ref: afdc4c4c2b996ec48ac9fee27cdaff685cc3c9ee
dir: /src/type1/t1driver.c/
/*******************************************************************
*
* t1driver.c
*
* High-level Type1 driver interface for FreeType 2.0
*
* Copyright 1996-1998 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 <t1driver.h>
#include <t1gload.h>
#include <t1afm.h>
#include <ftdebug.h>
#include <ftstream.h>
#include <psnames.h>
#undef FT_COMPONENT
#define FT_COMPONENT trace_t1driver
#ifndef T1_CONFIG_OPTION_NO_AFM
/*************************************************************************/
/* */
/* <Function> */
/* Get_Interface */
/* */
/* <Description> */
/* Each driver can provide one or more extensions to the base */
/* FreeType API. These can be used to access format specific */
/* features (e.g., all TrueType/OpenType resources share a common */
/* file structure and common tables which can be accessed through the */
/* `sfnt' interface), or more simply generic ones (e.g., the */
/* `postscript names' interface which can be used to retrieve the */
/* PostScript name of a given glyph index). */
/* */
/* <InOut> */
/* driver :: A handle to a driver object. */
/* */
/* <Input> */
/* interface :: A string designing the interface. Examples are */
/* `sfnt', `post_names', `charmaps', etc. */
/* */
/* <Return> */
/* A typeless pointer to the extension's interface (normally a table */
/* of function pointers). Returns NULL if the requested extension */
/* isn't available (i.e., wasn't compiled in the driver at build */
/* time). */
/* */
static
void* Get_Interface)( FT_Driver driver,
const FT_String* interface )
{
if ( strcmp( (const char*)interface, "attach_file" ) == 0 )
return T1_Read_AFM;
return 0;
}
/*************************************************************************/
/* */
/* <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
T1_Error Get_Kerning( T1_Face face,
T1_UInt left_glyph,
T1_UInt right_glyph,
T1_Vector* kerning )
{
T1_AFM* afm;
kerning->x = 0;
kerning->y = 0;
afm = (T1_AFM*)face->afm_data;
if (afm)
T1_Get_Kerning( afm, left_glyph, right_glyph, kerning );
return T1_Err_Ok;
}
#endif
/******************************************************************/
/* */
/* <Function> Set_Char_Sizes */
/* */
/* <Description> */
/* A driver method used to reset a size's character sizes */
/* (horizontal and vertical) expressed in fractional points. */
/* */
/* <Input> */
/* size :: handle to target size object */
/* char_width :: character width expressed in 26.6 points */
/* char_height :: character height expressed in 26.6 points */
/* */
/* <Return> */
/* FreeType error code. 0 means success */
/* */
static
T1_Error Set_Char_Sizes( T1_Size size,
T1_F26Dot6 char_width,
T1_F26Dot6 char_height,
T1_UInt horz_resolution,
T1_UInt vert_resolution )
{
FT_Size_Metrics* metrics;
T1_Face face;
if (!size)
return T1_Err_Invalid_Size_Handle;
if ( char_width < 1*64 ) char_width = 1*64;
if ( char_height < 1*64 ) char_height = 1*64;
metrics = &size->root.metrics;
face = (T1_Face)size->root.face;
metrics->x_ppem = ( char_width * horz_resolution + 36 )/72;
metrics->y_ppem = ( char_height * vert_resolution + 36 )/72;
metrics->x_ppem = ( metrics->x_ppem + 32 ) & -64;
metrics->y_ppem = ( metrics->y_ppem + 32 ) & -64;
metrics->x_scale = FT_MulDiv( metrics->x_ppem, 0x10000,
face->root.units_per_EM );
metrics->y_scale = FT_MulDiv( metrics->y_ppem, 0x10000,
face->root.units_per_EM );
metrics->x_ppem >>= 6;
metrics->y_ppem >>= 6;
size->valid = FALSE;
return T1_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> */
/* size :: handle to target size object */
/* */
/* pixel_width :: character width expressed in 26.6 points */
/* */
/* pixel_height :: character height expressed in 26.6 points */
/* */
/* char_size :: the corresponding character size in points */
/* This value is only sent to the TrueType */
/* bytecode interpreter, even though 99% of */
/* glyph programs will simply ignore it. A */
/* safe value there is the maximum of the */
/* pixel width and height (multiplied by */
/* 64 to make it a 26.6 fixed float !) */
/* <Return> */
/* FreeType error code. 0 means success */
/* */
static
T1_Error Set_Pixel_Sizes( T1_Size size,
T1_Int pixel_width,
T1_Int pixel_height )
{
FT_Size_Metrics* metrics;
T1_Face face;
if (!size)
return T1_Err_Invalid_Size_Handle;
if ( pixel_width < 1 ) pixel_width = 1;
if ( pixel_height < 1 ) pixel_height = 1;
metrics = &size->root.metrics;
face = (T1_Face)size->root.face;
metrics->x_ppem = pixel_width;
metrics->y_ppem = pixel_height;
metrics->x_scale = FT_MulDiv( metrics->x_ppem * 64,
0x10000, face->root.units_per_EM );
metrics->y_scale = FT_MulDiv( metrics->y_ppem * 64,
0x10000, face->root.units_per_EM );
size->valid = 0;
return T1_Reset_Size(size);
}
/*************************************************************************/
/* */
/* <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
T1_UInt Get_Char_Index( FT_CharMap charmap,
T1_Long charcode )
{
T1_Face face;
T1_UInt result = 0;
PSNames_Interface* psnames;
face = (T1_Face)charmap->face;
psnames = (PSNames_Interface*)face->psnames;
if (psnames)
switch (charmap->encoding)
{
/********************************************************************/
/* */
/* Unicode encoding support */
/* */
case ft_encoding_unicode:
{
/* use the "psnames" module to synthetize the Unicode charmap */
result = psnames->lookup_unicode( &face->unicode_map,
(T1_ULong)charcode );
/* the function returns 0xFFFF when the Unicode charcode has */
/* no corresponding glyph.. */
if (result == 0xFFFF)
result = 0;
goto Exit;
}
/********************************************************************/
/* */
/* Custom Type 1 encoding */
/* */
case ft_encoding_adobe_custom:
{
T1_Encoding* encoding = &face->type1.encoding;
if (charcode >= encoding->code_first &&
charcode <= encoding->code_last)
{
result = encoding->char_index[charcode];
}
goto Exit;
}
/********************************************************************/
/* */
/* Adobe Standard & Expert encoding support */
/* */
default:
if (charcode < 256)
{
FT_UInt code;
FT_Int n;
const char* glyph_name;
code = psnames->adobe_std_encoding[charcode];
if (charmap->encoding == ft_encoding_adobe_expert)
code = psnames->adobe_expert_encoding[charcode];
glyph_name = psnames->adobe_std_strings(code);
if (!glyph_name) break;
for ( n = 0; n < face->type1.num_glyphs; n++ )
{
const char* gname = face->type1.glyph_names[n];
if ( gname && gname[0] == glyph_name[0] &&
strcmp( gname, glyph_name ) == 0 )
{
result = n;
break;
}
}
}
}
Exit:
return result;
}
static
T1_Error Init_Face( FT_Stream stream,
FT_Int face_index,
T1_Face face )
{
T1_Error error;
error = T1_Init_Face(stream, face_index, face);
if (!error)
{
FT_Face root = &face->root;
FT_CharMap charmap = face->charmaprecs;
/* synthetize a Unicode charmap if there is support in the "psnames" */
/* module.. */
if (face->psnames)
{
PSNames_Interface* psnames = (PSNames_Interface*)face->psnames;
if (psnames->unicode_value)
{
error = psnames->build_unicodes( root->memory,
face->type1.num_glyphs,
(const char**)face->type1.glyph_names,
&face->unicode_map );
if (!error)
{
root->charmap = charmap;
charmap->face = (FT_Face)face;
charmap->encoding = ft_encoding_unicode;
charmap->platform_id = 3;
charmap->encoding_id = 1;
charmap++;
}
/* simply clear the error in case of failure (which really) */
/* means that out of memory or no unicode glyph names */
error = 0;
}
}
/* now, support either the standard, expert, or custom encodings */
charmap->face = (FT_Face)face;
charmap->platform_id = 7; /* a new platform id for Adobe fonts ?? */
switch (face->type1.encoding_type)
{
case t1_encoding_standard:
charmap->encoding = ft_encoding_adobe_standard;
charmap->encoding_id = 0;
break;
case t1_encoding_expert:
charmap->encoding = ft_encoding_adobe_expert;
charmap->encoding_id = 1;
break;
default:
charmap->encoding = ft_encoding_adobe_custom;
charmap->encoding_id = 2;
break;
}
root->charmaps = face->charmaps;
root->num_charmaps = charmap - face->charmaprecs + 1;
face->charmaps[0] = &face->charmaprecs[0];
face->charmaps[1] = &face->charmaprecs[1];
}
return error;
}
/******************************************************************/
/* */
/* <Struct> FT_DriverInterface */
/* */
/* <Description> */
/* A structure used to hold a font driver's basic interface */
/* used by the high-level parts of FreeType (or other apps) */
/* */
/* Most scalable drivers provide a specialized interface to */
/* access format-specific features. It can be retrieved with */
/* a call to the "get_format_interface", and should be defined */
/* in each font driver header (e.g. ttdriver.h, t1driver.h,..) */
/* */
/* All fields are function pointers .. */
/* */
/* */
/* <Fields> */
/* */
/* new_engine :: */
/* used to create and initialise a new driver object */
/* */
/* done_engine :: */
/* used to finalise and destroy a given driver object */
/* */
/* get_format_interface :: */
/* return a typeless pointer to the format-specific */
/* driver interface. */
/* */
/* new_face :: */
/* create a new face object from a resource */
/* */
/* done_face :: */
/* discards a face object, as well as all child objects */
/* ( sizes, charmaps, glyph slots ) */
/* */
/* get_face_properties :: */
/* return generic face properties */
/* */
/* get_kerning :: */
/* return the kerning vector corresponding to a pair */
/* of glyphs, expressed in unscaled font units. */
/* */
/* new_size :: */
/* create and initialise a new scalable size object. */
/* */
/* new_fixed_size :: */
/* create and initialise a new fixed-size object. */
/* */
/* done_size :: */
/* finalize a given face size object. */
/* */
/* set_size_resolutions :: */
/* reset a scalable size object's output resolutions */
/* */
/* set_size_char_sizes :: */
/* reset a scalable size object's character size */
/* */
/* set_pixel_sizes :: */
/* reset a face size object's pixel dimensions. Applies */
/* to both scalable and fixed faces. */
/* */
/* new_glyph_slot :: */
/* create and initialise a new glyph slot */
/* */
/* done_glyph_slot :: */
/* discard a given glyph slot */
/* */
/* load_glyph :: */
/* load a given glyph into a given slot */
/* */
/* get_glyph_metrics :: */
/* return a loaded glyph's metrics. */
/* */
EXPORT_FUNC
const FT_DriverInterface t1_driver_interface =
{
sizeof( FT_DriverRec ),
sizeof( T1_FaceRec ),
sizeof( T1_SizeRec ),
sizeof( T1_GlyphSlotRec ),
"type1",
1,
2,
0, /* format interface */
(FTDriver_initDriver) T1_Init_Driver,
(FTDriver_doneDriver) T1_Done_Driver,
#ifdef T1_CONFIG_OPTION_NO_AFM
(FTDriver_getInterface) 0,
#else
(FTDriver_getInterface) Get_Interface,
#endif
(FTDriver_initFace) Init_Face,
(FTDriver_doneFace) T1_Done_Face,
#ifdef T1_CONFIG_OPTION_NO_AFM
(FTDriver_getKerning) 0,
#else
(FTDriver_getKerning) Get_Kerning,
#endif
(FTDriver_initSize) T1_Init_Size,
(FTDriver_doneSize) T1_Done_Size,
(FTDriver_setCharSizes) Set_Char_Sizes,
(FTDriver_setPixelSizes) Set_Pixel_Sizes,
(FTDriver_initGlyphSlot) T1_Init_GlyphSlot,
(FTDriver_doneGlyphSlot) T1_Done_GlyphSlot,
(FTDriver_loadGlyph) T1_Load_Glyph,
(FTDriver_getCharIndex) Get_Char_Index,
};
/******************************************************************/
/* */
/* <Function> Get_FreeType_Driver_Interface */
/* */
/* <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> */
/* address of TrueType's driver generic interface. The */
/* forma-specific interface can then be retrieved through */
/* the method interface->get_format_interface.. */
/* */
#ifdef FT_CONFIG_OPTION_DYNAMIC_DRIVERS
EXPORT_FUNC
FT_DriverInterface* getDriverInterface( void )
{
return &t1_driver_interface;
}
#endif /* FT_CONFIG_OPTION_DYNAMIC_DRIVERS */