a7f276a281
This moves warping option from LIGHT to NORMAL mode. This makes LIGHT truly void of hinting in x-direction, with left side bearing never changed and right side bearing only altered by advance rounding. Therefore, LIGHT is now ready to return fractional advance. As a NORMAL option, warping substitutes normal hinting. * src/autofit/afcjk.c (af_cjk_hints_apply): Updated. * src/autofit/aflatin.c (af_latin_hints_apply): Updated. * src/autofit/aflatin2.c (af_latin2_hints_apply): Updated. * src/autofit/afloader.c (af_loader_load_glyph): Handle warping phantom points as normal.
722 lines
25 KiB
C
722 lines
25 KiB
C
/***************************************************************************/
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/* */
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/* afloader.c */
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/* */
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/* Auto-fitter glyph loading routines (body). */
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/* */
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/* Copyright 2003-2017 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/* */
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/***************************************************************************/
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#include "afglobal.h"
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#include "afloader.h"
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#include "afhints.h"
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#include "aferrors.h"
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#include "afmodule.h"
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#include "afpic.h"
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#include FT_INTERNAL_CALC_H
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/* Initialize glyph loader. */
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FT_LOCAL_DEF( void )
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af_loader_init( AF_Loader loader,
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AF_GlyphHints hints )
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{
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FT_ZERO( loader );
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loader->hints = hints;
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}
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/* Reset glyph loader and compute globals if necessary. */
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FT_LOCAL_DEF( FT_Error )
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af_loader_reset( AF_Loader loader,
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AF_Module module,
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FT_Face face )
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{
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FT_Error error = FT_Err_Ok;
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loader->face = face;
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loader->globals = (AF_FaceGlobals)face->autohint.data;
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if ( !loader->globals )
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{
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error = af_face_globals_new( face, &loader->globals, module );
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if ( !error )
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{
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face->autohint.data =
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(FT_Pointer)loader->globals;
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face->autohint.finalizer =
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(FT_Generic_Finalizer)af_face_globals_free;
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}
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}
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return error;
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}
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/* Finalize glyph loader. */
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FT_LOCAL_DEF( void )
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af_loader_done( AF_Loader loader )
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{
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loader->face = NULL;
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loader->globals = NULL;
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loader->hints = NULL;
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}
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#define af_intToFixed( i ) \
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( (FT_Fixed)( (FT_UInt32)(i) << 16 ) )
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#define af_fixedToInt( x ) \
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( (FT_Short)( ( (FT_UInt32)(x) + 0x8000U ) >> 16 ) )
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#define af_floatToFixed( f ) \
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( (FT_Fixed)( (f) * 65536.0 + 0.5 ) )
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static FT_Error
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af_loader_embolden_glyph_in_slot( AF_Loader loader,
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FT_Face face,
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AF_StyleMetrics style_metrics )
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{
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FT_Error error = FT_Err_Ok;
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FT_GlyphSlot slot = face->glyph;
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AF_FaceGlobals globals = loader->globals;
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AF_WritingSystemClass writing_system_class;
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FT_Size_Metrics* size_metrics = &face->size->internal->autohint_metrics;
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FT_Pos stdVW = 0;
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FT_Pos stdHW = 0;
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FT_Bool size_changed = size_metrics->x_ppem !=
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globals->stem_darkening_for_ppem;
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FT_Fixed em_size = af_intToFixed( face->units_per_EM );
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FT_Fixed em_ratio = FT_DivFix( af_intToFixed( 1000 ), em_size );
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FT_Matrix scale_down_matrix = { 0x10000L, 0, 0, 0x10000L };
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/* Skip stem darkening for broken fonts. */
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if ( !face->units_per_EM )
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{
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error = FT_ERR( Corrupted_Font_Header );
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goto Exit;
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}
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/*
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* We depend on the writing system (script analyzers) to supply
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* standard widths for the script of the glyph we are looking at. If
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* it can't deliver, stem darkening is disabled.
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*/
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writing_system_class =
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AF_WRITING_SYSTEM_CLASSES_GET[style_metrics->style_class->writing_system];
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if ( writing_system_class->style_metrics_getstdw )
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writing_system_class->style_metrics_getstdw( style_metrics,
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&stdHW,
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&stdVW );
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else
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{
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error = FT_ERR( Unimplemented_Feature );
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goto Exit;
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}
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if ( size_changed ||
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( stdVW > 0 && stdVW != globals->standard_vertical_width ) )
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{
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FT_Fixed darken_by_font_units_x, darken_x;
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darken_by_font_units_x =
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af_intToFixed( af_loader_compute_darkening( loader,
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face,
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stdVW ) );
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darken_x = FT_DivFix( FT_MulFix( darken_by_font_units_x,
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size_metrics->x_scale ),
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em_ratio );
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globals->standard_vertical_width = stdVW;
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globals->stem_darkening_for_ppem = size_metrics->x_ppem;
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globals->darken_x = af_fixedToInt( darken_x );
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}
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if ( size_changed ||
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( stdHW > 0 && stdHW != globals->standard_horizontal_width ) )
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{
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FT_Fixed darken_by_font_units_y, darken_y;
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darken_by_font_units_y =
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af_intToFixed( af_loader_compute_darkening( loader,
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face,
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stdHW ) );
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darken_y = FT_DivFix( FT_MulFix( darken_by_font_units_y,
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size_metrics->y_scale ),
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em_ratio );
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globals->standard_horizontal_width = stdHW;
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globals->stem_darkening_for_ppem = size_metrics->x_ppem;
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globals->darken_y = af_fixedToInt( darken_y );
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/*
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* Scale outlines down on the Y-axis to keep them inside their blue
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* zones. The stronger the emboldening, the stronger the downscaling
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* (plus heuristical padding to prevent outlines still falling out
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* their zones due to rounding).
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*
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* Reason: `FT_Outline_Embolden' works by shifting the rightmost
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* points of stems farther to the right, and topmost points farther
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* up. This positions points on the Y-axis outside their
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* pre-computed blue zones and leads to distortion when applying the
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* hints in the code further below. Code outside this emboldening
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* block doesn't know we are presenting it with modified outlines the
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* analyzer didn't see!
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*
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* An unfortunate side effect of downscaling is that the emboldening
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* effect is slightly decreased. The loss becomes more pronounced
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* versus the CFF driver at smaller sizes, e.g., at 9ppem and below.
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*/
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globals->scale_down_factor =
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FT_DivFix( em_size - ( darken_by_font_units_y + af_intToFixed( 8 ) ),
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em_size );
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}
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FT_Outline_EmboldenXY( &slot->outline,
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globals->darken_x,
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globals->darken_y );
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scale_down_matrix.yy = globals->scale_down_factor;
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FT_Outline_Transform( &slot->outline, &scale_down_matrix );
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Exit:
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return error;
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}
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/* Load the glyph at index into the current slot of a face and hint it. */
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FT_LOCAL_DEF( FT_Error )
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af_loader_load_glyph( AF_Loader loader,
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AF_Module module,
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FT_Face face,
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FT_UInt glyph_index,
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FT_Int32 load_flags )
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{
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FT_Error error;
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FT_Size size = face->size;
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FT_Size_Internal size_internal = size->internal;
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FT_GlyphSlot slot = face->glyph;
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FT_Slot_Internal slot_internal = slot->internal;
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FT_GlyphLoader gloader = slot_internal->loader;
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AF_GlyphHints hints = loader->hints;
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AF_ScalerRec scaler;
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AF_StyleMetrics style_metrics;
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FT_UInt style_options = AF_STYLE_NONE_DFLT;
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AF_StyleClass style_class;
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AF_WritingSystemClass writing_system_class;
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#ifdef FT_CONFIG_OPTION_PIC
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AF_FaceGlobals globals = loader->globals;
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#endif
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if ( !size )
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return FT_THROW( Invalid_Size_Handle );
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FT_ZERO( &scaler );
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if ( !size_internal->autohint_metrics.x_scale ||
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size_internal->autohint_mode != FT_LOAD_TARGET_MODE( load_flags ) )
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{
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/* switching between hinting modes usually means different scaling */
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/* values; this later on enforces recomputation of everything */
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/* related to the current size */
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size_internal->autohint_mode = FT_LOAD_TARGET_MODE( load_flags );
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size_internal->autohint_metrics = size->metrics;
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#ifdef AF_CONFIG_OPTION_TT_SIZE_METRICS
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{
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FT_Size_Metrics* size_metrics = &size_internal->autohint_metrics;
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/* set metrics to integer values and adjust scaling accordingly; */
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/* this is the same setup as with TrueType fonts, cf. function */
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/* `tt_size_reset' in file `ttobjs.c' */
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size_metrics->ascender = FT_PIX_ROUND(
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FT_MulFix( face->ascender,
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size_metrics->y_scale ) );
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size_metrics->descender = FT_PIX_ROUND(
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FT_MulFix( face->descender,
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size_metrics->y_scale ) );
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size_metrics->height = FT_PIX_ROUND(
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FT_MulFix( face->height,
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size_metrics->y_scale ) );
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size_metrics->x_scale = FT_DivFix( size_metrics->x_ppem << 6,
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face->units_per_EM );
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size_metrics->y_scale = FT_DivFix( size_metrics->y_ppem << 6,
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face->units_per_EM );
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size_metrics->max_advance = FT_PIX_ROUND(
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FT_MulFix( face->max_advance_width,
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size_metrics->x_scale ) );
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}
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#endif /* AF_CONFIG_OPTION_TT_SIZE_METRICS */
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}
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/*
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* TODO: This code currently doesn't support fractional advance widths,
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* i.e., placing hinted glyphs at anything other than integer
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* x-positions. This is only relevant for the warper code, which
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* scales and shifts glyphs to optimize blackness of stems (hinting on
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* the x-axis by nature places things on pixel integers, hinting on the
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* y-axis only, i.e., LIGHT mode, doesn't touch the x-axis). The delta
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* values of the scaler would need to be adjusted.
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*/
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scaler.face = face;
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scaler.x_scale = size_internal->autohint_metrics.x_scale;
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scaler.x_delta = 0;
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scaler.y_scale = size_internal->autohint_metrics.y_scale;
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scaler.y_delta = 0;
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scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
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scaler.flags = 0;
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/* note that the fallback style can't be changed anymore */
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/* after the first call of `af_loader_load_glyph' */
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error = af_loader_reset( loader, module, face );
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if ( error )
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goto Exit;
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#ifdef FT_OPTION_AUTOFIT2
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/* XXX: undocumented hook to activate the latin2 writing system. */
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if ( load_flags & ( 1UL << 20 ) )
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style_options = AF_STYLE_LTN2_DFLT;
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#endif
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/*
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* Glyphs (really code points) are assigned to scripts. Script
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* analysis is done lazily: For each glyph that passes through here,
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* the corresponding script analyzer is called, but returns immediately
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* if it has been run already.
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*/
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error = af_face_globals_get_metrics( loader->globals, glyph_index,
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style_options, &style_metrics );
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if ( error )
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goto Exit;
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style_class = style_metrics->style_class;
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writing_system_class =
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AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
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loader->metrics = style_metrics;
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if ( writing_system_class->style_metrics_scale )
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writing_system_class->style_metrics_scale( style_metrics, &scaler );
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else
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style_metrics->scaler = scaler;
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if ( writing_system_class->style_hints_init )
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{
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error = writing_system_class->style_hints_init( hints,
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style_metrics );
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if ( error )
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goto Exit;
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}
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/*
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* Do the main work of `af_loader_load_glyph'. Note that we never have
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* to deal with composite glyphs as those get loaded into
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* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function.
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* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies
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* FT_LOAD_NO_SCALE and as such the auto-hinter is never called.
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*/
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load_flags |= FT_LOAD_NO_SCALE |
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FT_LOAD_IGNORE_TRANSFORM |
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FT_LOAD_LINEAR_DESIGN;
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load_flags &= ~FT_LOAD_RENDER;
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error = FT_Load_Glyph( face, glyph_index, load_flags );
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if ( error )
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goto Exit;
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/*
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* Apply stem darkening (emboldening) here before hints are applied to
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* the outline. Glyphs are scaled down proportionally to the
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* emboldening so that curve points don't fall outside their
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* precomputed blue zones.
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*
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* Any emboldening done by the font driver (e.g., the CFF driver)
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* doesn't reach here because the autohinter loads the unprocessed
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* glyphs in font units for analysis (functions `af_*_metrics_init_*')
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* and then above to prepare it for the rasterizers by itself,
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* independently of the font driver. So emboldening must be done here,
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* within the autohinter.
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*
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* All glyphs to be autohinted pass through here one by one. The
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* standard widths can therefore change from one glyph to the next,
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* depending on what script a glyph is assigned to (each script has its
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* own set of standard widths and other metrics). The darkening amount
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* must therefore be recomputed for each size and
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* `standard_{vertical,horizontal}_width' change.
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*
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* Ignore errors and carry on without emboldening.
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*
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*/
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/* stem darkening only works well in `light' mode */
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if ( scaler.render_mode == FT_RENDER_MODE_LIGHT &&
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( !face->internal->no_stem_darkening ||
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( face->internal->no_stem_darkening < 0 &&
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!module->no_stem_darkening ) ) )
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af_loader_embolden_glyph_in_slot( loader, face, style_metrics );
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loader->transformed = slot_internal->glyph_transformed;
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if ( loader->transformed )
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{
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FT_Matrix inverse;
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loader->trans_matrix = slot_internal->glyph_matrix;
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loader->trans_delta = slot_internal->glyph_delta;
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inverse = loader->trans_matrix;
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if ( !FT_Matrix_Invert( &inverse ) )
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FT_Vector_Transform( &loader->trans_delta, &inverse );
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}
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switch ( slot->format )
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{
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case FT_GLYPH_FORMAT_OUTLINE:
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/* translate the loaded glyph when an internal transform is needed */
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if ( loader->transformed )
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FT_Outline_Translate( &slot->outline,
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loader->trans_delta.x,
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loader->trans_delta.y );
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/* compute original horizontal phantom points */
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/* (and ignore vertical ones) */
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loader->pp1.x = hints->x_delta;
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loader->pp1.y = hints->y_delta;
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loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
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hints->x_scale ) + hints->x_delta;
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loader->pp2.y = hints->y_delta;
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/* be sure to check for spacing glyphs */
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if ( slot->outline.n_points == 0 )
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goto Hint_Metrics;
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/* now load the slot image into the auto-outline */
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/* and run the automatic hinting process */
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if ( writing_system_class->style_hints_apply )
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writing_system_class->style_hints_apply( glyph_index,
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hints,
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&gloader->base.outline,
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style_metrics );
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/* we now need to adjust the metrics according to the change in */
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/* width/positioning that occurred during the hinting process */
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if ( scaler.render_mode != FT_RENDER_MODE_LIGHT )
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{
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FT_Pos old_rsb, old_lsb, new_lsb;
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FT_Pos pp1x_uh, pp2x_uh;
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AF_AxisHints axis = &hints->axis[AF_DIMENSION_HORZ];
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AF_Edge edge1 = axis->edges; /* leftmost edge */
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AF_Edge edge2 = edge1 +
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axis->num_edges - 1; /* rightmost edge */
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if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
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{
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old_rsb = loader->pp2.x - edge2->opos;
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/* loader->pp1.x is always zero at this point of time */
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old_lsb = edge1->opos /* - loader->pp1.x */;
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new_lsb = edge1->pos;
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/* remember unhinted values to later account */
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/* for rounding errors */
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pp1x_uh = new_lsb - old_lsb;
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pp2x_uh = edge2->pos + old_rsb;
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/* prefer too much space over too little space */
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/* for very small sizes */
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if ( old_lsb < 24 )
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pp1x_uh -= 8;
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if ( old_rsb < 24 )
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pp2x_uh += 8;
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loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
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loader->pp2.x = FT_PIX_ROUND( pp2x_uh );
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if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
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loader->pp1.x -= 64;
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if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
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loader->pp2.x += 64;
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slot->lsb_delta = loader->pp1.x - pp1x_uh;
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slot->rsb_delta = loader->pp2.x - pp2x_uh;
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}
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else
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{
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FT_Pos pp1x = loader->pp1.x;
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FT_Pos pp2x = loader->pp2.x;
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loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
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loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );
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slot->lsb_delta = loader->pp1.x - pp1x;
|
|
slot->rsb_delta = loader->pp2.x - pp2x;
|
|
}
|
|
}
|
|
/* `light' mode uses integer advance widths */
|
|
/* but sets `lsb_delta' and `rsb_delta' */
|
|
else
|
|
{
|
|
FT_Pos pp1x = loader->pp1.x;
|
|
FT_Pos pp2x = loader->pp2.x;
|
|
|
|
|
|
loader->pp1.x = FT_PIX_ROUND( pp1x );
|
|
loader->pp2.x = FT_PIX_ROUND( pp2x );
|
|
|
|
slot->lsb_delta = loader->pp1.x - pp1x;
|
|
slot->rsb_delta = loader->pp2.x - pp2x;
|
|
}
|
|
|
|
break;
|
|
|
|
default:
|
|
/* we don't support other formats (yet?) */
|
|
error = FT_THROW( Unimplemented_Feature );
|
|
}
|
|
|
|
Hint_Metrics:
|
|
{
|
|
FT_BBox bbox;
|
|
FT_Vector vvector;
|
|
|
|
|
|
vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
|
|
vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
|
|
vvector.x = FT_MulFix( vvector.x, style_metrics->scaler.x_scale );
|
|
vvector.y = FT_MulFix( vvector.y, style_metrics->scaler.y_scale );
|
|
|
|
/* transform the hinted outline if needed */
|
|
if ( loader->transformed )
|
|
{
|
|
FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
|
|
FT_Vector_Transform( &vvector, &loader->trans_matrix );
|
|
}
|
|
|
|
/* we must translate our final outline by -pp1.x and compute */
|
|
/* the new metrics */
|
|
if ( loader->pp1.x )
|
|
FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );
|
|
|
|
FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
|
|
|
|
bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
|
|
bbox.yMin = FT_PIX_FLOOR( bbox.yMin );
|
|
bbox.xMax = FT_PIX_CEIL( bbox.xMax );
|
|
bbox.yMax = FT_PIX_CEIL( bbox.yMax );
|
|
|
|
slot->metrics.width = bbox.xMax - bbox.xMin;
|
|
slot->metrics.height = bbox.yMax - bbox.yMin;
|
|
slot->metrics.horiBearingX = bbox.xMin;
|
|
slot->metrics.horiBearingY = bbox.yMax;
|
|
|
|
slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
|
|
slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );
|
|
|
|
/* for mono-width fonts (like Andale, Courier, etc.) we need */
|
|
/* to keep the original rounded advance width; ditto for */
|
|
/* digits if all have the same advance width */
|
|
if ( scaler.render_mode != FT_RENDER_MODE_LIGHT &&
|
|
( FT_IS_FIXED_WIDTH( slot->face ) ||
|
|
( af_face_globals_is_digit( loader->globals, glyph_index ) &&
|
|
style_metrics->digits_have_same_width ) ) )
|
|
{
|
|
slot->metrics.horiAdvance =
|
|
FT_MulFix( slot->metrics.horiAdvance,
|
|
style_metrics->scaler.x_scale );
|
|
|
|
/* Set delta values to 0. Otherwise code that uses them is */
|
|
/* going to ruin the fixed advance width. */
|
|
slot->lsb_delta = 0;
|
|
slot->rsb_delta = 0;
|
|
}
|
|
else
|
|
{
|
|
/* non-spacing glyphs must stay as-is */
|
|
if ( slot->metrics.horiAdvance )
|
|
slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
|
|
}
|
|
|
|
slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
|
|
style_metrics->scaler.y_scale );
|
|
|
|
slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
|
|
slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
|
|
|
|
slot->format = FT_GLYPH_FORMAT_OUTLINE;
|
|
}
|
|
|
|
Exit:
|
|
return error;
|
|
}
|
|
|
|
|
|
/*
|
|
* Compute amount of font units the face should be emboldened by, in
|
|
* analogy to the CFF driver's `cf2_computeDarkening' function. See there
|
|
* for details of the algorithm.
|
|
*
|
|
* XXX: Currently a crude adaption of the original algorithm. Do better?
|
|
*/
|
|
FT_LOCAL_DEF( FT_Int32 )
|
|
af_loader_compute_darkening( AF_Loader loader,
|
|
FT_Face face,
|
|
FT_Pos standard_width )
|
|
{
|
|
AF_Module module = loader->globals->module;
|
|
|
|
FT_UShort units_per_EM;
|
|
FT_Fixed ppem, em_ratio;
|
|
FT_Fixed stem_width, stem_width_per_1000, scaled_stem, darken_amount;
|
|
FT_Int log_base_2;
|
|
FT_Int x1, y1, x2, y2, x3, y3, x4, y4;
|
|
|
|
|
|
ppem = FT_MAX( af_intToFixed( 4 ),
|
|
af_intToFixed( face->size->metrics.x_ppem ) );
|
|
units_per_EM = face->units_per_EM;
|
|
|
|
em_ratio = FT_DivFix( af_intToFixed( 1000 ),
|
|
af_intToFixed ( units_per_EM ) );
|
|
if ( em_ratio < af_floatToFixed( .01 ) )
|
|
{
|
|
/* If something goes wrong, don't embolden. */
|
|
return 0;
|
|
}
|
|
|
|
x1 = module->darken_params[0];
|
|
y1 = module->darken_params[1];
|
|
x2 = module->darken_params[2];
|
|
y2 = module->darken_params[3];
|
|
x3 = module->darken_params[4];
|
|
y3 = module->darken_params[5];
|
|
x4 = module->darken_params[6];
|
|
y4 = module->darken_params[7];
|
|
|
|
if ( standard_width <= 0 )
|
|
{
|
|
stem_width = af_intToFixed( 75 ); /* taken from cf2font.c */
|
|
stem_width_per_1000 = stem_width;
|
|
}
|
|
else
|
|
{
|
|
stem_width = af_intToFixed( standard_width );
|
|
stem_width_per_1000 = FT_MulFix( stem_width, em_ratio );
|
|
}
|
|
|
|
log_base_2 = FT_MSB( (FT_UInt32)stem_width_per_1000 ) +
|
|
FT_MSB( (FT_UInt32)ppem );
|
|
|
|
if ( log_base_2 >= 46 )
|
|
{
|
|
/* possible overflow */
|
|
scaled_stem = af_intToFixed( x4 );
|
|
}
|
|
else
|
|
scaled_stem = FT_MulFix( stem_width_per_1000, ppem );
|
|
|
|
/* now apply the darkening parameters */
|
|
if ( scaled_stem < af_intToFixed( x1 ) )
|
|
darken_amount = FT_DivFix( af_intToFixed( y1 ), ppem );
|
|
|
|
else if ( scaled_stem < af_intToFixed( x2 ) )
|
|
{
|
|
FT_Int xdelta = x2 - x1;
|
|
FT_Int ydelta = y2 - y1;
|
|
FT_Int x = stem_width_per_1000 -
|
|
FT_DivFix( af_intToFixed( x1 ), ppem );
|
|
|
|
|
|
if ( !xdelta )
|
|
goto Try_x3;
|
|
|
|
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
|
|
FT_DivFix( af_intToFixed( y1 ), ppem );
|
|
}
|
|
|
|
else if ( scaled_stem < af_intToFixed( x3 ) )
|
|
{
|
|
Try_x3:
|
|
{
|
|
FT_Int xdelta = x3 - x2;
|
|
FT_Int ydelta = y3 - y2;
|
|
FT_Int x = stem_width_per_1000 -
|
|
FT_DivFix( af_intToFixed( x2 ), ppem );
|
|
|
|
|
|
if ( !xdelta )
|
|
goto Try_x4;
|
|
|
|
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
|
|
FT_DivFix( af_intToFixed( y2 ), ppem );
|
|
}
|
|
}
|
|
|
|
else if ( scaled_stem < af_intToFixed( x4 ) )
|
|
{
|
|
Try_x4:
|
|
{
|
|
FT_Int xdelta = x4 - x3;
|
|
FT_Int ydelta = y4 - y3;
|
|
FT_Int x = stem_width_per_1000 -
|
|
FT_DivFix( af_intToFixed( x3 ), ppem );
|
|
|
|
|
|
if ( !xdelta )
|
|
goto Use_y4;
|
|
|
|
darken_amount = FT_MulDiv( x, ydelta, xdelta ) +
|
|
FT_DivFix( af_intToFixed( y3 ), ppem );
|
|
}
|
|
}
|
|
|
|
else
|
|
{
|
|
Use_y4:
|
|
darken_amount = FT_DivFix( af_intToFixed( y4 ), ppem );
|
|
}
|
|
|
|
/* Convert darken_amount from per 1000 em to true character space. */
|
|
return af_fixedToInt( FT_DivFix( darken_amount, em_ratio ) );
|
|
}
|
|
|
|
|
|
/* END */
|