summaryrefslogtreecommitdiff
path: root/third_party/agg23/agg_rasterizer_scanline_aa.h
blob: 77e04edee94b63a95c93f36ec12d317e090f44ec (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475

//----------------------------------------------------------------------------
// 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.
//
//----------------------------------------------------------------------------
//
// The author gratefully acknowleges the support of David Turner,
// Robert Wilhelm, and Werner Lemberg - the authors of the FreeType
// libray - in producing this work. See http://www.freetype.org for details.
//
//----------------------------------------------------------------------------
// Contact: mcseem@antigrain.com
//          mcseemagg@yahoo.com
//          http://www.antigrain.com
//----------------------------------------------------------------------------
//
// Adaptation for 32-bit screen coordinates has been sponsored by
// Liberty Technology Systems, Inc., visit http://lib-sys.com
//
// Liberty Technology Systems, Inc. is the provider of
// PostScript and PDF technology for software developers.
//
//----------------------------------------------------------------------------
#ifndef AGG_RASTERIZER_SCANLINE_AA_INCLUDED
#define AGG_RASTERIZER_SCANLINE_AA_INCLUDED

#include "agg_array.h"
#include "agg_basics.h"
#include "agg_clip_liang_barsky.h"
#include "agg_math.h"
#include "agg_render_scanlines.h"
#include "core/fxcrt/fx_coordinates.h"
#include "core/fxcrt/fx_memory.h"

namespace agg
{
enum poly_base_scale_e {
    poly_base_shift = 8,
    poly_base_size  = 1 << poly_base_shift,
    poly_base_mask  = poly_base_size - 1
};
inline int poly_coord(FX_FLOAT c)
{
    return int(c * poly_base_size);
}
struct cell_aa  {
    int x;
    int y;
    int cover;
    int area;
    void set(int x, int y, int c, int a);
    void set_coord(int x, int y);
    void set_cover(int c, int a);
    void add_cover(int c, int a);
};
class outline_aa 
{
    enum cell_block_scale_e {
        cell_block_shift = 12,
        cell_block_size  = 1 << cell_block_shift,
        cell_block_mask  = cell_block_size - 1,
        cell_block_pool  = 256,
        cell_block_limit = 1024
    };
    struct sorted_y  {
        unsigned start;
        unsigned num;
    };
public:
    ~outline_aa();
    outline_aa();
    void reset();
    void move_to(int x, int y);
    void line_to(int x, int y);
    int min_x() const
    {
        return m_min_x;
    }
    int min_y() const
    {
        return m_min_y;
    }
    int max_x() const
    {
        return m_max_x;
    }
    int max_y() const
    {
        return m_max_y;
    }
    void sort_cells();
    unsigned total_cells() const
    {
        return m_num_cells;
    }
    unsigned scanline_num_cells(unsigned y) const
    {
        return m_sorted_y[y - m_min_y].num;
    }
    const cell_aa* const* scanline_cells(unsigned y) const
    {
        return m_sorted_cells.data() + m_sorted_y[y - m_min_y].start;
    }
    bool sorted() const
    {
        return m_sorted;
    }
private:
    outline_aa(const outline_aa&);
    const outline_aa& operator = (const outline_aa&);
    void set_cur_cell(int x, int y);
    void add_cur_cell();
    void render_hline(int ey, int x1, int y1, int x2, int y2);
    void render_line(int x1, int y1, int x2, int y2);
    void allocate_block();
private:
    unsigned  m_num_blocks;
    unsigned  m_max_blocks;
    unsigned  m_cur_block;
    unsigned  m_num_cells;
    cell_aa** m_cells;
    cell_aa*  m_cur_cell_ptr;
    pod_array<cell_aa*> m_sorted_cells;
    pod_array<sorted_y> m_sorted_y;
    cell_aa   m_cur_cell;
    int       m_cur_x;
    int       m_cur_y;
    int       m_min_x;
    int       m_min_y;
    int       m_max_x;
    int       m_max_y;
    bool      m_sorted;
};
class scanline_hit_test 
{
public:
    scanline_hit_test(int x) : m_x(x), m_hit(false) {}
    void reset_spans() {}
    void finalize(int) {}
    void add_cell(int x, int)
    {
        if(m_x == x) {
            m_hit = true;
        }
    }
    void add_span(int x, int len, int)
    {
        if(m_x >= x && m_x < x + len) {
            m_hit = true;
        }
    }
    unsigned num_spans() const
    {
        return 1;
    }
    bool hit() const
    {
        return m_hit;
    }
private:
    int  m_x;
    bool m_hit;
};
enum filling_rule_e {
    fill_non_zero,
    fill_even_odd
};
class rasterizer_scanline_aa 
{
    enum status {
        status_initial,
        status_line_to,
        status_closed
    };
public:
    enum aa_scale_e {
        aa_num   = 1 << 8,
        aa_mask  = aa_num - 1,
        aa_2num  = aa_num * 2,
        aa_2mask = aa_2num - 1
    };
    rasterizer_scanline_aa() :
        m_filling_rule(fill_non_zero),
        m_clipped_start_x(0),
        m_clipped_start_y(0),
        m_status(status_initial),
        m_clipping(false)
    {
    }
    ~rasterizer_scanline_aa() {}
    void filling_rule(filling_rule_e filling_rule)
    {
        m_filling_rule = filling_rule;
    }
    int min_x() const
    {
        return m_outline.min_x();
    }
    int min_y() const
    {
        return m_outline.min_y();
    }
    int max_x() const
    {
        return m_outline.max_x();
    }
    int max_y() const
    {
        return m_outline.max_y();
    }
    void reset()
    {
        m_outline.reset();
        m_status = status_initial;
    }
    void clip_box(FX_FLOAT x1, FX_FLOAT y1, FX_FLOAT x2, FX_FLOAT y2)
    {
        m_clip_box = rect(poly_coord(x1), poly_coord(y1),
                          poly_coord(x2), poly_coord(y2));
        m_clip_box.normalize();
        m_clipping = true;
    }
    void add_vertex(FX_FLOAT x, FX_FLOAT y, unsigned cmd)
    {
        if(is_close(cmd)) {
            close_polygon();
        } else {
            if(is_move_to(cmd)) {
                move_to(poly_coord(x), poly_coord(y));
            } else {
                if(is_vertex(cmd)) {
                    line_to(poly_coord(x), poly_coord(y));
                }
            }
        }
    }
    void move_to(int x, int y)
    {
        if(m_clipping) {
            if(m_outline.sorted()) {
                reset();
            }
            if(m_status == status_line_to) {
                close_polygon();
            }
            m_prev_x = m_start_x = x;
            m_prev_y = m_start_y = y;
            m_status = status_initial;
            m_prev_flags = clipping_flags(x, y, m_clip_box);
            if(m_prev_flags == 0) {
                move_to_no_clip(x, y);
            }
        } else {
            move_to_no_clip(x, y);
        }
    }
    void line_to(int x, int y)
    {
        if(m_clipping) {
            clip_segment(x, y);
        } else {
            line_to_no_clip(x, y);
        }
    }
    void close_polygon()
    {
        if (m_status != status_line_to) {
            return;
        }
        if(m_clipping) {
            clip_segment(m_start_x, m_start_y);
        }
        close_polygon_no_clip();
    }
    AGG_INLINE unsigned calculate_alpha(int area, bool no_smooth) const
    {
        int cover = area >> (poly_base_shift * 2 + 1 - 8);
        if(cover < 0) {
            cover = -cover;
        }
        if(m_filling_rule == fill_even_odd) {
            cover &= aa_2mask;
            if(cover > aa_num) {
                cover = aa_2num - cover;
            }
        }
        if (no_smooth) {
            cover = cover > aa_mask / 2 ? aa_mask : 0;
        }
        if(cover > aa_mask) {
            cover = aa_mask;
        }
        return cover;
    }
    AGG_INLINE void sort()
    {
        m_outline.sort_cells();
    }
    AGG_INLINE bool rewind_scanlines()
    {
        close_polygon();
        m_outline.sort_cells();
        if(m_outline.total_cells() == 0) {
            return false;
        }
        m_cur_y = m_outline.min_y();
        return true;
    }
    AGG_INLINE bool navigate_scanline(int y)
    {
        close_polygon();
        m_outline.sort_cells();
        if(m_outline.total_cells() == 0 ||
                y < m_outline.min_y() ||
                y > m_outline.max_y()) {
            return false;
        }
        m_cur_y = y;
        return true;
    }
    template<class Scanline> bool sweep_scanline(Scanline& sl, bool no_smooth)
    {
        for(;;) {
            if(m_cur_y > m_outline.max_y()) {
                return false;
            }
            sl.reset_spans();
            unsigned num_cells = m_outline.scanline_num_cells(m_cur_y);
            const cell_aa* const* cells = m_outline.scanline_cells(m_cur_y);
            int cover = 0;
            while(num_cells) {
                const cell_aa* cur_cell = *cells;
                int x    = cur_cell->x;
                int area = cur_cell->area;
                unsigned alpha;
                cover += cur_cell->cover;
                while(--num_cells) {
                    cur_cell = *++cells;
                    if(cur_cell->x != x) {
                        break;
                    }
                    area  += cur_cell->area;
                    cover += cur_cell->cover;
                }
                if(area) {
                    alpha = calculate_alpha((cover << (poly_base_shift + 1)) - area, no_smooth);
                    if(alpha) {
                        sl.add_cell(x, alpha);
                    }
                    x++;
                }
                if(num_cells && cur_cell->x > x) {
                    alpha = calculate_alpha(cover << (poly_base_shift + 1), no_smooth);
                    if(alpha) {
                        sl.add_span(x, cur_cell->x - x, alpha);
                    }
                }
            }
            if(sl.num_spans()) {
                break;
            }
            ++m_cur_y;
        }
        sl.finalize(m_cur_y);
        ++m_cur_y;
        return true;
    }
    template<class VertexSource>
    void add_path(VertexSource& vs, unsigned path_id = 0)
    {
        FX_FLOAT x;
        FX_FLOAT y;
        unsigned cmd;
        vs.rewind(path_id);
        while(!is_stop(cmd = vs.vertex(&x, &y))) {
            add_vertex(x, y, cmd);
        }
    }
    template<class VertexSource>
    void add_path_transformed(VertexSource& vs, const CFX_Matrix* pMatrix, unsigned path_id = 0)
    {
        FX_FLOAT x;
        FX_FLOAT y;
        unsigned cmd;
        vs.rewind(path_id);
        while(!is_stop(cmd = vs.vertex(&x, &y))) {
            if (pMatrix) {
                pMatrix->Transform(x, y);
            }
            add_vertex(x, y, cmd);
        }
    }
private:
    rasterizer_scanline_aa(const rasterizer_scanline_aa&);
    const rasterizer_scanline_aa&
    operator = (const rasterizer_scanline_aa&);
    void move_to_no_clip(int x, int y)
    {
        if(m_status == status_line_to) {
            close_polygon_no_clip();
        }
        m_outline.move_to(x * 1, y);
        m_clipped_start_x = x;
        m_clipped_start_y = y;
        m_status = status_line_to;
    }
    void line_to_no_clip(int x, int y)
    {
        if(m_status != status_initial) {
            m_outline.line_to(x * 1, y);
            m_status = status_line_to;
        }
    }
    void close_polygon_no_clip()
    {
        if(m_status == status_line_to) {
            m_outline.line_to(m_clipped_start_x * 1, m_clipped_start_y);
            m_status = status_closed;
        }
    }
    void clip_segment(int x, int y)
    {
        unsigned flags = clipping_flags(x, y, m_clip_box);
        if(m_prev_flags == flags) {
            if(flags == 0) {
                if(m_status == status_initial) {
                    move_to_no_clip(x, y);
                } else {
                    line_to_no_clip(x, y);
                }
            }
        } else {
            int cx[4];
            int cy[4];
            unsigned n = clip_liang_barsky(m_prev_x, m_prev_y,
                                           x, y,
                                           m_clip_box,
                                           cx, cy);
            const int* px = cx;
            const int* py = cy;
            while(n--) {
                if(m_status == status_initial) {
                    move_to_no_clip(*px++, *py++);
                } else {
                    line_to_no_clip(*px++, *py++);
                }
            }
        }
        m_prev_flags = flags;
        m_prev_x = x;
        m_prev_y = y;
    }
private:
    outline_aa     m_outline;
    filling_rule_e m_filling_rule;
    int            m_clipped_start_x;
    int            m_clipped_start_y;
    int            m_start_x;
    int            m_start_y;
    int            m_prev_x;
    int            m_prev_y;
    unsigned       m_prev_flags;
    unsigned       m_status;
    rect           m_clip_box;
    bool           m_clipping;
    int            m_cur_y;
};
}
#endif