harfbuzz-shaper.h revision 5569331642446be05292e3e1f8a51218827168cd 
1/*
2 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
3 *
4 * This is part of HarfBuzz, an OpenType Layout engine 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
25#ifndef HARFBUZZ_SHAPER_H
26#define HARFBUZZ_SHAPER_H
27
28#include "harfbuzz-global.h"
29#include "harfbuzz-gdef.h"
30#include "harfbuzz-gpos.h"
31#include "harfbuzz-gsub.h"
32#include "harfbuzz-external.h"
33#include "harfbuzz-stream-private.h"
34
35HB_BEGIN_HEADER
36
37typedef enum {
38        HB_Script_Common,
39        HB_Script_Greek,
40        HB_Script_Cyrillic,
41        HB_Script_Armenian,
42        HB_Script_Hebrew,
43        HB_Script_Arabic,
44        HB_Script_Syriac,
45        HB_Script_Thaana,
46        HB_Script_Devanagari,
47        HB_Script_Bengali,
48        HB_Script_Gurmukhi,
49        HB_Script_Gujarati,
50        HB_Script_Oriya,
51        HB_Script_Tamil,
52        HB_Script_Telugu,
53        HB_Script_Kannada,
54        HB_Script_Malayalam,
55        HB_Script_Sinhala,
56        HB_Script_Thai,
57        HB_Script_Lao,
58        HB_Script_Tibetan,
59        HB_Script_Myanmar,
60        HB_Script_Georgian,
61        HB_Script_Hangul,
62        HB_Script_Ogham,
63        HB_Script_Runic,
64        HB_Script_Khmer,
65        HB_Script_Nko,
66        HB_Script_Inherited,
67        HB_ScriptCount = HB_Script_Inherited
68        /*
69        HB_Script_Latin = Common,
70        HB_Script_Ethiopic = Common,
71        HB_Script_Cherokee = Common,
72        HB_Script_CanadianAboriginal = Common,
73        HB_Script_Mongolian = Common,
74        HB_Script_Hiragana = Common,
75        HB_Script_Katakana = Common,
76        HB_Script_Bopomofo = Common,
77        HB_Script_Han = Common,
78        HB_Script_Yi = Common,
79        HB_Script_OldItalic = Common,
80        HB_Script_Gothic = Common,
81        HB_Script_Deseret = Common,
82        HB_Script_Tagalog = Common,
83        HB_Script_Hanunoo = Common,
84        HB_Script_Buhid = Common,
85        HB_Script_Tagbanwa = Common,
86        HB_Script_Limbu = Common,
87        HB_Script_TaiLe = Common,
88        HB_Script_LinearB = Common,
89        HB_Script_Ugaritic = Common,
90        HB_Script_Shavian = Common,
91        HB_Script_Osmanya = Common,
92        HB_Script_Cypriot = Common,
93        HB_Script_Braille = Common,
94        HB_Script_Buginese = Common,
95        HB_Script_Coptic = Common,
96        HB_Script_NewTaiLue = Common,
97        HB_Script_Glagolitic = Common,
98        HB_Script_Tifinagh = Common,
99        HB_Script_SylotiNagri = Common,
100        HB_Script_OldPersian = Common,
101        HB_Script_Kharoshthi = Common,
102        HB_Script_Balinese = Common,
103        HB_Script_Cuneiform = Common,
104        HB_Script_Phoenician = Common,
105        HB_Script_PhagsPa = Common,
106        */
107} HB_Script;
108
109typedef struct
110{
111    hb_uint32 pos;
112    hb_uint32 length;
113    HB_Script script;
114    hb_uint8 bidiLevel;
115} HB_ScriptItem;
116
117typedef enum {
118    HB_NoBreak,
119    HB_SoftHyphen,
120    HB_Break,
121    HB_ForcedBreak
122} HB_LineBreakType;
123
124
125typedef struct {
126    /*HB_LineBreakType*/ unsigned lineBreakType  :2;
127    /*HB_Bool*/ unsigned whiteSpace              :1;     /* A unicode whitespace character, except NBSP, ZWNBSP */
128    /*HB_Bool*/ unsigned charStop                :1;     /* Valid cursor position (for left/right arrow) */
129    /*HB_Bool*/ unsigned wordBoundary            :1;
130    /*HB_Bool*/ unsigned sentenceBoundary        :1;
131    unsigned unused                  :2;
132} HB_CharAttributes;
133
134void HB_GetCharAttributes(const HB_UChar16 *string, hb_uint32 stringLength,
135                          const HB_ScriptItem *items, hb_uint32 numItems,
136                          HB_CharAttributes *attributes);
137
138/* requires HB_GetCharAttributes to be called before */
139void HB_GetWordBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
140                          const HB_ScriptItem *items, hb_uint32 numItems,
141                          HB_CharAttributes *attributes);
142
143/* requires HB_GetCharAttributes to be called before */
144void HB_GetSentenceBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
145                              const HB_ScriptItem *items, hb_uint32 numItems,
146                              HB_CharAttributes *attributes);
147
148
149typedef enum {
150    HB_LeftToRight = 0,
151    HB_RightToLeft = 1
152} HB_StringToGlyphsFlags;
153
154typedef enum {
155    HB_ShaperFlag_Default = 0,
156    HB_ShaperFlag_NoKerning = 1,
157    HB_ShaperFlag_UseDesignMetrics = 1 << 1,
158    /* Arabic vowels in some fonts (Times New Roman, at least) have
159       non-zero advances, when they should be zero.  Setting this shaper
160       flag causes us to zero out the advances for mark glyphs. */
161    HB_ShaperFlag_ForceMarksToZeroWidth = 1 << 2
162} HB_ShaperFlag;
163
164/*
165   highest value means highest priority for justification. Justification is done by first inserting kashidas
166   starting with the highest priority positions, then stretching spaces, afterwards extending inter char
167   spacing, and last spacing between arabic words.
168   NoJustification is for example set for arabic where no Kashida can be inserted or for diacritics.
169*/
170typedef enum {
171    HB_NoJustification= 0,   /* Justification can't be applied after this glyph */
172    HB_Arabic_Space   = 1,   /* This glyph represents a space inside arabic text */
173    HB_Character      = 2,   /* Inter-character justification point follows this glyph */
174    HB_Space          = 4,   /* This glyph represents a blank outside an Arabic run */
175    HB_Arabic_Normal  = 7,   /* Normal Middle-Of-Word glyph that connects to the right (begin) */
176    HB_Arabic_Waw     = 8,   /* Next character is final form of Waw/Ain/Qaf/Fa */
177    HB_Arabic_BaRa    = 9,   /* Next two chars are Ba + Ra/Ya/AlefMaksura */
178    HB_Arabic_Alef    = 10,  /* Next character is final form of Alef/Tah/Lam/Kaf/Gaf */
179    HB_Arabic_HaaDal  = 11,  /* Next character is final form of Haa/Dal/Taa Marbutah */
180    HB_Arabic_Seen    = 12,  /* Initial or Medial form Of Seen/Sad */
181    HB_Arabic_Kashida = 13   /* Kashida(U+640) in middle of word */
182} HB_JustificationClass;
183
184/* This structure is binary compatible with Uniscribe's SCRIPT_VISATTR. Would be nice to keep
185 * it like that. If this is a problem please tell Trolltech :)
186 */
187typedef struct {
188    unsigned justification   :4;  /* Justification class */
189    unsigned clusterStart    :1;  /* First glyph of representation of cluster */
190    unsigned mark            :1;  /* needs to be positioned around base char */
191    unsigned zeroWidth       :1;  /* ZWJ, ZWNJ etc, with no width */
192    unsigned dontPrint       :1;
193    unsigned combiningClass  :8;
194} HB_GlyphAttributes;
195
196typedef struct HB_FaceRec_ {
197    HB_Bool isSymbolFont;
198
199    HB_GDEF gdef;
200    HB_GSUB gsub;
201    HB_GPOS gpos;
202    HB_Bool supported_scripts[HB_ScriptCount];
203    HB_Buffer buffer;
204    HB_Script current_script;
205    int current_flags; /* HB_ShaperFlags */
206    HB_Bool has_opentype_kerning;
207    HB_Bool glyphs_substituted;
208    HB_GlyphAttributes *tmpAttributes;
209    unsigned int *tmpLogClusters;
210    int length;
211    int orig_nglyphs;
212} HB_FaceRec;
213
214typedef HB_Error (*HB_GetFontTableFunc)(void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length);
215
216HB_Face HB_NewFace(void *font, HB_GetFontTableFunc tableFunc);
217void HB_FreeFace(HB_Face face);
218
219typedef struct {
220    HB_Fixed x, y;
221    HB_Fixed width, height;
222    HB_Fixed xOffset, yOffset;
223} HB_GlyphMetrics;
224
225typedef enum {
226    HB_FontAscent
227} HB_FontMetric;
228
229typedef struct {
230    HB_Bool  (*convertStringToGlyphIndices)(HB_Font font, const HB_UChar16 *string, hb_uint32 length, HB_Glyph *glyphs, hb_uint32 *numGlyphs, HB_Bool rightToLeft);
231    void     (*getGlyphAdvances)(HB_Font font, const HB_Glyph *glyphs, hb_uint32 numGlyphs, HB_Fixed *advances, int flags /*HB_ShaperFlag*/);
232    HB_Bool  (*canRender)(HB_Font font, const HB_UChar16 *string, hb_uint32 length);
233    /* implementation needs to make sure to load a scaled glyph, so /no/ FT_LOAD_NO_SCALE */
234    HB_Error (*getPointInOutline)(HB_Font font, HB_Glyph glyph, int flags /*HB_ShaperFlag*/, hb_uint32 point, HB_Fixed *xpos, HB_Fixed *ypos, hb_uint32 *nPoints);
235    void     (*getGlyphMetrics)(HB_Font font, HB_Glyph glyph, HB_GlyphMetrics *metrics);
236    HB_Fixed (*getFontMetric)(HB_Font font, HB_FontMetric metric);
237} HB_FontClass;
238
239typedef struct HB_Font_ {
240    const HB_FontClass *klass;
241
242    /* Metrics */
243    HB_UShort x_ppem, y_ppem;
244    HB_16Dot16 x_scale, y_scale;
245
246    void *userData;
247} HB_FontRec;
248
249typedef struct HB_ShaperItem_ HB_ShaperItem;
250
251struct HB_ShaperItem_ {
252    const HB_UChar16 *string;               /* input: the Unicode UTF16 text to be shaped */
253    hb_uint32 stringLength;                 /* input: the length of the input in 16-bit words */
254    HB_ScriptItem item;                     /* input: the current run to be shaped: a run of text all in the same script that is a substring of <string> */
255    HB_Font font;                           /* input: the font: scale, units and function pointers supplying glyph indices and metrics */
256    HB_Face face;                           /* input: the shaper state; current script, access to the OpenType tables , etc. */
257    int shaperFlags;                        /* input (unused) should be set to 0; intended to support flags defined in HB_ShaperFlag */
258    HB_Bool glyphIndicesPresent;            /* input: true if the <glyphs> array contains glyph indices ready to be shaped */
259    hb_uint32 initialGlyphCount;            /* input: if glyphIndicesPresent is true, the number of glyph indices in the <glyphs> array */
260
261    hb_uint32 num_glyphs;                   /* input: capacity of output arrays <glyphs>, <attributes>, <advances>, <offsets>, and <log_clusters>; */
262                                            /* output: required capacity (may be larger than actual capacity) */
263
264    HB_Glyph *glyphs;                       /* output: <num_glyphs> indices of shaped glyphs */
265    HB_GlyphAttributes *attributes;         /* output: <num_glyphs> glyph attributes */
266    HB_Fixed *advances;                     /* output: <num_glyphs> advances */
267    HB_FixedPoint *offsets;                 /* output: <num_glyphs> offsets */
268    unsigned short *log_clusters;           /* output: for each output glyph, the index in the input of the start of its logical cluster */
269
270    /* internal */
271    HB_Bool kerning_applied;                /* output: true if kerning was applied by the shaper */
272};
273
274HB_Bool HB_ShapeItem(HB_ShaperItem *item);
275
276HB_END_HEADER
277
278#endif
279