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Diffstat (limited to 'gfx/harfbuzz/src/hb-aat-layout-just-table.hh')
| -rw-r--r-- | gfx/harfbuzz/src/hb-aat-layout-just-table.hh | 417 |
1 files changed, 417 insertions, 0 deletions
diff --git a/gfx/harfbuzz/src/hb-aat-layout-just-table.hh b/gfx/harfbuzz/src/hb-aat-layout-just-table.hh new file mode 100644 index 0000000000..49506e9f5a --- /dev/null +++ b/gfx/harfbuzz/src/hb-aat-layout-just-table.hh @@ -0,0 +1,417 @@ +/* + * Copyright © 2018 Ebrahim Byagowi + * + * This is part of HarfBuzz, a text shaping library. + * + * Permission is hereby granted, without written agreement and without + * license or royalty fees, to use, copy, modify, and distribute this + * software and its documentation for any purpose, provided that the + * above copyright notice and the following two paragraphs appear in + * all copies of this software. + * + * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR + * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES + * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN + * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH + * DAMAGE. + * + * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, + * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND + * FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS + * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO + * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. + */ + +#ifndef HB_AAT_LAYOUT_JUST_TABLE_HH +#define HB_AAT_LAYOUT_JUST_TABLE_HH + +#include "hb-aat-layout-common.hh" +#include "hb-ot-layout.hh" +#include "hb-open-type.hh" + +#include "hb-aat-layout-morx-table.hh" + +/* + * just -- Justification + * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6just.html + */ +#define HB_AAT_TAG_just HB_TAG('j','u','s','t') + + +namespace AAT { + +using namespace OT; + + +struct ActionSubrecordHeader +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + HBUINT16 actionClass; /* The JustClass value associated with this + * ActionSubrecord. */ + HBUINT16 actionType; /* The type of postcompensation action. */ + HBUINT16 actionLength; /* Length of this ActionSubrecord record, which + * must be a multiple of 4. */ + public: + DEFINE_SIZE_STATIC (6); +}; + +struct DecompositionAction +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + ActionSubrecordHeader + header; + HBFixed lowerLimit; /* If the distance factor is less than this value, + * then the ligature is decomposed. */ + HBFixed upperLimit; /* If the distance factor is greater than this value, + * then the ligature is decomposed. */ + HBUINT16 order; /* Numerical order in which this ligature will + * be decomposed; you may want infrequent ligatures + * to decompose before more frequent ones. The ligatures + * on the line of text will decompose in increasing + * value of this field. */ + ArrayOf<HBUINT16> + decomposedglyphs; + /* Number of 16-bit glyph indexes that follow; + * the ligature will be decomposed into these glyphs. + * + * Array of decomposed glyphs. */ + public: + DEFINE_SIZE_ARRAY (18, decomposedglyphs); +}; + +struct UnconditionalAddGlyphAction +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (c->check_struct (this)); + } + + protected: + ActionSubrecordHeader + header; + HBGlyphID addGlyph; /* Glyph that should be added if the distance factor + * is growing. */ + + public: + DEFINE_SIZE_STATIC (8); +}; + +struct ConditionalAddGlyphAction +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + protected: + ActionSubrecordHeader + header; + HBFixed substThreshold; /* Distance growth factor (in ems) at which + * this glyph is replaced and the growth factor + * recalculated. */ + HBGlyphID addGlyph; /* Glyph to be added as kashida. If this value is + * 0xFFFF, no extra glyph will be added. Note that + * generally when a glyph is added, justification + * will need to be redone. */ + HBGlyphID substGlyph; /* Glyph to be substituted for this glyph if the + * growth factor equals or exceeds the value of + * substThreshold. */ + public: + DEFINE_SIZE_STATIC (14); +}; + +struct DuctileGlyphAction +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + protected: + ActionSubrecordHeader + header; + HBUINT32 variationAxis; /* The 4-byte tag identifying the ductile axis. + * This would normally be 0x64756374 ('duct'), + * but you may use any axis the font contains. */ + HBFixed minimumLimit; /* The lowest value for the ductility axis tha + * still yields an acceptable appearance. Normally + * this will be 1.0. */ + HBFixed noStretchValue; /* This is the default value that corresponds to + * no change in appearance. Normally, this will + * be 1.0. */ + HBFixed maximumLimit; /* The highest value for the ductility axis that + * still yields an acceptable appearance. */ + public: + DEFINE_SIZE_STATIC (22); +}; + +struct RepeatedAddGlyphAction +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + protected: + ActionSubrecordHeader + header; + HBUINT16 flags; /* Currently unused; set to 0. */ + HBGlyphID glyph; /* Glyph that should be added if the distance factor + * is growing. */ + public: + DEFINE_SIZE_STATIC (10); +}; + +struct ActionSubrecord +{ + unsigned int get_length () const { return u.header.actionLength; } + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (unlikely (!c->check_struct (this))) + return_trace (false); + + switch (u.header.actionType) + { + case 0: return_trace (u.decompositionAction.sanitize (c)); + case 1: return_trace (u.unconditionalAddGlyphAction.sanitize (c)); + case 2: return_trace (u.conditionalAddGlyphAction.sanitize (c)); + // case 3: return_trace (u.stretchGlyphAction.sanitize (c)); + case 4: return_trace (u.decompositionAction.sanitize (c)); + case 5: return_trace (u.decompositionAction.sanitize (c)); + default: return_trace (true); + } + } + + protected: + union { + ActionSubrecordHeader header; + DecompositionAction decompositionAction; + UnconditionalAddGlyphAction unconditionalAddGlyphAction; + ConditionalAddGlyphAction conditionalAddGlyphAction; + /* StretchGlyphAction stretchGlyphAction; -- Not supported by CoreText */ + DuctileGlyphAction ductileGlyphAction; + RepeatedAddGlyphAction repeatedAddGlyphAction; + } u; /* Data. The format of this data depends on + * the value of the actionType field. */ + public: + DEFINE_SIZE_UNION (6, header); +}; + +struct PostcompensationActionChain +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + if (unlikely (!c->check_struct (this))) + return_trace (false); + + unsigned int offset = min_size; + for (unsigned int i = 0; i < count; i++) + { + const ActionSubrecord& subrecord = StructAtOffset<ActionSubrecord> (this, offset); + if (unlikely (!subrecord.sanitize (c))) return_trace (false); + offset += subrecord.get_length (); + } + + return_trace (true); + } + + protected: + HBUINT32 count; + + public: + DEFINE_SIZE_STATIC (4); +}; + +struct JustWidthDeltaEntry +{ + enum Flags + { + Reserved1 =0xE000,/* Reserved. You should set these bits to zero. */ + UnlimiteGap =0x1000,/* The glyph can take unlimited gap. When this + * glyph participates in the justification process, + * it and any other glyphs on the line having this + * bit set absorb all the remaining gap. */ + Reserved2 =0x0FF0,/* Reserved. You should set these bits to zero. */ + Priority =0x000F /* The justification priority of the glyph. */ + }; + + enum Priority + { + Kashida = 0, /* Kashida priority. This is the highest priority + * during justification. */ + Whitespace = 1, /* Whitespace priority. Any whitespace glyphs (as + * identified in the glyph properties table) will + * get this priority. */ + InterCharacter = 2, /* Inter-character priority. Give this to any + * remaining glyphs. */ + NullPriority = 3 /* Null priority. You should set this priority for + * glyphs that only participate in justification + * after the above priorities. Normally all glyphs + * have one of the previous three values. If you + * don't want a glyph to participate in justification, + * and you don't want to set its factors to zero, + * you may instead assign it to the null priority. */ + }; + + protected: + HBFixed beforeGrowLimit;/* The ratio by which the advance width of the + * glyph is permitted to grow on the left or top side. */ + HBFixed beforeShrinkLimit; + /* The ratio by which the advance width of the + * glyph is permitted to shrink on the left or top side. */ + HBFixed afterGrowLimit; /* The ratio by which the advance width of the glyph + * is permitted to shrink on the left or top side. */ + HBFixed afterShrinkLimit; + /* The ratio by which the advance width of the glyph + * is at most permitted to shrink on the right or + * bottom side. */ + HBUINT16 growFlags; /* Flags controlling the grow case. */ + HBUINT16 shrinkFlags; /* Flags controlling the shrink case. */ + + public: + DEFINE_SIZE_STATIC (20); +}; + +struct WidthDeltaPair +{ + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this))); + } + + protected: + HBUINT32 justClass; /* The justification category associated + * with the wdRecord field. Only 7 bits of + * this field are used. (The other bits are + * used as padding to guarantee longword + * alignment of the following record). */ + JustWidthDeltaEntry + wdRecord; /* The actual width delta record. */ + + public: + DEFINE_SIZE_STATIC (24); +}; + +typedef OT::LArrayOf<WidthDeltaPair> WidthDeltaCluster; + +struct JustificationCategory +{ + typedef void EntryData; + + enum Flags + { + SetMark =0x8000,/* If set, make the current glyph the marked + * glyph. */ + DontAdvance =0x4000,/* If set, don't advance to the next glyph before + * going to the new state. */ + MarkCategory =0x3F80,/* The justification category for the marked + * glyph if nonzero. */ + CurrentCategory =0x007F /* The justification category for the current + * glyph if nonzero. */ + }; + + bool sanitize (hb_sanitize_context_t *c, const void *base) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this) && + morphHeader.sanitize (c) && + stHeader.sanitize (c))); + } + + protected: + ChainSubtable<ObsoleteTypes> + morphHeader; /* Metamorphosis-style subtable header. */ + StateTable<ObsoleteTypes, EntryData> + stHeader; /* The justification insertion state table header */ + public: + DEFINE_SIZE_STATIC (30); +}; + +struct JustificationHeader +{ + bool sanitize (hb_sanitize_context_t *c, const void *base) const + { + TRACE_SANITIZE (this); + return_trace (likely (c->check_struct (this) && + justClassTable.sanitize (c, base, base) && + wdcTable.sanitize (c, base) && + pcTable.sanitize (c, base) && + lookupTable.sanitize (c, base))); + } + + protected: + OffsetTo<JustificationCategory> + justClassTable; /* Offset to the justification category state table. */ + OffsetTo<WidthDeltaCluster> + wdcTable; /* Offset from start of justification table to start + * of the subtable containing the width delta factors + * for the glyphs in your font. + * + * The width delta clusters table. */ + OffsetTo<PostcompensationActionChain> + pcTable; /* Offset from start of justification table to start + * of postcompensation subtable (set to zero if none). + * + * The postcompensation subtable, if present in the font. */ + Lookup<OffsetTo<WidthDeltaCluster>> + lookupTable; /* Lookup table associating glyphs with width delta + * clusters. See the description of Width Delta Clusters + * table for details on how to interpret the lookup values. */ + + public: + DEFINE_SIZE_MIN (8); +}; + +struct just +{ + static constexpr hb_tag_t tableTag = HB_AAT_TAG_just; + + bool sanitize (hb_sanitize_context_t *c) const + { + TRACE_SANITIZE (this); + + return_trace (likely (c->check_struct (this) && + version.major == 1 && + horizData.sanitize (c, this, this) && + vertData.sanitize (c, this, this))); + } + + protected: + FixedVersion<>version; /* Version of the justification table + * (0x00010000u for version 1.0). */ + HBUINT16 format; /* Format of the justification table (set to 0). */ + OffsetTo<JustificationHeader> + horizData; /* Byte offset from the start of the justification table + * to the header for tables that contain justification + * information for horizontal text. + * If you are not including this information, + * store 0. */ + OffsetTo<JustificationHeader> + vertData; /* ditto, vertical */ + + public: + DEFINE_SIZE_STATIC (10); +}; + +} /* namespace AAT */ + + +#endif /* HB_AAT_LAYOUT_JUST_TABLE_HH */ |