/***************************************************************************/ | |
/* */ | |
/* ftadvanc.c */ | |
/* */ | |
/* Quick computation of advance widths (body). */ | |
/* */ | |
/* Copyright 2008-2015 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_ADVANCES_H | |
#include FT_INTERNAL_OBJECTS_H | |
static FT_Error | |
_ft_face_scale_advances( FT_Face face, | |
FT_Fixed* advances, | |
FT_UInt count, | |
FT_Int32 flags ) | |
{ | |
FT_Fixed scale; | |
FT_UInt nn; | |
if ( flags & FT_LOAD_NO_SCALE ) | |
return FT_Err_Ok; | |
if ( face->size == NULL ) | |
return FT_THROW( Invalid_Size_Handle ); | |
if ( flags & FT_LOAD_VERTICAL_LAYOUT ) | |
scale = face->size->metrics.y_scale; | |
else | |
scale = face->size->metrics.x_scale; | |
/* this must be the same scaling as to get linear{Hori,Vert}Advance */ | |
/* (see `FT_Load_Glyph' implementation in src/base/ftobjs.c) */ | |
for ( nn = 0; nn < count; nn++ ) | |
advances[nn] = FT_MulDiv( advances[nn], scale, 64 ); | |
return FT_Err_Ok; | |
} | |
/* at the moment, we can perform fast advance retrieval only in */ | |
/* the following cases: */ | |
/* */ | |
/* - unscaled load */ | |
/* - unhinted load */ | |
/* - light-hinted load */ | |
#define LOAD_ADVANCE_FAST_CHECK( flags ) \ | |
( flags & ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING ) || \ | |
FT_LOAD_TARGET_MODE( flags ) == FT_RENDER_MODE_LIGHT ) | |
/* documentation is in ftadvanc.h */ | |
FT_EXPORT_DEF( FT_Error ) | |
FT_Get_Advance( FT_Face face, | |
FT_UInt gindex, | |
FT_Int32 flags, | |
FT_Fixed *padvance ) | |
{ | |
FT_Face_GetAdvancesFunc func; | |
if ( !face ) | |
return FT_THROW( Invalid_Face_Handle ); | |
if ( !padvance ) | |
return FT_THROW( Invalid_Argument ); | |
if ( gindex >= (FT_UInt)face->num_glyphs ) | |
return FT_THROW( Invalid_Glyph_Index ); | |
func = face->driver->clazz->get_advances; | |
if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) ) | |
{ | |
FT_Error error; | |
error = func( face, gindex, 1, flags, padvance ); | |
if ( !error ) | |
return _ft_face_scale_advances( face, padvance, 1, flags ); | |
if ( FT_ERR_NEQ( error, Unimplemented_Feature ) ) | |
return error; | |
} | |
return FT_Get_Advances( face, gindex, 1, flags, padvance ); | |
} | |
/* documentation is in ftadvanc.h */ | |
FT_EXPORT_DEF( FT_Error ) | |
FT_Get_Advances( FT_Face face, | |
FT_UInt start, | |
FT_UInt count, | |
FT_Int32 flags, | |
FT_Fixed *padvances ) | |
{ | |
FT_Face_GetAdvancesFunc func; | |
FT_UInt num, end, nn; | |
FT_Error error = FT_Err_Ok; | |
if ( !face ) | |
return FT_THROW( Invalid_Face_Handle ); | |
if ( !padvances ) | |
return FT_THROW( Invalid_Argument ); | |
num = (FT_UInt)face->num_glyphs; | |
end = start + count; | |
if ( start >= num || end < start || end > num ) | |
return FT_THROW( Invalid_Glyph_Index ); | |
if ( count == 0 ) | |
return FT_Err_Ok; | |
func = face->driver->clazz->get_advances; | |
if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) ) | |
{ | |
error = func( face, start, count, flags, padvances ); | |
if ( !error ) | |
return _ft_face_scale_advances( face, padvances, count, flags ); | |
if ( FT_ERR_NEQ( error, Unimplemented_Feature ) ) | |
return error; | |
} | |
error = FT_Err_Ok; | |
if ( flags & FT_ADVANCE_FLAG_FAST_ONLY ) | |
return FT_THROW( Unimplemented_Feature ); | |
flags |= (FT_UInt32)FT_LOAD_ADVANCE_ONLY; | |
for ( nn = 0; nn < count; nn++ ) | |
{ | |
error = FT_Load_Glyph( face, start + nn, flags ); | |
if ( error ) | |
break; | |
/* scale from 26.6 to 16.16 */ | |
padvances[nn] = ( flags & FT_LOAD_VERTICAL_LAYOUT ) | |
? face->glyph->advance.y << 10 | |
: face->glyph->advance.x << 10; | |
} | |
return error; | |
} | |
/* END */ |