1 /*
2 * Copyright © 2011 Google, Inc.
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 * Google Author(s): Behdad Esfahbod
25 */
26
27 #define HB_SHAPER fallback
28 #include "hb-shaper-impl-private.hh"
29
30
31 /*
32 * shaper face data
33 */
34
35 struct hb_fallback_shaper_face_data_t {};
36
37 hb_fallback_shaper_face_data_t *
_hb_fallback_shaper_face_data_create(hb_face_t * face HB_UNUSED)38 _hb_fallback_shaper_face_data_create (hb_face_t *face HB_UNUSED)
39 {
40 return (hb_fallback_shaper_face_data_t *) HB_SHAPER_DATA_SUCCEEDED;
41 }
42
43 void
_hb_fallback_shaper_face_data_destroy(hb_fallback_shaper_face_data_t * data HB_UNUSED)44 _hb_fallback_shaper_face_data_destroy (hb_fallback_shaper_face_data_t *data HB_UNUSED)
45 {
46 }
47
48
49 /*
50 * shaper font data
51 */
52
53 struct hb_fallback_shaper_font_data_t {};
54
55 hb_fallback_shaper_font_data_t *
_hb_fallback_shaper_font_data_create(hb_font_t * font HB_UNUSED)56 _hb_fallback_shaper_font_data_create (hb_font_t *font HB_UNUSED)
57 {
58 return (hb_fallback_shaper_font_data_t *) HB_SHAPER_DATA_SUCCEEDED;
59 }
60
61 void
_hb_fallback_shaper_font_data_destroy(hb_fallback_shaper_font_data_t * data HB_UNUSED)62 _hb_fallback_shaper_font_data_destroy (hb_fallback_shaper_font_data_t *data HB_UNUSED)
63 {
64 }
65
66
67 /*
68 * shaper shape_plan data
69 */
70
71 struct hb_fallback_shaper_shape_plan_data_t {};
72
73 hb_fallback_shaper_shape_plan_data_t *
_hb_fallback_shaper_shape_plan_data_create(hb_shape_plan_t * shape_plan HB_UNUSED,const hb_feature_t * user_features HB_UNUSED,unsigned int num_user_features HB_UNUSED)74 _hb_fallback_shaper_shape_plan_data_create (hb_shape_plan_t *shape_plan HB_UNUSED,
75 const hb_feature_t *user_features HB_UNUSED,
76 unsigned int num_user_features HB_UNUSED)
77 {
78 return (hb_fallback_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
79 }
80
81 void
_hb_fallback_shaper_shape_plan_data_destroy(hb_fallback_shaper_shape_plan_data_t * data HB_UNUSED)82 _hb_fallback_shaper_shape_plan_data_destroy (hb_fallback_shaper_shape_plan_data_t *data HB_UNUSED)
83 {
84 }
85
86
87 /*
88 * shaper
89 */
90
91 hb_bool_t
_hb_fallback_shape(hb_shape_plan_t * shape_plan HB_UNUSED,hb_font_t * font,hb_buffer_t * buffer,const hb_feature_t * features HB_UNUSED,unsigned int num_features HB_UNUSED)92 _hb_fallback_shape (hb_shape_plan_t *shape_plan HB_UNUSED,
93 hb_font_t *font,
94 hb_buffer_t *buffer,
95 const hb_feature_t *features HB_UNUSED,
96 unsigned int num_features HB_UNUSED)
97 {
98 /* TODO
99 *
100 * - Apply fallback kern.
101 * - Handle Variation Selectors?
102 * - Apply normalization?
103 *
104 * This will make the fallback shaper into a dumb "TrueType"
105 * shaper which many people unfortunately still request.
106 */
107
108 hb_codepoint_t space;
109 bool has_space = (bool) font->get_nominal_glyph (' ', &space);
110
111 buffer->clear_positions ();
112
113 hb_direction_t direction = buffer->props.direction;
114 hb_unicode_funcs_t *unicode = buffer->unicode;
115 unsigned int count = buffer->len;
116 hb_glyph_info_t *info = buffer->info;
117 hb_glyph_position_t *pos = buffer->pos;
118 for (unsigned int i = 0; i < count; i++)
119 {
120 if (has_space && unicode->is_default_ignorable (info[i].codepoint)) {
121 info[i].codepoint = space;
122 pos[i].x_advance = 0;
123 pos[i].y_advance = 0;
124 continue;
125 }
126 font->get_nominal_glyph (info[i].codepoint, &info[i].codepoint);
127 font->get_glyph_advance_for_direction (info[i].codepoint,
128 direction,
129 &pos[i].x_advance,
130 &pos[i].y_advance);
131 font->subtract_glyph_origin_for_direction (info[i].codepoint,
132 direction,
133 &pos[i].x_offset,
134 &pos[i].y_offset);
135 }
136
137 if (HB_DIRECTION_IS_BACKWARD (direction))
138 hb_buffer_reverse (buffer);
139
140 return true;
141 }
142