HarfBuzz text shaping engine
http://harfbuzz.github.io/
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180 lines
5.0 KiB
180 lines
5.0 KiB
/* |
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* Copyright © 2015 Google, Inc. |
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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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* Google Author(s): Behdad Esfahbod |
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*/ |
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#ifndef HB_OT_GLYF_TABLE_HH |
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#define HB_OT_GLYF_TABLE_HH |
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#include "hb-open-type-private.hh" |
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#include "hb-ot-head-table.hh" |
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namespace OT { |
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/* |
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* loca -- Index to Location |
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*/ |
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#define HB_OT_TAG_loca HB_TAG('l','o','c','a') |
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struct loca |
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{ |
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friend struct glyf; |
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static const hb_tag_t tableTag = HB_OT_TAG_loca; |
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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 (true); |
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} |
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protected: |
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UINT8 dataX[VAR]; /* Location data. */ |
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DEFINE_SIZE_ARRAY (0, dataX); |
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}; |
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/* |
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* glyf -- TrueType Glyph Data |
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*/ |
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#define HB_OT_TAG_glyf HB_TAG('g','l','y','f') |
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struct glyf |
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{ |
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static const hb_tag_t tableTag = HB_OT_TAG_glyf; |
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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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/* We don't check for anything specific here. The users of the |
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* struct do all the hard work... */ |
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return_trace (true); |
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} |
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struct GlyphHeader |
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{ |
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INT16 numberOfContours; /* If the number of contours is |
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* greater than or equal to zero, |
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* this is a simple glyph; if negative, |
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* this is a composite glyph. */ |
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FWORD xMin; /* Minimum x for coordinate data. */ |
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FWORD yMin; /* Minimum y for coordinate data. */ |
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FWORD xMax; /* Maximum x for coordinate data. */ |
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FWORD yMax; /* Maximum y for coordinate data. */ |
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DEFINE_SIZE_STATIC (10); |
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}; |
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struct accelerator_t |
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{ |
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inline void init (hb_face_t *face) |
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{ |
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hb_blob_t *head_blob = Sanitizer<head>::sanitize (face->reference_table (HB_OT_TAG_head)); |
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const head *head_table = Sanitizer<head>::lock_instance (head_blob); |
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if ((unsigned int) head_table->indexToLocFormat > 1 || head_table->glyphDataFormat != 0) |
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{ |
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/* Unknown format. Leave num_glyphs=0, that takes care of disabling us. */ |
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hb_blob_destroy (head_blob); |
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return; |
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} |
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short_offset = 0 == head_table->indexToLocFormat; |
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hb_blob_destroy (head_blob); |
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loca_blob = Sanitizer<loca>::sanitize (face->reference_table (HB_OT_TAG_loca)); |
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loca_table = Sanitizer<loca>::lock_instance (loca_blob); |
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glyf_blob = Sanitizer<glyf>::sanitize (face->reference_table (HB_OT_TAG_glyf)); |
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glyf_table = Sanitizer<glyf>::lock_instance (glyf_blob); |
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num_glyphs = MAX (1u, hb_blob_get_length (loca_blob) / (short_offset ? 2 : 4)) - 1; |
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glyf_len = hb_blob_get_length (glyf_blob); |
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} |
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inline void fini (void) |
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{ |
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hb_blob_destroy (loca_blob); |
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hb_blob_destroy (glyf_blob); |
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} |
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inline bool get_extents (hb_codepoint_t glyph, |
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hb_glyph_extents_t *extents) const |
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{ |
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if (unlikely (glyph >= num_glyphs)) |
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return false; |
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unsigned int start_offset, end_offset; |
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if (short_offset) |
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{ |
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const UINT16 *offsets = (const UINT16 *) loca_table->dataX; |
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start_offset = 2 * offsets[glyph]; |
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end_offset = 2 * offsets[glyph + 1]; |
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} |
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else |
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{ |
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const UINT32 *offsets = (const UINT32 *) loca_table->dataX; |
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start_offset = offsets[glyph]; |
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end_offset = offsets[glyph + 1]; |
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} |
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if (start_offset > end_offset || end_offset > glyf_len) |
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return false; |
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if (end_offset - start_offset < GlyphHeader::static_size) |
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return true; /* Empty glyph; zero extents. */ |
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const GlyphHeader &glyph_header = StructAtOffset<GlyphHeader> (glyf_table, start_offset); |
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extents->x_bearing = MIN (glyph_header.xMin, glyph_header.xMax); |
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extents->y_bearing = MAX (glyph_header.yMin, glyph_header.yMax); |
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extents->width = MAX (glyph_header.xMin, glyph_header.xMax) - extents->x_bearing; |
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extents->height = MIN (glyph_header.yMin, glyph_header.yMax) - extents->y_bearing; |
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return true; |
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} |
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private: |
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bool short_offset; |
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unsigned int num_glyphs; |
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const loca *loca_table; |
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const glyf *glyf_table; |
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hb_blob_t *loca_blob; |
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hb_blob_t *glyf_blob; |
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unsigned int glyf_len; |
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}; |
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protected: |
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UINT8 dataX[VAR]; /* Glyphs data. */ |
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DEFINE_SIZE_ARRAY (0, dataX); |
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}; |
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} /* namespace OT */ |
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#endif /* HB_OT_GLYF_TABLE_HH */
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