/* ftglue.c: 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 __OPENTYPE_FTGLUE_H__ #define __OPENTYPE_FTGLUE_H__ #include "fcint.h" #include <ft2build.h> #include FT_FREETYPE_H FT_BEGIN_HEADER #define SET_ERR(c) ( (error = (c)) != 0 ) #ifndef FTGLUE_API #define FTGLUE_API(x) extern FcPrivate x #endif #ifndef FTGLUE_APIDEF #define FTGLUE_APIDEF(x) x #endif /* stream macros used by the OpenType parser */ #define FILE_Pos() ftglue_stream_pos( stream ) #define FILE_Seek(pos) SET_ERR( ftglue_stream_seek( stream, pos ) ) #define ACCESS_Frame(size) SET_ERR( ftglue_stream_frame_enter( stream, size ) ) #define FORGET_Frame() 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() #define FT_SET_ERROR( expression ) \ ( ( error = (expression) ) != 0 ) FTGLUE_API( FT_Long ) ftglue_stream_pos( FT_Stream stream ); FTGLUE_API( FT_Error ) ftglue_stream_seek( FT_Stream stream, FT_Long pos ); FTGLUE_API( FT_Error ) ftglue_stream_frame_enter( FT_Stream stream, FT_ULong size ); FTGLUE_API( void ) ftglue_stream_frame_exit( FT_Stream stream ); FTGLUE_API( FT_Error ) ftglue_face_goto_table( FT_Face face, FT_ULong tag, FT_Stream stream ); FT_END_HEADER #endif /* __OPENTYPE_FTGLUE_H__ */