ref: 94a8918b8f76a23e1e8e20d26e0b0d195e61f582
dir: /src/autofit/afhints.c/
#include "afhints.h"
#ifdef AF_DEBUG
#include <stdio.h>
void
af_glyph_hints_dump_edges( AF_GlyphHints hints )
{
AF_Edge edges;
AF_Edge edge_limit;
AF_Segment segments;
FT_Int dimension;
edges = hints->horz_edges;
edge_limit = edges + hints->num_hedges;
segments = hints->horz_segments;
for ( dimension = 1; dimension >= 0; dimension-- )
{
AF_Edge edge;
printf ( "Table of %s edges:\n",
!dimension ? "vertical" : "horizontal" );
printf ( " [ index | pos | dir | link |"
" serif | blue | opos | pos ]\n" );
for ( edge = edges; edge < edge_limit; edge++ )
{
printf ( " [ %5d | %4d | %5s | %4d | %5d | %c | %5.2f | %5.2f ]\n",
edge - edges,
(int)edge->fpos,
edge->dir == AF_DIR_UP
? "up"
: ( edge->dir == AF_DIR_DOWN
? "down"
: ( edge->dir == AF_DIR_LEFT
? "left"
: ( edge->dir == AF_DIR_RIGHT
? "right"
: "none" ) ) ),
edge->link ? ( edge->link - edges ) : -1,
edge->serif ? ( edge->serif - edges ) : -1,
edge->blue_edge ? 'y' : 'n',
edge->opos / 64.0,
edge->pos / 64.0 );
}
edges = hints->vert_edges;
edge_limit = edges + hints->num_vedges;
segments = hints->vert_segments;
}
}
/* A function used to dump the array of linked segments */
void
af_glyph_hints_dump_segments( AF_GlyphHints hints )
{
AF_Segment segments;
AF_Segment segment_limit;
AF_Point points;
FT_Int dimension;
points = hints->points;
segments = hints->horz_segments;
segment_limit = segments + hints->num_hsegments;
for ( dimension = 1; dimension >= 0; dimension-- )
{
AF_Segment seg;
printf ( "Table of %s segments:\n",
!dimension ? "vertical" : "horizontal" );
printf ( " [ index | pos | dir | link | serif |"
" numl | first | start ]\n" );
for ( seg = segments; seg < segment_limit; seg++ )
{
printf ( " [ %5d | %4d | %5s | %4d | %5d | %4d | %5d | %5d ]\n",
seg - segments,
(int)seg->pos,
seg->dir == AF_DIR_UP
? "up"
: ( seg->dir == AF_DIR_DOWN
? "down"
: ( seg->dir == AF_DIR_LEFT
? "left"
: ( seg->dir == AF_DIR_RIGHT
? "right"
: "none" ) ) ),
seg->link ? ( seg->link - segments ) : -1,
seg->serif ? ( seg->serif - segments ) : -1,
(int)seg->num_linked,
seg->first - points,
seg->last - points );
}
segments = hints->vert_segments;
segment_limit = segments + hints->num_vsegments;
}
}
#endif /* AF_DEBUG */
/* compute the direction value of a given vector */
FT_LOCAL_DEF( AF_Direction )
af_direction_compute( FT_Pos dx,
FT_Pos dy )
{
AF_Direction dir;
FT_Pos ax = ABS( dx );
FT_Pos ay = ABS( dy );
dir = AF_DIR_NONE;
/* atan(1/12) == 4.7 degrees */
/* test for vertical direction */
if ( ax * 12 < ay )
{
dir = dy > 0 ? AF_DIR_UP : AF_DIR_DOWN;
}
/* test for horizontal direction */
else if ( ay * 12 < ax )
{
dir = dx > 0 ? AF_DIR_RIGHT : AF_DIR_LEFT;
}
return dir;
}
/* compute all inflex points in a given glyph */
static void
af_glyph_hints_compute_inflections( AF_GlyphHints hints )
{
AF_Point* contour = hints->contours;
AF_Point* contour_limit = contour + hints->num_contours;
/* do each contour separately */
for ( ; contour < contour_limit; contour++ )
{
AF_Point point = contour[0];
AF_Point first = point;
AF_Point start = point;
AF_Point end = point;
AF_Point before;
AF_Point after;
AF_Angle angle_in, angle_seg, angle_out;
AF_Angle diff_in, diff_out;
FT_Int finished = 0;
/* compute first segment in contour */
first = point;
start = end = first;
do
{
end = end->next;
if ( end == first )
goto Skip;
} while ( end->fx == first->fx && end->fy == first->fy );
angle_seg = af_angle_atan( end->fx - start->fx,
end->fy - start->fy );
/* extend the segment start whenever possible */
before = start;
do
{
do
{
start = before;
before = before->prev;
if ( before == first )
goto Skip;
} while ( before->fx == start->fx && before->fy == start->fy );
angle_in = af_angle_atan( start->fx - before->fx,
start->fy - before->fy );
} while ( angle_in == angle_seg );
first = start;
diff_in = af_angle_diff( angle_in, angle_seg );
/* now, process all segments in the contour */
do
{
/* first, extend current segment's end whenever possible */
after = end;
do
{
do
{
end = after;
after = after->next;
if ( after == first )
finished = 1;
} while ( end->fx == after->fx && end->fy == after->fy );
angle_out = af_angle_atan( after->fx - end->fx,
after->fy - end->fy );
} while ( angle_out == angle_seg );
diff_out = af_angle_diff( angle_seg, angle_out );
if ( ( diff_in ^ diff_out ) < 0 )
{
/* diff_in and diff_out have different signs, we have */
/* inflection points here... */
do
{
start->flags |= AF_FLAG_INFLECTION;
start = start->next;
} while ( start != end );
start->flags |= AF_FLAG_INFLECTION;
}
start = end;
end = after;
angle_seg = angle_out;
diff_in = diff_out;
} while ( !finished );
Skip:
;
}
}
FT_LOCAL_DEF( void )
af_glyph_hints_init( AF_GlyphHints hints,
FT_Memory memory )
{
FT_ZERO( hints );
hints->memory = memory;
}
FT_LOCAL_DEF( void )
af_glyph_hints_done( AF_GlyphHints hints )
{
if ( hints && hints->memory )
{
FT_Memory memory = hints->memory;
AF_Dimension dim;
/* note that we don't need to free the segment and edge
* buffers, since they're really within the hints->points array
*/
for ( dim = 0; dim < 2; dim++ )
{
AF_AxisHints axis = &hints->axis[ dim ];
axis->num_segments = 0;
axis->num_edges = 0;
axis->segments = NULL;
axis->edges = NULL;
}
FT_FREE( hints->contours );
hints->max_contours = 0;
hints->num_contours = 0;
FT_FREE( hints->points );
hints->num_points = 0;
hints->max_points = 0;
hints->memory = NULL;
}
}
FT_LOCAL_DEF( FT_Error )
af_glyph_hints_reset( AF_GlyphHints hints,
AF_Scaler scaler,
FT_Outline* outline )
{
FT_Error error = FT_Err_Ok;
AF_Point points;
FT_UInt old_max, new_max;
FT_Fixed x_scale = scaler->x_scale;
FT_Fixed y_scale = scaler->y_scale;
FT_Pos x_delta = scaler->x_delta;
FT_Pos y_delta = scaler->y_delta;
FT_Memory memory = hints->memory;
hints->scaler_flags = scaler->flags;
hints->other_flags = 0;
hints->num_points = 0;
hints->num_contours = 0;
hints->axis[0].num_segments = 0;
hints->axis[0].num_edges = 0;
hints->axis[1].num_segments = 0;
hints->axis[1].num_edges = 0;
/* first of all, reallocate the contours array when necessary
*/
new_max = (FT_UInt) outline->n_contours;
old_max = hints->max_contours;
if ( new_max > old_max )
{
new_max = (new_max + 3) & ~3;
if ( FT_RENEW_ARRAY( hints->contours, old_max, new_max ) )
goto Exit;
hints->max_contours = new_max;
}
/* then, reallocate the points, segments & edges arrays if needed --
* note that we reserved two additional point positions, used to
* hint metrics appropriately
*/
new_max = (FT_UInt)( outline->n_points + 2 );
old_max = hints->max_points;
if ( new_max > old_max )
{
FT_Byte* items;
FT_ULong off1, off2, off3;
/* we store in a single buffer the following arrays:
*
* - an array of N AF_PointRec items
* - an array of 2*N AF_SegmentRec items
* - an array of 2*N AF_EdgeRec items
*
*/
new_max = ( new_max + 2 + 7 ) & ~7;
#undef OFF_INCREMENT
#define OFF_INCREMENT( _off, _type, _count ) \
( FT_PAD_CEIL( _off, sizeof(_type) ) + (_count)*sizeof(_type))
off1 = OFF_INCREMENT( 0, AF_PointRec, new_max );
off2 = OFF_INCREMENT( off1, AF_SegmentRec, new_max );
off3 = OFF_INCREMENT( off2, AF_EdgeRec, new_max*2 );
FT_FREE( hints->points );
if ( FT_ALLOC( items, off3 ) )
{
hints->max_points = 0;
hints->axis[0].segments = NULL;
hints->axis[0].edges = NULL;
hints->axis[1].segments = NULL;
hints->axis[1].edges = NULL;
goto Exit;
}
/* readjust some pointers
*/
hints->max_points = new_max;
hints->points = (AF_Point) items;
hints->axis[0].segments = (AF_Segment)( items + off1 );
hints->axis[1].segments = hints->axis[0].segments + new_max;
hints->axis[0].edges = (AF_Edge) ( items + off2 );
hints->axis[1].edges = hints->axis[0].edges + new_max;
}
hints->num_points = outline->n_points;
hints->num_contours = outline->n_contours;
/* We can't rely on the value of `FT_Outline.flags' to know the fill */
/* direction used for a glyph, given that some fonts are broken (e.g. */
/* the Arphic ones). We thus recompute it each time we need to. */
/* */
hints->axis[ AF_DIMENSION_HORZ ].major_dir = AF_DIR_UP;
hints->axis[ AF_DIMENSION_VERT ].major_dir = AF_DIR_LEFT;
if ( FT_Outline_Get_Orientation( outline ) == FT_ORIENTATION_POSTSCRIPT )
{
hints->axis[ AF_DIMENSION_HORZ ].major_dir = AF_DIR_DOWN;
hints->axis[ AF_DIMENSION_VERT ].major_dir = AF_DIR_RIGHT;
}
hints->x_scale = x_scale;
hints->y_scale = y_scale;
hints->x_delta = x_delta;
hints->y_delta = y_delta;
points = hints->points;
if ( hints->num_points == 0 )
goto Exit;
{
AF_Point point;
AF_Point point_limit = points + hints->num_points;
/* compute coordinates & bezier flags */
{
FT_Vector* vec = outline->points;
char* tag = outline->tags;
for ( point = points; point < point_limit; point++, vec++, tag++ )
{
point->fx = vec->x;
point->fy = vec->y;
point->ox = point->x = FT_MulFix( vec->x, x_scale ) + x_delta;
point->oy = point->y = FT_MulFix( vec->y, y_scale ) + y_delta;
switch ( FT_CURVE_TAG( *tag ) )
{
case FT_CURVE_TAG_CONIC:
point->flags = AF_FLAG_CONIC;
break;
case FT_CURVE_TAG_CUBIC:
point->flags = AF_FLAG_CUBIC;
break;
default:
point->flags = 0;
;
}
}
}
/* compute `next' and `prev' */
{
FT_Int contour_index;
AF_Point prev;
AF_Point first;
AF_Point end;
contour_index = 0;
first = points;
end = points + outline->contours[0];
prev = end;
for ( point = points; point < point_limit; point++ )
{
point->prev = prev;
if ( point < end )
{
point->next = point + 1;
prev = point;
}
else
{
point->next = first;
contour_index++;
if ( point + 1 < point_limit )
{
end = points + outline->contours[contour_index];
first = point + 1;
prev = end;
}
}
}
}
/* set-up the contours array */
{
AF_Point* contour = hints->contours;
AF_Point* contour_limit = contour + hints->num_contours;
short* end = outline->contours;
short idx = 0;
for ( ; contour < contour_limit; contour++, end++ )
{
contour[0] = points + idx;
idx = (short)( end[0] + 1 );
}
}
/* compute directions of in & out vectors */
{
for ( point = points; point < point_limit; point++ )
{
AF_Point prev;
AF_Point next;
FT_Pos in_x, in_y, out_x, out_y;
prev = point->prev;
in_x = point->fx - prev->fx;
in_y = point->fy - prev->fy;
point->in_dir = af_direction_compute( in_x, in_y );
next = point->next;
out_x = next->fx - point->fx;
out_y = next->fy - point->fy;
point->out_dir = af_direction_compute( out_x, out_y );
if ( point->flags & ( AF_FLAG_CONIC | AF_FLAG_CUBIC ) )
{
Is_Weak_Point:
point->flags |= AF_FLAG_WEAK_INTERPOLATION;
}
else if ( point->out_dir == point->in_dir )
{
AF_Angle angle_in, angle_out, delta;
if ( point->out_dir != AF_DIR_NONE )
goto Is_Weak_Point;
angle_in = af_angle_atan( in_x, in_y );
angle_out = af_angle_atan( out_x, out_y );
delta = af_angle_diff( angle_in, angle_out );
if ( delta < 2 && delta > -2 )
goto Is_Weak_Point;
}
else if ( point->in_dir == -point->out_dir )
goto Is_Weak_Point;
}
}
}
/* compute inflection points
*/
af_glyph_hints_compute_inflections( hints );
Exit:
return error;
}
/*
*
* E D G E P O I N T G R I D - F I T T I N G
*
*/
FT_LOCAL_DEF( void )
af_glyph_hints_align_edge_points( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_AxisHints axis = & hints->axis[ dim ];
AF_Edge edges = axis->edges;
AF_Edge edge_limit = edges + axis->num_edges;
AF_Edge edge;
for ( edge = edges; edge < edge_limit; edge++ )
{
/* move the points of each segment */
/* in each edge to the edge's position */
AF_Segment seg = edge->first;
do
{
AF_Point point = seg->first;
for (;;)
{
if ( dim == AF_DIMENSION_HORZ )
{
point->x = edge->pos;
point->flags |= AF_FLAG_TOUCH_X;
}
else
{
point->y = edge->pos;
point->flags |= AF_FLAG_TOUCH_Y;
}
if ( point == seg->last )
break;
point = point->next;
}
seg = seg->edge_next;
} while ( seg != edge->first );
}
}
/*
*
* S T R O N G P O I N T I N T E R P O L A T I O N
*
*/
/* hint the strong points -- this is equivalent to the TrueType `IP' */
/* hinting instruction */
FT_LOCAL_DEF( void )
af_glyph_hints_align_strong_points( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_Point points = hints->points;
AF_Point point_limit = points + hints->num_points;
AF_AxisHints axis = &hints->axis[dim];
AF_Edge edges = axis->edges;
AF_Edge edge_limit = edges + axis->num_edges;
AF_Flags touch_flag;
if ( dim == AF_DIMENSION_HORZ )
touch_flag = AF_FLAG_TOUCH_X;
else
touch_flag = AF_FLAG_TOUCH_Y;
if ( edges < edge_limit )
{
AF_Point point;
AF_Edge edge;
for ( point = points; point < point_limit; point++ )
{
FT_Pos u, ou, fu; /* point position */
FT_Pos delta;
if ( point->flags & touch_flag )
continue;
/* if this point is candidate to weak interpolation, we will */
/* interpolate it after all strong points have been processed */
if ( ( point->flags & AF_FLAG_WEAK_INTERPOLATION ) &&
!( point->flags & AF_FLAG_INFLECTION ) )
continue;
if ( dim == AF_DIMENSION_VERT )
{
u = point->fy;
ou = point->oy;
}
else
{
u = point->fx;
ou = point->ox;
}
fu = u;
/* is the point before the first edge? */
edge = edges;
delta = edge->fpos - u;
if ( delta >= 0 )
{
u = edge->pos - ( edge->opos - ou );
goto Store_Point;
}
/* is the point after the last edge? */
edge = edge_limit - 1;
delta = u - edge->fpos;
if ( delta >= 0 )
{
u = edge->pos + ( ou - edge->opos );
goto Store_Point;
}
{
FT_UInt min, max, mid;
FT_Pos fpos;
/* find enclosing edges */
min = 0;
max = edge_limit - edges;
while ( min < max )
{
mid = ( max + min ) >> 1;
edge = edges + mid;
fpos = edge->fpos;
if ( u < fpos )
max = mid;
else if ( u > fpos )
min = mid + 1;
else
{
/* we are on the edge */
u = edge->pos;
goto Store_Point;
}
}
{
AF_Edge before = edges + min - 1;
AF_Edge after = edges + min + 0;
/* assert( before && after && before != after ) */
if ( before->scale == 0 )
before->scale = FT_DivFix( after->pos - before->pos,
after->fpos - before->fpos );
u = before->pos + FT_MulFix( fu - before->fpos,
before->scale );
}
}
Store_Point:
/* save the point position */
if ( dim == AF_DIMENSION_HORZ )
point->x = u;
else
point->y = u;
point->flags |= touch_flag;
}
}
}
/*
*
* W E A K P O I N T I N T E R P O L A T I O N
*
*/
static void
af_iup_shift( AF_Point p1,
AF_Point p2,
AF_Point ref )
{
AF_Point p;
FT_Pos delta = ref->u - ref->v;
for ( p = p1; p < ref; p++ )
p->u = p->v + delta;
for ( p = ref + 1; p <= p2; p++ )
p->u = p->v + delta;
}
static void
af_iup_interp( AF_Point p1,
AF_Point p2,
AF_Point ref1,
AF_Point ref2 )
{
AF_Point p;
FT_Pos u;
FT_Pos v1 = ref1->v;
FT_Pos v2 = ref2->v;
FT_Pos d1 = ref1->u - v1;
FT_Pos d2 = ref2->u - v2;
if ( p1 > p2 )
return;
if ( v1 == v2 )
{
for ( p = p1; p <= p2; p++ )
{
u = p->v;
if ( u <= v1 )
u += d1;
else
u += d2;
p->u = u;
}
return;
}
if ( v1 < v2 )
{
for ( p = p1; p <= p2; p++ )
{
u = p->v;
if ( u <= v1 )
u += d1;
else if ( u >= v2 )
u += d2;
else
u = ref1->u + FT_MulDiv( u - v1, ref2->u - ref1->u, v2 - v1 );
p->u = u;
}
}
else
{
for ( p = p1; p <= p2; p++ )
{
u = p->v;
if ( u <= v2 )
u += d2;
else if ( u >= v1 )
u += d1;
else
u = ref1->u + FT_MulDiv( u - v1, ref2->u - ref1->u, v2 - v1 );
p->u = u;
}
}
}
FT_LOCAL_DEF( void )
af_glyph_hints_align_weak_points( AF_GlyphHints hints,
AF_Dimension dim )
{
AF_Point points = hints->points;
AF_Point point_limit = points + hints->num_points;
AF_Point* contour = hints->contours;
AF_Point* contour_limit = contour + hints->num_contours;
AF_Flags touch_flag;
AF_Point point;
AF_Point end_point;
AF_Point first_point;
/* PASS 1: Move segment points to edge positions */
if ( dim == AF_DIMENSION_HORZ )
{
touch_flag = AF_FLAG_TOUCH_X;
for ( point = points; point < point_limit; point++ )
{
point->u = point->x;
point->v = point->ox;
}
}
else
{
touch_flag = AF_FLAG_TOUCH_Y;
for ( point = points; point < point_limit; points++ )
{
point->u = point->y;
point->v = point->oy;
}
}
point = points;
for ( ; contour < contour_limit; contour++ )
{
point = *contour;
end_point = point->prev;
first_point = point;
while ( point <= end_point && !( point->flags & touch_flag ) )
point++;
if ( point <= end_point )
{
AF_Point first_touched = point;
AF_Point cur_touched = point;
point++;
while ( point <= end_point )
{
if ( point->flags & touch_flag )
{
/* we found two successive touched points; we interpolate */
/* all contour points between them */
af_iup_interp( cur_touched + 1, point - 1,
cur_touched, point );
cur_touched = point;
}
point++;
}
if ( cur_touched == first_touched )
{
/* this is a special case: only one point was touched in the */
/* contour; we thus simply shift the whole contour */
af_iup_shift( first_point, end_point, cur_touched );
}
else
{
/* now interpolate after the last touched point to the end */
/* of the contour */
af_iup_interp( cur_touched + 1, end_point,
cur_touched, first_touched );
/* if the first contour point isn't touched, interpolate */
/* from the contour start to the first touched point */
if ( first_touched > points )
af_iup_interp( first_point, first_touched - 1,
cur_touched, first_touched );
}
}
}
/* now save the interpolated values back to x/y */
if ( dim == AF_DIMENSION_HORZ )
{
for ( point = points; point < point_limit; point++ )
point->x = point->u;
}
else
{
for ( point = points; point < point_limit; point++ )
point->y = point->u;
}
}