1 /*
2  * Copyright © 2021  Behdad Esfahbod.
3  *
4  *  This is part of HarfBuzz, a text shaping library.
5  *
6  * Permission is hereby granted, without written agreement and without
7  * license or royalty fees, to use, copy, modify, and distribute this
8  * software and its documentation for any purpose, provided that the
9  * above copyright notice and the following two paragraphs appear in
10  * all copies of this software.
11  *
12  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
13  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
14  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
15  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
16  * DAMAGE.
17  *
18  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
19  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
20  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
21  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
22  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
23  */
24 
25 #include "hb.hh"
26 
27 #ifndef HB_NO_OT_SHAPE
28 
29 #include "hb-ot-shape-complex-syllabic.hh"
30 
31 
32 void
hb_syllabic_insert_dotted_circles(hb_font_t * font,hb_buffer_t * buffer,unsigned int broken_syllable_type,unsigned int dottedcircle_category,int repha_category)33 hb_syllabic_insert_dotted_circles (hb_font_t *font,
34 				   hb_buffer_t *buffer,
35 				   unsigned int broken_syllable_type,
36 				   unsigned int dottedcircle_category,
37 				   int repha_category)
38 {
39   if (unlikely (buffer->flags & HB_BUFFER_FLAG_DO_NOT_INSERT_DOTTED_CIRCLE))
40     return;
41 
42   /* Note: This loop is extra overhead, but should not be measurable.
43    * TODO Use a buffer scratch flag to remove the loop. */
44   bool has_broken_syllables = false;
45   unsigned int count = buffer->len;
46   hb_glyph_info_t *info = buffer->info;
47   for (unsigned int i = 0; i < count; i++)
48     if ((info[i].syllable() & 0x0F) == broken_syllable_type)
49     {
50       has_broken_syllables = true;
51       break;
52     }
53   if (likely (!has_broken_syllables))
54     return;
55 
56 
57   hb_codepoint_t dottedcircle_glyph;
58   if (!font->get_nominal_glyph (0x25CCu, &dottedcircle_glyph))
59     return;
60 
61   hb_glyph_info_t dottedcircle = {0};
62   dottedcircle.codepoint = 0x25CCu;
63   dottedcircle.complex_var_u8_category() = dottedcircle_category;
64   dottedcircle.codepoint = dottedcircle_glyph;
65 
66   buffer->clear_output ();
67 
68   buffer->idx = 0;
69   unsigned int last_syllable = 0;
70   while (buffer->idx < buffer->len && buffer->successful)
71   {
72     unsigned int syllable = buffer->cur().syllable();
73     if (unlikely (last_syllable != syllable && (syllable & 0x0F) == broken_syllable_type))
74     {
75       last_syllable = syllable;
76 
77       hb_glyph_info_t ginfo = dottedcircle;
78       ginfo.cluster = buffer->cur().cluster;
79       ginfo.mask = buffer->cur().mask;
80       ginfo.syllable() = buffer->cur().syllable();
81 
82       /* Insert dottedcircle after possible Repha. */
83       if (repha_category != -1)
84       {
85 	while (buffer->idx < buffer->len && buffer->successful &&
86 	       last_syllable == buffer->cur().syllable() &&
87 	       buffer->cur().complex_var_u8_category() == (unsigned) repha_category)
88 	  (void) buffer->next_glyph ();
89       }
90 
91       (void) buffer->output_info (ginfo);
92     }
93     else
94       (void) buffer->next_glyph ();
95   }
96   buffer->swap_buffers ();
97 }
98 
99 
100 #endif
101