ref: 1603378b918c1b1c02d14fbb7a9d8aa0ae2380e9
dir: /src/truetype/ttdriver.c/
/****************************************************************************
*
* ttdriver.c
*
* TrueType font driver implementation (body).
*
* Copyright (C) 1996-2022 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 <freetype/internal/ftdebug.h>
#include <freetype/internal/ftstream.h>
#include <freetype/internal/sfnt.h>
#include <freetype/internal/services/svfntfmt.h>
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include <freetype/ftmm.h>
#include <freetype/internal/services/svmm.h>
#include <freetype/internal/services/svmetric.h>
#endif
#include <freetype/internal/services/svtteng.h>
#include <freetype/internal/services/svttglyf.h>
#include <freetype/internal/services/svprop.h>
#include <freetype/ftdriver.h>
#include "ttdriver.h"
#include "ttgload.h"
#include "ttpload.h"
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
#include "ttgxvar.h"
#endif
#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 ttdriver
/*
* PROPERTY SERVICE
*
*/
static FT_Error
tt_property_set( FT_Module module, /* TT_Driver */
const char* property_name,
const void* value,
FT_Bool value_is_string )
{
FT_Error error = FT_Err_Ok;
TT_Driver driver = (TT_Driver)module;
#ifndef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
FT_UNUSED( value_is_string );
#endif
if ( !ft_strcmp( property_name, "interpreter-version" ) )
{
FT_UInt interpreter_version;
#ifdef FT_CONFIG_OPTION_ENVIRONMENT_PROPERTIES
if ( value_is_string )
{
const char* s = (const char*)value;
interpreter_version = (FT_UInt)ft_strtol( s, NULL, 10 );
}
else
#endif
{
FT_UInt* iv = (FT_UInt*)value;
interpreter_version = *iv;
}
if ( interpreter_version == TT_INTERPRETER_VERSION_35
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_INFINALITY
|| interpreter_version == TT_INTERPRETER_VERSION_38
#endif
#ifdef TT_SUPPORT_SUBPIXEL_HINTING_MINIMAL
|| interpreter_version == TT_INTERPRETER_VERSION_40
#endif
)
driver->interpreter_version = interpreter_version;
else
error = FT_ERR( Unimplemented_Feature );
return error;
}
FT_TRACE2(( "tt_property_set: missing property `%s'\n",
property_name ));
return FT_THROW( Missing_Property );
}
static FT_Error
tt_property_get( FT_Module module, /* TT_Driver */
const char* property_name,
const void* value )
{
FT_Error error = FT_Err_Ok;
TT_Driver driver = (TT_Driver)module;
FT_UInt interpreter_version = driver->interpreter_version;
if ( !ft_strcmp( property_name, "interpreter-version" ) )
{
FT_UInt* val = (FT_UInt*)value;
*val = interpreter_version;
return error;
}
FT_TRACE2(( "tt_property_get: missing property `%s'\n",
property_name ));
return FT_THROW( Missing_Property );
}
FT_DEFINE_SERVICE_PROPERTIESREC(
tt_service_properties,
(FT_Properties_SetFunc)tt_property_set, /* set_property */
(FT_Properties_GetFunc)tt_property_get /* get_property */
)
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** F A C E S ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**************************************************************************
*
* @Function:
* tt_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
tt_get_kerning( FT_Face ttface, /* TT_Face */
FT_UInt left_glyph,
FT_UInt right_glyph,
FT_Vector* kerning )
{
TT_Face face = (TT_Face)ttface;
SFNT_Service sfnt = (SFNT_Service)face->sfnt;
kerning->x = 0;
kerning->y = 0;
if ( sfnt )
kerning->x = sfnt->get_kerning( face, left_glyph, right_glyph );
return 0;
}
static FT_Error
tt_get_advances( FT_Face ttface,
FT_UInt start,
FT_UInt count,
FT_Int32 flags,
FT_Fixed *advances )
{
FT_UInt nn;
TT_Face face = (TT_Face)ttface;
/* XXX: TODO: check for sbits */
if ( flags & FT_LOAD_VERTICAL_LAYOUT )
{
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* no fast retrieval for blended MM fonts without VVAR table */
if ( ( FT_IS_NAMED_INSTANCE( ttface ) || FT_IS_VARIATION( ttface ) ) &&
!( face->variation_support & TT_FACE_FLAG_VAR_VADVANCE ) )
return FT_THROW( Unimplemented_Feature );
#endif
for ( nn = 0; nn < count; nn++ )
{
FT_Short tsb;
FT_UShort ah;
/* since we don't need `tsb', we use zero for `yMax' parameter */
TT_Get_VMetrics( face, start + nn, 0, &tsb, &ah );
advances[nn] = ah;
}
}
else
{
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
/* no fast retrieval for blended MM fonts without HVAR table */
if ( ( FT_IS_NAMED_INSTANCE( ttface ) || FT_IS_VARIATION( ttface ) ) &&
!( face->variation_support & TT_FACE_FLAG_VAR_HADVANCE ) )
return FT_THROW( Unimplemented_Feature );
#endif
for ( nn = 0; nn < count; nn++ )
{
FT_Short lsb;
FT_UShort aw;
TT_Get_HMetrics( face, start + nn, &lsb, &aw );
advances[nn] = aw;
}
}
return FT_Err_Ok;
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** S I Z E S ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
static FT_Error
tt_size_select( FT_Size size,
FT_ULong strike_index )
{
TT_Face ttface = (TT_Face)size->face;
TT_Size ttsize = (TT_Size)size;
FT_Error error = FT_Err_Ok;
ttsize->strike_index = strike_index;
if ( FT_IS_SCALABLE( size->face ) )
{
/* use the scaled metrics, even when tt_size_reset fails */
FT_Select_Metrics( size->face, strike_index );
tt_size_reset( ttsize, 0 ); /* ignore return value */
}
else
{
SFNT_Service sfnt = (SFNT_Service)ttface->sfnt;
FT_Size_Metrics* size_metrics = &size->metrics;
error = sfnt->load_strike_metrics( ttface,
strike_index,
size_metrics );
if ( error )
ttsize->strike_index = 0xFFFFFFFFUL;
}
return error;
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
static FT_Error
tt_size_request( FT_Size size,
FT_Size_Request req )
{
TT_Size ttsize = (TT_Size)size;
FT_Error error = FT_Err_Ok;
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
if ( FT_HAS_FIXED_SIZES( size->face ) )
{
TT_Face ttface = (TT_Face)size->face;
SFNT_Service sfnt = (SFNT_Service)ttface->sfnt;
FT_ULong strike_index;
error = sfnt->set_sbit_strike( ttface, req, &strike_index );
if ( error )
ttsize->strike_index = 0xFFFFFFFFUL;
else
return tt_size_select( size, strike_index );
}
#endif /* TT_CONFIG_OPTION_EMBEDDED_BITMAPS */
{
FT_Error err = FT_Request_Metrics( size->face, req );
if ( err )
{
error = err;
goto Exit;
}
}
if ( FT_IS_SCALABLE( size->face ) )
{
error = tt_size_reset( ttsize, 0 );
#ifdef TT_USE_BYTECODE_INTERPRETER
/* for the `MPS' bytecode instruction we need the point size */
if ( !error )
{
FT_UInt resolution =
ttsize->metrics->x_ppem > ttsize->metrics->y_ppem
? req->horiResolution
: req->vertResolution;
/* if we don't have a resolution value, assume 72dpi */
if ( req->type == FT_SIZE_REQUEST_TYPE_SCALES ||
!resolution )
resolution = 72;
ttsize->point_size = FT_MulDiv( ttsize->ttmetrics.ppem,
64 * 72,
resolution );
}
#endif
}
Exit:
return error;
}
/**************************************************************************
*
* @Function:
* tt_glyph_load
*
* @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
* FT_LOAD_XXX 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
tt_glyph_load( FT_GlyphSlot ttslot, /* TT_GlyphSlot */
FT_Size ttsize, /* TT_Size */
FT_UInt glyph_index,
FT_Int32 load_flags )
{
TT_GlyphSlot slot = (TT_GlyphSlot)ttslot;
TT_Size size = (TT_Size)ttsize;
FT_Face face = ttslot->face;
FT_Error error;
if ( !slot )
return FT_THROW( Invalid_Slot_Handle );
if ( !size )
return FT_THROW( Invalid_Size_Handle );
if ( !face )
return FT_THROW( Invalid_Face_Handle );
#ifdef FT_CONFIG_OPTION_INCREMENTAL
if ( glyph_index >= (FT_UInt)face->num_glyphs &&
!face->internal->incremental_interface )
#else
if ( glyph_index >= (FT_UInt)face->num_glyphs )
#endif
return FT_THROW( Invalid_Argument );
if ( load_flags & FT_LOAD_NO_HINTING )
{
/* both FT_LOAD_NO_HINTING and FT_LOAD_NO_AUTOHINT */
/* are necessary to disable hinting for tricky fonts */
if ( FT_IS_TRICKY( face ) )
load_flags &= ~FT_LOAD_NO_HINTING;
if ( load_flags & FT_LOAD_NO_AUTOHINT )
load_flags |= FT_LOAD_NO_HINTING;
}
if ( load_flags & ( FT_LOAD_NO_RECURSE | FT_LOAD_NO_SCALE ) )
{
load_flags |= FT_LOAD_NO_BITMAP | FT_LOAD_NO_SCALE;
if ( !FT_IS_TRICKY( face ) )
load_flags |= FT_LOAD_NO_HINTING;
}
/* use hinted metrics only if we load a glyph with hinting */
size->metrics = ( load_flags & FT_LOAD_NO_HINTING )
? &ttsize->metrics
: &size->hinted_metrics;
/* now fill in the glyph slot with outline/bitmap/layered */
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;
}
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
/**** ****/
/**** ****/
/**** D R I V E R I N T E R F A C E ****/
/**** ****/
/**** ****/
/*************************************************************************/
/*************************************************************************/
/*************************************************************************/
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_DEFINE_SERVICE_MULTIMASTERSREC(
tt_service_gx_multi_masters,
(FT_Get_MM_Func) NULL, /* get_mm */
(FT_Set_MM_Design_Func) NULL, /* set_mm_design */
(FT_Set_MM_Blend_Func) TT_Set_MM_Blend, /* set_mm_blend */
(FT_Get_MM_Blend_Func) TT_Get_MM_Blend, /* get_mm_blend */
(FT_Get_MM_Var_Func) TT_Get_MM_Var, /* get_mm_var */
(FT_Set_Var_Design_Func) TT_Set_Var_Design, /* set_var_design */
(FT_Get_Var_Design_Func) TT_Get_Var_Design, /* get_var_design */
(FT_Set_Instance_Func) TT_Set_Named_Instance, /* set_instance */
(FT_Set_MM_WeightVector_Func)NULL, /* set_mm_weightvector */
(FT_Get_MM_WeightVector_Func)NULL, /* get_mm_weightvector */
(FT_Get_Var_Blend_Func) tt_get_var_blend, /* get_var_blend */
(FT_Done_Blend_Func) tt_done_blend /* done_blend */
)
FT_DEFINE_SERVICE_METRICSVARIATIONSREC(
tt_service_metrics_variations,
(FT_HAdvance_Adjust_Func)tt_hadvance_adjust, /* hadvance_adjust */
(FT_LSB_Adjust_Func) NULL, /* lsb_adjust */
(FT_RSB_Adjust_Func) NULL, /* rsb_adjust */
(FT_VAdvance_Adjust_Func)tt_vadvance_adjust, /* vadvance_adjust */
(FT_TSB_Adjust_Func) NULL, /* tsb_adjust */
(FT_BSB_Adjust_Func) NULL, /* bsb_adjust */
(FT_VOrg_Adjust_Func) NULL, /* vorg_adjust */
(FT_Metrics_Adjust_Func) tt_apply_mvar /* metrics_adjust */
)
#endif /* TT_CONFIG_OPTION_GX_VAR_SUPPORT */
static const FT_Service_TrueTypeEngineRec tt_service_truetype_engine =
{
#ifdef TT_USE_BYTECODE_INTERPRETER
FT_TRUETYPE_ENGINE_TYPE_PATENTED
#else /* !TT_USE_BYTECODE_INTERPRETER */
FT_TRUETYPE_ENGINE_TYPE_NONE
#endif /* TT_USE_BYTECODE_INTERPRETER */
};
FT_DEFINE_SERVICE_TTGLYFREC(
tt_service_truetype_glyf,
(TT_Glyf_GetLocationFunc)tt_face_get_location /* get_location */
)
#ifdef TT_CONFIG_OPTION_GX_VAR_SUPPORT
FT_DEFINE_SERVICEDESCREC6(
tt_services,
FT_SERVICE_ID_FONT_FORMAT, FT_FONT_FORMAT_TRUETYPE,
FT_SERVICE_ID_MULTI_MASTERS, &tt_service_gx_multi_masters,
FT_SERVICE_ID_METRICS_VARIATIONS, &tt_service_metrics_variations,
FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
FT_SERVICE_ID_TT_GLYF, &tt_service_truetype_glyf,
FT_SERVICE_ID_PROPERTIES, &tt_service_properties )
#else
FT_DEFINE_SERVICEDESCREC4(
tt_services,
FT_SERVICE_ID_FONT_FORMAT, FT_FONT_FORMAT_TRUETYPE,
FT_SERVICE_ID_TRUETYPE_ENGINE, &tt_service_truetype_engine,
FT_SERVICE_ID_TT_GLYF, &tt_service_truetype_glyf,
FT_SERVICE_ID_PROPERTIES, &tt_service_properties )
#endif
FT_CALLBACK_DEF( FT_Module_Interface )
tt_get_interface( FT_Module driver, /* TT_Driver */
const char* tt_interface )
{
FT_Library library;
FT_Module_Interface result;
FT_Module sfntd;
SFNT_Service sfnt;
result = ft_service_list_lookup( tt_services, tt_interface );
if ( result )
return result;
if ( !driver )
return NULL;
library = driver->library;
if ( !library )
return NULL;
/* only return the default interface from the SFNT module */
sfntd = FT_Get_Module( library, "sfnt" );
if ( sfntd )
{
sfnt = (SFNT_Service)( sfntd->clazz->module_interface );
if ( sfnt )
return sfnt->get_interface( driver, tt_interface );
}
return 0;
}
/* The FT_DriverInterface structure is defined in ftdriver.h. */
#ifdef TT_USE_BYTECODE_INTERPRETER
#define TT_HINTER_FLAG FT_MODULE_DRIVER_HAS_HINTER
#else
#define TT_HINTER_FLAG 0
#endif
#ifdef TT_CONFIG_OPTION_EMBEDDED_BITMAPS
#define TT_SIZE_SELECT tt_size_select
#else
#define TT_SIZE_SELECT 0
#endif
FT_DEFINE_DRIVER(
tt_driver_class,
FT_MODULE_FONT_DRIVER |
FT_MODULE_DRIVER_SCALABLE |
TT_HINTER_FLAG,
sizeof ( TT_DriverRec ),
"truetype", /* driver name */
0x10000L, /* driver version == 1.0 */
0x20000L, /* driver requires FreeType 2.0 or above */
NULL, /* module-specific interface */
tt_driver_init, /* FT_Module_Constructor module_init */
tt_driver_done, /* FT_Module_Destructor module_done */
tt_get_interface, /* FT_Module_Requester get_interface */
sizeof ( TT_FaceRec ),
sizeof ( TT_SizeRec ),
sizeof ( FT_GlyphSlotRec ),
tt_face_init, /* FT_Face_InitFunc init_face */
tt_face_done, /* FT_Face_DoneFunc done_face */
tt_size_init, /* FT_Size_InitFunc init_size */
tt_size_done, /* FT_Size_DoneFunc done_size */
tt_slot_init, /* FT_Slot_InitFunc init_slot */
NULL, /* FT_Slot_DoneFunc done_slot */
tt_glyph_load, /* FT_Slot_LoadFunc load_glyph */
tt_get_kerning, /* FT_Face_GetKerningFunc get_kerning */
NULL, /* FT_Face_AttachFunc attach_file */
tt_get_advances, /* FT_Face_GetAdvancesFunc get_advances */
tt_size_request, /* FT_Size_RequestFunc request_size */
TT_SIZE_SELECT /* FT_Size_SelectFunc select_size */
)
/* END */