xref: /haiku/headers/libs/agg/agg_rendering_buffer.h (revision 95bac3fda53a4cb21880712d7b43f8c21db32a2e)
1 //----------------------------------------------------------------------------
2 // Anti-Grain Geometry - Version 2.2
3 // Copyright (C) 2002-2004 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 //
16 // class rendering_buffer
17 //
18 //----------------------------------------------------------------------------
19 
20 #ifndef AGG_RENDERING_BUFFER_INCLUDED
21 #define AGG_RENDERING_BUFFER_INCLUDED
22 
23 #include "agg_basics.h"
24 
25 namespace agg
26 {
27 
28     //==========================================================row_ptr_cache
29     template<class T> class row_ptr_cache
30     {
31     public:
32         //--------------------------------------------------------------------
33         struct row_data
34         {
35             int x1, x2;
36             const int8u* ptr;
37             row_data() {}
38             row_data(int x1_, int x2_, const int8u* ptr_) :
39                 x1(x1_), x2(x2_), ptr(ptr_) {}
40         };
41 
42         //-------------------------------------------------------------------
43         ~row_ptr_cache()
44         {
45             delete [] m_rows;
46         }
47 
48         //-------------------------------------------------------------------
49         row_ptr_cache() :
50             m_buf(0),
51             m_rows(0),
52             m_width(0),
53             m_height(0),
54             m_stride(0),
55             m_max_height(0)
56         {
57         }
58 
59         //--------------------------------------------------------------------
60         row_ptr_cache(T* buf, unsigned width, unsigned height, int stride) :
61             m_buf(0),
62             m_rows(0),
63             m_width(0),
64             m_height(0),
65             m_stride(0),
66             m_max_height(0)
67         {
68             attach(buf, width, height, stride);
69         }
70 
71         //--------------------------------------------------------------------
72         void attach(T* buf, unsigned width, unsigned height, int stride)
73         {
74             m_buf = buf;
75             m_width = width;
76             m_height = height;
77             m_stride = stride;
78             if(height > m_max_height)
79             {
80                 delete [] m_rows;
81                 m_rows = new T* [m_max_height = height];
82             }
83 
84             T* row_ptr = m_buf;
85 
86             if(stride < 0)
87             {
88                 row_ptr = m_buf - int(height - 1) * stride;
89             }
90 
91             T** rows = m_rows;
92 
93             while(height--)
94             {
95                 *rows++ = row_ptr;
96                 row_ptr += stride;
97             }
98         }
99 
100         //--------------------------------------------------------------------
101         const T* buf()    const { return m_buf;    }
102         unsigned width()  const { return m_width;  }
103         unsigned height() const { return m_height; }
104         int      stride() const { return m_stride; }
105         unsigned stride_abs() const
106         {
107             return (m_stride < 0) ?
108                 unsigned(-m_stride) :
109                 unsigned(m_stride);
110         }
111 
112         //--------------------------------------------------------------------
113         T* row(unsigned y) { return m_rows[y]; }
114         const T* row(unsigned y) const { return m_rows[y]; }
115         T const* const* rows() const { return m_rows; }
116 
117         //--------------------------------------------------------------------
118         void copy_from(const row_ptr_cache<T>& mtx)
119         {
120             unsigned h = height();
121             if(mtx.height() < h) h = mtx.height();
122 
123             unsigned l = stride_abs();
124             if(mtx.stride_abs() < l) l = mtx.stride_abs();
125 
126             l *= sizeof(T);
127 
128             unsigned y;
129             for (y = 0; y < h; y++)
130             {
131                 memcpy(row(y), mtx.row(y), l);
132             }
133         }
134 
135         //--------------------------------------------------------------------
136         void clear(T value)
137         {
138             unsigned y;
139             for(y = 0; y < height(); y++)
140             {
141                 T* p = row(y);
142                 unsigned x;
143                 for(x = 0; x < stride_abs(); x++)
144                 {
145                     *p++ = value;
146                 }
147             }
148         }
149 
150 
151     private:
152         //--------------------------------------------------------------------
153         // Prohibit copying
154         row_ptr_cache(const row_ptr_cache<T>&);
155         const row_ptr_cache<T>& operator = (const row_ptr_cache<T>&);
156 
157     private:
158         //--------------------------------------------------------------------
159         T*       m_buf;        // Pointer to renrdering buffer
160         T**      m_rows;       // Pointers to each row of the buffer
161         unsigned m_width;      // Width in pixels
162         unsigned m_height;     // Height in pixels
163         int      m_stride;     // Number of bytes per row. Can be < 0
164         unsigned m_max_height; // The maximal height (currently allocated)
165     };
166 
167 
168 
169     //========================================================rendering_buffer
170     typedef row_ptr_cache<int8u> rendering_buffer;
171 
172 }
173 
174 
175 #endif
176