2 * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
4 * This is part of HarfBuzz, an OpenType Layout engine library.
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9 * above copyright notice and the following two paragraphs appear in
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25 #ifndef HARFBUZZ_SHAPER_H
26 #define HARFBUZZ_SHAPER_H
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"
37 #ifdef HB_USE_PACKED_STRUCTS
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
48 typedef unsigned hb_bitfield;
50 typedef hb_uint8 hb_bitfield;
83 HB_ScriptCount = HB_Script_Inherited
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,
137 } HB_StringToGlyphsFlags;
140 HB_ShaperFlag_Default = 0,
141 HB_ShaperFlag_NoKerning = 1,
142 HB_ShaperFlag_UseDesignMetrics = 2
146 highest value means highest priority for justification. Justification is done by first inserting kashidas
147 starting with the highest priority positions, then stretching spaces, afterwards extending inter char
148 spacing, and last spacing between arabic words.
149 NoJustification is for example set for arabic where no Kashida can be inserted or for diacritics.
152 HB_NoJustification= 0, /* Justification can't be applied after this glyph */
153 HB_Arabic_Space = 1, /* This glyph represents a space inside arabic text */
154 HB_Character = 2, /* Inter-character justification point follows this glyph */
155 HB_Space = 4, /* This glyph represents a blank outside an Arabic run */
156 HB_Arabic_Normal = 7, /* Normal Middle-Of-Word glyph that connects to the right (begin) */
157 HB_Arabic_Waw = 8, /* Next character is final form of Waw/Ain/Qaf/Fa */
158 HB_Arabic_BaRa = 9, /* Next two chars are Ba + Ra/Ya/AlefMaksura */
159 HB_Arabic_Alef = 10, /* Next character is final form of Alef/Tah/Lam/Kaf/Gaf */
160 HB_Arabic_HaaDal = 11, /* Next character is final form of Haa/Dal/Taa Marbutah */
161 HB_Arabic_Seen = 12, /* Initial or Medial form Of Seen/Sad */
162 HB_Arabic_Kashida = 13 /* Kashida(U+640) in middle of word */
163 } HB_JustificationClass;
165 /* This structure is binary compatible with Uniscribe's SCRIPT_VISATTR. Would be nice to keep
166 * it like that. If this is a problem please tell Trolltech :)
169 hb_bitfield justification :4; /* Justification class */
170 hb_bitfield clusterStart :1; /* First glyph of representation of cluster */
171 hb_bitfield mark :1; /* needs to be positioned around base char */
172 hb_bitfield zeroWidth :1; /* ZWJ, ZWNJ etc, with no width */
173 hb_bitfield dontPrint :1;
174 hb_bitfield combiningClass :8;
175 } HB_GlyphAttributes;
177 typedef struct HB_FaceRec_ {
178 HB_Bool isSymbolFont;
183 HB_Bool supported_scripts[HB_ScriptCount];
185 HB_Script current_script;
186 int current_flags; /* HB_ShaperFlags */
187 HB_Bool has_opentype_kerning;
188 HB_Bool glyphs_substituted;
189 HB_GlyphAttributes *tmpAttributes;
190 unsigned int *tmpLogClusters;
195 typedef HB_Error (*HB_GetFontTableFunc)(void *font, HB_Tag tag, HB_Byte *buffer, HB_UInt *length);
197 HB_Face HB_NewFace(void *font, HB_GetFontTableFunc tableFunc);
198 void HB_FreeFace(HB_Face face);
202 HB_Fixed width, height;
203 HB_Fixed xOffset, yOffset;
211 HB_Bool (*convertStringToGlyphIndices)(HB_Font font, const HB_UChar16 *string, hb_uint32 length, HB_Glyph *glyphs, hb_uint32 *numGlyphs, HB_Bool rightToLeft);
212 void (*getGlyphAdvances)(HB_Font font, const HB_Glyph *glyphs, hb_uint32 numGlyphs, HB_Fixed *advances, int flags /*HB_ShaperFlag*/);
213 HB_Bool (*canRender)(HB_Font font, const HB_UChar16 *string, hb_uint32 length);
214 /* implementation needs to make sure to load a scaled glyph, so /no/ FT_LOAD_NO_SCALE */
215 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);
216 void (*getGlyphMetrics)(HB_Font font, HB_Glyph glyph, HB_GlyphMetrics *metrics);
217 HB_Fixed (*getFontMetric)(HB_Font font, HB_FontMetric metric);
220 typedef struct HB_Font_ {
221 const HB_FontClass *klass;
224 HB_UShort x_ppem, y_ppem;
225 HB_16Dot16 x_scale, y_scale;
230 #ifdef HB_USE_PACKED_STRUCTS
234 typedef struct HB_ShaperItem_ HB_ShaperItem;
236 struct HB_ShaperItem_ {
237 const HB_UChar16 *string; /* input: the Unicode UTF16 text to be shaped */
238 hb_uint32 stringLength; /* input: the length of the input in 16-bit words */
239 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> */
240 HB_Font font; /* input: the font: scale, units and function pointers supplying glyph indices and metrics */
241 HB_Face face; /* input: the shaper state; current script, access to the OpenType tables , etc. */
242 int shaperFlags; /* input (unused) should be set to 0; intended to support flags defined in HB_ShaperFlag */
243 HB_Bool glyphIndicesPresent; /* input: true if the <glyphs> array contains glyph indices ready to be shaped */
244 hb_uint32 initialGlyphCount; /* input: if glyphIndicesPresent is true, the number of glyph indices in the <glyphs> array */
246 hb_uint32 num_glyphs; /* input: capacity of output arrays <glyphs>, <attributes>, <advances>, <offsets>, and <log_clusters>; */
247 /* output: required capacity (may be larger than actual capacity) */
249 HB_Glyph *glyphs; /* output: <num_glyphs> indices of shaped glyphs */
250 HB_GlyphAttributes *attributes; /* output: <num_glyphs> glyph attributes */
251 HB_Fixed *advances; /* output: <num_glyphs> advances */
252 HB_FixedPoint *offsets; /* output: <num_glyphs> offsets */
253 unsigned short *log_clusters; /* output: for each output glyph, the index in the input of the start of its logical cluster */
254 /* XXX the discription for log_clusters is wrong. It maps each input position to output glyph position! */
257 HB_Bool kerning_applied; /* output: true if kerning was applied by the shaper */
260 HB_Bool HB_ShapeItem(HB_ShaperItem *item);