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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  
35  HB_BEGIN_HEADER
36  
37  #ifdef HB_USE_PACKED_STRUCTS
38  #pragma pack(push, 1)
39  #endif
40  
41  /*
42     using anything else than signed or unsigned for bitfields in C is non standard,
43     but accepted by almost all compilers. And it gives a significant reduction in
44     memory consumption as HB_CharAttributes and HB_GlyphAttributes will not have
45     a 4 byte alignment
46  */
47  #ifdef  __xlC__
48  typedef unsigned hb_bitfield;
49  #else
50  typedef hb_uint8 hb_bitfield;
51  #endif
52  
53  typedef enum {
54          HB_Script_Common,
55          HB_Script_Greek,
56          HB_Script_Cyrillic,
57          HB_Script_Armenian,
58          HB_Script_Hebrew,
59          HB_Script_Arabic,
60          HB_Script_Syriac,
61          HB_Script_Thaana,
62          HB_Script_Devanagari,
63          HB_Script_Bengali,
64          HB_Script_Gurmukhi,
65          HB_Script_Gujarati,
66          HB_Script_Oriya,
67          HB_Script_Tamil,
68          HB_Script_Telugu,
69          HB_Script_Kannada,
70          HB_Script_Malayalam,
71          HB_Script_Sinhala,
72          HB_Script_Thai,
73          HB_Script_Lao,
74          HB_Script_Tibetan,
75          HB_Script_Myanmar,
76          HB_Script_Georgian,
77          HB_Script_Hangul,
78          HB_Script_Ogham,
79          HB_Script_Runic,
80          HB_Script_Khmer,
81          HB_Script_Nko,
82          HB_Script_Inherited,
83          HB_ScriptCount = HB_Script_Inherited
84          /*
85          HB_Script_Latin = Common,
86          HB_Script_Ethiopic = Common,
87          HB_Script_Cherokee = Common,
88          HB_Script_CanadianAboriginal = Common,
89          HB_Script_Mongolian = Common,
90          HB_Script_Hiragana = Common,
91          HB_Script_Katakana = Common,
92          HB_Script_Bopomofo = Common,
93          HB_Script_Han = Common,
94          HB_Script_Yi = Common,
95          HB_Script_OldItalic = Common,
96          HB_Script_Gothic = Common,
97          HB_Script_Deseret = Common,
98          HB_Script_Tagalog = Common,
99          HB_Script_Hanunoo = Common,
100          HB_Script_Buhid = Common,
101          HB_Script_Tagbanwa = Common,
102          HB_Script_Limbu = Common,
103          HB_Script_TaiLe = Common,
104          HB_Script_LinearB = Common,
105          HB_Script_Ugaritic = Common,
106          HB_Script_Shavian = Common,
107          HB_Script_Osmanya = Common,
108          HB_Script_Cypriot = Common,
109          HB_Script_Braille = Common,
110          HB_Script_Buginese = Common,
111          HB_Script_Coptic = Common,
112          HB_Script_NewTaiLue = Common,
113          HB_Script_Glagolitic = Common,
114          HB_Script_Tifinagh = Common,
115          HB_Script_SylotiNagri = Common,
116          HB_Script_OldPersian = Common,
117          HB_Script_Kharoshthi = Common,
118          HB_Script_Balinese = Common,
119          HB_Script_Cuneiform = Common,
120          HB_Script_Phoenician = Common,
121          HB_Script_PhagsPa = Common,
122          */
123  } HB_Script;
124  
125  typedef struct
126  {
127      hb_uint32 pos;
128      hb_uint32 length;
129      HB_Script script;
130      hb_uint8 bidiLevel;
131  } HB_ScriptItem;
132  
133  typedef enum {
134      HB_NoBreak,
135      HB_SoftHyphen,
136      HB_Break,
137      HB_ForcedBreak
138  } HB_LineBreakType;
139  
140  
141  typedef struct {
142      /*HB_LineBreakType*/ hb_bitfield lineBreakType  :2;
143      /*HB_Bool*/ hb_bitfield whiteSpace              :1;     /* A unicode whitespace character, except NBSP, ZWNBSP */
144      /*HB_Bool*/ hb_bitfield charStop                :1;     /* Valid cursor position (for left/right arrow) */
145      /*HB_Bool*/ hb_bitfield wordBoundary            :1;
146      /*HB_Bool*/ hb_bitfield sentenceBoundary        :1;
147      hb_bitfield unused                  :2;
148  } HB_CharAttributes;
149  
150  void HB_GetCharAttributes(const HB_UChar16 *string, hb_uint32 stringLength,
151                            const HB_ScriptItem *items, hb_uint32 numItems,
152                            HB_CharAttributes *attributes);
153  
154  /* requires HB_GetCharAttributes to be called before */
155  void HB_GetWordBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
156                            const HB_ScriptItem *items, hb_uint32 numItems,
157                            HB_CharAttributes *attributes);
158  
159  /* requires HB_GetCharAttributes to be called before */
160  void HB_GetSentenceBoundaries(const HB_UChar16 *string, hb_uint32 stringLength,
161                                const HB_ScriptItem *items, hb_uint32 numItems,
162                                HB_CharAttributes *attributes);
163  
164  
165  typedef enum {
166      HB_LeftToRight = 0,
167      HB_RightToLeft = 1
168  } HB_StringToGlyphsFlags;
169  
170  typedef enum {
171      HB_ShaperFlag_Default = 0,
172      HB_ShaperFlag_NoKerning = 1,
173      HB_ShaperFlag_UseDesignMetrics = 2
174  } HB_ShaperFlag;
175  
176  /*
177     highest value means highest priority for justification. Justification is done by first inserting kashidas
178     starting with the highest priority positions, then stretching spaces, afterwards extending inter char
179     spacing, and last spacing between arabic words.
180     NoJustification is for example set for arabic where no Kashida can be inserted or for diacritics.
181  */
182  typedef enum {
183      HB_NoJustification= 0,   /* Justification can't be applied after this glyph */
184      HB_Arabic_Space   = 1,   /* This glyph represents a space inside arabic text */
185      HB_Character      = 2,   /* Inter-character justification point follows this glyph */
186      HB_Space          = 4,   /* This glyph represents a blank outside an Arabic run */
187      HB_Arabic_Normal  = 7,   /* Normal Middle-Of-Word glyph that connects to the right (begin) */
188      HB_Arabic_Waw     = 8,   /* Next character is final form of Waw/Ain/Qaf/Fa */
189      HB_Arabic_BaRa    = 9,   /* Next two chars are Ba + Ra/Ya/AlefMaksura */
190      HB_Arabic_Alef    = 10,  /* Next character is final form of Alef/Tah/Lam/Kaf/Gaf */
191      HB_Arabic_HaaDal  = 11,  /* Next character is final form of Haa/Dal/Taa Marbutah */
192      HB_Arabic_Seen    = 12,  /* Initial or Medial form Of Seen/Sad */
193      HB_Arabic_Kashida = 13   /* Kashida(U+640) in middle of word */
194  } HB_JustificationClass;
195  
196  /* This structure is binary compatible with Uniscribe's SCRIPT_VISATTR. Would be nice to keep
197   * it like that. If this is a problem please tell Trolltech :)
198   */
199  typedef struct {
200      hb_bitfield justification   :4;  /* Justification class */
201      hb_bitfield clusterStart    :1;  /* First glyph of representation of cluster */
202      hb_bitfield mark            :1;  /* needs to be positioned around base char */
203      hb_bitfield zeroWidth       :1;  /* ZWJ, ZWNJ etc, with no width */
204      hb_bitfield dontPrint       :1;
205      hb_bitfield combiningClass  :8;
206  } HB_GlyphAttributes;
207  
208  typedef struct HB_FaceRec_ {
209      HB_Bool isSymbolFont;
210  
211      HB_GDEF gdef;
212      HB_GSUB gsub;
213      HB_GPOS gpos;
214      HB_Bool supported_scripts[HB_ScriptCount];
215      HB_Buffer buffer;
216      HB_Script current_script;
217      int current_flags; /* HB_ShaperFlags */
218      HB_Bool has_opentype_kerning;
219      HB_Bool glyphs_substituted;
220      HB_GlyphAttributes *tmpAttributes;
221      unsigned int *tmpLogClusters;
222      int length;
223      int orig_nglyphs;
224  } HB_FaceRec;
225  
226  typedef HB_Error (*HB_GetFontTableFunc)(void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length);
227  
228  HB_Face HB_NewFace(void *font, HB_GetFontTableFunc tableFunc);
229  void HB_FreeFace(HB_Face face);
230  
231  typedef struct {
232      HB_Fixed x, y;
233      HB_Fixed width, height;
234      HB_Fixed xOffset, yOffset;
235  } HB_GlyphMetrics;
236  
237  typedef enum {
238      HB_FontAscent
239  } HB_FontMetric;
240  
241  typedef struct {
242      HB_Bool  (*convertStringToGlyphIndices)(HB_Font font, const HB_UChar16 *string, hb_uint32 length, HB_Glyph *glyphs, hb_uint32 *numGlyphs, HB_Bool rightToLeft);
243      void     (*getGlyphAdvances)(HB_Font font, const HB_Glyph *glyphs, hb_uint32 numGlyphs, HB_Fixed *advances, int flags /*HB_ShaperFlag*/);
244      HB_Bool  (*canRender)(HB_Font font, const HB_UChar16 *string, hb_uint32 length);
245      /* implementation needs to make sure to load a scaled glyph, so /no/ FT_LOAD_NO_SCALE */
246      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);
247      void     (*getGlyphMetrics)(HB_Font font, HB_Glyph glyph, HB_GlyphMetrics *metrics);
248      HB_Fixed (*getFontMetric)(HB_Font font, HB_FontMetric metric);
249  } HB_FontClass;
250  
251  typedef struct HB_Font_ {
252      const HB_FontClass *klass;
253  
254      /* Metrics */
255      HB_UShort x_ppem, y_ppem;
256      HB_16Dot16 x_scale, y_scale;
257  
258      void *userData;
259  } HB_FontRec;
260  
261  #ifdef HB_USE_PACKED_STRUCTS
262  #pragma pack(pop)
263  #endif
264  
265  typedef struct HB_ShaperItem_ HB_ShaperItem;
266  
267  struct HB_ShaperItem_ {
268      const HB_UChar16 *string;               /* input: the Unicode UTF16 text to be shaped */
269      hb_uint32 stringLength;                 /* input: the length of the input in 16-bit words */
270      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> */
271      HB_Font font;                           /* input: the font: scale, units and function pointers supplying glyph indices and metrics */
272      HB_Face face;                           /* input: the shaper state; current script, access to the OpenType tables , etc. */
273      int shaperFlags;                        /* input (unused) should be set to 0; intended to support flags defined in HB_ShaperFlag */
274      HB_Bool glyphIndicesPresent;            /* input: true if the <glyphs> array contains glyph indices ready to be shaped */
275      hb_uint32 initialGlyphCount;            /* input: if glyphIndicesPresent is true, the number of glyph indices in the <glyphs> array */
276  
277      hb_uint32 num_glyphs;                   /* input: capacity of output arrays <glyphs>, <attributes>, <advances>, <offsets>, and <log_clusters>; */
278                                              /* output: required capacity (may be larger than actual capacity) */
279  
280      HB_Glyph *glyphs;                       /* output: <num_glyphs> indices of shaped glyphs */
281      HB_GlyphAttributes *attributes;         /* output: <num_glyphs> glyph attributes */
282      HB_Fixed *advances;                     /* output: <num_glyphs> advances */
283      HB_FixedPoint *offsets;                 /* output: <num_glyphs> offsets */
284      unsigned short *log_clusters;           /* output: for each output glyph, the index in the input of the start of its logical cluster */
285  
286      /* internal */
287      HB_Bool kerning_applied;                /* output: true if kerning was applied by the shaper */
288  };
289  
290  HB_Bool HB_ShapeItem(HB_ShaperItem *item);
291  
292  HB_END_HEADER
293  
294  #endif
295