src/java.desktop/share/native/libfontmanager/harfbuzz/hb-ot-kern-table.hh
changeset 48274 51772bf1fb0c
child 50352 25db2c8f3cf8
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.desktop/share/native/libfontmanager/harfbuzz/hb-ot-kern-table.hh	Thu Dec 07 11:55:06 2017 -0800
@@ -0,0 +1,389 @@
+/*
+ * 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-open-type-private.hh"
+
+namespace OT {
+
+
+/*
+ * kern -- Kerning
+ */
+
+#define HB_OT_TAG_kern HB_TAG('k','e','r','n')
+
+struct hb_glyph_pair_t
+{
+  hb_codepoint_t left;
+  hb_codepoint_t right;
+};
+
+struct KernPair
+{
+  inline int get_kerning (void) const
+  { return value; }
+
+  inline int cmp (const hb_glyph_pair_t &o) const
+  {
+    int ret = left.cmp (o.left);
+    if (ret) return ret;
+    return right.cmp (o.right);
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (this));
+  }
+
+  protected:
+  GlyphID       left;
+  GlyphID       right;
+  FWORD         value;
+  public:
+  DEFINE_SIZE_STATIC (6);
+};
+
+struct KernSubTableFormat0
+{
+  inline int get_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+  {
+    hb_glyph_pair_t pair = {left, right};
+    int i = pairs.bsearch (pair);
+    if (i == -1)
+      return 0;
+    return pairs[i].get_kerning ();
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (pairs.sanitize (c));
+  }
+
+  protected:
+  BinSearchArrayOf<KernPair> pairs;     /* Array of kerning pairs. */
+  public:
+  DEFINE_SIZE_ARRAY (8, pairs);
+};
+
+struct KernClassTable
+{
+  inline unsigned int get_class (hb_codepoint_t g) const { return classes[g - firstGlyph]; }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (firstGlyph.sanitize (c) && classes.sanitize (c));
+  }
+
+  protected:
+  USHORT                firstGlyph;     /* First glyph in class range. */
+  ArrayOf<USHORT>       classes;        /* Glyph classes. */
+  public:
+  DEFINE_SIZE_ARRAY (4, classes);
+};
+
+struct KernSubTableFormat2
+{
+  inline int get_kerning (hb_codepoint_t left, hb_codepoint_t right, const char *end) const
+  {
+    unsigned int l = (this+leftClassTable).get_class (left);
+    unsigned int r = (this+leftClassTable).get_class (left);
+    unsigned int offset = l * rowWidth + r * sizeof (FWORD);
+    const FWORD *arr = &(this+array);
+    if (unlikely ((const void *) arr < (const void *) this || (const void *) arr >= (const void *) end))
+      return 0;
+    const FWORD *v = &StructAtOffset<FWORD> (arr, offset);
+    if (unlikely ((const void *) v < (const void *) arr || (const void *) (v + 1) > (const void *) end))
+      return 0;
+    return *v;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (rowWidth.sanitize (c) &&
+                  leftClassTable.sanitize (c, this) &&
+                  rightClassTable.sanitize (c, this) &&
+                  array.sanitize (c, this));
+  }
+
+  protected:
+  USHORT        rowWidth;       /* The width, in bytes, of a row in the table. */
+  OffsetTo<KernClassTable>
+                leftClassTable; /* Offset from beginning of this subtable to
+                                 * left-hand class table. */
+  OffsetTo<KernClassTable>
+                rightClassTable;/* Offset from beginning of this subtable to
+                                 * right-hand class table. */
+  OffsetTo<FWORD>
+                array;          /* Offset from beginning of this subtable to
+                                 * the start of the kerning array. */
+  public:
+  DEFINE_SIZE_MIN (8);
+};
+
+struct KernSubTable
+{
+  inline int get_kerning (hb_codepoint_t left, hb_codepoint_t right, const char *end, unsigned int format) const
+  {
+    switch (format) {
+    case 0: return u.format0.get_kerning (left, right);
+    case 2: return u.format2.get_kerning (left, right, end);
+    default:return 0;
+    }
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c, unsigned int format) const
+  {
+    TRACE_SANITIZE (this);
+    switch (format) {
+    case 0: return_trace (u.format0.sanitize (c));
+    case 2: return_trace (u.format2.sanitize (c));
+    default:return_trace (true);
+    }
+  }
+
+  protected:
+  union {
+  KernSubTableFormat0   format0;
+  KernSubTableFormat2   format2;
+  } u;
+  public:
+  DEFINE_SIZE_MIN (0);
+};
+
+
+template <typename T>
+struct KernSubTableWrapper
+{
+  /* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
+  inline const T* thiz (void) const { return static_cast<const T *> (this); }
+
+  inline bool is_horizontal (void) const
+  { return (thiz()->coverage & T::COVERAGE_CHECK_FLAGS) == T::COVERAGE_CHECK_HORIZONTAL; }
+
+  inline bool is_override (void) const
+  { return bool (thiz()->coverage & T::COVERAGE_OVERRIDE_FLAG); }
+
+  inline int get_kerning (hb_codepoint_t left, hb_codepoint_t right, const char *end) const
+  { return thiz()->subtable.get_kerning (left, right, end, thiz()->format); }
+
+  inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right, const char *end) const
+  { return is_horizontal () ? get_kerning (left, right, end) : 0; }
+
+  inline unsigned int get_size (void) const { return thiz()->length; }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    return_trace (c->check_struct (thiz()) &&
+                  thiz()->length >= thiz()->min_size &&
+                  c->check_array (thiz(), 1, thiz()->length) &&
+                  thiz()->subtable.sanitize (c, thiz()->format));
+  }
+};
+
+template <typename T>
+struct KernTable
+{
+  /* https://en.wikipedia.org/wiki/Curiously_recurring_template_pattern */
+  inline const T* thiz (void) const { return static_cast<const T *> (this); }
+
+  inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right, unsigned int table_length) const
+  {
+    int v = 0;
+    const typename T::SubTableWrapper *st = CastP<typename T::SubTableWrapper> (thiz()->data);
+    unsigned int count = thiz()->nTables;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (st->is_override ())
+        v = 0;
+      v += st->get_h_kerning (left, right, table_length + (const char *) this);
+      st = &StructAfter<typename T::SubTableWrapper> (*st);
+    }
+    return v;
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (unlikely (!c->check_struct (thiz()) ||
+                  thiz()->version != T::VERSION))
+      return_trace (false);
+
+    const typename T::SubTableWrapper *st = CastP<typename T::SubTableWrapper> (thiz()->data);
+    unsigned int count = thiz()->nTables;
+    for (unsigned int i = 0; i < count; i++)
+    {
+      if (unlikely (!st->sanitize (c)))
+        return_trace (false);
+      st = &StructAfter<typename T::SubTableWrapper> (*st);
+    }
+
+    return_trace (true);
+  }
+};
+
+struct KernOT : KernTable<KernOT>
+{
+  friend struct KernTable<KernOT>;
+
+  static const uint16_t VERSION = 0x0000u;
+
+  struct SubTableWrapper : KernSubTableWrapper<SubTableWrapper>
+  {
+    friend struct KernSubTableWrapper<SubTableWrapper>;
+
+    enum coverage_flags_t {
+      COVERAGE_DIRECTION_FLAG   = 0x01u,
+      COVERAGE_MINIMUM_FLAG     = 0x02u,
+      COVERAGE_CROSSSTREAM_FLAG = 0x04u,
+      COVERAGE_OVERRIDE_FLAG    = 0x08u,
+
+      COVERAGE_VARIATION_FLAG   = 0x00u, /* Not supported. */
+
+      COVERAGE_CHECK_FLAGS      = 0x07u,
+      COVERAGE_CHECK_HORIZONTAL = 0x01u
+    };
+
+    protected:
+    USHORT      versionZ;       /* Unused. */
+    USHORT      length;         /* Length of the subtable (including this header). */
+    BYTE        format;         /* Subtable format. */
+    BYTE        coverage;       /* Coverage bits. */
+    KernSubTable subtable;      /* Subtable data. */
+    public:
+    DEFINE_SIZE_MIN (6);
+  };
+
+  protected:
+  USHORT        version;        /* Version--0x0000u */
+  USHORT        nTables;        /* Number of subtables in the kerning table. */
+  BYTE          data[VAR];
+  public:
+  DEFINE_SIZE_ARRAY (4, data);
+};
+
+struct KernAAT : KernTable<KernAAT>
+{
+  friend struct KernTable<KernAAT>;
+
+  static const uint32_t VERSION = 0x00010000u;
+
+  struct SubTableWrapper : KernSubTableWrapper<SubTableWrapper>
+  {
+    friend struct KernSubTableWrapper<SubTableWrapper>;
+
+    enum coverage_flags_t {
+      COVERAGE_DIRECTION_FLAG   = 0x80u,
+      COVERAGE_CROSSSTREAM_FLAG = 0x40u,
+      COVERAGE_VARIATION_FLAG   = 0x20u,
+
+      COVERAGE_OVERRIDE_FLAG    = 0x00u, /* Not supported. */
+
+      COVERAGE_CHECK_FLAGS      = 0xE0u,
+      COVERAGE_CHECK_HORIZONTAL = 0x00u
+    };
+
+    protected:
+    ULONG       length;         /* Length of the subtable (including this header). */
+    BYTE        coverage;       /* Coverage bits. */
+    BYTE        format;         /* Subtable format. */
+    USHORT      tupleIndex;     /* The tuple index (used for variations fonts).
+                                 * This value specifies which tuple this subtable covers. */
+    KernSubTable subtable;      /* Subtable data. */
+    public:
+    DEFINE_SIZE_MIN (8);
+  };
+
+  protected:
+  ULONG         version;        /* Version--0x00010000u */
+  ULONG         nTables;        /* Number of subtables in the kerning table. */
+  BYTE          data[VAR];
+  public:
+  DEFINE_SIZE_ARRAY (8, data);
+};
+
+struct kern
+{
+  static const hb_tag_t tableTag = HB_OT_TAG_kern;
+
+  inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right, unsigned int table_length) const
+  {
+    switch (u.major) {
+    case 0: return u.ot.get_h_kerning (left, right, table_length);
+    case 1: return u.aat.get_h_kerning (left, right, table_length);
+    default:return 0;
+    }
+  }
+
+  inline bool sanitize (hb_sanitize_context_t *c) const
+  {
+    TRACE_SANITIZE (this);
+    if (!u.major.sanitize (c)) return_trace (false);
+    switch (u.major) {
+    case 0: return_trace (u.ot.sanitize (c));
+    case 1: return_trace (u.aat.sanitize (c));
+    default:return_trace (true);
+    }
+  }
+
+  struct accelerator_t
+  {
+    inline void init (const kern *table_, unsigned int table_length_)
+    {
+      table = table_;
+      table_length = table_length_;
+    }
+    inline void fini (void) {}
+
+    inline int get_h_kerning (hb_codepoint_t left, hb_codepoint_t right) const
+    { return table->get_h_kerning (left, right, table_length); }
+
+    private:
+    const kern *table;
+    unsigned int table_length;
+  };
+
+  protected:
+  union {
+  USHORT                major;
+  KernOT                ot;
+  KernAAT               aat;
+  } u;
+  public:
+  DEFINE_SIZE_UNION (2, major);
+};
+
+} /* namespace OT */
+
+
+#endif /* HB_OT_KERN_TABLE_HH */