32  {
33  subpixel_shift = SubpixelShift,
34  subpixel_scale = 1 << subpixel_shift
35  };
36 
37 
38  //----------------------------------------------------------------
40  m_subdiv_shift(4),
41  m_subdiv_size(1 << m_subdiv_shift),
42  m_subdiv_mask(m_subdiv_size - 1) {}
43 
44  span_subdiv_adaptor(interpolator_type& interpolator,
45  unsigned subdiv_shift = 4) :
46  m_subdiv_shift(subdiv_shift),
47  m_subdiv_size(1 << m_subdiv_shift),
48  m_subdiv_mask(m_subdiv_size - 1),
49  m_interpolator(&interpolator) {}
50 
51  span_subdiv_adaptor(interpolator_type& interpolator,
52  double x, double y, unsigned len,
53  unsigned subdiv_shift = 4) :
54  m_subdiv_shift(subdiv_shift),
55  m_subdiv_size(1 << m_subdiv_shift),
56  m_subdiv_mask(m_subdiv_size - 1),
57  m_interpolator(&interpolator)
58  {
59  begin(x, y, len);
60  }
61 
62 
63  //----------------------------------------------------------------
64  const interpolator_type& interpolator() const { return *m_interpolator; }
65  void interpolator(interpolator_type& intr) { m_interpolator = &intr; }
66 
67  //----------------------------------------------------------------
68  const trans_type& transformer() const
69  {
70  return *m_interpolator->transformer();
71  }
72  void transformer(const trans_type& trans)
73  {
74  m_interpolator->transformer(trans);
75  }
76 
77  //----------------------------------------------------------------
78  unsigned subdiv_shift() const { return m_subdiv_shift; }
79  void subdiv_shift(unsigned shift)
80  {
81  m_subdiv_shift = shift;
82  m_subdiv_size = 1 << m_subdiv_shift;
83  m_subdiv_mask = m_subdiv_size - 1;
84  }
85 
86  //----------------------------------------------------------------
87  void begin(double x, double y, unsigned len)
88  {
89  m_pos = 1;
90  m_src_x = iround(x * subpixel_scale) + subpixel_scale;
91  m_src_y = y;
92  m_len = len;
93  if(len > m_subdiv_size) len = m_subdiv_size;
94  m_interpolator->begin(x, y, len);
95  }
96 
97  //----------------------------------------------------------------
98  void operator++()
99  {
100  ++(*m_interpolator);
101  if(m_pos >= m_subdiv_size)
102  {
103  unsigned len = m_len;
104  if(len > m_subdiv_size) len = m_subdiv_size;
105  m_interpolator->resynchronize(double(m_src_x) / double(subpixel_scale) + len,
106  m_src_y,
107  len);
108  m_pos = 0;
109  }
110  m_src_x += subpixel_scale;
111  ++m_pos;
112  --m_len;
113  }
114 
115  //----------------------------------------------------------------
116  void coordinates(int* x, int* y) const
117  {
118  m_interpolator->coordinates(x, y);
119  }
120 
121  //----------------------------------------------------------------
122  void local_scale(int* x, int* y) const
123  {
124  m_interpolator->local_scale(x, y);
125  }
126 
127 
128  private:
129  unsigned m_subdiv_shift;
130  unsigned m_subdiv_size;
131  unsigned m_subdiv_mask;
132  interpolator_type* m_interpolator;
133  int m_src_x;
134  double m_src_y;
135  unsigned m_pos;
136  unsigned m_len;
137  };
138 
139 }
140 
141 #endif
Definition: agg_arc.cpp:24