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Diffstat (limited to 'trunk/pango/opentype/ftglue.h')
| -rw-r--r-- | trunk/pango/opentype/ftglue.h | 150 |
1 files changed, 150 insertions, 0 deletions
diff --git a/trunk/pango/opentype/ftglue.h b/trunk/pango/opentype/ftglue.h new file mode 100644 index 00000000..84de7f35 --- /dev/null +++ b/trunk/pango/opentype/ftglue.h @@ -0,0 +1,150 @@ +/* ftglue.h: Glue code for compiling the OpenType code from + * FreeType 1 using only the public API of FreeType 2 + * + * By David Turner, The FreeType Project (www.freetype.org) + * + * This code is explicitely put in the public domain + * + * ========================================================================== + * + * the OpenType parser codes was originally written as an extension to + * FreeType 1.x. As such, its source code was embedded within the library, + * and used many internal FreeType functions to deal with memory and + * stream i/o. + * + * When it was 'salvaged' for Pango and Qt, the code was "ported" to FreeType 2, + * which basically means that some macro tricks were performed in order to + * directly access FT2 _internal_ functions. + * + * these functions were never part of FT2 public API, and _did_ change between + * various releases. This created chaos for many users: when they upgraded the + * FreeType library on their system, they couldn't run Gnome anymore since + * Pango refused to link. + * + * Very fortunately, it's possible to completely avoid this problem because + * the FT_StreamRec and FT_MemoryRec structure types, which describe how + * memory and stream implementations interface with the rest of the font + * library, have always been part of the public API, and never changed. + * + * What we do thus is re-implement, within the OpenType parser, the few + * functions that depend on them. This only adds one or two kilobytes of + * code, and ensures that the parser can work with _any_ version + * of FreeType installed on your system. How sweet... ! + * + * Note that we assume that Pango doesn't use any other internal functions + * from FreeType. It used to in old versions, but this should no longer + * be the case. (crossing my fingers). + * + * - David Turner + * - The FreeType Project (www.freetype.org) + * + * PS: This "glue" code is explicitely put in the public domain + */ +#ifndef FTGLUE_H +#define FTGLUE_H + +#include <ft2build.h> +#include FT_FREETYPE_H + +FT_BEGIN_HEADER + + +/* utility macros */ + +#define SET_ERR(c) ( (error = (c)) != 0 ) + +#ifndef FTGLUE_API +#define FTGLUE_API(x) extern x +#endif + +#ifndef FTGLUE_APIDEF +#define FTGLUE_APIDEF(x) x +#endif + +/* stream macros used by the OpenType parser */ +#define FILE_Pos() _hb_ftglue_stream_pos( stream ) +#define FILE_Seek(pos) SET_ERR( _hb_ftglue_stream_seek( stream, pos ) ) +#define ACCESS_Frame(size) SET_ERR( _hb_ftglue_stream_frame_enter( stream, size ) ) +#define FORGET_Frame() _hb_ftglue_stream_frame_exit( stream ) + +#define GET_Byte() (*stream->cursor++) +#define GET_Short() (stream->cursor += 2, (FT_Short)( \ + (*(((FT_Byte*)stream->cursor)-2) << 8) | \ + *(((FT_Byte*)stream->cursor)-1) \ + )) +#define GET_Long() (stream->cursor += 4, (FT_Long)( \ + (*(((FT_Byte*)stream->cursor)-4) << 24) | \ + (*(((FT_Byte*)stream->cursor)-3) << 16) | \ + (*(((FT_Byte*)stream->cursor)-2) << 8) | \ + *(((FT_Byte*)stream->cursor)-1) \ + )) + + +#define GET_Char() ((FT_Char)GET_Byte()) +#define GET_UShort() ((FT_UShort)GET_Short()) +#define GET_ULong() ((FT_ULong)GET_Long()) +#define GET_Tag4() GET_ULong() + +FTGLUE_API( FT_Long ) +_hb_ftglue_stream_pos( FT_Stream stream ); + +FTGLUE_API( FT_Error ) +_hb_ftglue_stream_seek( FT_Stream stream, + FT_Long pos ); + +FTGLUE_API( FT_Error ) +_hb_ftglue_stream_frame_enter( FT_Stream stream, + FT_ULong size ); + +FTGLUE_API( void ) +_hb_ftglue_stream_frame_exit( FT_Stream stream ); + +FTGLUE_API( FT_Error ) +_hb_ftglue_face_goto_table( FT_Face face, + FT_ULong tag, + FT_Stream stream ); + +/* memory macros used by the OpenType parser */ +#define ALLOC(_ptr,_size) \ + ( (_ptr) = _hb_ftglue_alloc( memory, _size, &error ), error != 0 ) + +#define REALLOC(_ptr,_oldsz,_newsz) \ + ( (_ptr) = _hb_ftglue_realloc( memory, (_ptr), (_oldsz), (_newsz), &error ), error != 0 ) + +#define FREE(_ptr) \ + do { \ + if ( (_ptr) ) \ + { \ + _hb_ftglue_free( memory, _ptr ); \ + _ptr = NULL; \ + } \ + } while (0) + +#define ALLOC_ARRAY(_ptr,_count,_type) \ + ALLOC(_ptr,(_count)*sizeof(_type)) + +#define REALLOC_ARRAY(_ptr,_oldcnt,_newcnt,_type) \ + REALLOC(_ptr,(_oldcnt)*sizeof(_type),(_newcnt)*sizeof(_type)) + +#define MEM_Copy(dest,source,count) memcpy( (char*)(dest), (const char*)(source), (size_t)(count) ) + + +FTGLUE_API( FT_Pointer ) +_hb_ftglue_alloc( FT_Memory memory, + FT_ULong size, + FT_Error *perror_ ); + +FTGLUE_API( FT_Pointer ) +_hb_ftglue_realloc( FT_Memory memory, + FT_Pointer block, + FT_ULong old_size, + FT_ULong new_size, + FT_Error *perror_ ); + +FTGLUE_API( void ) +_hb_ftglue_free( FT_Memory memory, + FT_Pointer block ); + +FT_END_HEADER + +#endif /* FTGLUE_H */ |