| /* |
| * Copyright © 2017 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 |
| */ |
| |
| #ifndef HB_OT_KERN_TABLE_HH |
| #define HB_OT_KERN_TABLE_HH |
| |
| #include "hb-aat-layout-kerx-table.hh" |
| |
| |
| /* |
| * kern -- Kerning |
| * https://docs.microsoft.com/en-us/typography/opentype/spec/kern |
| * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6kern.html |
| */ |
| #define HB_OT_TAG_kern HB_TAG('k','e','r','n') |
| |
| |
| namespace OT { |
| |
| |
| template <typename KernSubTableHeader> |
| struct KernSubTableFormat3 |
| { |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { |
| hb_array_t<const FWORD> kernValue = kernValueZ.as_array (kernValueCount); |
| hb_array_t<const HBUINT8> leftClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (kernValue).as_array (glyphCount); |
| hb_array_t<const HBUINT8> rightClass = StructAfter<const UnsizedArrayOf<HBUINT8>> (leftClass).as_array (glyphCount); |
| hb_array_t<const HBUINT8> kernIndex = StructAfter<const UnsizedArrayOf<HBUINT8>> (rightClass).as_array (leftClassCount * rightClassCount); |
| |
| unsigned int leftC = leftClass[left]; |
| unsigned int rightC = rightClass[right]; |
| if (unlikely (leftC >= leftClassCount || rightC >= rightClassCount)) |
| return 0; |
| unsigned int i = leftC * rightClassCount + rightC; |
| return kernValue[kernIndex[i]]; |
| } |
| |
| bool apply (AAT::hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| if (!c->plan->requested_kerning) |
| return false; |
| |
| if (header.coverage & header.Backwards) |
| return false; |
| |
| hb_kern_machine_t<KernSubTableFormat3> machine (*this, header.coverage & header.CrossStream); |
| machine.kern (c->font, c->buffer, c->plan->kern_mask); |
| |
| return_trace (true); |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (c->check_struct (this) && |
| c->check_range (kernValueZ, |
| kernValueCount * sizeof (FWORD) + |
| glyphCount * 2 + |
| leftClassCount * rightClassCount)); |
| } |
| |
| protected: |
| KernSubTableHeader |
| header; |
| HBUINT16 glyphCount; /* The number of glyphs in this font. */ |
| HBUINT8 kernValueCount; /* The number of kerning values. */ |
| HBUINT8 leftClassCount; /* The number of left-hand classes. */ |
| HBUINT8 rightClassCount;/* The number of right-hand classes. */ |
| HBUINT8 flags; /* Set to zero (reserved for future use). */ |
| UnsizedArrayOf<FWORD> |
| kernValueZ; /* The kerning values. |
| * Length kernValueCount. */ |
| #if 0 |
| UnsizedArrayOf<HBUINT8> |
| leftClass; /* The left-hand classes. |
| * Length glyphCount. */ |
| UnsizedArrayOf<HBUINT8> |
| rightClass; /* The right-hand classes. |
| * Length glyphCount. */ |
| UnsizedArrayOf<HBUINT8>kernIndex; |
| /* The indices into the kernValue array. |
| * Length leftClassCount * rightClassCount */ |
| #endif |
| public: |
| DEFINE_SIZE_ARRAY (KernSubTableHeader::static_size + 6, kernValueZ); |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KernSubTable |
| { |
| unsigned int get_size () const { return u.header.length; } |
| unsigned int get_type () const { return u.header.format; } |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { |
| switch (get_type ()) { |
| /* This method hooks up to hb_font_t's get_h_kerning. Only support Format0. */ |
| case 0: return u.format0.get_kerning (left, right); |
| default:return 0; |
| } |
| } |
| |
| template <typename context_t, typename ...Ts> |
| typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const |
| { |
| unsigned int subtable_type = get_type (); |
| TRACE_DISPATCH (this, subtable_type); |
| switch (subtable_type) { |
| case 0: return_trace (c->dispatch (u.format0)); |
| #ifndef HB_NO_AAT_SHAPE |
| case 1: return_trace (u.header.apple ? c->dispatch (u.format1, hb_forward<Ts> (ds)...) : c->default_return_value ()); |
| #endif |
| case 2: return_trace (c->dispatch (u.format2)); |
| #ifndef HB_NO_AAT_SHAPE |
| case 3: return_trace (u.header.apple ? c->dispatch (u.format3, hb_forward<Ts> (ds)...) : c->default_return_value ()); |
| #endif |
| default: return_trace (c->default_return_value ()); |
| } |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| if (unlikely (!u.header.sanitize (c) || |
| u.header.length < u.header.min_size || |
| !c->check_range (this, u.header.length))) return_trace (false); |
| |
| return_trace (dispatch (c)); |
| } |
| |
| public: |
| union { |
| KernSubTableHeader header; |
| AAT::KerxSubTableFormat0<KernSubTableHeader> format0; |
| AAT::KerxSubTableFormat1<KernSubTableHeader> format1; |
| AAT::KerxSubTableFormat2<KernSubTableHeader> format2; |
| KernSubTableFormat3<KernSubTableHeader> format3; |
| } u; |
| public: |
| DEFINE_SIZE_MIN (KernSubTableHeader::static_size); |
| }; |
| |
| |
| struct KernOTSubTableHeader |
| { |
| static constexpr bool apple = false; |
| typedef AAT::ObsoleteTypes Types; |
| |
| unsigned tuple_count () const { return 0; } |
| bool is_horizontal () const { return (coverage & Horizontal); } |
| |
| enum Coverage |
| { |
| Horizontal = 0x01u, |
| Minimum = 0x02u, |
| CrossStream = 0x04u, |
| Override = 0x08u, |
| |
| /* Not supported: */ |
| Backwards = 0x00u, |
| Variation = 0x00u, |
| }; |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (c->check_struct (this)); |
| } |
| |
| public: |
| HBUINT16 versionZ; /* Unused. */ |
| HBUINT16 length; /* Length of the subtable (including this header). */ |
| HBUINT8 format; /* Subtable format. */ |
| HBUINT8 coverage; /* Coverage bits. */ |
| public: |
| DEFINE_SIZE_STATIC (6); |
| }; |
| |
| struct KernOT : AAT::KerxTable<KernOT> |
| { |
| friend struct AAT::KerxTable<KernOT>; |
| |
| static constexpr hb_tag_t tableTag = HB_OT_TAG_kern; |
| static constexpr unsigned minVersion = 0u; |
| |
| typedef KernOTSubTableHeader SubTableHeader; |
| typedef SubTableHeader::Types Types; |
| typedef KernSubTable<SubTableHeader> SubTable; |
| |
| protected: |
| HBUINT16 version; /* Version--0x0000u */ |
| HBUINT16 tableCount; /* Number of subtables in the kerning table. */ |
| SubTable firstSubTable; /* Subtables. */ |
| public: |
| DEFINE_SIZE_MIN (4); |
| }; |
| |
| |
| struct KernAATSubTableHeader |
| { |
| static constexpr bool apple = true; |
| typedef AAT::ObsoleteTypes Types; |
| |
| unsigned tuple_count () const { return 0; } |
| bool is_horizontal () const { return !(coverage & Vertical); } |
| |
| enum Coverage |
| { |
| Vertical = 0x80u, |
| CrossStream = 0x40u, |
| Variation = 0x20u, |
| |
| /* Not supported: */ |
| Backwards = 0x00u, |
| }; |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (c->check_struct (this)); |
| } |
| |
| public: |
| HBUINT32 length; /* Length of the subtable (including this header). */ |
| HBUINT8 coverage; /* Coverage bits. */ |
| HBUINT8 format; /* Subtable format. */ |
| HBUINT16 tupleIndex; /* The tuple index (used for variations fonts). |
| * This value specifies which tuple this subtable covers. |
| * Note: We don't implement. */ |
| public: |
| DEFINE_SIZE_STATIC (8); |
| }; |
| |
| struct KernAAT : AAT::KerxTable<KernAAT> |
| { |
| friend struct AAT::KerxTable<KernAAT>; |
| |
| static constexpr hb_tag_t tableTag = HB_OT_TAG_kern; |
| static constexpr unsigned minVersion = 0x00010000u; |
| |
| typedef KernAATSubTableHeader SubTableHeader; |
| typedef SubTableHeader::Types Types; |
| typedef KernSubTable<SubTableHeader> SubTable; |
| |
| protected: |
| HBUINT32 version; /* Version--0x00010000u */ |
| HBUINT32 tableCount; /* Number of subtables in the kerning table. */ |
| SubTable firstSubTable; /* Subtables. */ |
| public: |
| DEFINE_SIZE_MIN (8); |
| }; |
| |
| struct kern |
| { |
| static constexpr hb_tag_t tableTag = HB_OT_TAG_kern; |
| |
| bool has_data () const { return u.version32; } |
| unsigned get_type () const { return u.major; } |
| |
| bool has_state_machine () const |
| { |
| switch (get_type ()) { |
| case 0: return u.ot.has_state_machine (); |
| #ifndef HB_NO_AAT_SHAPE |
| case 1: return u.aat.has_state_machine (); |
| #endif |
| default:return false; |
| } |
| } |
| |
| bool has_cross_stream () const |
| { |
| switch (get_type ()) { |
| case 0: return u.ot.has_cross_stream (); |
| #ifndef HB_NO_AAT_SHAPE |
| case 1: return u.aat.has_cross_stream (); |
| #endif |
| default:return false; |
| } |
| } |
| |
| int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { |
| switch (get_type ()) { |
| case 0: return u.ot.get_h_kerning (left, right); |
| #ifndef HB_NO_AAT_SHAPE |
| case 1: return u.aat.get_h_kerning (left, right); |
| #endif |
| default:return 0; |
| } |
| } |
| |
| bool apply (AAT::hb_aat_apply_context_t *c) const |
| { return dispatch (c); } |
| |
| template <typename context_t, typename ...Ts> |
| typename context_t::return_t dispatch (context_t *c, Ts&&... ds) const |
| { |
| unsigned int subtable_type = get_type (); |
| TRACE_DISPATCH (this, subtable_type); |
| switch (subtable_type) { |
| case 0: return_trace (c->dispatch (u.ot, hb_forward<Ts> (ds)...)); |
| #ifndef HB_NO_AAT_SHAPE |
| case 1: return_trace (c->dispatch (u.aat, hb_forward<Ts> (ds)...)); |
| #endif |
| default: return_trace (c->default_return_value ()); |
| } |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| if (!u.version32.sanitize (c)) return_trace (false); |
| return_trace (dispatch (c)); |
| } |
| |
| protected: |
| union { |
| HBUINT32 version32; |
| HBUINT16 major; |
| KernOT ot; |
| #ifndef HB_NO_AAT_SHAPE |
| KernAAT aat; |
| #endif |
| } u; |
| public: |
| DEFINE_SIZE_UNION (4, version32); |
| }; |
| |
| } /* namespace OT */ |
| |
| |
| #endif /* HB_OT_KERN_TABLE_HH */ |