| /* |
| * Copyright © 2011,2012 Google, Inc. |
| * |
| * 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. |
| * |
| * Google Author(s): Behdad Esfahbod, Roderick Sheeter |
| */ |
| |
| #ifndef HB_OT_HMTX_TABLE_HH |
| #define HB_OT_HMTX_TABLE_HH |
| |
| #include "hb-open-type.hh" |
| #include "hb-ot-maxp-table.hh" |
| #include "hb-ot-hhea-table.hh" |
| #include "hb-ot-var-hvar-table.hh" |
| #include "hb-ot-metrics.hh" |
| |
| /* |
| * hmtx -- Horizontal Metrics |
| * https://docs.microsoft.com/en-us/typography/opentype/spec/hmtx |
| * vmtx -- Vertical Metrics |
| * https://docs.microsoft.com/en-us/typography/opentype/spec/vmtx |
| */ |
| #define HB_OT_TAG_hmtx HB_TAG('h','m','t','x') |
| #define HB_OT_TAG_vmtx HB_TAG('v','m','t','x') |
| |
| |
| HB_INTERNAL bool |
| _glyf_get_leading_bearing_with_var_unscaled (hb_font_t *font, hb_codepoint_t glyph, bool is_vertical, int *lsb); |
| |
| HB_INTERNAL unsigned |
| _glyf_get_advance_with_var_unscaled (hb_font_t *font, hb_codepoint_t glyph, bool is_vertical); |
| |
| |
| namespace OT { |
| |
| |
| struct LongMetric |
| { |
| UFWORD advance; /* Advance width/height. */ |
| FWORD sb; /* Leading (left/top) side bearing. */ |
| public: |
| DEFINE_SIZE_STATIC (4); |
| }; |
| |
| |
| template <typename T/*Data table type*/, typename H/*Header table type*/, typename V/*Var table type*/> |
| struct hmtxvmtx |
| { |
| bool sanitize (hb_sanitize_context_t *c HB_UNUSED) const |
| { |
| TRACE_SANITIZE (this); |
| /* We don't check for anything specific here. The users of the |
| * struct do all the hard work... */ |
| return_trace (true); |
| } |
| |
| |
| bool subset_update_header (hb_subset_plan_t *plan, |
| unsigned int num_hmetrics) const |
| { |
| hb_blob_t *src_blob = hb_sanitize_context_t ().reference_table<H> (plan->source, H::tableTag); |
| hb_blob_t *dest_blob = hb_blob_copy_writable_or_fail (src_blob); |
| hb_blob_destroy (src_blob); |
| |
| if (unlikely (!dest_blob)) { |
| return false; |
| } |
| |
| unsigned int length; |
| H *table = (H *) hb_blob_get_data (dest_blob, &length); |
| table->numberOfLongMetrics = num_hmetrics; |
| |
| bool result = plan->add_table (H::tableTag, dest_blob); |
| hb_blob_destroy (dest_blob); |
| |
| return result; |
| } |
| |
| template<typename Iterator, |
| hb_requires (hb_is_iterator (Iterator))> |
| void serialize (hb_serialize_context_t *c, |
| Iterator it, |
| unsigned num_long_metrics) |
| { |
| unsigned idx = 0; |
| for (auto _ : it) |
| { |
| if (idx < num_long_metrics) |
| { |
| LongMetric lm; |
| lm.advance = _.first; |
| lm.sb = _.second; |
| if (unlikely (!c->embed<LongMetric> (&lm))) return; |
| } |
| else |
| { |
| FWORD *sb = c->allocate_size<FWORD> (FWORD::static_size); |
| if (unlikely (!sb)) return; |
| *sb = _.second; |
| } |
| idx++; |
| } |
| } |
| |
| bool subset (hb_subset_context_t *c) const |
| { |
| TRACE_SUBSET (this); |
| |
| T *table_prime = c->serializer->start_embed <T> (); |
| if (unlikely (!table_prime)) return_trace (false); |
| |
| accelerator_t _mtx (c->plan->source); |
| unsigned num_long_metrics; |
| { |
| /* Determine num_long_metrics to encode. */ |
| auto& plan = c->plan; |
| num_long_metrics = plan->num_output_glyphs (); |
| hb_codepoint_t old_gid = 0; |
| unsigned int last_advance = plan->old_gid_for_new_gid (num_long_metrics - 1, &old_gid) ? _mtx.get_advance_without_var_unscaled (old_gid) : 0; |
| while (num_long_metrics > 1 && |
| last_advance == (plan->old_gid_for_new_gid (num_long_metrics - 2, &old_gid) ? _mtx.get_advance_without_var_unscaled (old_gid) : 0)) |
| { |
| num_long_metrics--; |
| } |
| } |
| |
| auto it = |
| + hb_range (c->plan->num_output_glyphs ()) |
| | hb_map ([c, &_mtx] (unsigned _) |
| { |
| hb_codepoint_t old_gid; |
| if (!c->plan->old_gid_for_new_gid (_, &old_gid)) |
| return hb_pair (0u, 0); |
| int lsb = 0; |
| (void) _mtx.get_leading_bearing_without_var_unscaled (old_gid, &lsb); |
| return hb_pair (_mtx.get_advance_without_var_unscaled (old_gid), +lsb); |
| }) |
| ; |
| |
| table_prime->serialize (c->serializer, it, num_long_metrics); |
| |
| if (unlikely (c->serializer->in_error ())) |
| return_trace (false); |
| |
| // Amend header num hmetrics |
| if (unlikely (!subset_update_header (c->plan, num_long_metrics))) |
| return_trace (false); |
| |
| return_trace (true); |
| } |
| |
| struct accelerator_t |
| { |
| friend struct hmtxvmtx; |
| |
| accelerator_t (hb_face_t *face) |
| { |
| table = hb_sanitize_context_t ().reference_table<hmtxvmtx> (face, T::tableTag); |
| var_table = hb_sanitize_context_t ().reference_table<V> (face, T::variationsTag); |
| |
| default_advance = T::is_horizontal ? hb_face_get_upem (face) / 2 : hb_face_get_upem (face); |
| |
| /* Populate count variables and sort them out as we go */ |
| |
| unsigned int len = table.get_length (); |
| if (len & 1) |
| len--; |
| |
| num_long_metrics = T::is_horizontal ? |
| face->table.hhea->numberOfLongMetrics : |
| #ifndef HB_NO_VERTICAL |
| face->table.vhea->numberOfLongMetrics |
| #else |
| 0 |
| #endif |
| ; |
| if (unlikely (num_long_metrics * 4 > len)) |
| num_long_metrics = len / 4; |
| len -= num_long_metrics * 4; |
| |
| num_bearings = face->table.maxp->get_num_glyphs (); |
| |
| if (unlikely (num_bearings < num_long_metrics)) |
| num_bearings = num_long_metrics; |
| if (unlikely ((num_bearings - num_long_metrics) * 2 > len)) |
| num_bearings = num_long_metrics + len / 2; |
| len -= (num_bearings - num_long_metrics) * 2; |
| |
| /* We MUST set num_bearings to zero if num_long_metrics is zero. |
| * Our get_advance() depends on that. */ |
| if (unlikely (!num_long_metrics)) |
| num_bearings = num_long_metrics = 0; |
| |
| num_advances = num_bearings + len / 2; |
| num_glyphs = face->get_num_glyphs (); |
| if (num_glyphs < num_advances) |
| num_glyphs = num_advances; |
| } |
| ~accelerator_t () |
| { |
| table.destroy (); |
| var_table.destroy (); |
| } |
| |
| bool has_data () const { return (bool) num_bearings; } |
| |
| bool get_leading_bearing_without_var_unscaled (hb_codepoint_t glyph, |
| int *lsb) const |
| { |
| if (glyph < num_long_metrics) |
| { |
| *lsb = table->longMetricZ[glyph].sb; |
| return true; |
| } |
| |
| if (unlikely (glyph >= num_bearings)) |
| return false; |
| |
| const FWORD *bearings = (const FWORD *) &table->longMetricZ[num_long_metrics]; |
| *lsb = bearings[glyph - num_long_metrics]; |
| return true; |
| } |
| |
| bool get_leading_bearing_with_var_unscaled (hb_font_t *font, |
| hb_codepoint_t glyph, |
| int *lsb) const |
| { |
| if (!font->num_coords) |
| return get_leading_bearing_without_var_unscaled (glyph, lsb); |
| |
| #ifndef HB_NO_VAR |
| float delta; |
| if (var_table->get_lsb_delta_unscaled (glyph, font->coords, font->num_coords, &delta) && |
| get_leading_bearing_without_var_unscaled (glyph, lsb)) |
| { |
| *lsb += roundf (delta); |
| return true; |
| } |
| |
| return _glyf_get_leading_bearing_with_var_unscaled (font, glyph, T::tableTag == HB_OT_TAG_vmtx, lsb); |
| #else |
| return false; |
| #endif |
| } |
| |
| unsigned int get_advance_without_var_unscaled (hb_codepoint_t glyph) const |
| { |
| /* OpenType case. */ |
| if (glyph < num_bearings) |
| return table->longMetricZ[hb_min (glyph, (uint32_t) num_long_metrics - 1)].advance; |
| |
| /* If num_advances is zero, it means we don't have the metrics table |
| * for this direction: return default advance. Otherwise, there's a |
| * well-defined answer. */ |
| if (unlikely (!num_advances)) |
| return default_advance; |
| |
| #ifdef HB_NO_BORING_EXPANSION |
| return 0; |
| #endif |
| |
| if (unlikely (glyph >= num_glyphs)) |
| return 0; |
| |
| /* num_bearings <= glyph < num_glyphs; |
| * num_bearings <= num_advances */ |
| |
| /* TODO Optimize */ |
| |
| if (num_bearings == num_advances) |
| return get_advance_without_var_unscaled (num_bearings - 1); |
| |
| const FWORD *bearings = (const FWORD *) &table->longMetricZ[num_long_metrics]; |
| const UFWORD *advances = (const UFWORD *) &bearings[num_bearings - num_long_metrics]; |
| |
| return advances[hb_min (glyph - num_bearings, num_advances - num_bearings - 1)]; |
| } |
| |
| unsigned get_advance_with_var_unscaled (hb_codepoint_t glyph, |
| hb_font_t *font, |
| VariationStore::cache_t *store_cache = nullptr) const |
| { |
| unsigned int advance = get_advance_without_var_unscaled (glyph); |
| |
| #ifndef HB_NO_VAR |
| if (unlikely (glyph >= num_bearings) || !font->num_coords) |
| return advance; |
| |
| if (var_table.get_length ()) |
| return advance + roundf (var_table->get_advance_delta_unscaled (glyph, |
| font->coords, font->num_coords, |
| store_cache)); // TODO Optimize?! |
| |
| return _glyf_get_advance_with_var_unscaled (font, glyph, T::tableTag == HB_OT_TAG_vmtx); |
| #else |
| return advance; |
| #endif |
| } |
| |
| protected: |
| // 0 <= num_long_metrics <= num_bearings <= num_advances <= num_glyphs |
| unsigned num_long_metrics; |
| unsigned num_bearings; |
| unsigned num_advances; |
| unsigned num_glyphs; |
| |
| unsigned int default_advance; |
| |
| public: |
| hb_blob_ptr_t<hmtxvmtx> table; |
| hb_blob_ptr_t<V> var_table; |
| }; |
| |
| protected: |
| UnsizedArrayOf<LongMetric> |
| longMetricZ; /* Paired advance width and leading |
| * bearing values for each glyph. The |
| * value numOfHMetrics comes from |
| * the 'hhea' table. If the font is |
| * monospaced, only one entry need |
| * be in the array, but that entry is |
| * required. The last entry applies to |
| * all subsequent glyphs. */ |
| /*UnsizedArrayOf<FWORD> leadingBearingX;*/ |
| /* Here the advance is assumed |
| * to be the same as the advance |
| * for the last entry above. The |
| * number of entries in this array is |
| * derived from numGlyphs (from 'maxp' |
| * table) minus numberOfLongMetrics. |
| * This generally is used with a run |
| * of monospaced glyphs (e.g., Kanji |
| * fonts or Courier fonts). Only one |
| * run is allowed and it must be at |
| * the end. This allows a monospaced |
| * font to vary the side bearing |
| * values for each glyph. */ |
| /*UnsizedArrayOf<UFWORD>advancesX;*/ |
| /* TODO Document. */ |
| public: |
| DEFINE_SIZE_ARRAY (0, longMetricZ); |
| }; |
| |
| struct hmtx : hmtxvmtx<hmtx, hhea, HVAR> { |
| static constexpr hb_tag_t tableTag = HB_OT_TAG_hmtx; |
| static constexpr hb_tag_t variationsTag = HB_OT_TAG_HVAR; |
| static constexpr bool is_horizontal = true; |
| }; |
| struct vmtx : hmtxvmtx<vmtx, vhea, VVAR> { |
| static constexpr hb_tag_t tableTag = HB_OT_TAG_vmtx; |
| static constexpr hb_tag_t variationsTag = HB_OT_TAG_VVAR; |
| static constexpr bool is_horizontal = false; |
| }; |
| |
| struct hmtx_accelerator_t : hmtx::accelerator_t { |
| hmtx_accelerator_t (hb_face_t *face) : hmtx::accelerator_t (face) {} |
| }; |
| struct vmtx_accelerator_t : vmtx::accelerator_t { |
| vmtx_accelerator_t (hb_face_t *face) : vmtx::accelerator_t (face) {} |
| }; |
| |
| } /* namespace OT */ |
| |
| |
| #endif /* HB_OT_HMTX_TABLE_HH */ |