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[autofit] Code shuffling. 

Also improve some comments and remove unused code.

No functional change.

* src/autofit/afloader.c (af_loader_load_g): Merged with...
(af_loader_load_glyph): ...this function.
Split off emboldening code into...
(af_loader_embolden_glyph_in_slot): ... this function.
This commit is contained in:
Nikolaus Waxweiler 2016-11-27 16:30:53 +01:00 committed by Werner Lemberg
parent 7815050334
commit b37b799c56
2 changed files with 268 additions and 258 deletions
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13
ChangeLog
View File

@ -1,3 +1,16 @@
2016-11-27 Nikolaus Waxweiler <madigens@gmail.com>
[autofit] Code shuffling.
Also improve some comments and remove unused code.
No functional change.
* src/autofit/afloader.c (af_loader_load_g): Merged with...
(af_loader_load_glyph): ...this function.
Split off emboldening code into...
(af_loader_embolden_glyph_in_slot): ... this function.
2016-11-17 Werner Lemberg <wl@gnu.org>
Better support of LLP64 systems with gcc (and clang).

513
src/autofit/afloader.c
View File

@ -86,161 +86,258 @@
( (FT_Fixed)( (f) * 65536.0 + 0.5 ) )
/* Do the main work of `af_loader_load_glyph'. Note that we never */
/* have to deal with composite glyphs as those get loaded into */
/* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function. */
/* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies */
/* FT_LOAD_NO_SCALE and as such the auto-hinter is never called. */
static FT_Error
af_loader_load_g( AF_Loader loader,
AF_Scaler scaler,
FT_UInt glyph_index,
FT_Int32 load_flags )
af_loader_embolden_glyph_in_slot( AF_Loader loader,
FT_Face face,
AF_StyleMetrics style_metrics )
{
AF_Module module = loader->globals->module;
FT_Error error = FT_Err_Ok;
FT_Error error;
FT_Face face = loader->face;
AF_StyleMetrics metrics = loader->metrics;
AF_GlyphHints hints = loader->hints;
FT_GlyphSlot slot = face->glyph;
AF_FaceGlobals globals = loader->globals;
AF_WritingSystemClass writing_system_class;
FT_Pos stdVW = 0;
FT_Pos stdHW = 0;
FT_Bool size_changed = face->size->metrics.x_ppem
!= globals->stem_darkening_for_ppem;
FT_Fixed em_size = af_intToFixed( face->units_per_EM );
FT_Fixed em_ratio = FT_DivFix( af_intToFixed( 1000 ), em_size );
FT_Matrix scale_down_matrix = { 0x10000L, 0, 0, 0x10000L };
/* Skip stem darkening for broken fonts. */
if ( !face->units_per_EM )
{
error = FT_Err_Corrupted_Font_Header;
goto Exit;
}
/*
* We depend on the writing system (script analyzers) to supply
* standard widths for the script of the glyph we are looking at. If
* it can't deliver, stem darkening is disabled.
*/
writing_system_class =
AF_WRITING_SYSTEM_CLASSES_GET[style_metrics->style_class->writing_system];
if ( writing_system_class->style_metrics_getstdw )
writing_system_class->style_metrics_getstdw( style_metrics,
&stdHW,
&stdVW );
else
{
error = FT_Err_Unimplemented_Feature;
goto Exit;
}
if ( size_changed ||
( stdVW > 0 && stdVW != globals->standard_vertical_width ) )
{
FT_Fixed darken_by_font_units_x, darken_x;
darken_by_font_units_x =
af_intToFixed( af_loader_compute_darkening( loader,
face,
stdVW ) );
darken_x = FT_DivFix( FT_MulFix( darken_by_font_units_x,
face->size->metrics.x_scale ),
em_ratio );
globals->standard_vertical_width = stdVW;
globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
globals->darken_x = af_fixedToInt( darken_x );
}
if ( size_changed ||
( stdHW > 0 && stdHW != globals->standard_horizontal_width ) )
{
FT_Fixed darken_by_font_units_y, darken_y;
darken_by_font_units_y =
af_intToFixed( af_loader_compute_darkening( loader,
face,
stdHW ) );
darken_y = FT_DivFix( FT_MulFix( darken_by_font_units_y,
face->size->metrics.y_scale ),
em_ratio );
globals->standard_horizontal_width = stdHW;
globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
globals->darken_y = af_fixedToInt( darken_y );
/*
* Scale outlines down on the Y-axis to keep them inside their blue
* zones. The stronger the emboldening, the stronger the downscaling
* (plus heuristical padding to prevent outlines still falling out
* their zones due to rounding).
*
* Reason: `FT_Outline_Embolden' works by shifting the rightmost
* points of stems farther to the right, and topmost points farther
* up. This positions points on the Y-axis outside their
* pre-computed blue zones and leads to distortion when applying the
* hints in the code further below. Code outside this emboldening
* block doesn't know we are presenting it with modified outlines the
* analyzer didn't see!
*
* An unfortunate side effect of downscaling is that the emboldening
* effect is slightly decreased. The loss becomes more pronounced
* versus the CFF driver at smaller sizes, e.g., at 9ppem and below.
*/
globals->scale_down_factor =
FT_DivFix( em_size - ( darken_by_font_units_y + af_intToFixed( 8 ) ),
em_size );
}
FT_Outline_EmboldenXY( &slot->outline,
globals->darken_x,
globals->darken_y );
scale_down_matrix.yy = globals->scale_down_factor;
FT_Outline_Transform( &slot->outline, &scale_down_matrix );
Exit:
return error;
}
/* Load the glyph at index into the current slot of a face and hint it. */
FT_LOCAL_DEF( FT_Error )
af_loader_load_glyph( AF_Loader loader,
AF_Module module,
FT_Face face,
FT_UInt glyph_index,
FT_Int32 load_flags )
{
FT_Error error;
FT_Size size = face->size;
FT_GlyphSlot slot = face->glyph;
FT_Slot_Internal internal = slot->internal;
FT_GlyphLoader gloader = internal->loader;
FT_Int32 flags;
AF_GlyphHints hints = loader->hints;
AF_ScalerRec scaler;
AF_StyleMetrics style_metrics;
FT_UInt style_options = AF_STYLE_NONE_DFLT;
AF_StyleClass style_class;
AF_WritingSystemClass writing_system_class;
#ifdef FT_CONFIG_OPTION_PIC
AF_FaceGlobals globals = loader->globals;
#endif
flags = load_flags | FT_LOAD_LINEAR_DESIGN;
error = FT_Load_Glyph( face, glyph_index, flags );
if ( !size )
return FT_THROW( Invalid_Size_Handle );
FT_ZERO( &scaler );
/*
* TODO: This code currently doesn't support fractional advance widths,
* i.e. placing hinted glyphs at anything other than integer
* x-positions. This is only relevant for the warper code, which
* scales and shifts glyphs to optimize blackness of stems (hinting on
* the x-axis by nature places things on pixel integers, hinting on the
* y-axis only, i.e. LIGHT mode, doesn't touch the x-axis). The delta
* values of the scaler would need to be adjusted.
*/
scaler.face = face;
scaler.x_scale = size->metrics.x_scale;
scaler.x_delta = 0;
scaler.y_scale = size->metrics.y_scale;
scaler.y_delta = 0;
scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
scaler.flags = 0;
error = af_loader_reset( loader, module, face );
if ( error )
goto Exit;
#ifdef FT_OPTION_AUTOFIT2
/* XXX: undocumented hook to activate the latin2 writing system. */
if ( load_flags & ( 1UL << 20 ) )
style_options = AF_STYLE_LTN2_DFLT;
#endif
/*
* Glyphs (really code points) are assigned to scripts. Script
* analysis is done lazily: For each glyph that passes through here,
* the corresponding script analyzer is called, but returns immediately
* if it has been run already.
*/
error = af_face_globals_get_metrics( loader->globals, glyph_index,
style_options, &style_metrics );
if ( error )
goto Exit;
style_class = style_metrics->style_class;
writing_system_class =
AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
loader->metrics = style_metrics;
if ( writing_system_class->style_metrics_scale )
writing_system_class->style_metrics_scale( style_metrics, &scaler );
else
style_metrics->scaler = scaler;
if ( writing_system_class->style_hints_init )
{
error = writing_system_class->style_hints_init( hints,
style_metrics );
if ( error )
goto Exit;
}
/*
* Do the main work of `af_loader_load_glyph'. Note that we never have
* to deal with composite glyphs as those get loaded into
* FT_GLYPH_FORMAT_OUTLINE by the recursed `FT_Load_Glyph' function.
* In the rare cases where FT_LOAD_NO_RECURSE is set, it implies
* FT_LOAD_NO_SCALE and as such the auto-hinter is never called.
*/
load_flags |= FT_LOAD_NO_SCALE |
FT_LOAD_IGNORE_TRANSFORM |
FT_LOAD_LINEAR_DESIGN;
load_flags &= ~FT_LOAD_RENDER;
error = FT_Load_Glyph( face, glyph_index, load_flags );
if ( error )
goto Exit;
/*
* Apply stem darkening (emboldening) here before hints are applied to
* the outline. Glyphs are scaled down proportionally to the
* emboldening so that curve points don't fall outside their precomputed
* blue zones.
* Apply stem darkening (emboldening) here before hints are applied to
* the outline. Glyphs are scaled down proportionally to the
* emboldening so that curve points don't fall outside their
* precomputed blue zones.
*
* Any emboldening done by the font driver (e.g., the CFF driver)
* doesn't reach here because the autohinter loads the unprocessed
* glyphs in font units for analysis (functions `af_*_metrics_init_*')
* and then above to prepare it for the rasterizers by itself,
* independently of the font driver. So emboldening must be done here,
* within the autohinter.
* Any emboldening done by the font driver (e.g., the CFF driver)
* doesn't reach here because the autohinter loads the unprocessed
* glyphs in font units for analysis (functions `af_*_metrics_init_*')
* and then above to prepare it for the rasterizers by itself,
* independently of the font driver. So emboldening must be done here,
* within the autohinter.
*
* All glyphs to be autohinted pass through here one by one. The
* standard widths can therefore change from one glyph to the next,
* depending on what script a glyph is assigned to (each script has its
* own set of standard widths and other metrics). The darkening amount
* must therefore be recomputed for each size and
* `standard_{vertical,horizontal}_width' change.
* All glyphs to be autohinted pass through here one by one. The
* standard widths can therefore change from one glyph to the next,
* depending on what script a glyph is assigned to (each script has its
* own set of standard widths and other metrics). The darkening amount
* must therefore be recomputed for each size and
* `standard_{vertical,horizontal}_width' change.
*
* Ignore errors and carry on without emboldening.
*/
if ( !module->no_stem_darkening )
{
AF_FaceGlobals globals = loader->globals;
AF_WritingSystemClass writing_system_class;
af_loader_embolden_glyph_in_slot( loader, face, style_metrics );
FT_Pos stdVW = 0;
FT_Pos stdHW = 0;
FT_Bool size_changed = face->size->metrics.x_ppem
!= globals->stem_darkening_for_ppem;
FT_Fixed em_size = af_intToFixed( face->units_per_EM );
FT_Fixed em_ratio = FT_DivFix( af_intToFixed( 1000 ), em_size );
FT_Matrix scale_down_matrix = { 0x10000L, 0, 0, 0x10000L };
/* Skip stem darkening for broken fonts. */
if ( !face->units_per_EM )
goto After_Emboldening;
/*
* We depend on the writing system (script analyzers) to supply
* standard widths for the script of the glyph we are looking at. If
* it can't deliver, stem darkening is effectively disabled.
*/
writing_system_class =
AF_WRITING_SYSTEM_CLASSES_GET[metrics->style_class->writing_system];
if ( writing_system_class->style_metrics_getstdw )
writing_system_class->style_metrics_getstdw( metrics,
&stdHW,
&stdVW );
else
goto After_Emboldening;
if ( size_changed ||
( stdVW > 0 && stdVW != globals->standard_vertical_width ) )
{
FT_Fixed darken_by_font_units_x, darken_x;
darken_by_font_units_x =
af_intToFixed( af_loader_compute_darkening( loader,
face,
stdVW ) );
darken_x = FT_DivFix( FT_MulFix( darken_by_font_units_x,
face->size->metrics.x_scale ),
em_ratio );
globals->standard_vertical_width = stdVW;
globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
globals->darken_x = af_fixedToInt( darken_x );
}
if ( size_changed ||
( stdHW > 0 && stdHW != globals->standard_horizontal_width ) )
{
FT_Fixed darken_by_font_units_y, darken_y;
darken_by_font_units_y =
af_intToFixed( af_loader_compute_darkening( loader,
face,
stdHW ) );
darken_y = FT_DivFix( FT_MulFix( darken_by_font_units_y,
face->size->metrics.y_scale ),
em_ratio );
globals->standard_horizontal_width = stdHW;
globals->stem_darkening_for_ppem = face->size->metrics.x_ppem;
globals->darken_y = af_fixedToInt( darken_y );
/*
* Scale outlines down on the Y-axis to keep them inside their blue
* zones. The stronger the emboldening, the stronger the
* downscaling (plus heuristical padding to prevent outlines still
* falling out their zones due to rounding).
*
* Reason: `FT_Outline_Embolden' works by shifting the rightmost
* points of stems farther to the right, and topmost points farther
* up. This positions points on the Y-axis outside their
* pre-computed blue zones and leads to distortion when applying the
* hints in the code further below. Code outside this emboldening
* block doesn't know we are presenting it with modified outlines
* the analyzer didn't see!
*
* An unfortunate side effect of downscaling is that the emboldening
* effect is slightly decreased. The loss becomes more pronounced
* versus the CFF driver at smaller sizes, e.g., at 9ppem and below.
*/
globals->scale_down_factor =
FT_DivFix( em_size - ( darken_by_font_units_y + af_intToFixed( 8 ) ),
em_size );
}
FT_Outline_EmboldenXY( &slot->outline,
globals->darken_x,
globals->darken_y );
scale_down_matrix.yy = globals->scale_down_factor;
FT_Outline_Transform( &slot->outline, &scale_down_matrix );
}
After_Emboldening:
loader->transformed = internal->glyph_transformed;
if ( loader->transformed )
{
@ -264,8 +361,8 @@
loader->trans_delta.x,
loader->trans_delta.y );
/* compute original horizontal phantom points (and ignore */
/* vertical ones) */
/* compute original horizontal phantom points */
/* (and ignore vertical ones) */
loader->pp1.x = hints->x_delta;
loader->pp1.y = hints->y_delta;
loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
@ -276,30 +373,28 @@
if ( slot->outline.n_points == 0 )
goto Hint_Metrics;
/* now load the slot image into the auto-outline and run the */
/* automatic hinting process */
/* now load the slot image into the auto-outline */
/* and run the automatic hinting process */
{
#ifdef FT_CONFIG_OPTION_PIC
AF_FaceGlobals globals = loader->globals;
AF_FaceGlobals globals = loader->globals;
#endif
AF_StyleClass style_class = metrics->style_class;
AF_WritingSystemClass writing_system_class =
AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
if ( writing_system_class->style_hints_apply )
writing_system_class->style_hints_apply( glyph_index,
hints,
&gloader->base.outline,
metrics );
style_metrics );
}
/* we now need to adjust the metrics according to the change in */
/* width/positioning that occurred during the hinting process */
if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
if ( scaler.render_mode != FT_RENDER_MODE_LIGHT )
{
FT_Pos old_rsb, old_lsb, new_lsb;
FT_Pos pp1x_uh, pp2x_uh;
FT_Pos old_rsb, old_lsb, new_lsb;
FT_Pos pp1x_uh, pp2x_uh;
AF_AxisHints axis = &hints->axis[AF_DIMENSION_HORZ];
AF_Edge edge1 = axis->edges; /* leftmost edge */
AF_Edge edge2 = edge1 +
@ -313,9 +408,6 @@
old_lsb = edge1->opos /* - loader->pp1.x */;
new_lsb = edge1->pos;
/* remember unhinted values to later account */
/* for rounding errors */
pp1x_uh = new_lsb - old_lsb;
pp2x_uh = edge2->pos + old_rsb;
@ -381,8 +473,8 @@
vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );
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 )
@ -390,12 +482,12 @@
FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
FT_Vector_Transform( &vvector, &loader->trans_matrix );
}
#if 1
/* 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 );
#endif
FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
bbox.xMin = FT_PIX_FLOOR( bbox.xMin );
@ -414,20 +506,14 @@
/* 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 0
if ( !FT_IS_FIXED_WIDTH( slot->face ) )
slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
else
slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
x_scale );
#else
if ( scaler->render_mode != FT_RENDER_MODE_LIGHT &&
if ( scaler.render_mode != FT_RENDER_MODE_LIGHT &&
( FT_IS_FIXED_WIDTH( slot->face ) ||
( af_face_globals_is_digit( loader->globals, glyph_index ) &&
metrics->digits_have_same_width ) ) )
style_metrics->digits_have_same_width ) ) )
{
slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
metrics->scaler.x_scale );
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. */
@ -440,23 +526,13 @@
if ( slot->metrics.horiAdvance )
slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
}
#endif
slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
metrics->scaler.y_scale );
style_metrics->scaler.y_scale );
slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );
slot->metrics.vertAdvance = FT_PIX_ROUND( slot->metrics.vertAdvance );
#if 0
/* reassign all outline fields except flags to protect them */
slot->outline.n_contours = internal->loader->base.outline.n_contours;
slot->outline.n_points = internal->loader->base.outline.n_points;
slot->outline.points = internal->loader->base.outline.points;
slot->outline.tags = internal->loader->base.outline.tags;
slot->outline.contours = internal->loader->base.outline.contours;
#endif
slot->format = FT_GLYPH_FORMAT_OUTLINE;
}
@ -465,85 +541,6 @@
}
/* Load a glyph. */
FT_LOCAL_DEF( FT_Error )
af_loader_load_glyph( AF_Loader loader,
AF_Module module,
FT_Face face,
FT_UInt gindex,
FT_Int32 load_flags )
{
FT_Error error;
FT_Size size = face->size;
AF_ScalerRec scaler;
if ( !size )
return FT_THROW( Invalid_Size_Handle );
FT_ZERO( &scaler );
scaler.face = face;
scaler.x_scale = size->metrics.x_scale;
scaler.x_delta = 0; /* XXX: TODO: add support for sub-pixel hinting */
scaler.y_scale = size->metrics.y_scale;
scaler.y_delta = 0; /* XXX: TODO: add support for sub-pixel hinting */
scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
scaler.flags = 0; /* XXX: fix this */
error = af_loader_reset( loader, module, face );
if ( !error )
{
AF_StyleMetrics metrics;
FT_UInt options = AF_STYLE_NONE_DFLT;
#ifdef FT_OPTION_AUTOFIT2
/* XXX: undocumented hook to activate the latin2 writing system */
if ( load_flags & ( 1UL << 20 ) )
options = AF_STYLE_LTN2_DFLT;
#endif
error = af_face_globals_get_metrics( loader->globals, gindex,
options, &metrics );
if ( !error )
{
#ifdef FT_CONFIG_OPTION_PIC
AF_FaceGlobals globals = loader->globals;
#endif
AF_StyleClass style_class = metrics->style_class;
AF_WritingSystemClass writing_system_class =
AF_WRITING_SYSTEM_CLASSES_GET[style_class->writing_system];
loader->metrics = metrics;
if ( writing_system_class->style_metrics_scale )
writing_system_class->style_metrics_scale( metrics, &scaler );
else
metrics->scaler = scaler;
load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
load_flags &= ~FT_LOAD_RENDER;
if ( writing_system_class->style_hints_init )
{
error = writing_system_class->style_hints_init( loader->hints,
metrics );
if ( error )
goto Exit;
}
error = af_loader_load_g( loader, &scaler, gindex, load_flags );
}
}
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