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 bool has_space;
109 hb_codepoint_t space;
110 has_space = font->get_glyph (' ', 0, &space);
111
112 buffer->clear_positions ();
113
114 unsigned int count = buffer->len;
115
116 for (unsigned int i = 0; i < count; i++)
117 {
118 if (has_space && buffer->unicode->is_default_ignorable (buffer->info[i].codepoint)) {
119 buffer->info[i].codepoint = space;
120 buffer->pos[i].x_advance = 0;
121 buffer->pos[i].y_advance = 0;
122 continue;
123 }
124 font->get_glyph (buffer->info[i].codepoint, 0, &buffer->info[i].codepoint);
125 font->get_glyph_advance_for_direction (buffer->info[i].codepoint,
126 buffer->props.direction,
127 &buffer->pos[i].x_advance,
128 &buffer->pos[i].y_advance);
129 font->subtract_glyph_origin_for_direction (buffer->info[i].codepoint,
130 buffer->props.direction,
131 &buffer->pos[i].x_offset,
132 &buffer->pos[i].y_offset);
133 }
134
135 if (HB_DIRECTION_IS_BACKWARD (buffer->props.direction))
136 hb_buffer_reverse (buffer);
137
138 return true;
139 }
140