xref: /haiku/headers/libs/agg/agg_span_subdiv_adaptor.h (revision ed24eb5ff12640d052171c6a7feba37fab8a75d1)
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>
25     class span_subdiv_adaptor
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         //----------------------------------------------------------------
39         span_subdiv_adaptor() :
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
142