0,0 → 1,162 |
/***************************************************************************/ |
/* */ |
/* ftadvanc.c */ |
/* */ |
/* Quick computation of advance widths (body). */ |
/* */ |
/* Copyright 2008, 2009, 2011, 2013 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. */ |
/* */ |
/***************************************************************************/ |
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#include <ft2build.h> |
#include FT_INTERNAL_DEBUG_H |
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#include FT_ADVANCES_H |
#include FT_INTERNAL_OBJECTS_H |
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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; |
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if ( flags & FT_LOAD_NO_SCALE ) |
return FT_Err_Ok; |
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if ( face->size == NULL ) |
return FT_THROW( Invalid_Size_Handle ); |
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if ( flags & FT_LOAD_VERTICAL_LAYOUT ) |
scale = face->size->metrics.y_scale; |
else |
scale = face->size->metrics.x_scale; |
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/* this must be the same scaling as to get linear{Hori,Vert}Advance */ |
/* (see `FT_Load_Glyph' implementation in src/base/ftobjs.c) */ |
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for ( nn = 0; nn < count; nn++ ) |
advances[nn] = FT_MulDiv( advances[nn], scale, 64 ); |
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return FT_Err_Ok; |
} |
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/* at the moment, we can perform fast advance retrieval only in */ |
/* the following cases: */ |
/* */ |
/* - unscaled load */ |
/* - unhinted load */ |
/* - light-hinted load */ |
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#define LOAD_ADVANCE_FAST_CHECK( flags ) \ |
( flags & ( FT_LOAD_NO_SCALE | FT_LOAD_NO_HINTING ) || \ |
FT_LOAD_TARGET_MODE( flags ) == FT_RENDER_MODE_LIGHT ) |
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/* documentation is in ftadvanc.h */ |
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FT_EXPORT_DEF( FT_Error ) |
FT_Get_Advance( FT_Face face, |
FT_UInt gindex, |
FT_Int32 flags, |
FT_Fixed *padvance ) |
{ |
FT_Face_GetAdvancesFunc func; |
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if ( !face ) |
return FT_THROW( Invalid_Face_Handle ); |
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if ( gindex >= (FT_UInt)face->num_glyphs ) |
return FT_THROW( Invalid_Glyph_Index ); |
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func = face->driver->clazz->get_advances; |
if ( func && LOAD_ADVANCE_FAST_CHECK( flags ) ) |
{ |
FT_Error error; |
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error = func( face, gindex, 1, flags, padvance ); |
if ( !error ) |
return _ft_face_scale_advances( face, padvance, 1, flags ); |
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if ( FT_ERR_NEQ( error, Unimplemented_Feature ) ) |
return error; |
} |
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return FT_Get_Advances( face, gindex, 1, flags, padvance ); |
} |
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/* documentation is in ftadvanc.h */ |
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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; |
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if ( !face ) |
return FT_THROW( Invalid_Face_Handle ); |
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num = (FT_UInt)face->num_glyphs; |
end = start + count; |
if ( start >= num || end < start || end > num ) |
return FT_THROW( Invalid_Glyph_Index ); |
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if ( count == 0 ) |
return FT_Err_Ok; |
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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 ); |
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if ( FT_ERR_NEQ( error, Unimplemented_Feature ) ) |
return error; |
} |
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error = FT_Err_Ok; |
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if ( flags & FT_ADVANCE_FLAG_FAST_ONLY ) |
return FT_THROW( Unimplemented_Feature ); |
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flags |= (FT_UInt32)FT_LOAD_ADVANCE_ONLY; |
for ( nn = 0; nn < count; nn++ ) |
{ |
error = FT_Load_Glyph( face, start + nn, flags ); |
if ( error ) |
break; |
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/* scale from 26.6 to 16.16 */ |
padvances[nn] = ( flags & FT_LOAD_VERTICAL_LAYOUT ) |
? face->glyph->advance.y << 10 |
: face->glyph->advance.x << 10; |
} |
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return error; |
} |
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/* END */ |