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//
16// class rendering_buffer_dynarow
17//
18//----------------------------------------------------------------------------
19
20#ifndef AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
21#define AGG_RENDERING_BUFFER_DYNAROW_INCLUDED
22
23#include "agg_array.h"
24
25namespace agg
26{
27
28    //===============================================rendering_buffer_dynarow
29    // Rendering buffer class with dynamic allocation of the rows.
30    // The rows are allocated as needed when requesting for span_ptr().
31    // The class automatically calculates min_x and max_x for each row.
32    // Generally it's more efficient to use this class as a temporary buffer
33    // for rendering a few lines and then to blend it with another buffer.
34    //
35    class rendering_buffer_dynarow
36    {
37    public:
38        //----------------------------------------------------------------------
39        struct row_data
40        {
41            int x1, x2;
42            const int8u* ptr;
43        };
44
45        //-------------------------------------------------------------------
46        ~rendering_buffer_dynarow()
47        {
48            init(0,0,0);
49        }
50
51        //-------------------------------------------------------------------
52        rendering_buffer_dynarow() :
53            m_rows(),
54            m_width(0),
55            m_height(0),
56            m_byte_width(0)
57        {
58        }
59
60        // Allocate and clear the buffer
61        //--------------------------------------------------------------------
62        rendering_buffer_dynarow(unsigned width, unsigned height,
63                                 unsigned byte_width) :
64            m_rows(height),
65            m_width(width),
66            m_height(height),
67            m_byte_width(byte_width)
68        {
69            memset(&m_rows[0], 0, sizeof(row_data) * height);
70        }
71
72        // Allocate and clear the buffer
73        //--------------------------------------------------------------------
74        void init(unsigned width, unsigned height, unsigned byte_width)
75        {
76            unsigned i;
77            for(i = 0; i < m_height; ++i)
78            {
79                pod_allocator<int8u>::deallocate((int8u*)m_rows[i].ptr, m_byte_width);
80            }
81            if(width && height)
82            {
83                m_width  = width;
84                m_height = height;
85                m_byte_width = byte_width;
86                m_rows.resize(height);
87                memset(&m_rows[0], 0, sizeof(row_data) * height);
88            }
89        }
90
91        //--------------------------------------------------------------------
92        unsigned width()      const { return m_width;  }
93        unsigned height()     const { return m_height; }
94        unsigned byte_width() const { return m_byte_width; }
95
96        // The main function used for rendering. Returns pointer to the
97        // pre-allocated span. Memory for the row is allocated as needed.
98        //--------------------------------------------------------------------
99        int8u* row_ptr(int x, int y, unsigned len)
100        {
101            row_data* r = &m_rows[y];
102            int x2 = x + len - 1;
103            if(r->ptr)
104            {
105                if(x  < r->x1) { r->x1 = x;  }
106                if(x2 > r->x2) { r->x2 = x2; }
107            }
108            else
109            {
110                int8u* p = pod_allocator<int8u>::allocate(m_byte_width);
111                r->ptr = p;
112                r->x1  = x;
113                r->x2  = x2;
114                memset(p, 0, m_byte_width);
115            }
116            return (int8u*)r->ptr;
117        }
118
119        //--------------------------------------------------------------------
120        const int8u* row_ptr(int y) const { return m_rows[y].ptr; }
121              int8u* row_ptr(int y)       { return row_ptr(0, y, m_width); }
122        row_data     row    (int y) const { return m_rows[y]; }
123
124    private:
125        //--------------------------------------------------------------------
126        // Prohibit copying
127        rendering_buffer_dynarow(const rendering_buffer_dynarow&);
128        const rendering_buffer_dynarow& operator = (const rendering_buffer_dynarow&);
129
130    private:
131        //--------------------------------------------------------------------
132        pod_array<row_data> m_rows;       // Pointers to each row of the buffer
133        unsigned            m_width;      // Width in pixels
134        unsigned            m_height;     // Height in pixels
135        unsigned            m_byte_width; // Width in bytes
136    };
137
138
139}
140
141
142#endif
143