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[pshinter] Merge extrema and inflex analyses.
Any point on the horizontal or vertical segment, which can either be either extreme or inflection point is now marked. This makes separate inflection algorithm unnecessary. This simplifies the algorithm without noticeable rendering differences. * src/pshinter/pshalgo.c (psh_glyph_compute_extrema): Rewrite to detect both extrema and inflection points. Determine the their direction instantly.
This commit is contained in:
Alexei Podtelezhnikov
parent
676e8b8637
commit
e3a0652b6d
1 changed files with 20 additions and 217 deletions
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@ -35,10 +35,6 @@
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#endif
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#define COMPUTE_INFLEXS /* compute inflection points to optimize `S' */
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/* and similar glyphs */
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/*************************************************************************/
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/*************************************************************************/
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/***** *****/
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@ -920,117 +916,6 @@
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#define psh_corner_orientation ft_corner_orientation
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#ifdef COMPUTE_INFLEXS
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/* compute all inflex points in a given glyph */
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static void
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psh_glyph_compute_inflections( PSH_Glyph glyph )
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{
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FT_UInt n;
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for ( n = 0; n < glyph->num_contours; n++ )
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{
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PSH_Point first, start, end, before, after;
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FT_Pos in_x, in_y, out_x, out_y;
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FT_Int orient_prev, orient_cur;
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FT_Int finished = 0;
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/* we need at least 4 points to create an inflection point */
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if ( glyph->contours[n].count < 4 )
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continue;
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/* compute first segment in contour */
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first = glyph->contours[n].start;
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start = end = first;
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do
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{
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end = end->next;
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if ( end == first )
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goto Skip;
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in_x = end->org_u - start->org_u;
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in_y = end->org_v - start->org_v;
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} while ( in_x == 0 && in_y == 0 );
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/* extend the segment start whenever possible */
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before = start;
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do
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{
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do
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{
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start = before;
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before = before->prev;
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if ( before == first )
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goto Skip;
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out_x = start->org_u - before->org_u;
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out_y = start->org_v - before->org_v;
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} while ( out_x == 0 && out_y == 0 );
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orient_prev = psh_corner_orientation( in_x, in_y, out_x, out_y );
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} while ( orient_prev == 0 );
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first = start;
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in_x = out_x;
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in_y = out_y;
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/* now, process all segments in the contour */
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do
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{
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/* first, extend current segment's end whenever possible */
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after = end;
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do
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{
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do
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{
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end = after;
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after = after->next;
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if ( after == first )
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finished = 1;
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out_x = after->org_u - end->org_u;
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out_y = after->org_v - end->org_v;
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} while ( out_x == 0 && out_y == 0 );
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orient_cur = psh_corner_orientation( in_x, in_y, out_x, out_y );
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} while ( orient_cur == 0 );
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if ( ( orient_cur ^ orient_prev ) < 0 )
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{
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do
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{
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psh_point_set_inflex( start );
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start = start->next;
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}
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while ( start != end );
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psh_point_set_inflex( start );
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}
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start = end;
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end = after;
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orient_prev = orient_cur;
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in_x = out_x;
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in_y = out_y;
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} while ( !finished );
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Skip:
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;
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}
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}
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#endif /* COMPUTE_INFLEXS */
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static void
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psh_glyph_done( PSH_Glyph glyph )
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{
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@ -1258,11 +1143,6 @@
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glyph->outline = outline;
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glyph->globals = globals;
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#ifdef COMPUTE_INFLEXS
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psh_glyph_load_points( glyph, 0 );
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psh_glyph_compute_inflections( glyph );
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#endif /* COMPUTE_INFLEXS */
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/* now deal with hints tables */
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error = psh_hint_table_init( &glyph->hint_tables [0],
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&ps_hints->dimension[0].hints,
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@ -1285,123 +1165,47 @@
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}
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/* compute all extrema in a glyph for a given dimension */
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/* compute all extreme and inflection points */
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/* in a glyph for a given dimension */
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static void
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psh_glyph_compute_extrema( PSH_Glyph glyph )
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{
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FT_UInt n;
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/* first of all, compute all local extrema */
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for ( n = 0; n < glyph->num_contours; n++ )
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{
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PSH_Point first = glyph->contours[n].start;
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PSH_Point point, before, after;
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PSH_Point first, point, before, after;
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/* we need at least 3 points to create an extremum */
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if ( glyph->contours[n].count < 3 )
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continue;
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point = first;
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before = point;
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first = glyph->contours[n].start;
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point = first->prev;
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after = first;
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do
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{
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before = before->prev;
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if ( before == first )
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goto Next;
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} while ( before->org_u == point->org_u );
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first = point = before->next;
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for (;;)
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{
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after = point;
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do
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{
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after = after->next;
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if ( after == first )
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goto Next;
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} while ( after->org_u == point->org_u );
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if ( before->org_u < point->org_u )
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{
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if ( after->org_u < point->org_u )
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{
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/* local maximum */
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goto Extremum;
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}
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}
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else /* before->org_u > point->org_u */
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{
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if ( after->org_u > point->org_u )
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{
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/* local minimum */
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Extremum:
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do
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{
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psh_point_set_extremum( point );
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point = point->next;
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} while ( point != after );
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}
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}
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before = after->prev;
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before = point;
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point = after;
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after = point->next;
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} /* for */
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if ( ( before->org_u < point->org_u && point->org_u < after->org_u ) ||
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( before->org_u > point->org_u && point->org_u > after->org_u ) )
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continue;
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Next:
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;
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}
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/* otherwise this is either extremum or inflection point */
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psh_point_set_extremum( point );
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/* for each extremum, determine its direction along the */
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/* orthogonal axis */
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for ( n = 0; n < glyph->num_points; n++ )
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{
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PSH_Point point, before, after;
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/* also note its direction */
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if ( before->org_v < after->org_v )
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psh_point_set_positive( point );
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else if ( before->org_v > after->org_v )
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psh_point_set_negative( point );
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point = &glyph->points[n];
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before = point;
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after = point;
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if ( psh_point_is_extremum( point ) )
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{
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do
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{
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before = before->prev;
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if ( before == point )
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goto Skip;
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} while ( before->org_v == point->org_v );
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do
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{
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after = after->next;
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if ( after == point )
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goto Skip;
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} while ( after->org_v == point->org_v );
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}
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if ( before->org_v < point->org_v &&
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after->org_v > point->org_v )
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{
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psh_point_set_positive( point );
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}
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else if ( before->org_v > point->org_v &&
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after->org_v < point->org_v )
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{
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psh_point_set_negative( point );
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}
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Skip:
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;
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} while ( after != first );
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}
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}
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@ -1837,8 +1641,7 @@
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point->dir_in != point->dir_out )
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continue;
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if ( !psh_point_is_extremum( point ) &&
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!psh_point_is_inflex( point ) )
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if ( !psh_point_is_extremum( point ) )
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continue;
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point->flags &= ~PSH_POINT_SMOOTH;
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