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fontinfo.h
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1
2 // File: fontinfo.h
3 // Description: Font information classes abstracted from intproto.h/cpp.
4 // Author: rays@google.com (Ray Smith)
5 // Created: Tue May 17 17:08:01 PDT 2011
6 //
7 // (C) Copyright 2011, Google Inc.
8 // Licensed under the Apache License, Version 2.0 (the "License");
9 // you may not use this file except in compliance with the License.
10 // You may obtain a copy of the License at
11 // http://www.apache.org/licenses/LICENSE-2.0
12 // Unless required by applicable law or agreed to in writing, software
13 // distributed under the License is distributed on an "AS IS" BASIS,
14 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 // See the License for the specific language governing permissions and
16 // limitations under the License.
17 //
19
20
21 #ifndef TESSERACT_CCSTRUCT_FONTINFO_H_
22 #define TESSERACT_CCSTRUCT_FONTINFO_H_
23
24 #include "genericvector.h"
25 #include "host.h"
26 #include "unichar.h"
27
28 namespace tesseract {
29
30 // Struct for information about spacing between characters in a particular font.
31 struct FontSpacingInfo {
32 inT16 x_gap_before;
33 inT16 x_gap_after;
34 GenericVector<UNICHAR_ID> kerned_unichar_ids;
35 GenericVector<inT16> kerned_x_gaps;
36 };
37
38 /*
39 * font_properties contains properties about boldness, italicness, fixed pitch,
40 * serif, fraktur
41 */
42 struct FontInfo {
43 FontInfo() : name(NULL), spacing_vec(NULL) {}
44 ~FontInfo() {}
45 // Reserves unicharset_size spots in spacing_vec.
46 void init_spacing(int unicharset_size) {
47 spacing_vec = new GenericVector<FontSpacingInfo *>();
48 spacing_vec->init_to_size(unicharset_size, NULL);
49 }
50 // Adds the given pointer to FontSpacingInfo to spacing_vec member
51 // (FontInfo class takes ownership of the pointer).
52 // Note: init_spacing should be called before calling this function.
53 void add_spacing(UNICHAR_ID uch_id, FontSpacingInfo *spacing_info) {
54 ASSERT_HOST(spacing_vec != NULL && spacing_vec->size() > uch_id);
55 (*spacing_vec)[uch_id] = spacing_info;
56 }
57
58 // Returns the pointer to FontSpacingInfo for the given UNICHAR_ID.
59 const FontSpacingInfo *get_spacing(UNICHAR_ID uch_id) const {
60 return (spacing_vec == NULL || spacing_vec->size() <= uch_id) ?
61 NULL : (*spacing_vec)[uch_id];
62 }
63
64 // Fills spacing with the value of the x gap expected between the two given
65 // UNICHAR_IDs. Returns true on success.
66 bool get_spacing(UNICHAR_ID prev_uch_id,
67 UNICHAR_ID uch_id,
68 int *spacing) const {
69 const FontSpacingInfo *prev_fsi = this->get_spacing(prev_uch_id);
70 const FontSpacingInfo *fsi = this->get_spacing(uch_id);
71 if (prev_fsi == NULL || fsi == NULL) return false;
72 int i = 0;
73 for (; i < prev_fsi->kerned_unichar_ids.size(); ++i) {
74 if (prev_fsi->kerned_unichar_ids[i] == uch_id) break;
75 }
76 if (i < prev_fsi->kerned_unichar_ids.size()) {
77 *spacing = prev_fsi->kerned_x_gaps[i];
78 } else {
79 *spacing = prev_fsi->x_gap_after + fsi->x_gap_before;
80 }
81 return true;
82 }
83
84 bool is_italic() const { return properties & 1; }
85 bool is_bold() const { return (properties & 2) != 0; }
86 bool is_fixed_pitch() const { return (properties & 4) != 0; }
87 bool is_serif() const { return (properties & 8) != 0; }
88 bool is_fraktur() const { return (properties & 16) != 0; }
89
90 char* name;
91 uinT32 properties;
92 // The universal_id is a field reserved for the initialization process
93 // to assign a unique id number to all fonts loaded for the current
94 // combination of languages. This id will then be returned by
95 // ResultIterator::WordFontAttributes.
96 inT32 universal_id;
97 // Horizontal spacing between characters (indexed by UNICHAR_ID).
98 GenericVector<FontSpacingInfo *> *spacing_vec;
99 };
100
101 // Every class (character) owns a FontSet that represents all the fonts that can
102 // render this character.
103 // Since almost all the characters from the same script share the same set of
104 // fonts, the sets are shared over multiple classes (see
105 // Classify::fontset_table_). Thus, a class only store an id to a set.
106 // Because some fonts cannot render just one character of a set, there are a
107 // lot of FontSet that differ only by one font. Rather than storing directly
108 // the FontInfo in the FontSet structure, it's better to share FontInfos among
109 // FontSets (Classify::fontinfo_table_).
110 struct FontSet {
111 int size;
112 int* configs; // FontInfo ids
113 };
114
115 // Compare FontInfo structures.
116 bool CompareFontInfo(const FontInfo& fi1, const FontInfo& fi2);
117 // Compare FontSet structures.
118 bool CompareFontSet(const FontSet& fs1, const FontSet& fs2);
119 // Deletion callbacks for GenericVector.
120 void FontInfoDeleteCallback(FontInfo f);
121 void FontSetDeleteCallback(FontSet fs);
122
123 // Callbacks used by UnicityTable to read/write FontInfo/FontSet structures.
124 bool read_info(FILE* f, FontInfo* fi, bool swap);
125 bool write_info(FILE* f, const FontInfo& fi);
126 bool read_spacing_info(FILE *f, FontInfo* fi, bool swap);
127 bool write_spacing_info(FILE* f, const FontInfo& fi);
128 bool read_set(FILE* f, FontSet* fs, bool swap);
129 bool write_set(FILE* f, const FontSet& fs);
130
131 } // namespace tesseract.
132
133 #endif /* THIRD_PARTY_TESSERACT_CCSTRUCT_FONTINFO_H_ */