1 /*
2  * Copyright © 2012  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 #ifndef HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
28 #define HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH
29 
30 #include "hb-private.hh"
31 
32 
33 #include "hb-ot-shape-complex-private.hh"
34 #include "hb-ot-shape-private.hh" /* XXX Remove */
35 
36 
37 #define INDIC_TABLE_ELEMENT_TYPE uint16_t
38 
39 /* Cateories used in the OpenType spec:
40  * https://www.microsoft.com/typography/otfntdev/devanot/shaping.aspx
41  */
42 /* Note: This enum is duplicated in the -machine.rl source file.
43  * Not sure how to avoid duplication. */
44 enum indic_category_t {
45   OT_X = 0,
46   OT_C = 1,
47   OT_V = 2,
48   OT_N = 3,
49   OT_H = 4,
50   OT_ZWNJ = 5,
51   OT_ZWJ = 6,
52   OT_M = 7,
53   OT_SM = 8,
54   OT_VD = 9,
55   OT_A = 10,
56   OT_PLACEHOLDER = 11,
57   OT_DOTTEDCIRCLE = 12,
58   OT_RS = 13, /* Register Shifter, used in Khmer OT spec. */
59   OT_Coeng = 14, /* Khmer-style Virama. */
60   OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
61   OT_Ra = 16,
62   OT_CM = 17,  /* Consonant-Medial. */
63   OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
64   OT_CM2 = 31 /* Consonant-Medial, second slot. */
65 };
66 
67 #define MEDIAL_FLAGS (FLAG (OT_CM) | FLAG (OT_CM2))
68 
69 /* Note:
70  *
71  * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
72  * cannot happen in a consonant syllable.  The plus side however is, we can call the
73  * consonant syllable logic from the vowel syllable function and get it all right! */
74 #define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
75 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
76 #define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng))
77 
78 
79 /* Visual positions in a syllable from left to right. */
80 enum indic_position_t {
81   POS_START,
82 
83   POS_RA_TO_BECOME_REPH,
84   POS_PRE_M,
85   POS_PRE_C,
86 
87   POS_BASE_C,
88   POS_AFTER_MAIN,
89 
90   POS_ABOVE_C,
91 
92   POS_BEFORE_SUB,
93   POS_BELOW_C,
94   POS_AFTER_SUB,
95 
96   POS_BEFORE_POST,
97   POS_POST_C,
98   POS_AFTER_POST,
99 
100   POS_FINAL_C,
101   POS_SMVD,
102 
103   POS_END
104 };
105 
106 /* Categories used in IndicSyllabicCategory.txt from UCD. */
107 enum indic_syllabic_category_t {
108   INDIC_SYLLABIC_CATEGORY_OTHER				= OT_X,
109 
110   INDIC_SYLLABIC_CATEGORY_AVAGRAHA			= OT_Symbol,
111   INDIC_SYLLABIC_CATEGORY_BINDU				= OT_SM,
112   INDIC_SYLLABIC_CATEGORY_BRAHMI_JOINING_NUMBER		= OT_PLACEHOLDER, /* Don't care. */
113   INDIC_SYLLABIC_CATEGORY_CANTILLATION_MARK		= OT_A,
114   INDIC_SYLLABIC_CATEGORY_CONSONANT			= OT_C,
115   INDIC_SYLLABIC_CATEGORY_CONSONANT_DEAD		= OT_C,
116   INDIC_SYLLABIC_CATEGORY_CONSONANT_FINAL		= OT_CM,
117   INDIC_SYLLABIC_CATEGORY_CONSONANT_HEAD_LETTER		= OT_C,
118   INDIC_SYLLABIC_CATEGORY_CONSONANT_KILLER		= OT_M, /* U+17CD only. */
119   INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL		= OT_CM,
120   INDIC_SYLLABIC_CATEGORY_CONSONANT_PLACEHOLDER		= OT_PLACEHOLDER,
121   INDIC_SYLLABIC_CATEGORY_CONSONANT_PRECEDING_REPHA	= OT_Repha,
122   INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED		= OT_X, /* Don't care. */
123   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED		= OT_CM,
124   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA	= OT_N,
125   INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER	= OT_Repha, /* TODO */
126   INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK		= OT_SM,
127   INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER		= OT_Coeng,
128   INDIC_SYLLABIC_CATEGORY_JOINER			= OT_ZWJ,
129   INDIC_SYLLABIC_CATEGORY_MODIFYING_LETTER		= OT_X,
130   INDIC_SYLLABIC_CATEGORY_NON_JOINER			= OT_ZWNJ,
131   INDIC_SYLLABIC_CATEGORY_NUKTA				= OT_N,
132   INDIC_SYLLABIC_CATEGORY_NUMBER			= OT_PLACEHOLDER,
133   INDIC_SYLLABIC_CATEGORY_NUMBER_JOINER			= OT_PLACEHOLDER, /* Don't care. */
134   INDIC_SYLLABIC_CATEGORY_PURE_KILLER			= OT_M, /* Is like a vowel matra. */
135   INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER		= OT_RS,
136   INDIC_SYLLABIC_CATEGORY_SYLLABLE_MODIFIER		= OT_M, /* Misc Khmer signs. */
137   INDIC_SYLLABIC_CATEGORY_TONE_LETTER			= OT_X,
138   INDIC_SYLLABIC_CATEGORY_TONE_MARK			= OT_N,
139   INDIC_SYLLABIC_CATEGORY_VIRAMA			= OT_H,
140   INDIC_SYLLABIC_CATEGORY_VISARGA			= OT_SM,
141   INDIC_SYLLABIC_CATEGORY_VOWEL				= OT_V,
142   INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT		= OT_M,
143   INDIC_SYLLABIC_CATEGORY_VOWEL_INDEPENDENT		= OT_V
144 };
145 
146 /* Categories used in IndicSMatraCategory.txt from UCD */
147 enum indic_matra_category_t {
148   INDIC_MATRA_CATEGORY_NOT_APPLICABLE			= POS_END,
149 
150   INDIC_MATRA_CATEGORY_LEFT				= POS_PRE_C,
151   INDIC_MATRA_CATEGORY_TOP				= POS_ABOVE_C,
152   INDIC_MATRA_CATEGORY_BOTTOM				= POS_BELOW_C,
153   INDIC_MATRA_CATEGORY_RIGHT				= POS_POST_C,
154 
155   /* These should resolve to the position of the last part of the split sequence. */
156   INDIC_MATRA_CATEGORY_BOTTOM_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
157   INDIC_MATRA_CATEGORY_LEFT_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
158   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM			= INDIC_MATRA_CATEGORY_BOTTOM,
159   INDIC_MATRA_CATEGORY_TOP_AND_BOTTOM_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
160   INDIC_MATRA_CATEGORY_TOP_AND_LEFT			= INDIC_MATRA_CATEGORY_TOP,
161   INDIC_MATRA_CATEGORY_TOP_AND_LEFT_AND_RIGHT		= INDIC_MATRA_CATEGORY_RIGHT,
162   INDIC_MATRA_CATEGORY_TOP_AND_RIGHT			= INDIC_MATRA_CATEGORY_RIGHT,
163 
164   INDIC_MATRA_CATEGORY_OVERSTRUCK			= POS_AFTER_MAIN,
165   INDIC_MATRA_CATEGORY_VISUAL_ORDER_LEFT		= POS_PRE_M
166 };
167 
168 #define INDIC_COMBINE_CATEGORIES(S,M) \
169   ( \
170     ASSERT_STATIC_EXPR_ZERO (S < 255 && M < 255) + \
171     ( S | \
172      ( \
173       ( \
174        S == INDIC_SYLLABIC_CATEGORY_CONSONANT_MEDIAL || \
175        S == INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK || \
176        S == INDIC_SYLLABIC_CATEGORY_REGISTER_SHIFTER || \
177        S == INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA || \
178        S == INDIC_SYLLABIC_CATEGORY_VIRAMA || \
179        S == INDIC_SYLLABIC_CATEGORY_VOWEL_DEPENDENT || \
180        false \
181        ? M : INDIC_MATRA_CATEGORY_NOT_APPLICABLE \
182       ) << 8 \
183      ) \
184     ) \
185    )
186 
187 HB_INTERNAL INDIC_TABLE_ELEMENT_TYPE
188 hb_indic_get_categories (hb_codepoint_t u);
189 
190 #endif /* HB_OT_SHAPE_COMPLEX_INDIC_PRIVATE_HH */
191