提交 6ad8d5f3 编写于 作者: B Behdad Esfahbod

[HB] Simplify some basic things

上级 f96ffd43
......@@ -179,7 +179,7 @@ struct Null <Type> \
{ \
if (HB_UNLIKELY (data == NULL)) return Null(Type); \
const Type& t = (const Type&)*data; \
if (HB_UNLIKELY (t.version.major != Major)) return Null(Type); \
if (HB_UNLIKELY (!t.version.major || t.version.major > Major)) return Null(Type); \
return t; \
}
......@@ -251,12 +251,16 @@ DEFINE_NULL_DATA (Tag, 4, _NULL_TAG_INIT);
#undef _NULL_TAG_INIT
/* Glyph index number, same as uint16 (length = 16 bits) */
DEFINE_INT_TYPE_STRUCT (GlyphID, u, 16);
typedef USHORT GlyphID;
/* Offset to a table, same as uint16 (length = 16 bits), Null offset = 0x0000 */
DEFINE_INT_TYPE_STRUCT (Offset, u, 16);
typedef USHORT Offset;
/* LongOffset to a table, same as uint32 (length = 32 bits), Null offset = 0x00000000 */
typedef ULONG LongOffset;
/* Template subclasses of Offset and LongOffset that do the dereferencing. Use: (this+memberName) */
/* Template subclass of Offset that does the dereferencing. Use: (this+memberName) */
template <typename Type>
struct OffsetTo : Offset
{
......@@ -270,6 +274,19 @@ struct OffsetTo : Offset
template <typename Base, typename Type>
inline const Type& operator + (const Base &base, OffsetTo<Type> offset) { return offset (base); }
template <typename Type>
struct LongOffsetTo : LongOffset
{
inline const Type& operator() (const void *base) const
{
unsigned int offset = *this;
if (HB_UNLIKELY (!offset)) return Null(Type);
return (const Type&)*((const char *) base + offset);
}
};
template <typename Base, typename Type>
inline const Type& operator + (const Base &base, LongOffsetTo<Type> offset) { return offset (base); }
/* CheckSum */
struct CheckSum : ULONG
......@@ -293,9 +310,9 @@ ASSERT_SIZE (CheckSum, 4);
struct FixedVersion
{
inline operator uint32_t(void) const { return major << 16 + minor; }
inline operator uint32_t (void) const { return major << 16 + minor; }
SHORT major;
USHORT major;
USHORT minor;
};
ASSERT_SIZE (FixedVersion, 4);
......@@ -341,10 +358,36 @@ struct HeadlessArrayOf
Type array[];
};
/* An array with a ULONG number of elements. */
template <typename Type>
struct LongArrayOf
{
inline const Type& operator [] (unsigned int i) const
{
if (HB_UNLIKELY (i >= len)) return Null(Type);
return array[i];
}
inline unsigned int get_size () const
{
return sizeof (len) + len * sizeof (array[0]);
}
ULONG len;
Type array[];
};
/* Array of Offset's */
template <typename Type>
struct OffsetArrayOf : ArrayOf<OffsetTo<Type> > {};
/* Array of LongOffset's */
template <typename Type>
struct LongOffsetArrayOf : ArrayOf<LongOffsetTo<Type> > {};
/* LongArray of LongOffset's */
template <typename Type>
struct LongOffsetLongArrayOf : LongArrayOf<LongOffsetTo<Type> > {};
/* An array type is one that contains a variable number of objects
* as its last item. An array object is extended with get_len()
* methods, as well as overloaded [] operator. */
......@@ -369,16 +412,6 @@ struct TTCHeader;
typedef struct TableDirectory
{
friend struct OpenTypeFontFile;
friend struct OffsetTable;
inline bool is_null (void) const { return length == 0; }
inline const Tag& get_tag (void) const { return tag; }
inline unsigned long get_checksum (void) const { return checkSum; }
inline unsigned long get_offset (void) const { return offset; }
inline unsigned long get_length (void) const { return length; }
private:
Tag tag; /* 4-byte identifier. */
CheckSum checkSum; /* CheckSum for this table. */
ULONG offset; /* Offset from beginning of TrueType font
......@@ -417,17 +450,15 @@ struct TTCHeader
{
friend struct OpenTypeFontFile;
private:
/* OpenTypeFontFaces, in no particular order */
DEFINE_OFFSET_ARRAY_TYPE (OffsetTable, offsetTable, numFonts);
STATIC_DEFINE_GET_FOR_DATA_CHECK_MAJOR_VERSION (TTCHeader, 2);
private:
Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
ULONG version; /* Version of the TTC Header (1.0 or 2.0),
* 0x00010000 or 0x00020000 */
ULONG numFonts; /* Number of fonts in TTC */
ULONG offsetTable[]; /* Array of offsets to the OffsetTable for each font
* from the beginning of the file */
Tag ttcTag; /* TrueType Collection ID string: 'ttcf' */
FixedVersion version; /* Version of the TTC Header (1.0 or 2.0),
* 0x00010000 or 0x00020000 */
LongOffsetLongArrayOf<OffsetTable>
table; /* Array of offsets to the OffsetTable for each font
* from the beginning of the file */
};
ASSERT_SIZE (TTCHeader, 12);
......@@ -446,11 +477,8 @@ struct OpenTypeFontFile
DEFINE_ARRAY_INTERFACE (OpenTypeFontFace, face); /* get_face_count(), get_face(i) */
inline const Tag& get_tag (void) const { return tag; }
/* This is how you get a table */
inline const char* get_table_data (const OpenTypeTable& table) const { return (*this)[table]; }
inline char* get_table_data (const OpenTypeTable& table) { return (*this)[table]; }
private:
inline const char* operator[] (const OpenTypeTable& table) const
......@@ -469,7 +497,7 @@ struct OpenTypeFontFile
switch (tag) {
default: return 0;
case TrueTypeTag: case CFFTag: return 1;
case TTCTag: return ((const TTCHeader&)*this).get_len();
case TTCTag: return TTCHeader::get_for_data ((const char *) this).table.len;
}
}
const OpenTypeFontFace& operator[] (unsigned int i) const
......@@ -478,11 +506,11 @@ struct OpenTypeFontFile
switch (tag) {
default: /* Never happens because of the if above */
case TrueTypeTag: case CFFTag: return (const OffsetTable&)*this;
case TTCTag: return ((const TTCHeader&)*this)[i];
case TTCTag: return this+TTCHeader::get_for_data ((const char *) this).table[i];
}
}
private:
public:
Tag tag; /* 4-byte identifier. */
};
ASSERT_SIZE (OpenTypeFontFile, 4);
......
......@@ -48,7 +48,7 @@ main (int argc, char **argv)
const OpenTypeFontFile &ot = OpenTypeFontFile::get_for_data (font_data);
switch (ot.get_tag()) {
switch (ot.tag) {
case OpenTypeFontFile::TrueTypeTag:
printf ("OpenType font with TrueType outlines\n");
break;
......@@ -74,9 +74,11 @@ main (int argc, char **argv)
for (int n_table = 0; n_table < num_tables; n_table++) {
const OpenTypeTable &table = font.get_table (n_table);
printf (" Table %2d of %2d: %.4s (0x%08lx+0x%08lx)\n", n_table, num_tables,
(const char *)table.get_tag(), table.get_offset(), table.get_length());
(const char *)table.tag,
(unsigned int) table.offset,
(unsigned int) table.length);
switch (table.get_tag ()) {
switch (table.tag) {
case GSUBGPOS::GSUBTag:
case GSUBGPOS::GPOSTag:
......
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