Edit
kc3-lang/freetype/src/autofit/afhints.c
Werner Lemberg
- src/autofit/afhints.c
-
/***************************************************************************/ /* */ /* afhints.c */ /* */ /* Auto-fitter hinting routines (body). */ /* */ /* Copyright 2003-2007, 2009-2013 by */ /* David Turner, Robert Wilhelm, and Werner Lemberg. */ /* */ /* This file is part of the FreeType project, and may only be used, */ /* modified, and distributed under the terms of the FreeType project */ /* license, LICENSE.TXT. By continuing to use, modify, or distribute */ /* this file you indicate that you have read the license and */ /* understand and accept it fully. */ /* */ /***************************************************************************/ #include "afhints.h" #include "aferrors.h" #include FT_INTERNAL_CALC_H #include FT_INTERNAL_DEBUG_H /*************************************************************************/ /* */ /* The macro FT_COMPONENT is used in trace mode. It is an implicit */ /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log */ /* messages during execution. */ /* */ #undef FT_COMPONENT #define FT_COMPONENT trace_afhints /* Get new segment for given axis. */ FT_LOCAL_DEF( FT_Error ) af_axis_hints_new_segment( AF_AxisHints axis, FT_Memory memory, AF_Segment *asegment ) { FT_Error error = FT_Err_Ok; AF_Segment segment = NULL; if ( axis->num_segments >= axis->max_segments ) { FT_Int old_max = axis->max_segments; FT_Int new_max = old_max; FT_Int big_max = (FT_Int)( FT_INT_MAX / sizeof ( *segment ) ); if ( old_max >= big_max ) { error = FT_THROW( Out_Of_Memory ); goto Exit; } new_max += ( new_max >> 2 ) + 4; if ( new_max < old_max || new_max > big_max ) new_max = big_max; if ( FT_RENEW_ARRAY( axis->segments, old_max, new_max ) ) goto Exit; axis->max_segments = new_max; } segment = axis->segments + axis->num_segments++; Exit: *asegment = segment; return error; } /* Get new edge for given axis, direction, and position. */ FT_LOCAL( FT_Error ) af_axis_hints_new_edge( AF_AxisHints axis, FT_Int fpos, AF_Direction dir, FT_Memory memory, AF_Edge *anedge ) { FT_Error error = FT_Err_Ok; AF_Edge edge = NULL; AF_Edge edges; if ( axis->num_edges >= axis->max_edges ) { FT_Int old_max = axis->max_edges; FT_Int new_max = old_max; FT_Int big_max = (FT_Int)( FT_INT_MAX / sizeof ( *edge ) ); if ( old_max >= big_max ) { error = FT_THROW( Out_Of_Memory ); goto Exit; } new_max += ( new_max >> 2 ) + 4; if ( new_max < old_max || new_max > big_max ) new_max = big_max; if ( FT_RENEW_ARRAY( axis->edges, old_max, new_max ) ) goto Exit; axis->max_edges = new_max; } edges = axis->edges; edge = edges + axis->num_edges; while ( edge > edges ) { if ( edge[-1].fpos < fpos ) break; /* we want the edge with same position and minor direction */ /* to appear before those in the major one in the list */ if ( edge[-1].fpos == fpos && dir == axis->major_dir ) break; edge[0] = edge[-1]; edge--; } axis->num_edges++; FT_ZERO( edge ); edge->fpos = (FT_Short)fpos; edge->dir = (FT_Char)dir; Exit: *anedge = edge; return error; } #ifdef FT_DEBUG_AUTOFIT #include FT_CONFIG_STANDARD_LIBRARY_H static const char* af_dir_str( AF_Direction dir ) { const char* result; switch ( dir ) { case AF_DIR_UP: result = "up"; break; case AF_DIR_DOWN: result = "down"; break; case AF_DIR_LEFT: result = "left"; break; case AF_DIR_RIGHT: result = "right"; break; default: result = "none"; } return result; } #define AF_INDEX_NUM( ptr, base ) ( (ptr) ? ( (ptr) - (base) ) : -1 ) #ifdef __cplusplus extern "C" { #endif void af_glyph_hints_dump_points( AF_GlyphHints hints ) { AF_Point points = hints->points; AF_Point limit = points + hints->num_points; AF_Point point; FT_TRACE7(( "Table of points:\n" " [ index | xorg | yorg | xscale | yscale" " | xfit | yfit | flags ]\n" )); for ( point = points; point < limit; point++ ) FT_TRACE7(( " [ %5d | %5d | %5d | %6.2f | %6.2f" " | %5.2f | %5.2f | %c%c%c%c%c%c ]\n", point - points, point->fx, point->fy, point->ox / 64.0, point->oy / 64.0, point->x / 64.0, point->y / 64.0, ( point->flags & AF_FLAG_WEAK_INTERPOLATION ) ? 'w' : ' ', ( point->flags & AF_FLAG_INFLECTION ) ? 'i' : ' ', ( point->flags & AF_FLAG_EXTREMA_X ) ? '<' : ' ', ( point->flags & AF_FLAG_EXTREMA_Y ) ? 'v' : ' ', ( point->flags & AF_FLAG_ROUND_X ) ? '(' : ' ', ( point->flags & AF_FLAG_ROUND_Y ) ? 'u' : ' ')); FT_TRACE7(( "\n" )); } #ifdef __cplusplus } #endif static const char* af_edge_flags_to_string( AF_Edge_Flags flags ) { static char temp[32]; int pos = 0; if ( flags & AF_EDGE_ROUND ) { ft_memcpy( temp + pos, "round", 5 ); pos += 5; } if ( flags & AF_EDGE_SERIF ) { if ( pos > 0 ) temp[pos++] = ' '; ft_memcpy( temp + pos, "serif", 5 ); pos += 5; } if ( pos == 0 ) return "normal"; temp[pos] = '\0'; return temp; } /* Dump the array of linked segments. */ #ifdef __cplusplus extern "C" { #endif void af_glyph_hints_dump_segments( AF_GlyphHints hints ) { FT_Int dimension; for ( dimension = 1; dimension >= 0; dimension-- ) { AF_AxisHints axis = &hints->axis[dimension]; AF_Point points = hints->points; AF_Edge edges = axis->edges; AF_Segment segments = axis->segments; AF_Segment limit = segments + axis->num_segments; AF_Segment seg; FT_TRACE7(( "Table of %s segments:\n", dimension == AF_DIMENSION_HORZ ? "vertical" : "horizontal" )); if ( axis->num_segments ) FT_TRACE7(( " [ index | pos | dir | from" " | to | link | serif | edge" " | height | extra | flags ]\n" )); else FT_TRACE7(( " (none)\n" )); for ( seg = segments; seg < limit; seg++ ) FT_TRACE7(( " [ %5d | %5.2g | %5s | %4d" " | %4d | %4d | %5d | %4d" " | %6d | %5d | %11s ]\n", seg - segments, dimension == AF_DIMENSION_HORZ ? (int)seg->first->ox / 64.0 : (int)seg->first->oy / 64.0, af_dir_str( (AF_Direction)seg->dir ), AF_INDEX_NUM( seg->first, points ), AF_INDEX_NUM( seg->last, points ), AF_INDEX_NUM( seg->link, segments ), AF_INDEX_NUM( seg->serif, segments ), AF_INDEX_NUM( seg->edge, edges ), seg->height, seg->height - ( seg->max_coord - seg->min_coord ), af_edge_flags_to_string( (AF_Edge_Flags)seg->flags ) )); FT_TRACE7(( "\n" )); } } #ifdef __cplusplus } #endif /* Fetch number of segments. */ #ifdef __cplusplus extern "C" { #endif FT_Error af_glyph_hints_get_num_segments( AF_GlyphHints hints, FT_Int dimension, FT_Int* num_segments ) { AF_Dimension dim; AF_AxisHints axis; dim = ( dimension == 0 ) ? AF_DIMENSION_HORZ : AF_DIMENSION_VERT; axis = &hints->axis[dim]; *num_segments = axis->num_segments; return FT_Err_Ok; } #ifdef __cplusplus } #endif /* Fetch offset of segments into user supplied offset array. */ #ifdef __cplusplus extern "C" { #endif FT_Error af_glyph_hints_get_segment_offset( AF_GlyphHints hints, FT_Int dimension, FT_Int idx, FT_Pos* offset ) { AF_Dimension dim; AF_AxisHints axis; AF_Segment seg; if ( !offset ) return FT_THROW( Invalid_Argument ); dim = ( dimension == 0 ) ? AF_DIMENSION_HORZ : AF_DIMENSION_VERT; axis = &hints->axis[dim]; if ( idx < 0 || idx >= axis->num_segments ) return FT_THROW( Invalid_Argument ); seg = &axis->segments[idx]; *offset = ( dim == AF_DIMENSION_HORZ ) ? seg->first->ox : seg->first->oy; return FT_Err_Ok; } #ifdef __cplusplus } #endif /* Dump the array of linked edges. */ #ifdef __cplusplus extern "C" { #endif void af_glyph_hints_dump_edges( AF_GlyphHints hints ) { FT_Int dimension; for ( dimension = 1; dimension >= 0; dimension-- ) { AF_AxisHints axis = &hints->axis[dimension]; AF_Edge edges = axis->edges; AF_Edge limit = edges + axis->num_edges; AF_Edge edge; /* * note: AF_DIMENSION_HORZ corresponds to _vertical_ edges * since they have a constant X coordinate. */ FT_TRACE7(( "Table of %s edges:\n", dimension == AF_DIMENSION_HORZ ? "vertical" : "horizontal" )); if ( axis->num_edges ) FT_TRACE7(( " [ index | pos | dir | link" " | serif | blue | opos | pos | flags ]\n" )); else FT_TRACE7(( " (none)\n" )); for ( edge = edges; edge < limit; edge++ ) FT_TRACE7(( " [ %5d | %5.2g | %5s | %4d" " | %5d | %c | %5.2f | %5.2f | %11s ]\n", edge - edges, (int)edge->opos / 64.0, af_dir_str( (AF_Direction)edge->dir ), AF_INDEX_NUM( edge->link, edges ), AF_INDEX_NUM( edge->serif, edges ), edge->blue_edge ? 'y' : 'n', edge->opos / 64.0, edge->pos / 64.0, af_edge_flags_to_string( (AF_Edge_Flags)edge->flags ) )); FT_TRACE7(( "\n" )); } } #ifdef __cplusplus } #endif #else /* !FT_DEBUG_AUTOFIT */ /* these empty stubs are only used to link the `ftgrid' test program */ /* if debugging is disabled */ #ifdef __cplusplus extern "C" { #endif void af_glyph_hints_dump_points( AF_GlyphHints hints ) { FT_UNUSED( hints ); } void af_glyph_hints_dump_segments( AF_GlyphHints hints ) { FT_UNUSED( hints ); } FT_Error af_glyph_hints_get_num_segments( AF_GlyphHints hints, FT_Int dimension, FT_Int* num_segments ) { FT_UNUSED( hints ); FT_UNUSED( dimension ); FT_UNUSED( num_segments ); return 0; } FT_Error af_glyph_hints_get_segment_offset( AF_GlyphHints hints, FT_Int dimension, FT_Int idx, FT_Pos* offset ) { FT_UNUSED( hints ); FT_UNUSED( dimension ); FT_UNUSED( idx ); FT_UNUSED( offset ); return 0; } void af_glyph_hints_dump_edges( AF_GlyphHints hints ) { FT_UNUSED( hints ); } #ifdef __cplusplus } #endif #endif /* !FT_DEBUG_AUTOFIT */ /* Compute the direction value of a given vector. */ FT_LOCAL_DEF( AF_Direction ) af_direction_compute( FT_Pos dx, FT_Pos dy ) { FT_Pos ll, ss; /* long and short arm lengths */ AF_Direction dir; /* candidate direction */ if ( dy >= dx ) { if ( dy >= -dx ) { dir = AF_DIR_UP; ll = dy; ss = dx; } else { dir = AF_DIR_LEFT; ll = -dx; ss = dy; } } else /* dy < dx */ { if ( dy >= -dx ) { dir = AF_DIR_RIGHT; ll = dx; ss = dy; } else { dir = AF_DIR_DOWN; ll = dy; ss = dx; } } /* return no direction if arm lengths differ too much */ /* (value 14 is heuristic, corresponding to approx. 4.1 degrees) */ ss *= 14; if ( FT_ABS( ll ) <= FT_ABS( ss ) ) dir = AF_DIR_NONE; return dir; } 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 ) { FT_Memory memory = hints->memory; int dim; if ( !( hints && hints->memory ) ) return; /* * note that we don't need to free the segment and edge * buffers since they are really within the hints->points array */ for ( dim = 0; dim < AF_DIMENSION_MAX; dim++ ) { AF_AxisHints axis = &hints->axis[dim]; axis->num_segments = 0; axis->max_segments = 0; FT_FREE( axis->segments ); axis->num_edges = 0; axis->max_edges = 0; FT_FREE( axis->edges ); } 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; } /* Reset metrics. */ FT_LOCAL_DEF( void ) af_glyph_hints_rescale( AF_GlyphHints hints, AF_ScriptMetrics metrics ) { hints->metrics = metrics; hints->scaler_flags = metrics->scaler.flags; } /* Recompute all AF_Point in AF_GlyphHints from the definitions */ /* in a source outline. */ FT_LOCAL_DEF( FT_Error ) af_glyph_hints_reload( AF_GlyphHints hints, FT_Outline* outline ) { FT_Error error = FT_Err_Ok; AF_Point points; FT_UInt old_max, new_max; FT_Fixed x_scale = hints->x_scale; FT_Fixed y_scale = hints->y_scale; FT_Pos x_delta = hints->x_delta; FT_Pos y_delta = hints->y_delta; FT_Memory memory = hints->memory; 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 if necessary */ new_max = (FT_UInt)outline->n_contours; old_max = hints->max_contours; if ( new_max > old_max ) { new_max = ( new_max + 3 ) & ~3; /* round up to a multiple of 4 */ if ( FT_RENEW_ARRAY( hints->contours, old_max, new_max ) ) goto Exit; hints->max_contours = new_max; } /* * then reallocate the points arrays if necessary -- * note that we reserve 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 ) { new_max = ( new_max + 2 + 7 ) & ~7; /* round up to a multiple of 8 */ if ( FT_RENEW_ARRAY( hints->points, old_max, new_max ) ) goto Exit; hints->max_points = 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; hints->xmin_delta = 0; hints->xmax_delta = 0; 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, next and prev */ { FT_Vector* vec = outline->points; char* tag = outline->tags; AF_Point end = points + outline->contours[0]; AF_Point prev = end; FT_Int contour_index = 0; for ( point = points; point < point_limit; point++, vec++, tag++ ) { point->fx = (FT_Short)vec->x; point->fy = (FT_Short)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 = AF_FLAG_NONE; } point->prev = prev; prev->next = point; prev = point; if ( point == end ) { if ( ++contour_index < outline->n_contours ) { end = points + outline->contours[contour_index]; 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 */ { AF_Point first = points; AF_Point prev = NULL; FT_Pos in_x = 0; FT_Pos in_y = 0; AF_Direction in_dir = AF_DIR_NONE; FT_Pos last_good_in_x = 0; FT_Pos last_good_in_y = 0; FT_UInt units_per_em = hints->metrics->scaler.face->units_per_EM; FT_Int near_limit = 20 * units_per_em / 2048; for ( point = points; point < point_limit; point++ ) { AF_Point next; FT_Pos out_x, out_y; if ( point == first ) { prev = first->prev; in_x = first->fx - prev->fx; in_y = first->fy - prev->fy; last_good_in_x = in_x; last_good_in_y = in_y; if ( FT_ABS( in_x ) + FT_ABS( in_y ) < near_limit ) { /* search first non-near point to get a good `in_dir' value */ AF_Point point_ = prev; while ( point_ != first ) { AF_Point prev_ = point_->prev; FT_Pos in_x_ = point_->fx - prev_->fx; FT_Pos in_y_ = point_->fy - prev_->fy; if ( FT_ABS( in_x_ ) + FT_ABS( in_y_ ) >= near_limit ) { last_good_in_x = in_x_; last_good_in_y = in_y_; break; } point_ = prev_; } } in_dir = af_direction_compute( in_x, in_y ); first = prev + 1; } point->in_dir = (FT_Char)in_dir; /* check whether the current point is near to the previous one */ /* (value 20 in `near_limit' is heuristic; we use Taxicab */ /* metrics for the test) */ if ( FT_ABS( in_x ) + FT_ABS( in_y ) < near_limit ) point->flags |= AF_FLAG_NEAR; else { last_good_in_x = in_x; last_good_in_y = in_y; } next = point->next; out_x = next->fx - point->fx; out_y = next->fy - point->fy; in_dir = af_direction_compute( out_x, out_y ); point->out_dir = (FT_Char)in_dir; /* Check for weak points. The remaining points not collected */ /* in edges are then implicitly classified as strong points. */ if ( point->flags & AF_FLAG_CONTROL ) { /* control points are always weak */ Is_Weak_Point: point->flags |= AF_FLAG_WEAK_INTERPOLATION; } else if ( point->out_dir == point->in_dir ) { if ( point->out_dir != AF_DIR_NONE ) { /* current point lies on a horizontal or */ /* vertical segment (but doesn't start or end it) */ goto Is_Weak_Point; } /* test whether `in' and `out' direction is approximately */ /* the same (and use the last good `in' vector in case */ /* the current point is near to the previous one) */ if ( ft_corner_is_flat( point->flags & AF_FLAG_NEAR ? last_good_in_x : in_x, point->flags & AF_FLAG_NEAR ? last_good_in_y : in_y, out_x, out_y ) ) { /* current point lies on a straight, diagonal line */ /* (more or less) */ goto Is_Weak_Point; } } else if ( point->in_dir == -point->out_dir ) { /* current point forms a spike */ goto Is_Weak_Point; } in_x = out_x; in_y = out_y; prev = point; } } } Exit: return error; } /* Store the hinted outline in an FT_Outline structure. */ FT_LOCAL_DEF( void ) af_glyph_hints_save( AF_GlyphHints hints, FT_Outline* outline ) { AF_Point point = hints->points; AF_Point limit = point + hints->num_points; FT_Vector* vec = outline->points; char* tag = outline->tags; for ( ; point < limit; point++, vec++, tag++ ) { vec->x = point->x; vec->y = point->y; if ( point->flags & AF_FLAG_CONIC ) tag[0] = FT_CURVE_TAG_CONIC; else if ( point->flags & AF_FLAG_CUBIC ) tag[0] = FT_CURVE_TAG_CUBIC; else tag[0] = FT_CURVE_TAG_ON; } } /**************************************************************** * * EDGE POINT GRID-FITTING * ****************************************************************/ /* Align all points of an edge to the same coordinate value, */ /* either horizontally or vertically. */ FT_LOCAL_DEF( void ) af_glyph_hints_align_edge_points( AF_GlyphHints hints, AF_Dimension dim ) { AF_AxisHints axis = & hints->axis[dim]; AF_Segment segments = axis->segments; AF_Segment segment_limit = segments + axis->num_segments; AF_Segment seg; if ( dim == AF_DIMENSION_HORZ ) { for ( seg = segments; seg < segment_limit; seg++ ) { AF_Edge edge = seg->edge; AF_Point point, first, last; if ( edge == NULL ) continue; first = seg->first; last = seg->last; point = first; for (;;) { point->x = edge->pos; point->flags |= AF_FLAG_TOUCH_X; if ( point == last ) break; point = point->next; } } } else { for ( seg = segments; seg < segment_limit; seg++ ) { AF_Edge edge = seg->edge; AF_Point point, first, last; if ( edge == NULL ) continue; first = seg->first; last = seg->last; point = first; for (;;) { point->y = edge->pos; point->flags |= AF_FLAG_TOUCH_Y; if ( point == last ) break; point = point->next; } } } } /**************************************************************** * * STRONG POINT INTERPOLATION * ****************************************************************/ /* 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 */ /* 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_PtrDist min, max, mid; FT_Pos fpos; /* find enclosing edges */ min = 0; max = edge_limit - edges; #if 1 /* for a small number of edges, a linear search is better */ if ( max <= 8 ) { FT_PtrDist nn; for ( nn = 0; nn < max; nn++ ) if ( edges[nn].fpos >= u ) break; if ( edges[nn].fpos == u ) { u = edges[nn].pos; goto Store_Point; } min = nn; } else #endif 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; } } /* point is not on an edge */ { 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; } } } /**************************************************************** * * WEAK POINT INTERPOLATION * ****************************************************************/ /* Shift the original coordinates of all points between `p1' and */ /* `p2' to get hinted coordinates, using the same difference as */ /* given by `ref'. */ static void af_iup_shift( AF_Point p1, AF_Point p2, AF_Point ref ) { AF_Point p; FT_Pos delta = ref->u - ref->v; if ( delta == 0 ) return; for ( p = p1; p < ref; p++ ) p->u = p->v + delta; for ( p = ref + 1; p <= p2; p++ ) p->u = p->v + delta; } /* Interpolate the original coordinates of all points between `p1' and */ /* `p2' to get hinted coordinates, using `ref1' and `ref2' as the */ /* reference points. The `u' and `v' members are the current and */ /* original coordinate values, respectively. */ /* */ /* Details can be found in the TrueType bytecode specification. */ 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; } } } /* Hint the weak points -- this is equivalent to the TrueType `IUP' */ /* hinting instruction. */ 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; point++ ) { point->u = point->y; point->v = point->oy; } } point = points; for ( ; contour < contour_limit; contour++ ) { AF_Point first_touched, last_touched; point = *contour; end_point = point->prev; first_point = point; /* find first touched point */ for (;;) { if ( point > end_point ) /* no touched point in contour */ goto NextContour; if ( point->flags & touch_flag ) break; point++; } first_touched = point; last_touched = point; for (;;) { FT_ASSERT( point <= end_point && ( point->flags & touch_flag ) != 0 ); /* skip any touched neighbours */ while ( point < end_point && ( point[1].flags & touch_flag ) != 0 ) point++; last_touched = point; /* find the next touched point, if any */ point++; for (;;) { if ( point > end_point ) goto EndContour; if ( ( point->flags & touch_flag ) != 0 ) break; point++; } /* interpolate between last_touched and point */ af_iup_interp( last_touched + 1, point - 1, last_touched, point ); } EndContour: /* special case: only one point was touched */ if ( last_touched == first_touched ) af_iup_shift( first_point, end_point, first_touched ); else /* interpolate the last part */ { if ( last_touched < end_point ) af_iup_interp( last_touched + 1, end_point, last_touched, first_touched ); if ( first_touched > points ) af_iup_interp( first_point, first_touched - 1, last_touched, first_touched ); } NextContour: ; } /* 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; } } #ifdef AF_CONFIG_OPTION_USE_WARPER /* Apply (small) warp scale and warp delta for given dimension. */ FT_LOCAL_DEF( void ) af_glyph_hints_scale_dim( AF_GlyphHints hints, AF_Dimension dim, FT_Fixed scale, FT_Pos delta ) { AF_Point points = hints->points; AF_Point points_limit = points + hints->num_points; AF_Point point; if ( dim == AF_DIMENSION_HORZ ) { for ( point = points; point < points_limit; point++ ) point->x = FT_MulFix( point->fx, scale ) + delta; } else { for ( point = points; point < points_limit; point++ ) point->y = FT_MulFix( point->fy, scale ) + delta; } } #endif /* AF_CONFIG_OPTION_USE_WARPER */ /* END */