| /***************************************************************************/ |
| /* */ |
| /* ttdriver.c */ |
| /* */ |
| /* TrueType font driver implementation (body). */ |
| /* */ |
| /* Copyright 1996-2001 by */ |
| /* David Turner, Robert Wilhelm, and Werner Lemberg. */ |
| /* */ |
| /* This file is part of the FreeType project, and may only be used, */ |
| /* modified, and distributed under the terms of the FreeType project */ |
| /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ |
| /* this file you indicate that you have read the license and */ |
| /* understand and accept it fully. */ |
| /* */ |
| /***************************************************************************/ |
| |
| |
| #include <ft2build.h> |
| #include FT_INTERNAL_DEBUG_H |
| #include FT_INTERNAL_STREAM_H |
| #include FT_INTERNAL_SFNT_H |
| #include FT_TRUETYPE_IDS_H |
| |
| #include "ttdriver.h" |
| #include "ttgload.h" |
| |
| #include "tterrors.h" |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ |
| /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ |
| /* messages during execution. */ |
| /* */ |
| #undef FT_COMPONENT |
| #define FT_COMPONENT trace_ttdriver |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** ****/ |
| /**** F A C E S ****/ |
| /**** ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| #undef PAIR_TAG |
| #define PAIR_TAG( left, right ) ( ( (FT_ULong)left << 16 ) | \ |
| (FT_ULong)right ) |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Get_Kerning */ |
| /* */ |
| /* <Description> */ |
| /* A driver method used to return the kerning vector between two */ |
| /* glyphs of the same face. */ |
| /* */ |
| /* <Input> */ |
| /* face :: A handle to the source face object. */ |
| /* */ |
| /* left_glyph :: The index of the left glyph in the kern pair. */ |
| /* */ |
| /* right_glyph :: The index of the right glyph in the kern pair. */ |
| /* */ |
| /* <Output> */ |
| /* kerning :: The kerning vector. This is in font units for */ |
| /* scalable formats, and in pixels for fixed-sizes */ |
| /* formats. */ |
| /* */ |
| /* <Return> */ |
| /* FreeType error code. 0 means success. */ |
| /* */ |
| /* <Note> */ |
| /* Only horizontal layouts (left-to-right & right-to-left) are */ |
| /* supported by this function. Other layouts, or more sophisticated */ |
| /* kernings, are out of scope of this method (the basic driver */ |
| /* interface is meant to be simple). */ |
| /* */ |
| /* They can be implemented by format-specific interfaces. */ |
| /* */ |
| static FT_Error |
| Get_Kerning( TT_Face face, |
| FT_UInt left_glyph, |
| FT_UInt right_glyph, |
| FT_Vector* kerning ) |
| { |
| TT_Kern_0_Pair* pair; |
| |
| |
| if ( !face ) |
| return TT_Err_Invalid_Face_Handle; |
| |
| kerning->x = 0; |
| kerning->y = 0; |
| |
| if ( face->kern_pairs ) |
| { |
| /* there are some kerning pairs in this font file! */ |
| FT_ULong search_tag = PAIR_TAG( left_glyph, right_glyph ); |
| FT_Long left, right; |
| |
| |
| left = 0; |
| right = face->num_kern_pairs - 1; |
| |
| while ( left <= right ) |
| { |
| FT_Int middle = left + ( ( right - left ) >> 1 ); |
| FT_ULong cur_pair; |
| |
| |
| pair = face->kern_pairs + middle; |
| cur_pair = PAIR_TAG( pair->left, pair->right ); |
| |
| if ( cur_pair == search_tag ) |
| goto Found; |
| |
| if ( cur_pair < search_tag ) |
| left = middle + 1; |
| else |
| right = middle - 1; |
| } |
| } |
| |
| Exit: |
| return TT_Err_Ok; |
| |
| Found: |
| kerning->x = pair->value; |
| goto Exit; |
| } |
| |
| |
| #undef PAIR_TAG |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** ****/ |
| /**** S I Z E S ****/ |
| /**** ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Set_Char_Sizes */ |
| /* */ |
| /* <Description> */ |
| /* A driver method used to reset a size's character sizes (horizontal */ |
| /* and vertical) expressed in fractional points. */ |
| /* */ |
| /* <Input> */ |
| /* char_width :: The character width expressed in 26.6 */ |
| /* fractional points. */ |
| /* */ |
| /* char_height :: The character height expressed in 26.6 */ |
| /* fractional points. */ |
| /* */ |
| /* horz_resolution :: The horizontal resolution of the output device. */ |
| /* */ |
| /* vert_resolution :: The vertical resolution of the output device. */ |
| /* */ |
| /* <InOut> */ |
| /* size :: A handle to the target size object. */ |
| /* */ |
| /* <Return> */ |
| /* FreeType error code. 0 means success. */ |
| /* */ |
| static FT_Error |
| Set_Char_Sizes( TT_Size size, |
| FT_F26Dot6 char_width, |
| FT_F26Dot6 char_height, |
| FT_UInt horz_resolution, |
| FT_UInt vert_resolution ) |
| { |
| FT_Size_Metrics* metrics = &size->root.metrics; |
| TT_Face face = (TT_Face)size->root.face; |
| FT_Long dim_x, dim_y; |
| |
| |
| /* This bit flag, when set, indicates that the pixel size must be */ |
| /* truncated to an integer. Nearly all TrueType fonts have this */ |
| /* bit set, as hinting won't work really well otherwise. */ |
| /* */ |
| /* However, for those rare fonts who do not set it, we override */ |
| /* the default computations performed by the base layer. I */ |
| /* really don't know whether this is useful, but hey, that's the */ |
| /* spec :-) */ |
| /* */ |
| if ( ( face->header.Flags & 8 ) == 0 ) |
| { |
| /* Compute pixel sizes in 26.6 units */ |
| dim_x = ( char_width * horz_resolution + 36 ) / 72; |
| dim_y = ( char_height * vert_resolution + 36 ) / 72; |
| |
| metrics->x_scale = FT_DivFix( dim_x, face->root.units_per_EM ); |
| metrics->y_scale = FT_DivFix( dim_y, face->root.units_per_EM ); |
| |
| metrics->x_ppem = (FT_UShort)( dim_x >> 6 ); |
| metrics->y_ppem = (FT_UShort)( dim_y >> 6 ); |
| } |
| |
| size->ttmetrics.valid = FALSE; |
| #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS |
| size->strike_index = 0xFFFF; |
| #endif |
| |
| return TT_Reset_Size( size ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Set_Pixel_Sizes */ |
| /* */ |
| /* <Description> */ |
| /* A driver method used to reset a size's character sizes (horizontal */ |
| /* and vertical) expressed in integer pixels. */ |
| /* */ |
| /* <Input> */ |
| /* pixel_width :: The character width expressed in integer pixels. */ |
| /* */ |
| /* pixel_height :: The character height expressed in integer pixels. */ |
| /* */ |
| /* <InOut> */ |
| /* size :: A handle to the target size object. */ |
| /* */ |
| /* <Return> */ |
| /* FreeType error code. 0 means success. */ |
| /* */ |
| static FT_Error |
| Set_Pixel_Sizes( TT_Size size, |
| FT_UInt pixel_width, |
| FT_UInt pixel_height ) |
| { |
| FT_UNUSED( pixel_width ); |
| FT_UNUSED( pixel_height ); |
| |
| /* many things have been pre-computed by the base layer */ |
| |
| size->ttmetrics.valid = FALSE; |
| #ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS |
| size->strike_index = 0xFFFF; |
| #endif |
| |
| return TT_Reset_Size( size ); |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Load_Glyph */ |
| /* */ |
| /* <Description> */ |
| /* A driver method used to load a glyph within a given glyph slot. */ |
| /* */ |
| /* <Input> */ |
| /* slot :: A handle to the target slot object where the glyph */ |
| /* will be loaded. */ |
| /* */ |
| /* size :: A handle to the source face size at which the glyph */ |
| /* must be scaled, loaded, etc. */ |
| /* */ |
| /* glyph_index :: The index of the glyph in the font file. */ |
| /* */ |
| /* load_flags :: A flag indicating what to load for this glyph. The */ |
| /* FTLOAD_??? constants can be used to control the */ |
| /* glyph loading process (e.g., whether the outline */ |
| /* should be scaled, whether to load bitmaps or not, */ |
| /* whether to hint the outline, etc). */ |
| /* */ |
| /* <Return> */ |
| /* FreeType error code. 0 means success. */ |
| /* */ |
| static FT_Error |
| Load_Glyph( TT_GlyphSlot slot, |
| TT_Size size, |
| FT_UShort glyph_index, |
| FT_UInt load_flags ) |
| { |
| FT_Error error; |
| |
| |
| if ( !slot ) |
| return TT_Err_Invalid_Slot_Handle; |
| |
| /* check whether we want a scaled outline or bitmap */ |
| if ( !size ) |
| load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING; |
| |
| if ( load_flags & FT_LOAD_NO_SCALE ) |
| size = NULL; |
| |
| /* reset the size object if necessary */ |
| if ( size ) |
| { |
| /* these two object must have the same parent */ |
| if ( size->root.face != slot->face ) |
| return TT_Err_Invalid_Face_Handle; |
| |
| if ( !size->ttmetrics.valid ) |
| { |
| if ( FT_SET_ERROR( TT_Reset_Size( size ) ) ) |
| return error; |
| } |
| } |
| |
| /* now load the glyph outline if necessary */ |
| error = TT_Load_Glyph( size, slot, glyph_index, load_flags ); |
| |
| /* force drop-out mode to 2 - irrelevant now */ |
| /* slot->outline.dropout_mode = 2; */ |
| |
| return error; |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** ****/ |
| /**** C H A R A C T E R M A P P I N G S ****/ |
| /**** ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Get_Char_Index */ |
| /* */ |
| /* <Description> */ |
| /* Uses a charmap to return a given character code's glyph index. */ |
| /* */ |
| /* <Input> */ |
| /* charmap :: A handle to the source charmap object. */ |
| /* charcode :: The character code. */ |
| /* */ |
| /* <Return> */ |
| /* Glyph index. 0 means `undefined character code'. */ |
| /* */ |
| static FT_UInt |
| Get_Char_Index( TT_CharMap charmap, |
| FT_Long charcode ) |
| { |
| FT_Error error; |
| TT_Face face; |
| TT_CMapTable* cmap; |
| |
| |
| cmap = &charmap->cmap; |
| face = (TT_Face)charmap->root.face; |
| |
| /* Load table if needed */ |
| if ( !cmap->loaded ) |
| { |
| SFNT_Interface* sfnt = (SFNT_Interface*)face->sfnt; |
| |
| |
| error = sfnt->load_charmap( face, cmap, face->root.stream ); |
| if ( error ) |
| return 0; |
| |
| cmap->loaded = TRUE; |
| } |
| |
| if ( cmap->get_index ) |
| return cmap->get_index( cmap, charcode ); |
| else |
| return 0; |
| } |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* Get_Next_Char */ |
| /* */ |
| /* <Description> */ |
| /* Uses a charmap to return the next encoded char. */ |
| /* */ |
| /* <Input> */ |
| /* charmap :: A handle to the source charmap object. */ |
| /* charcode :: The character code. */ |
| /* */ |
| /* <Return> */ |
| /* Next char code. 0 means `no more encoded characters'. */ |
| /* */ |
| static FT_UInt |
| Get_Next_Char( TT_CharMap charmap, |
| FT_Long charcode ) |
| { |
| FT_Error error; |
| TT_Face face; |
| TT_CMapTable* cmap; |
| |
| |
| cmap = &charmap->cmap; |
| face = (TT_Face)charmap->root.face; |
| |
| /* Load table if needed */ |
| if ( !cmap->loaded ) |
| { |
| SFNT_Interface* sfnt = (SFNT_Interface*)face->sfnt; |
| |
| |
| error = sfnt->load_charmap( face, cmap, face->root.stream ); |
| if ( error ) |
| return 0; |
| |
| cmap->loaded = TRUE; |
| } |
| |
| if ( cmap->get_next_char ) |
| return cmap->get_next_char ( cmap, charcode ); |
| else |
| return 0; |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** ****/ |
| /**** D R I V E R I N T E R F A C E ****/ |
| /**** ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| static FT_Module_Interface |
| tt_get_interface( TT_Driver driver, |
| const char* interface ) |
| { |
| FT_Module sfntd = FT_Get_Module( driver->root.root.library, |
| "sfnt" ); |
| SFNT_Interface* sfnt; |
| |
| |
| /* only return the default interface from the SFNT module */ |
| if ( sfntd ) |
| { |
| sfnt = (SFNT_Interface*)( sfntd->clazz->module_interface ); |
| if ( sfnt ) |
| return sfnt->get_interface( FT_MODULE( driver ), interface ); |
| } |
| |
| return 0; |
| } |
| |
| |
| /* The FT_DriverInterface structure is defined in ftdriver.h. */ |
| |
| FT_CALLBACK_TABLE_DEF |
| const FT_Driver_Class tt_driver_class = |
| { |
| { |
| ft_module_font_driver | |
| ft_module_driver_scalable | |
| #ifdef TT_CONFIG_OPTION_BYTECODE_INTERPRETER |
| ft_module_driver_has_hinter, |
| #else |
| 0, |
| #endif |
| |
| sizeof ( TT_DriverRec ), |
| |
| "truetype", /* driver name */ |
| 0x10000L, /* driver version == 1.0 */ |
| 0x20000L, /* driver requires FreeType 2.0 or above */ |
| |
| (void*)0, /* driver specific interface */ |
| |
| (FT_Module_Constructor)TT_Init_Driver, |
| (FT_Module_Destructor) TT_Done_Driver, |
| (FT_Module_Requester) tt_get_interface, |
| }, |
| |
| sizeof ( TT_FaceRec ), |
| sizeof ( TT_SizeRec ), |
| sizeof ( FT_GlyphSlotRec ), |
| |
| |
| (FTDriver_initFace) TT_Init_Face, |
| (FTDriver_doneFace) TT_Done_Face, |
| (FTDriver_initSize) TT_Init_Size, |
| (FTDriver_doneSize) TT_Done_Size, |
| (FTDriver_initGlyphSlot)0, |
| (FTDriver_doneGlyphSlot)0, |
| |
| (FTDriver_setCharSizes) Set_Char_Sizes, |
| (FTDriver_setPixelSizes)Set_Pixel_Sizes, |
| (FTDriver_loadGlyph) Load_Glyph, |
| (FTDriver_getCharIndex) Get_Char_Index, |
| |
| (FTDriver_getKerning) Get_Kerning, |
| (FTDriver_attachFile) 0, |
| (FTDriver_getAdvances) 0, |
| |
| (FTDriver_getNextChar) Get_Next_Char |
| }; |
| |
| |
| #ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS |
| |
| |
| /*************************************************************************/ |
| /* */ |
| /* <Function> */ |
| /* getDriverClass */ |
| /* */ |
| /* <Description> */ |
| /* This function is used when compiling the TrueType driver as a */ |
| /* shared library (`.DLL' or `.so'). It will be used by the */ |
| /* high-level library of FreeType to retrieve the address of the */ |
| /* driver's generic interface. */ |
| /* */ |
| /* It shouldn't be implemented in a static build, as each driver must */ |
| /* have the same function as an exported entry point. */ |
| /* */ |
| /* <Return> */ |
| /* The address of the TrueType's driver generic interface. The */ |
| /* format-specific interface can then be retrieved through the method */ |
| /* interface->get_format_interface. */ |
| /* */ |
| FT_EXPORT_DEF( const FT_Driver_Class* ) |
| getDriverClass( void ) |
| { |
| return &tt_driver_class; |
| } |
| |
| |
| #endif /* CONFIG_OPTION_DYNAMIC_DRIVERS */ |
| |
| |
| /* END */ |
