From 894c0228caa88d98a909bd7385f079eee49bdaee Mon Sep 17 00:00:00 2001 From: Werner Lemberg Date: Fri, 15 Jul 2016 10:23:11 +0200 Subject: [PATCH] [autofit] For edges, reject segments wider than 1px (#41334). * src/autofit/afhints.h (AF_SegmentRec): New member `delta'. * src/autofit/aflatin.c (af_latin_hints_compute_segments): Compute `delta'. (af_latin_hints_compute_edges): Reject segments with a delta larger than 0.5px. --- ChangeLog | 11 +++++++++++ src/autofit/afhints.h | 1 + src/autofit/aflatin.c | 21 +++++++++++++++------ 3 files changed, 27 insertions(+), 6 deletions(-) diff --git a/ChangeLog b/ChangeLog index b2400c238..887e61179 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,14 @@ +2016-07-15 Werner Lemberg + + [autofit] For edges, reject segments wider than 1px (#41334). + + * src/autofit/afhints.h (AF_SegmentRec): New member `delta'. + + * src/autofit/aflatin.c (af_latin_hints_compute_segments): Compute + `delta'. + (af_latin_hints_compute_edges): Reject segments with a delta larger + than 0.5px. + 2016-07-14 Werner Lemberg * include/freetype/freetype.h (FT_IS_NAMED_INSTANCE): New macro. diff --git a/src/autofit/afhints.h b/src/autofit/afhints.h index 5142e6ed2..4fdf732d4 100644 --- a/src/autofit/afhints.h +++ b/src/autofit/afhints.h @@ -260,6 +260,7 @@ FT_BEGIN_HEADER FT_Byte flags; /* edge/segment flags for this segment */ FT_Char dir; /* segment direction */ FT_Short pos; /* position of segment */ + FT_Short delta; /* deviation from segment position */ FT_Short min_coord; /* minimum coordinate of segment */ FT_Short max_coord; /* maximum coordinate of segment */ FT_Short height; /* the hinted segment height */ diff --git a/src/autofit/aflatin.c b/src/autofit/aflatin.c index 7ccf3f6e3..fd4be9925 100644 --- a/src/autofit/aflatin.c +++ b/src/autofit/aflatin.c @@ -1536,8 +1536,9 @@ /* points are different: we are just leaving an edge, thus */ /* record a new segment */ - segment->last = point; - segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); + segment->last = point; + segment->pos = (FT_Short)( ( min_pos + max_pos ) >> 1 ); + segment->delta = (FT_Short)FT_ABS( ( max_pos - min_pos ) >> 1 ); /* a segment is round if either its first or last point */ /* is a control point, and the length of the on points */ @@ -1966,6 +1967,7 @@ FT_Fixed scale; FT_Pos edge_distance_threshold; FT_Pos segment_length_threshold; + FT_Pos segment_width_threshold; axis->num_edges = 0; @@ -1987,9 +1989,15 @@ * corresponding threshold in font units. */ if ( dim == AF_DIMENSION_HORZ ) - segment_length_threshold = FT_DivFix( 64, hints->y_scale ); + segment_length_threshold = FT_DivFix( 64, hints->y_scale ); else - segment_length_threshold = 0; + segment_length_threshold = 0; + + /* + * Similarly, we ignore segments that have a width delta + * larger than 0.5px (i.e., a width larger than 1px). + */ + segment_width_threshold = FT_DivFix( 32, scale ); /*********************************************************************/ /* */ @@ -2022,9 +2030,10 @@ FT_Int ee; - /* ignore too short segments and, in this loop, */ - /* one-point segments without a direction */ + /* ignore too short segments, too wide ones, and, in this loop, */ + /* one-point segments without a direction */ if ( seg->height < segment_length_threshold || + seg->delta > segment_width_threshold || seg->dir == AF_DIR_NONE ) continue;