Commit 63bef9a588c3410007ead16e4121830cc1b1b2e2
2014-05-01T07:16:05
[autofit] Fix handling of neutral blue zones in stems. * src/autofit/afhints.h (AF_Edge_Flags): New value `AF_EDGE_NEUTRAL'. * src/autofit/aflatin.c (af_latin_hints_compute_blue_edges): Trace neutral blue zones with AF_EDGE_NEUTRAL. (af_latin_hint_edges): Skip neutral blue zones if necessary.
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diff --git a/ChangeLog b/ChangeLog
index ddc68ce..11dc4c2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2014-05-01 Werner Lemberg <wl@gnu.org>
+
+ [autofit] Fix handling of neutral blue zones in stems.
+
+ * src/autofit/afhints.h (AF_Edge_Flags): New value
+ `AF_EDGE_NEUTRAL'.
+
+ * src/autofit/aflatin.c (af_latin_hints_compute_blue_edges): Trace
+ neutral blue zones with AF_EDGE_NEUTRAL.
+ (af_latin_hint_edges): Skip neutral blue zones if necessary.
+
2014-04-28 Werner Lemberg <wl@gnu.org>
[autofit] Introduce neutral blue zones to the latin module.
diff --git a/src/autofit/afhints.h b/src/autofit/afhints.h
index 6e1b1ff..c0ebd0d 100644
--- a/src/autofit/afhints.h
+++ b/src/autofit/afhints.h
@@ -244,10 +244,11 @@ FT_BEGIN_HEADER
/* edge hint flags */
typedef enum AF_Edge_Flags_
{
- AF_EDGE_NORMAL = 0,
- AF_EDGE_ROUND = 1 << 0,
- AF_EDGE_SERIF = 1 << 1,
- AF_EDGE_DONE = 1 << 2
+ AF_EDGE_NORMAL = 0,
+ AF_EDGE_ROUND = 1 << 0,
+ AF_EDGE_SERIF = 1 << 1,
+ AF_EDGE_DONE = 1 << 2,
+ AF_EDGE_NEUTRAL = 1 << 3 /* set if edge aligns to a neutral blue zone */
} AF_Edge_Flags;
diff --git a/src/autofit/aflatin.c b/src/autofit/aflatin.c
index 825c361..a0d9ebc 100644
--- a/src/autofit/aflatin.c
+++ b/src/autofit/aflatin.c
@@ -1841,8 +1841,9 @@
for ( ; edge < edge_limit; edge++ )
{
FT_UInt bb;
- AF_Width best_blue = NULL;
- FT_Pos best_dist; /* initial threshold */
+ AF_Width best_blue = NULL;
+ FT_Bool best_blue_is_neutral = 0;
+ FT_Pos best_dist; /* initial threshold */
/* compute the initial threshold as a fraction of the EM size */
@@ -1856,7 +1857,7 @@
for ( bb = 0; bb < latin->blue_count; bb++ )
{
AF_LatinBlue blue = latin->blues + bb;
- FT_Bool is_top_blue, is_major_dir;
+ FT_Bool is_top_blue, is_neutral_blue, is_major_dir;
/* skip inactive blue zones (i.e., those that are too large) */
@@ -1867,12 +1868,15 @@
/* direction); if it is a bottom zone, check for left edges (in */
/* the major direction) -- this assumes the TrueType convention */
/* for the orientation of contours */
- is_top_blue = (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
- is_major_dir = FT_BOOL( edge->dir == axis->major_dir );
+ is_top_blue =
+ (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_TOP ) != 0 );
+ is_neutral_blue =
+ (FT_Byte)( ( blue->flags & AF_LATIN_BLUE_NEUTRAL ) != 0);
+ is_major_dir =
+ FT_BOOL( edge->dir == axis->major_dir );
/* neutral blue zones are handled for both directions */
- if ( is_top_blue ^ is_major_dir ||
- blue->flags & AF_LATIN_BLUE_NEUTRAL )
+ if ( is_top_blue ^ is_major_dir || is_neutral_blue )
{
FT_Pos dist;
@@ -1885,8 +1889,9 @@
dist = FT_MulFix( dist, scale );
if ( dist < best_dist )
{
- best_dist = dist;
- best_blue = &blue->ref;
+ best_dist = dist;
+ best_blue = &blue->ref;
+ best_blue_is_neutral = is_neutral_blue;
}
/* now compare it to the overshoot position and check whether */
@@ -1894,9 +1899,9 @@
/* reference position of a top zone, or under the reference */
/* position of a bottom zone (provided we don't have a */
/* neutral blue zone) */
- if ( edge->flags & AF_EDGE_ROUND &&
- dist != 0 &&
- !( blue->flags & AF_LATIN_BLUE_NEUTRAL ) )
+ if ( edge->flags & AF_EDGE_ROUND &&
+ dist != 0 &&
+ !is_neutral_blue )
{
FT_Bool is_under_ref = FT_BOOL( edge->fpos < blue->ref.org );
@@ -1910,8 +1915,9 @@
dist = FT_MulFix( dist, scale );
if ( dist < best_dist )
{
- best_dist = dist;
- best_blue = &blue->shoot;
+ best_dist = dist;
+ best_blue = &blue->shoot;
+ best_blue_is_neutral = is_neutral_blue;
}
}
}
@@ -1919,7 +1925,11 @@
}
if ( best_blue )
+ {
edge->blue_edge = best_blue;
+ if ( best_blue_is_neutral )
+ edge->flags |= AF_EDGE_NEUTRAL;
+ }
}
}
@@ -2304,14 +2314,41 @@
if ( edge->flags & AF_EDGE_DONE )
continue;
- blue = edge->blue_edge;
edge1 = NULL;
edge2 = edge->link;
+ /*
+ * If a stem contains both a neutral and a non-neutral blue zone,
+ * skip the neutral one. Otherwise, outlines with different
+ * directions might be incorrectly aligned at the same vertical
+ * position.
+ *
+ * If we have two neutral blue zones, skip one of them.
+ *
+ */
+ if ( edge->blue_edge && edge2 && edge2->blue_edge )
+ {
+ FT_Byte neutral = edge->flags & AF_EDGE_NEUTRAL;
+ FT_Byte neutral2 = edge2->flags & AF_EDGE_NEUTRAL;
+
+
+ if ( ( neutral && neutral2 ) || neutral2 )
+ {
+ edge2->blue_edge = NULL;
+ edge2->flags &= ~AF_EDGE_NEUTRAL;
+ }
+ else if ( neutral )
+ {
+ edge->blue_edge = NULL;
+ edge->flags &= ~AF_EDGE_NEUTRAL;
+ }
+ }
+
+ blue = edge->blue_edge;
if ( blue )
edge1 = edge;
- /* flip edges if the other stem is aligned to a blue zone */
+ /* flip edges if the other edge is aligned to a blue zone */
else if ( edge2 && edge2->blue_edge )
{
blue = edge2->blue_edge;
@@ -2378,7 +2415,7 @@
/* this should not happen, but it's better to be safe */
if ( edge2->blue_edge )
{
- FT_TRACE5(( " ASSERTION FAILED for edge %d\n", edge2-edges ));
+ FT_TRACE5(( " ASSERTION FAILED for edge %d\n", edge2 - edges ));
af_latin_align_linked_edge( hints, dim, edge2, edge );
edge->flags |= AF_EDGE_DONE;