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,const int * coords HB_UNUSED,unsigned int num_coords 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 const int *coords HB_UNUSED,
78 unsigned int num_coords HB_UNUSED)
79 {
80 return (hb_fallback_shaper_shape_plan_data_t *) HB_SHAPER_DATA_SUCCEEDED;
81 }
82
83 void
_hb_fallback_shaper_shape_plan_data_destroy(hb_fallback_shaper_shape_plan_data_t * data HB_UNUSED)84 _hb_fallback_shaper_shape_plan_data_destroy (hb_fallback_shaper_shape_plan_data_t *data HB_UNUSED)
85 {
86 }
87
88
89 /*
90 * shaper
91 */
92
93 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)94 _hb_fallback_shape (hb_shape_plan_t *shape_plan HB_UNUSED,
95 hb_font_t *font,
96 hb_buffer_t *buffer,
97 const hb_feature_t *features HB_UNUSED,
98 unsigned int num_features HB_UNUSED)
99 {
100 /* TODO
101 *
102 * - Apply fallback kern.
103 * - Handle Variation Selectors?
104 * - Apply normalization?
105 *
106 * This will make the fallback shaper into a dumb "TrueType"
107 * shaper which many people unfortunately still request.
108 */
109
110 hb_codepoint_t space;
111 bool has_space = (bool) font->get_nominal_glyph (' ', &space);
112
113 buffer->clear_positions ();
114
115 hb_direction_t direction = buffer->props.direction;
116 hb_unicode_funcs_t *unicode = buffer->unicode;
117 unsigned int count = buffer->len;
118 hb_glyph_info_t *info = buffer->info;
119 hb_glyph_position_t *pos = buffer->pos;
120 for (unsigned int i = 0; i < count; i++)
121 {
122 if (has_space && unicode->is_default_ignorable (info[i].codepoint)) {
123 info[i].codepoint = space;
124 pos[i].x_advance = 0;
125 pos[i].y_advance = 0;
126 continue;
127 }
128 font->get_nominal_glyph (info[i].codepoint, &info[i].codepoint);
129 font->get_glyph_advance_for_direction (info[i].codepoint,
130 direction,
131 &pos[i].x_advance,
132 &pos[i].y_advance);
133 font->subtract_glyph_origin_for_direction (info[i].codepoint,
134 direction,
135 &pos[i].x_offset,
136 &pos[i].y_offset);
137 }
138
139 if (HB_DIRECTION_IS_BACKWARD (direction))
140 hb_buffer_reverse (buffer);
141
142 return true;
143 }
144