756 lines
22 KiB
C
756 lines
22 KiB
C
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#include "aflatin.h"
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FT_LOCAL_DEF( void )
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af_latin_hints_compute_segments( AF_OutlineHints hints,
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AF_Dimension dim )
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{
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AF_AxisHints axis = &hints->axis[dim];
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AF_Segment segments = axis->segments;
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AF_Segment segment = segments;
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FT_Int num_segments = 0;
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AF_Point* contour = hints->contours;
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AF_Point* contour_limit = contour + hints->num_contours;
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AF_Direction major_dir;
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#ifdef AF_HINT_METRICS
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AF_Point min_point = 0;
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AF_Point max_point = 0;
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FT_Pos min_coord = 32000;
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FT_Pos max_coord = -32000;
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#endif
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major_dir = ABS( axis->major_dir );
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segment_dir = major_dir;
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/* set up (u,v) in each point */
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af_setup_uv( outline, (dim == AF_DIMENSION_HORZ)
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? AF_UV_FXY,
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: AF_UV_FYX );
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/* do each contour separately */
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for ( ; contour < contour_limit; contour++ )
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{
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AF_Point point = contour[0];
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AF_Point last = point->prev;
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int on_edge = 0;
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FT_Pos min_pos = 32000; /* minimum segment pos != min_coord */
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FT_Pos max_pos = -32000; /* maximum segment pos != max_coord */
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FT_Bool passed;
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#ifdef AF_HINT_METRICS
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if ( point->u < min_coord )
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{
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min_coord = point->u;
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min_point = point;
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}
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if ( point->u > max_coord )
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{
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max_coord = point->u;
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max_point = point;
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}
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#endif
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if ( point == last ) /* skip singletons -- just in case */
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continue;
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if ( ABS( last->out_dir ) == major_dir &&
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ABS( point->out_dir ) == major_dir )
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{
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/* we are already on an edge, try to locate its start */
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last = point;
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for (;;)
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{
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point = point->prev;
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if ( ABS( point->out_dir ) != major_dir )
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{
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point = point->next;
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break;
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}
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if ( point == last )
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break;
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}
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}
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last = point;
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passed = 0;
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for (;;)
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{
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FT_Pos u, v;
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if ( on_edge )
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{
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u = point->u;
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if ( u < min_pos )
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min_pos = u;
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if ( u > max_pos )
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max_pos = u;
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if ( point->out_dir != segment_dir || point == last )
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{
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/* we are just leaving an edge; record a new segment! */
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segment->last = point;
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segment->pos = ( min_pos + max_pos ) >> 1;
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/* a segment is round if either its first or last point */
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/* is a control point */
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if ( ( segment->first->flags | point->flags ) &
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AF_FLAG_CONTROL )
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segment->flags |= AF_EDGE_ROUND;
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/* compute segment size */
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min_pos = max_pos = point->v;
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v = segment->first->v;
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if ( v < min_pos )
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min_pos = v;
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if ( v > max_pos )
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max_pos = v;
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segment->min_coord = min_pos;
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segment->max_coord = max_pos;
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on_edge = 0;
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num_segments++;
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segment++;
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/* fallthrough */
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}
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}
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/* now exit if we are at the start/end point */
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if ( point == last )
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{
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if ( passed )
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break;
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passed = 1;
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}
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if ( !on_edge && ABS( point->out_dir ) == major_dir )
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{
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/* this is the start of a new segment! */
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segment_dir = point->out_dir;
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/* clear all segment fields */
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FT_ZERO( segment );
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segment->dir = segment_dir;
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segment->flags = AF_EDGE_NORMAL;
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min_pos = max_pos = point->u;
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segment->first = point;
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segment->last = point;
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segment->contour = contour;
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segment->score = 32000;
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segment->link = NULL;
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on_edge = 1;
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#ifdef AF_HINT_METRICS
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if ( point == max_point )
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max_point = 0;
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if ( point == min_point )
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min_point = 0;
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#endif
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}
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point = point->next;
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}
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} /* contours */
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#ifdef AF_HINT_METRICS
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/* we need to ensure that there are edges on the left-most and */
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/* right-most points of the glyph in order to hint the metrics; */
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/* we do this by inserting fake segments when needed */
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if ( dim == AF_DIMENSION_HORZ )
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{
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AF_Point point = hints->points;
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AF_Point point_limit = point + hints->num_points;
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FT_Pos min_pos = 32000;
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FT_Pos max_pos = -32000;
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min_point = 0;
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max_point = 0;
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/* compute minimum and maximum points */
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for ( ; point < point_limit; point++ )
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{
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FT_Pos x = point->fx;
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if ( x < min_pos )
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{
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min_pos = x;
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min_point = point;
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}
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if ( x > max_pos )
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{
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max_pos = x;
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max_point = point;
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}
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}
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/* insert minimum segment */
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if ( min_point )
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{
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/* clear all segment fields */
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FT_ZERO( segment );
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segment->dir = segment_dir;
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segment->flags = AF_EDGE_NORMAL;
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segment->first = min_point;
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segment->last = min_point;
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segment->pos = min_pos;
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segment->score = 32000;
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segment->link = NULL;
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num_segments++;
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segment++;
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}
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/* insert maximum segment */
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if ( max_point )
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{
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/* clear all segment fields */
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FT_ZERO( segment );
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segment->dir = segment_dir;
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segment->flags = AF_EDGE_NORMAL;
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segment->first = max_point;
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segment->last = max_point;
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segment->pos = max_pos;
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segment->score = 32000;
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segment->link = NULL;
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num_segments++;
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segment++;
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}
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}
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#endif /* AF_HINT_METRICS */
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axis->num_segments = num_segments;
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}
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FT_LOCAL_DEF( void )
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af_latin_hints_link_segments( AF_OutlineHints hints,
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AF_Dimension dim )
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{
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AF_AxisHints axis = &hints->axis[dim];
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AF_Segment segments = axis->segments;
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AF_Segment segment_limit = segments + axis->num_segments;
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AF_Direction major_dir = axis->major_dir;
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AF_Segment seg1, seg2;
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/* now compare each segment to the others */
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for ( seg1 = segments; seg1 < segment_limit; seg1++ )
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{
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/* the fake segments are introduced to hint the metrics -- */
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/* we must never link them to anything */
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if ( seg1->first == seg1->last || seg1->dir != major_dir )
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continue;
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for ( seg2 = segments; seg2 < segment_limit; seg2++ )
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if ( seg2 != seg1 && seg1->dir + seg2->dir == 0 )
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{
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FT_Pos pos1 = seg1->pos;
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FT_Pos pos2 = seg2->pos;
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FT_Pos dist = pos2 - pos1;
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if ( dist < 0 )
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continue;
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{
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FT_Pos min = seg1->min_coord;
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FT_Pos max = seg1->max_coord;
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FT_Pos len, score;
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if ( min < seg2->min_coord )
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min = seg2->min_coord;
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if ( max > seg2->max_coord )
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max = seg2->max_coord;
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len = max - min;
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if ( len >= 8 )
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{
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score = dist + 3000 / len;
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if ( score < seg1->score )
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{
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seg1->score = score;
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seg1->link = seg2;
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}
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if ( score < seg2->score )
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{
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seg2->score = score;
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seg2->link = seg1;
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}
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}
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}
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}
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}
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/* now, compute the `serif' segments */
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for ( seg1 = segments; seg1 < segment_limit; seg1++ )
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{
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seg2 = seg1->link;
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if ( seg2 )
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{
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seg2->num_linked++;
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if ( seg2->link != seg1 )
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{
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seg1->link = 0;
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seg1->serif = seg2->link;
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}
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}
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}
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}
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FT_LOCAL_DEF( void )
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af_latin_hints_compute_edges( AF_OutlineHints hints,
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AF_Dimension dim )
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{
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AF_AxisHints axis = &hints->axis[dim];
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AF_Edge edges = axis->edges;
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AF_Edge edge, edge_limit;
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AF_Segment segments = axis->segments;
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AF_Segment segment_limit = segments + axis->num_segments;
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AF_Segment seg;
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AF_Direction up_dir;
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FT_Fixed scale;
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FT_Pos edge_distance_threshold;
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scale = ( dim == AF_DIMENSION_HORZ ) ? hints->x_scale
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: hints->y_scale;
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up_dir = ( dim == AF_DIMENSION_HORZ ) ? AF_DIR_UP
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: AF_DIR_RIGHT;
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/*********************************************************************/
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/* */
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/* We will begin by generating a sorted table of edges for the */
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/* current direction. To do so, we simply scan each segment and try */
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/* to find an edge in our table that corresponds to its position. */
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/* */
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/* If no edge is found, we create and insert a new edge in the */
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/* sorted table. Otherwise, we simply add the segment to the edge's */
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/* list which will be processed in the second step to compute the */
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/* edge's properties. */
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/* */
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/* Note that the edges table is sorted along the segment/edge */
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/* position. */
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/* */
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/*********************************************************************/
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edge_distance_threshold = FT_MulFix( outline->edge_distance_threshold,
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scale );
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if ( edge_distance_threshold > 64 / 4 )
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edge_distance_threshold = 64 / 4;
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edge_distance_threshold = FT_DivFix( edge_distance_threshold,
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scale );
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edge_limit = edges;
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for ( seg = segments; seg < segment_limit; seg++ )
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{
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AF_Edge found = 0;
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/* look for an edge corresponding to the segment */
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for ( edge = edges; edge < edge_limit; edge++ )
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{
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FT_Pos dist;
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dist = seg->pos - edge->fpos;
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if ( dist < 0 )
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dist = -dist;
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if ( dist < edge_distance_threshold )
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{
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found = edge;
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break;
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}
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}
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if ( !found )
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{
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/* insert a new edge in the list and */
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/* sort according to the position */
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while ( edge > edges && edge[-1].fpos > seg->pos )
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{
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edge[0] = edge[-1];
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edge--;
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}
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edge_limit++;
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/* clear all edge fields */
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FT_MEM_ZERO( edge, sizeof ( *edge ) );
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/* add the segment to the new edge's list */
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edge->first = seg;
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edge->last = seg;
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edge->fpos = seg->pos;
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edge->opos = edge->pos = FT_MulFix( seg->pos, scale );
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seg->edge_next = seg;
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}
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else
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{
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/* if an edge was found, simply add the segment to the edge's */
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/* list */
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seg->edge_next = edge->first;
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edge->last->edge_next = seg;
|
||
|
|
edge->last = seg;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
*p_num_edges = (FT_Int)( edge_limit - edges );
|
||
|
|
|
||
|
|
|
||
|
|
/*********************************************************************/
|
||
|
|
/* */
|
||
|
|
/* Good, we will now compute each edge's properties according to */
|
||
|
|
/* segments found on its position. Basically, these are: */
|
||
|
|
/* */
|
||
|
|
/* - edge's main direction */
|
||
|
|
/* - stem edge, serif edge or both (which defaults to stem then) */
|
||
|
|
/* - rounded edge, straight or both (which defaults to straight) */
|
||
|
|
/* - link for edge */
|
||
|
|
/* */
|
||
|
|
/*********************************************************************/
|
||
|
|
|
||
|
|
/* first of all, set the `edge' field in each segment -- this is */
|
||
|
|
/* required in order to compute edge links */
|
||
|
|
|
||
|
|
/* Note that I've tried to remove this loop, setting
|
||
|
|
* the "edge" field of each segment directly in the
|
||
|
|
* code above. For some reason, it slows down execution
|
||
|
|
* speed -- on a Sun.
|
||
|
|
*/
|
||
|
|
for ( edge = edges; edge < edge_limit; edge++ )
|
||
|
|
{
|
||
|
|
seg = edge->first;
|
||
|
|
if ( seg )
|
||
|
|
do
|
||
|
|
{
|
||
|
|
seg->edge = edge;
|
||
|
|
seg = seg->edge_next;
|
||
|
|
}
|
||
|
|
while ( seg != edge->first );
|
||
|
|
}
|
||
|
|
|
||
|
|
/* now, compute each edge properties */
|
||
|
|
for ( edge = edges; edge < edge_limit; edge++ )
|
||
|
|
{
|
||
|
|
FT_Int is_round = 0; /* does it contain round segments? */
|
||
|
|
FT_Int is_straight = 0; /* does it contain straight segments? */
|
||
|
|
FT_Pos ups = 0; /* number of upwards segments */
|
||
|
|
FT_Pos downs = 0; /* number of downwards segments */
|
||
|
|
|
||
|
|
|
||
|
|
seg = edge->first;
|
||
|
|
|
||
|
|
do
|
||
|
|
{
|
||
|
|
FT_Bool is_serif;
|
||
|
|
|
||
|
|
|
||
|
|
/* check for roundness of segment */
|
||
|
|
if ( seg->flags & AF_EDGE_ROUND )
|
||
|
|
is_round++;
|
||
|
|
else
|
||
|
|
is_straight++;
|
||
|
|
|
||
|
|
/* check for segment direction */
|
||
|
|
if ( seg->dir == up_dir )
|
||
|
|
ups += seg->max_coord-seg->min_coord;
|
||
|
|
else
|
||
|
|
downs += seg->max_coord-seg->min_coord;
|
||
|
|
|
||
|
|
/* check for links -- if seg->serif is set, then seg->link must */
|
||
|
|
/* be ignored */
|
||
|
|
is_serif = (FT_Bool)( seg->serif && seg->serif->edge != edge );
|
||
|
|
|
||
|
|
if ( seg->link || is_serif )
|
||
|
|
{
|
||
|
|
AF_Edge edge2;
|
||
|
|
AF_Segment seg2;
|
||
|
|
|
||
|
|
|
||
|
|
edge2 = edge->link;
|
||
|
|
seg2 = seg->link;
|
||
|
|
|
||
|
|
if ( is_serif )
|
||
|
|
{
|
||
|
|
seg2 = seg->serif;
|
||
|
|
edge2 = edge->serif;
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( edge2 )
|
||
|
|
{
|
||
|
|
FT_Pos edge_delta;
|
||
|
|
FT_Pos seg_delta;
|
||
|
|
|
||
|
|
|
||
|
|
edge_delta = edge->fpos - edge2->fpos;
|
||
|
|
if ( edge_delta < 0 )
|
||
|
|
edge_delta = -edge_delta;
|
||
|
|
|
||
|
|
seg_delta = seg->pos - seg2->pos;
|
||
|
|
if ( seg_delta < 0 )
|
||
|
|
seg_delta = -seg_delta;
|
||
|
|
|
||
|
|
if ( seg_delta < edge_delta )
|
||
|
|
edge2 = seg2->edge;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
edge2 = seg2->edge;
|
||
|
|
|
||
|
|
#ifdef FT_CONFIG_CHESTER_SERIF
|
||
|
|
if ( is_serif )
|
||
|
|
{
|
||
|
|
edge->serif = edge2;
|
||
|
|
edge2->flags |= AF_EDGE_SERIF;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
edge->link = edge2;
|
||
|
|
#else /* !FT_CONFIG_CHESTER_SERIF */
|
||
|
|
if ( is_serif )
|
||
|
|
edge->serif = edge2;
|
||
|
|
else
|
||
|
|
edge->link = edge2;
|
||
|
|
#endif /* !FT_CONFIG_CHESTER_SERIF */
|
||
|
|
}
|
||
|
|
|
||
|
|
seg = seg->edge_next;
|
||
|
|
|
||
|
|
} while ( seg != edge->first );
|
||
|
|
|
||
|
|
/* set the round/straight flags */
|
||
|
|
edge->flags = AF_EDGE_NORMAL;
|
||
|
|
|
||
|
|
if ( is_round > 0 && is_round >= is_straight )
|
||
|
|
edge->flags |= AF_EDGE_ROUND;
|
||
|
|
|
||
|
|
/* set the edge's main direction */
|
||
|
|
edge->dir = AF_DIR_NONE;
|
||
|
|
|
||
|
|
if ( ups > downs )
|
||
|
|
edge->dir = up_dir;
|
||
|
|
|
||
|
|
else if ( ups < downs )
|
||
|
|
edge->dir = -up_dir;
|
||
|
|
|
||
|
|
else if ( ups == downs )
|
||
|
|
edge->dir = 0; /* both up and down! */
|
||
|
|
|
||
|
|
/* gets rid of serifs if link is set */
|
||
|
|
/* XXX: This gets rid of many unpleasant artefacts! */
|
||
|
|
/* Example: the `c' in cour.pfa at size 13 */
|
||
|
|
|
||
|
|
if ( edge->serif && edge->link )
|
||
|
|
edge->serif = 0;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*************************************************************************/
|
||
|
|
/* */
|
||
|
|
/* <Function> */
|
||
|
|
/* af_outline_detect_features */
|
||
|
|
/* */
|
||
|
|
/* <Description> */
|
||
|
|
/* Performs feature detection on a given AF_OutlineRec object. */
|
||
|
|
/* */
|
||
|
|
FT_LOCAL_DEF( void )
|
||
|
|
af_latin_hints_detect_features( AF_OutlineHints hints,
|
||
|
|
AF_Dimension dim )
|
||
|
|
{
|
||
|
|
af_latin_hints_compute_segments( hints, dim );
|
||
|
|
af_latin_hints_link_segments ( hints, dim );
|
||
|
|
af_latin_hints_compute_edges ( hints dim );
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*************************************************************************/
|
||
|
|
/* */
|
||
|
|
/* <Function> */
|
||
|
|
/* af_outline_compute_blue_edges */
|
||
|
|
/* */
|
||
|
|
/* <Description> */
|
||
|
|
/* Computes the `blue edges' in a given outline (i.e. those that must */
|
||
|
|
/* be snapped to a blue zone edge (top or bottom). */
|
||
|
|
/* */
|
||
|
|
FT_LOCAL_DEF( void )
|
||
|
|
af_latin_hints_compute_blue_edges( AF_OutlineHints outline,
|
||
|
|
AF_Face_Globals face_globals )
|
||
|
|
{
|
||
|
|
AF_Edge edge = outline->horz_edges;
|
||
|
|
AF_Edge edge_limit = edge + outline->num_hedges;
|
||
|
|
AF_Globals globals = &face_globals->design;
|
||
|
|
FT_Fixed y_scale = outline->y_scale;
|
||
|
|
|
||
|
|
FT_Bool blue_active[AF_BLUE_MAX];
|
||
|
|
|
||
|
|
|
||
|
|
/* compute which blue zones are active, i.e. have their scaled */
|
||
|
|
/* size < 3/4 pixels */
|
||
|
|
{
|
||
|
|
AF_Blue blue;
|
||
|
|
FT_Bool check = 0;
|
||
|
|
|
||
|
|
|
||
|
|
for ( blue = AF_BLUE_CAPITAL_TOP; blue < AF_BLUE_MAX; blue++ )
|
||
|
|
{
|
||
|
|
FT_Pos ref, shoot, dist;
|
||
|
|
|
||
|
|
|
||
|
|
ref = globals->blue_refs[blue];
|
||
|
|
shoot = globals->blue_shoots[blue];
|
||
|
|
dist = ref - shoot;
|
||
|
|
if ( dist < 0 )
|
||
|
|
dist = -dist;
|
||
|
|
|
||
|
|
blue_active[blue] = 0;
|
||
|
|
|
||
|
|
if ( FT_MulFix( dist, y_scale ) < 48 )
|
||
|
|
{
|
||
|
|
blue_active[blue] = 1;
|
||
|
|
check = 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/* return immediately if no blue zone is active */
|
||
|
|
if ( !check )
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* for each horizontal edge search the blue zone which is closest */
|
||
|
|
for ( ; edge < edge_limit; edge++ )
|
||
|
|
{
|
||
|
|
AF_Blue blue;
|
||
|
|
FT_Pos* best_blue = 0;
|
||
|
|
FT_Pos best_dist; /* initial threshold */
|
||
|
|
|
||
|
|
|
||
|
|
/* compute the initial threshold as a fraction of the EM size */
|
||
|
|
best_dist = FT_MulFix( face_globals->face->units_per_EM / 40, y_scale );
|
||
|
|
|
||
|
|
#ifdef FT_CONFIG_CHESTER_SMALL_F
|
||
|
|
if ( best_dist > 64 / 2 )
|
||
|
|
best_dist = 64 / 2;
|
||
|
|
#else
|
||
|
|
if ( best_dist > 64 / 4 )
|
||
|
|
best_dist = 64 / 4;
|
||
|
|
#endif
|
||
|
|
|
||
|
|
for ( blue = AF_BLUE_CAPITAL_TOP; blue < AF_BLUE_MAX; blue++ )
|
||
|
|
{
|
||
|
|
/* if it is a top zone, check for right edges -- if it is a bottom */
|
||
|
|
/* zone, check for left edges */
|
||
|
|
/* */
|
||
|
|
/* of course, that's for TrueType XXX */
|
||
|
|
FT_Bool is_top_blue =
|
||
|
|
FT_BOOL( AF_IS_TOP_BLUE( blue ) );
|
||
|
|
FT_Bool is_major_dir =
|
||
|
|
FT_BOOL( edge->dir == outline->horz_major_dir );
|
||
|
|
|
||
|
|
|
||
|
|
if ( !blue_active[blue] )
|
||
|
|
continue;
|
||
|
|
|
||
|
|
/* if it is a top zone, the edge must be against the major */
|
||
|
|
/* direction; if it is a bottom zone, it must be in the major */
|
||
|
|
/* direction */
|
||
|
|
if ( is_top_blue ^ is_major_dir )
|
||
|
|
{
|
||
|
|
FT_Pos dist;
|
||
|
|
FT_Pos* blue_pos = globals->blue_refs + blue;
|
||
|
|
|
||
|
|
|
||
|
|
/* first of all, compare it to the reference position */
|
||
|
|
dist = edge->fpos - *blue_pos;
|
||
|
|
if ( dist < 0 )
|
||
|
|
dist = -dist;
|
||
|
|
|
||
|
|
dist = FT_MulFix( dist, y_scale );
|
||
|
|
if ( dist < best_dist )
|
||
|
|
{
|
||
|
|
best_dist = dist;
|
||
|
|
best_blue = blue_pos;
|
||
|
|
}
|
||
|
|
|
||
|
|
/* now, compare it to the overshoot position if the edge is */
|
||
|
|
/* rounded, and if the edge is over the reference position of a */
|
||
|
|
/* top zone, or under the reference position of a bottom zone */
|
||
|
|
if ( edge->flags & AF_EDGE_ROUND && dist != 0 )
|
||
|
|
{
|
||
|
|
FT_Bool is_under_ref = FT_BOOL( edge->fpos < *blue_pos );
|
||
|
|
|
||
|
|
|
||
|
|
if ( is_top_blue ^ is_under_ref )
|
||
|
|
{
|
||
|
|
blue_pos = globals->blue_shoots + blue;
|
||
|
|
dist = edge->fpos - *blue_pos;
|
||
|
|
if ( dist < 0 )
|
||
|
|
dist = -dist;
|
||
|
|
|
||
|
|
dist = FT_MulFix( dist, y_scale );
|
||
|
|
if ( dist < best_dist )
|
||
|
|
{
|
||
|
|
best_dist = dist;
|
||
|
|
best_blue = blue_pos;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
if ( best_blue )
|
||
|
|
edge->blue_edge = best_blue;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*************************************************************************/
|
||
|
|
/* */
|
||
|
|
/* <Function> */
|
||
|
|
/* af_outline_scale_blue_edges */
|
||
|
|
/* */
|
||
|
|
/* <Description> */
|
||
|
|
/* This function must be called before hinting in order to re-adjust */
|
||
|
|
/* the contents of the detected edges (basically change the `blue */
|
||
|
|
/* edge' pointer from `design units' to `scaled ones'). */
|
||
|
|
/* */
|
||
|
|
FT_LOCAL_DEF( void )
|
||
|
|
af_outline_hints_scale_blue_edges( AF_OutlineHints hints ) outline,
|
||
|
|
{
|
||
|
|
AF_AxisHints axis = &hints->axis[ AF_DIMENSION_VERT ];
|
||
|
|
AF_Edge edge = axis->edges;
|
||
|
|
AF_Edge edge_limit = edge + axis->num_edges;
|
||
|
|
FT_Pos delta;
|
||
|
|
|
||
|
|
|
||
|
|
delta = globals->scaled.blue_refs - globals->design.blue_refs;
|
||
|
|
|
||
|
|
for ( ; edge < edge_limit; edge++ )
|
||
|
|
{
|
||
|
|
if ( edge->blue_edge )
|
||
|
|
edge->blue_edge += delta;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|