[aat] Implement bsln table parsing (#943)
Ebrahim Byagowi
7 years ago
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3 changed files with 159 additions and 1 deletions
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/*
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* Copyright © 2018 Ebrahim Byagowi |
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* |
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* This is part of HarfBuzz, a text shaping library. |
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* |
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* Permission is hereby granted, without written agreement and without |
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* license or royalty fees, to use, copy, modify, and distribute this |
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* software and its documentation for any purpose, provided that the |
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* above copyright notice and the following two paragraphs appear in |
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* all copies of this software. |
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* |
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* IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR |
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* DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES |
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* ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN |
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* IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH |
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* DAMAGE. |
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* |
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* THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING, |
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* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND |
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* FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE PROVIDED HEREUNDER IS |
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* ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO |
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* PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS. |
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*/ |
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#ifndef HB_AAT_LAYOUT_BSLN_TABLE_HH |
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#define HB_AAT_LAYOUT_BSLN_TABLE_HH |
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#include "hb-aat-layout-common-private.hh" |
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#define HB_AAT_TAG_bsln HB_TAG('b','s','l','n') |
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namespace AAT { |
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struct BaselineTableFormat0Part |
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{ |
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inline bool sanitize (hb_sanitize_context_t *c) const |
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{ |
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TRACE_SANITIZE (this); |
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return_trace (c->check_struct (this)); |
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} |
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protected: |
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// Roman, Ideographic centered, Ideographic low, Hanging and Math
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// are the default defined ones, but any other maybe accessed also.
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HBINT16 deltas[32]; /* These are the FUnit distance deltas from
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* the font's natural baseline to the other |
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* baselines used in the font. */ |
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public: |
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DEFINE_SIZE_STATIC (64); |
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}; |
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struct BaselineTableFormat1Part |
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{ |
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inline bool sanitize (hb_sanitize_context_t *c) const |
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{ |
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TRACE_SANITIZE (this); |
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return_trace (c->check_struct (this) && lookupTable.sanitize (c)); |
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} |
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protected: |
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HBINT16 deltas[32]; /* ditto */ |
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Lookup<HBUINT16> |
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lookupTable; /* Lookup table that maps glyphs to their
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* baseline values. */ |
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public: |
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DEFINE_SIZE_MIN (66); |
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}; |
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struct BaselineTableFormat2Part |
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{ |
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inline bool sanitize (hb_sanitize_context_t *c) const |
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{ |
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TRACE_SANITIZE (this); |
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return_trace (c->check_struct (this)); |
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} |
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protected: |
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GlyphID stdGlyph; /* The specific glyph index number in this
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* font that is used to set the baseline values. |
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* This is the standard glyph. |
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* This glyph must contain a set of control points |
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* (whose numbers are contained in the ctlPoints field) |
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* that are used to determine baseline distances. */ |
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HBUINT16 ctlPoints[32]; /* Set of control point numbers,
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* associated with the standard glyph. |
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* A value of 0xFFFF means there is no corresponding |
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* control point in the standard glyph. */ |
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public: |
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DEFINE_SIZE_STATIC (66); |
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}; |
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struct BaselineTableFormat3Part |
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{ |
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inline bool sanitize (hb_sanitize_context_t *c) const |
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{ |
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TRACE_SANITIZE (this); |
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return_trace (c->check_struct (this) && lookupTable.sanitize (c)); |
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} |
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protected: |
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GlyphID stdGlyph; /* ditto */ |
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HBUINT16 ctlPoints[32]; /* ditto */ |
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Lookup<HBUINT16> |
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lookupTable; /* Lookup table that maps glyphs to their
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* baseline values. */ |
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public: |
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DEFINE_SIZE_MIN (68); |
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}; |
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/*
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* bsln -- Baseline table |
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* https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6bsln.html
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*/ |
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struct bsln |
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{ |
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static const hb_tag_t tableTag = HB_AAT_TAG_bsln; |
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inline bool sanitize (hb_sanitize_context_t *c) const |
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{ |
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TRACE_SANITIZE (this); |
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if (!(c->check_struct (this) && defaultBaseline < 32)) |
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return_trace (false); |
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switch (format) { |
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case 0: return_trace (parts.format0.sanitize (c)); |
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case 1: return_trace (parts.format1.sanitize (c)); |
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case 2: return_trace (parts.format2.sanitize (c)); |
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case 3: return_trace (parts.format3.sanitize (c)); |
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default:return_trace (true); |
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} |
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} |
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protected: |
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FixedVersion<>version; /* Version number of the Baseline table. */ |
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HBUINT16 format; /* Format of the baseline table. Only one baseline
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* format may be selected for the font. */ |
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HBUINT16 defaultBaseline;/* Default baseline value for all glyphs.
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* This value can be from 0 through 31. */ |
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union { |
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// Distance-Based Formats
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BaselineTableFormat0Part format0; |
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BaselineTableFormat1Part format1; |
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// Control Point-based Formats
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BaselineTableFormat2Part format2; |
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BaselineTableFormat3Part format3; |
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} parts; |
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public: |
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DEFINE_SIZE_MIN (8); |
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}; |
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} /* namespace AAT */ |
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#endif /* HB_AAT_LAYOUT_BSLN_TABLE_HH */ |
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