| /* |
| * Copyright © 2018 Ebrahim Byagowi |
| * Copyright © 2018 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_AAT_LAYOUT_KERX_TABLE_HH |
| #define HB_AAT_LAYOUT_KERX_TABLE_HH |
| |
| #include "hb-kern.hh" |
| #include "hb-aat-layout-ankr-table.hh" |
| |
| /* |
| * kerx -- Extended Kerning |
| * https://developer.apple.com/fonts/TrueType-Reference-Manual/RM06/Chap6kerx.html |
| */ |
| #define HB_AAT_TAG_kerx HB_TAG('k','e','r','x') |
| |
| |
| namespace AAT { |
| |
| using namespace OT; |
| |
| |
| static inline int |
| kerxTupleKern (int value, |
| unsigned int tupleCount, |
| const void *base, |
| hb_aat_apply_context_t *c) |
| { |
| if (likely (!tupleCount || !c)) return value; |
| |
| unsigned int offset = value; |
| const FWORD *pv = &StructAtOffset<FWORD> (base, offset); |
| if (unlikely (!c->sanitizer.check_array (pv, tupleCount))) return 0; |
| return *pv; |
| } |
| |
| |
| struct hb_glyph_pair_t |
| { |
| hb_codepoint_t left; |
| hb_codepoint_t right; |
| }; |
| |
| struct KernPair |
| { |
| int get_kerning () const { return value; } |
| |
| int cmp (const hb_glyph_pair_t &o) const |
| { |
| int ret = left.cmp (o.left); |
| if (ret) return ret; |
| return right.cmp (o.right); |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (c->check_struct (this)); |
| } |
| |
| protected: |
| HBGlyphID16 left; |
| HBGlyphID16 right; |
| FWORD value; |
| public: |
| DEFINE_SIZE_STATIC (6); |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KerxSubTableFormat0 |
| { |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right, |
| hb_aat_apply_context_t *c = nullptr) const |
| { |
| hb_glyph_pair_t pair = {left, right}; |
| int v = pairs.bsearch (pair).get_kerning (); |
| return kerxTupleKern (v, header.tuple_count (), this, c); |
| } |
| |
| bool apply (hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| if (!c->plan->requested_kerning) |
| return false; |
| |
| if (header.coverage & header.Backwards) |
| return false; |
| |
| accelerator_t accel (*this, c); |
| hb_kern_machine_t<accelerator_t> machine (accel, header.coverage & header.CrossStream); |
| machine.kern (c->font, c->buffer, c->plan->kern_mask); |
| |
| return_trace (true); |
| } |
| |
| struct accelerator_t |
| { |
| const KerxSubTableFormat0 &table; |
| hb_aat_apply_context_t *c; |
| |
| accelerator_t (const KerxSubTableFormat0 &table_, |
| hb_aat_apply_context_t *c_) : |
| table (table_), c (c_) {} |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { return table.get_kerning (left, right, c); } |
| }; |
| |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (likely (pairs.sanitize (c))); |
| } |
| |
| protected: |
| KernSubTableHeader header; |
| BinSearchArrayOf<KernPair, typename KernSubTableHeader::Types::HBUINT> |
| pairs; /* Sorted kern records. */ |
| public: |
| DEFINE_SIZE_ARRAY (KernSubTableHeader::static_size + 16, pairs); |
| }; |
| |
| |
| template <bool extended> |
| struct Format1Entry; |
| |
| template <> |
| struct Format1Entry<true> |
| { |
| enum Flags |
| { |
| Push = 0x8000, /* If set, push this glyph on the kerning stack. */ |
| DontAdvance = 0x4000, /* If set, don't advance to the next glyph |
| * before going to the new state. */ |
| Reset = 0x2000, /* If set, reset the kerning data (clear the stack) */ |
| Reserved = 0x1FFF, /* Not used; set to 0. */ |
| }; |
| |
| struct EntryData |
| { |
| HBUINT16 kernActionIndex;/* Index into the kerning value array. If |
| * this index is 0xFFFF, then no kerning |
| * is to be performed. */ |
| public: |
| DEFINE_SIZE_STATIC (2); |
| }; |
| |
| static bool performAction (const Entry<EntryData> &entry) |
| { return entry.data.kernActionIndex != 0xFFFF; } |
| |
| static unsigned int kernActionIndex (const Entry<EntryData> &entry) |
| { return entry.data.kernActionIndex; } |
| }; |
| template <> |
| struct Format1Entry<false> |
| { |
| enum Flags |
| { |
| Push = 0x8000, /* If set, push this glyph on the kerning stack. */ |
| DontAdvance = 0x4000, /* If set, don't advance to the next glyph |
| * before going to the new state. */ |
| Offset = 0x3FFF, /* Byte offset from beginning of subtable to the |
| * value table for the glyphs on the kerning stack. */ |
| |
| Reset = 0x0000, /* Not supported? */ |
| }; |
| |
| typedef void EntryData; |
| |
| static bool performAction (const Entry<EntryData> &entry) |
| { return entry.flags & Offset; } |
| |
| static unsigned int kernActionIndex (const Entry<EntryData> &entry) |
| { return entry.flags & Offset; } |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KerxSubTableFormat1 |
| { |
| typedef typename KernSubTableHeader::Types Types; |
| typedef typename Types::HBUINT HBUINT; |
| |
| typedef Format1Entry<Types::extended> Format1EntryT; |
| typedef typename Format1EntryT::EntryData EntryData; |
| |
| struct driver_context_t |
| { |
| static constexpr bool in_place = true; |
| enum |
| { |
| DontAdvance = Format1EntryT::DontAdvance, |
| }; |
| |
| driver_context_t (const KerxSubTableFormat1 *table_, |
| hb_aat_apply_context_t *c_) : |
| c (c_), |
| table (table_), |
| /* Apparently the offset kernAction is from the beginning of the state-machine, |
| * similar to offsets in morx table, NOT from beginning of this table, like |
| * other subtables in kerx. Discovered via testing. */ |
| kernAction (&table->machine + table->kernAction), |
| depth (0), |
| crossStream (table->header.coverage & table->header.CrossStream) {} |
| |
| bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED, |
| const Entry<EntryData> &entry) |
| { return Format1EntryT::performAction (entry); } |
| void transition (StateTableDriver<Types, EntryData> *driver, |
| const Entry<EntryData> &entry) |
| { |
| hb_buffer_t *buffer = driver->buffer; |
| unsigned int flags = entry.flags; |
| |
| if (flags & Format1EntryT::Reset) |
| depth = 0; |
| |
| if (flags & Format1EntryT::Push) |
| { |
| if (likely (depth < ARRAY_LENGTH (stack))) |
| stack[depth++] = buffer->idx; |
| else |
| depth = 0; /* Probably not what CoreText does, but better? */ |
| } |
| |
| if (Format1EntryT::performAction (entry) && depth) |
| { |
| unsigned int tuple_count = hb_max (1u, table->header.tuple_count ()); |
| |
| unsigned int kern_idx = Format1EntryT::kernActionIndex (entry); |
| kern_idx = Types::byteOffsetToIndex (kern_idx, &table->machine, kernAction.arrayZ); |
| const FWORD *actions = &kernAction[kern_idx]; |
| if (!c->sanitizer.check_array (actions, depth, tuple_count)) |
| { |
| depth = 0; |
| return; |
| } |
| |
| hb_mask_t kern_mask = c->plan->kern_mask; |
| |
| /* From Apple 'kern' spec: |
| * "Each pops one glyph from the kerning stack and applies the kerning value to it. |
| * The end of the list is marked by an odd value... */ |
| bool last = false; |
| while (!last && depth) |
| { |
| unsigned int idx = stack[--depth]; |
| int v = *actions; |
| actions += tuple_count; |
| if (idx >= buffer->len) continue; |
| |
| /* "The end of the list is marked by an odd value..." */ |
| last = v & 1; |
| v &= ~1; |
| |
| hb_glyph_position_t &o = buffer->pos[idx]; |
| |
| if (HB_DIRECTION_IS_HORIZONTAL (buffer->props.direction)) |
| { |
| if (crossStream) |
| { |
| /* The following flag is undocumented in the spec, but described |
| * in the 'kern' table example. */ |
| if (v == -0x8000) |
| { |
| o.attach_type() = OT::Layout::GPOS_impl::ATTACH_TYPE_NONE; |
| o.attach_chain() = 0; |
| o.y_offset = 0; |
| } |
| else if (o.attach_type()) |
| { |
| o.y_offset += c->font->em_scale_y (v); |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; |
| } |
| } |
| else if (buffer->info[idx].mask & kern_mask) |
| { |
| o.x_advance += c->font->em_scale_x (v); |
| o.x_offset += c->font->em_scale_x (v); |
| } |
| } |
| else |
| { |
| if (crossStream) |
| { |
| /* CoreText doesn't do crossStream kerning in vertical. We do. */ |
| if (v == -0x8000) |
| { |
| o.attach_type() = OT::Layout::GPOS_impl::ATTACH_TYPE_NONE; |
| o.attach_chain() = 0; |
| o.x_offset = 0; |
| } |
| else if (o.attach_type()) |
| { |
| o.x_offset += c->font->em_scale_x (v); |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; |
| } |
| } |
| else if (buffer->info[idx].mask & kern_mask) |
| { |
| o.y_advance += c->font->em_scale_y (v); |
| o.y_offset += c->font->em_scale_y (v); |
| } |
| } |
| } |
| } |
| } |
| |
| private: |
| hb_aat_apply_context_t *c; |
| const KerxSubTableFormat1 *table; |
| const UnsizedArrayOf<FWORD> &kernAction; |
| unsigned int stack[8]; |
| unsigned int depth; |
| bool crossStream; |
| }; |
| |
| bool apply (hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| if (!c->plan->requested_kerning && |
| !(header.coverage & header.CrossStream)) |
| return false; |
| |
| driver_context_t dc (this, c); |
| |
| StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->font->face); |
| driver.drive (&dc); |
| |
| return_trace (true); |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| /* The rest of array sanitizations are done at run-time. */ |
| return_trace (likely (c->check_struct (this) && |
| machine.sanitize (c))); |
| } |
| |
| protected: |
| KernSubTableHeader header; |
| StateTable<Types, EntryData> machine; |
| NNOffsetTo<UnsizedArrayOf<FWORD>, HBUINT> kernAction; |
| public: |
| DEFINE_SIZE_STATIC (KernSubTableHeader::static_size + 5 * sizeof (HBUINT)); |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KerxSubTableFormat2 |
| { |
| typedef typename KernSubTableHeader::Types Types; |
| typedef typename Types::HBUINT HBUINT; |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right, |
| hb_aat_apply_context_t *c) const |
| { |
| unsigned int num_glyphs = c->sanitizer.get_num_glyphs (); |
| unsigned int l = (this+leftClassTable).get_class (left, num_glyphs, 0); |
| unsigned int r = (this+rightClassTable).get_class (right, num_glyphs, 0); |
| |
| const UnsizedArrayOf<FWORD> &arrayZ = this+array; |
| unsigned int kern_idx = l + r; |
| kern_idx = Types::offsetToIndex (kern_idx, this, arrayZ.arrayZ); |
| const FWORD *v = &arrayZ[kern_idx]; |
| if (unlikely (!v->sanitize (&c->sanitizer))) return 0; |
| |
| return kerxTupleKern (*v, header.tuple_count (), this, c); |
| } |
| |
| bool apply (hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| if (!c->plan->requested_kerning) |
| return false; |
| |
| if (header.coverage & header.Backwards) |
| return false; |
| |
| accelerator_t accel (*this, c); |
| hb_kern_machine_t<accelerator_t> machine (accel, header.coverage & header.CrossStream); |
| machine.kern (c->font, c->buffer, c->plan->kern_mask); |
| |
| return_trace (true); |
| } |
| |
| struct accelerator_t |
| { |
| const KerxSubTableFormat2 &table; |
| hb_aat_apply_context_t *c; |
| |
| accelerator_t (const KerxSubTableFormat2 &table_, |
| hb_aat_apply_context_t *c_) : |
| table (table_), c (c_) {} |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { return table.get_kerning (left, right, c); } |
| }; |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (likely (c->check_struct (this) && |
| leftClassTable.sanitize (c, this) && |
| rightClassTable.sanitize (c, this) && |
| c->check_range (this, array))); |
| } |
| |
| protected: |
| KernSubTableHeader header; |
| HBUINT rowWidth; /* The width, in bytes, of a row in the table. */ |
| NNOffsetTo<typename Types::ClassTypeWide, HBUINT> |
| leftClassTable; /* Offset from beginning of this subtable to |
| * left-hand class table. */ |
| NNOffsetTo<typename Types::ClassTypeWide, HBUINT> |
| rightClassTable;/* Offset from beginning of this subtable to |
| * right-hand class table. */ |
| NNOffsetTo<UnsizedArrayOf<FWORD>, HBUINT> |
| array; /* Offset from beginning of this subtable to |
| * the start of the kerning array. */ |
| public: |
| DEFINE_SIZE_STATIC (KernSubTableHeader::static_size + 4 * sizeof (HBUINT)); |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KerxSubTableFormat4 |
| { |
| typedef ExtendedTypes Types; |
| |
| struct EntryData |
| { |
| HBUINT16 ankrActionIndex;/* Either 0xFFFF (for no action) or the index of |
| * the action to perform. */ |
| public: |
| DEFINE_SIZE_STATIC (2); |
| }; |
| |
| struct driver_context_t |
| { |
| static constexpr bool in_place = true; |
| enum Flags |
| { |
| Mark = 0x8000, /* If set, remember this glyph as the marked glyph. */ |
| DontAdvance = 0x4000, /* If set, don't advance to the next glyph before |
| * going to the new state. */ |
| Reserved = 0x3FFF, /* Not used; set to 0. */ |
| }; |
| |
| enum SubTableFlags |
| { |
| ActionType = 0xC0000000, /* A two-bit field containing the action type. */ |
| Unused = 0x3F000000, /* Unused - must be zero. */ |
| Offset = 0x00FFFFFF, /* Masks the offset in bytes from the beginning |
| * of the subtable to the beginning of the control |
| * point table. */ |
| }; |
| |
| driver_context_t (const KerxSubTableFormat4 *table, |
| hb_aat_apply_context_t *c_) : |
| c (c_), |
| action_type ((table->flags & ActionType) >> 30), |
| ankrData ((HBUINT16 *) ((const char *) &table->machine + (table->flags & Offset))), |
| mark_set (false), |
| mark (0) {} |
| |
| bool is_actionable (StateTableDriver<Types, EntryData> *driver HB_UNUSED, |
| const Entry<EntryData> &entry) |
| { return entry.data.ankrActionIndex != 0xFFFF; } |
| void transition (StateTableDriver<Types, EntryData> *driver, |
| const Entry<EntryData> &entry) |
| { |
| hb_buffer_t *buffer = driver->buffer; |
| |
| if (mark_set && entry.data.ankrActionIndex != 0xFFFF && buffer->idx < buffer->len) |
| { |
| hb_glyph_position_t &o = buffer->cur_pos(); |
| switch (action_type) |
| { |
| case 0: /* Control Point Actions.*/ |
| { |
| /* Indexed into glyph outline. */ |
| /* Each action (record in ankrData) contains two 16-bit fields, so we must |
| double the ankrActionIndex to get the correct offset here. */ |
| const HBUINT16 *data = &ankrData[entry.data.ankrActionIndex * 2]; |
| if (!c->sanitizer.check_array (data, 2)) return; |
| unsigned int markControlPoint = *data++; |
| unsigned int currControlPoint = *data++; |
| hb_position_t markX = 0; |
| hb_position_t markY = 0; |
| hb_position_t currX = 0; |
| hb_position_t currY = 0; |
| if (!c->font->get_glyph_contour_point_for_origin (c->buffer->info[mark].codepoint, |
| markControlPoint, |
| HB_DIRECTION_LTR /*XXX*/, |
| &markX, &markY) || |
| !c->font->get_glyph_contour_point_for_origin (c->buffer->cur ().codepoint, |
| currControlPoint, |
| HB_DIRECTION_LTR /*XXX*/, |
| &currX, &currY)) |
| return; |
| |
| o.x_offset = markX - currX; |
| o.y_offset = markY - currY; |
| } |
| break; |
| |
| case 1: /* Anchor Point Actions. */ |
| { |
| /* Indexed into 'ankr' table. */ |
| /* Each action (record in ankrData) contains two 16-bit fields, so we must |
| double the ankrActionIndex to get the correct offset here. */ |
| const HBUINT16 *data = &ankrData[entry.data.ankrActionIndex * 2]; |
| if (!c->sanitizer.check_array (data, 2)) return; |
| unsigned int markAnchorPoint = *data++; |
| unsigned int currAnchorPoint = *data++; |
| const Anchor &markAnchor = c->ankr_table->get_anchor (c->buffer->info[mark].codepoint, |
| markAnchorPoint, |
| c->sanitizer.get_num_glyphs ()); |
| const Anchor &currAnchor = c->ankr_table->get_anchor (c->buffer->cur ().codepoint, |
| currAnchorPoint, |
| c->sanitizer.get_num_glyphs ()); |
| |
| o.x_offset = c->font->em_scale_x (markAnchor.xCoordinate) - c->font->em_scale_x (currAnchor.xCoordinate); |
| o.y_offset = c->font->em_scale_y (markAnchor.yCoordinate) - c->font->em_scale_y (currAnchor.yCoordinate); |
| } |
| break; |
| |
| case 2: /* Control Point Coordinate Actions. */ |
| { |
| /* Each action contains four 16-bit fields, so we multiply the ankrActionIndex |
| by 4 to get the correct offset for the given action. */ |
| const FWORD *data = (const FWORD *) &ankrData[entry.data.ankrActionIndex * 4]; |
| if (!c->sanitizer.check_array (data, 4)) return; |
| int markX = *data++; |
| int markY = *data++; |
| int currX = *data++; |
| int currY = *data++; |
| |
| o.x_offset = c->font->em_scale_x (markX) - c->font->em_scale_x (currX); |
| o.y_offset = c->font->em_scale_y (markY) - c->font->em_scale_y (currY); |
| } |
| break; |
| } |
| o.attach_type() = OT::Layout::GPOS_impl::ATTACH_TYPE_MARK; |
| o.attach_chain() = (int) mark - (int) buffer->idx; |
| buffer->scratch_flags |= HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT; |
| } |
| |
| if (entry.flags & Mark) |
| { |
| mark_set = true; |
| mark = buffer->idx; |
| } |
| } |
| |
| private: |
| hb_aat_apply_context_t *c; |
| unsigned int action_type; |
| const HBUINT16 *ankrData; |
| bool mark_set; |
| unsigned int mark; |
| }; |
| |
| bool apply (hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| driver_context_t dc (this, c); |
| |
| StateTableDriver<Types, EntryData> driver (machine, c->buffer, c->font->face); |
| driver.drive (&dc); |
| |
| return_trace (true); |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| /* The rest of array sanitizations are done at run-time. */ |
| return_trace (likely (c->check_struct (this) && |
| machine.sanitize (c))); |
| } |
| |
| protected: |
| KernSubTableHeader header; |
| StateTable<Types, EntryData> machine; |
| HBUINT32 flags; |
| public: |
| DEFINE_SIZE_STATIC (KernSubTableHeader::static_size + 20); |
| }; |
| |
| template <typename KernSubTableHeader> |
| struct KerxSubTableFormat6 |
| { |
| enum Flags |
| { |
| ValuesAreLong = 0x00000001, |
| }; |
| |
| bool is_long () const { return flags & ValuesAreLong; } |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right, |
| hb_aat_apply_context_t *c) const |
| { |
| unsigned int num_glyphs = c->sanitizer.get_num_glyphs (); |
| if (is_long ()) |
| { |
| const typename U::Long &t = u.l; |
| unsigned int l = (this+t.rowIndexTable).get_value_or_null (left, num_glyphs); |
| unsigned int r = (this+t.columnIndexTable).get_value_or_null (right, num_glyphs); |
| unsigned int offset = l + r; |
| if (unlikely (offset < l)) return 0; /* Addition overflow. */ |
| if (unlikely (hb_unsigned_mul_overflows (offset, sizeof (FWORD32)))) return 0; |
| const FWORD32 *v = &StructAtOffset<FWORD32> (&(this+t.array), offset * sizeof (FWORD32)); |
| if (unlikely (!v->sanitize (&c->sanitizer))) return 0; |
| return kerxTupleKern (*v, header.tuple_count (), &(this+vector), c); |
| } |
| else |
| { |
| const typename U::Short &t = u.s; |
| unsigned int l = (this+t.rowIndexTable).get_value_or_null (left, num_glyphs); |
| unsigned int r = (this+t.columnIndexTable).get_value_or_null (right, num_glyphs); |
| unsigned int offset = l + r; |
| const FWORD *v = &StructAtOffset<FWORD> (&(this+t.array), offset * sizeof (FWORD)); |
| if (unlikely (!v->sanitize (&c->sanitizer))) return 0; |
| return kerxTupleKern (*v, header.tuple_count (), &(this+vector), c); |
| } |
| } |
| |
| bool apply (hb_aat_apply_context_t *c) const |
| { |
| TRACE_APPLY (this); |
| |
| if (!c->plan->requested_kerning) |
| return false; |
| |
| if (header.coverage & header.Backwards) |
| return false; |
| |
| accelerator_t accel (*this, c); |
| hb_kern_machine_t<accelerator_t> machine (accel, 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 (likely (c->check_struct (this) && |
| (is_long () ? |
| ( |
| u.l.rowIndexTable.sanitize (c, this) && |
| u.l.columnIndexTable.sanitize (c, this) && |
| c->check_range (this, u.l.array) |
| ) : ( |
| u.s.rowIndexTable.sanitize (c, this) && |
| u.s.columnIndexTable.sanitize (c, this) && |
| c->check_range (this, u.s.array) |
| )) && |
| (header.tuple_count () == 0 || |
| c->check_range (this, vector)))); |
| } |
| |
| struct accelerator_t |
| { |
| const KerxSubTableFormat6 &table; |
| hb_aat_apply_context_t *c; |
| |
| accelerator_t (const KerxSubTableFormat6 &table_, |
| hb_aat_apply_context_t *c_) : |
| table (table_), c (c_) {} |
| |
| int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { return table.get_kerning (left, right, c); } |
| }; |
| |
| protected: |
| KernSubTableHeader header; |
| HBUINT32 flags; |
| HBUINT16 rowCount; |
| HBUINT16 columnCount; |
| union U |
| { |
| struct Long |
| { |
| NNOffset32To<Lookup<HBUINT32>> rowIndexTable; |
| NNOffset32To<Lookup<HBUINT32>> columnIndexTable; |
| NNOffset32To<UnsizedArrayOf<FWORD32>> array; |
| } l; |
| struct Short |
| { |
| NNOffset32To<Lookup<HBUINT16>> rowIndexTable; |
| NNOffset32To<Lookup<HBUINT16>> columnIndexTable; |
| NNOffset32To<UnsizedArrayOf<FWORD>> array; |
| } s; |
| } u; |
| NNOffset32To<UnsizedArrayOf<FWORD>> vector; |
| public: |
| DEFINE_SIZE_STATIC (KernSubTableHeader::static_size + 24); |
| }; |
| |
| |
| struct KerxSubTableHeader |
| { |
| typedef ExtendedTypes Types; |
| |
| unsigned tuple_count () const { return tupleCount; } |
| bool is_horizontal () const { return !(coverage & Vertical); } |
| |
| enum Coverage |
| { |
| Vertical = 0x80000000u, /* Set if table has vertical kerning values. */ |
| CrossStream = 0x40000000u, /* Set if table has cross-stream kerning values. */ |
| Variation = 0x20000000u, /* Set if table has variation kerning values. */ |
| Backwards = 0x10000000u, /* If clear, process the glyphs forwards, that |
| * is, from first to last in the glyph stream. |
| * If we, process them from last to first. |
| * This flag only applies to state-table based |
| * 'kerx' subtables (types 1 and 4). */ |
| Reserved = 0x0FFFFF00u, /* Reserved, set to zero. */ |
| SubtableType= 0x000000FFu, /* Subtable type. */ |
| }; |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| return_trace (c->check_struct (this)); |
| } |
| |
| public: |
| HBUINT32 length; |
| HBUINT32 coverage; |
| HBUINT32 tupleCount; |
| public: |
| DEFINE_SIZE_STATIC (12); |
| }; |
| |
| struct KerxSubTable |
| { |
| friend struct kerx; |
| |
| unsigned int get_size () const { return u.header.length; } |
| unsigned int get_type () const { return u.header.coverage & u.header.SubtableType; } |
| |
| 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, std::forward<Ts> (ds)...)); |
| case 1: return_trace (c->dispatch (u.format1, std::forward<Ts> (ds)...)); |
| case 2: return_trace (c->dispatch (u.format2, std::forward<Ts> (ds)...)); |
| case 4: return_trace (c->dispatch (u.format4, std::forward<Ts> (ds)...)); |
| case 6: return_trace (c->dispatch (u.format6, std::forward<Ts> (ds)...)); |
| default: return_trace (c->default_return_value ()); |
| } |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| if (!u.header.sanitize (c) || |
| u.header.length <= u.header.static_size || |
| !c->check_range (this, u.header.length)) |
| return_trace (false); |
| |
| return_trace (dispatch (c)); |
| } |
| |
| public: |
| union { |
| KerxSubTableHeader header; |
| KerxSubTableFormat0<KerxSubTableHeader> format0; |
| KerxSubTableFormat1<KerxSubTableHeader> format1; |
| KerxSubTableFormat2<KerxSubTableHeader> format2; |
| KerxSubTableFormat4<KerxSubTableHeader> format4; |
| KerxSubTableFormat6<KerxSubTableHeader> format6; |
| } u; |
| public: |
| DEFINE_SIZE_MIN (12); |
| }; |
| |
| |
| /* |
| * The 'kerx' Table |
| */ |
| |
| template <typename T> |
| struct KerxTable |
| { |
| /* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */ |
| const T* thiz () const { return static_cast<const T *> (this); } |
| |
| bool has_state_machine () const |
| { |
| typedef typename T::SubTable SubTable; |
| |
| const SubTable *st = &thiz()->firstSubTable; |
| unsigned int count = thiz()->tableCount; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| if (st->get_type () == 1) |
| return true; |
| st = &StructAfter<SubTable> (*st); |
| } |
| return false; |
| } |
| |
| bool has_cross_stream () const |
| { |
| typedef typename T::SubTable SubTable; |
| |
| const SubTable *st = &thiz()->firstSubTable; |
| unsigned int count = thiz()->tableCount; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| if (st->u.header.coverage & st->u.header.CrossStream) |
| return true; |
| st = &StructAfter<SubTable> (*st); |
| } |
| return false; |
| } |
| |
| int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const |
| { |
| typedef typename T::SubTable SubTable; |
| |
| int v = 0; |
| const SubTable *st = &thiz()->firstSubTable; |
| unsigned int count = thiz()->tableCount; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| if ((st->u.header.coverage & (st->u.header.Variation | st->u.header.CrossStream)) || |
| !st->u.header.is_horizontal ()) |
| continue; |
| v += st->get_kerning (left, right); |
| st = &StructAfter<SubTable> (*st); |
| } |
| return v; |
| } |
| |
| bool apply (AAT::hb_aat_apply_context_t *c) const |
| { |
| typedef typename T::SubTable SubTable; |
| |
| bool ret = false; |
| bool seenCrossStream = false; |
| c->set_lookup_index (0); |
| const SubTable *st = &thiz()->firstSubTable; |
| unsigned int count = thiz()->tableCount; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| bool reverse; |
| |
| if (!T::Types::extended && (st->u.header.coverage & st->u.header.Variation)) |
| goto skip; |
| |
| if (HB_DIRECTION_IS_HORIZONTAL (c->buffer->props.direction) != st->u.header.is_horizontal ()) |
| goto skip; |
| |
| reverse = bool (st->u.header.coverage & st->u.header.Backwards) != |
| HB_DIRECTION_IS_BACKWARD (c->buffer->props.direction); |
| |
| if (!c->buffer->message (c->font, "start subtable %d", c->lookup_index)) |
| goto skip; |
| |
| if (!seenCrossStream && |
| (st->u.header.coverage & st->u.header.CrossStream)) |
| { |
| /* Attach all glyphs into a chain. */ |
| seenCrossStream = true; |
| hb_glyph_position_t *pos = c->buffer->pos; |
| unsigned int count = c->buffer->len; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| pos[i].attach_type() = OT::Layout::GPOS_impl::ATTACH_TYPE_CURSIVE; |
| pos[i].attach_chain() = HB_DIRECTION_IS_FORWARD (c->buffer->props.direction) ? -1 : +1; |
| /* We intentionally don't set HB_BUFFER_SCRATCH_FLAG_HAS_GPOS_ATTACHMENT, |
| * since there needs to be a non-zero attachment for post-positioning to |
| * be needed. */ |
| } |
| } |
| |
| if (reverse) |
| c->buffer->reverse (); |
| |
| { |
| /* See comment in sanitize() for conditional here. */ |
| hb_sanitize_with_object_t with (&c->sanitizer, i < count - 1 ? st : (const SubTable *) nullptr); |
| ret |= st->dispatch (c); |
| } |
| |
| if (reverse) |
| c->buffer->reverse (); |
| |
| (void) c->buffer->message (c->font, "end subtable %d", c->lookup_index); |
| |
| skip: |
| st = &StructAfter<SubTable> (*st); |
| c->set_lookup_index (c->lookup_index + 1); |
| } |
| |
| return ret; |
| } |
| |
| bool sanitize (hb_sanitize_context_t *c) const |
| { |
| TRACE_SANITIZE (this); |
| if (unlikely (!thiz()->version.sanitize (c) || |
| (unsigned) thiz()->version < (unsigned) T::minVersion || |
| !thiz()->tableCount.sanitize (c))) |
| return_trace (false); |
| |
| typedef typename T::SubTable SubTable; |
| |
| const SubTable *st = &thiz()->firstSubTable; |
| unsigned int count = thiz()->tableCount; |
| for (unsigned int i = 0; i < count; i++) |
| { |
| if (unlikely (!st->u.header.sanitize (c))) |
| return_trace (false); |
| /* OpenType kern table has 2-byte subtable lengths. That's limiting. |
| * MS implementation also only supports one subtable, of format 0, |
| * anyway. Certain versions of some fonts, like Calibry, contain |
| * kern subtable that exceeds 64kb. Looks like, the subtable length |
| * is simply ignored. Which makes sense. It's only needed if you |
| * have multiple subtables. To handle such fonts, we just ignore |
| * the length for the last subtable. */ |
| hb_sanitize_with_object_t with (c, i < count - 1 ? st : (const SubTable *) nullptr); |
| |
| if (unlikely (!st->sanitize (c))) |
| return_trace (false); |
| |
| st = &StructAfter<SubTable> (*st); |
| } |
| |
| return_trace (true); |
| } |
| }; |
| |
| struct kerx : KerxTable<kerx> |
| { |
| friend struct KerxTable<kerx>; |
| |
| static constexpr hb_tag_t tableTag = HB_AAT_TAG_kerx; |
| static constexpr unsigned minVersion = 2u; |
| |
| typedef KerxSubTableHeader SubTableHeader; |
| typedef SubTableHeader::Types Types; |
| typedef KerxSubTable SubTable; |
| |
| bool has_data () const { return version; } |
| |
| protected: |
| HBUINT16 version; /* The version number of the extended kerning table |
| * (currently 2, 3, or 4). */ |
| HBUINT16 unused; /* Set to 0. */ |
| HBUINT32 tableCount; /* The number of subtables included in the extended kerning |
| * table. */ |
| SubTable firstSubTable; /* Subtables. */ |
| /*subtableGlyphCoverageArray*/ /* Only if version >= 3. We don't use. */ |
| |
| public: |
| DEFINE_SIZE_MIN (8); |
| }; |
| |
| |
| } /* namespace AAT */ |
| |
| |
| #endif /* HB_AAT_LAYOUT_KERX_TABLE_HH */ |