initial commit

1 files changed, 1227 insertions, 0 deletions

diff --git a/src/freetype/afhints.c b/src/freetype/afhints.c
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index 0000000..1378553
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+++ b/src/freetype/afhints.c
@@ -0,0 +1,1227 @@
+/***************************************************************************/
+/*                                                                         */
+/*  afhints.c                                                              */
+/*                                                                         */
+/*    Auto-fitter hinting routines (body).                                 */
+/*                                                                         */
+/*  Copyright 2003-2018 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 < AF_SEGMENTS_EMBEDDED )
+    {
+      if ( !axis->segments )
+      {
+        axis->segments     = axis->embedded.segments;
+        axis->max_segments = AF_SEGMENTS_EMBEDDED;
+      }
+    }
+    else 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 ( axis->segments == axis->embedded.segments )
+      {
+        if ( FT_NEW_ARRAY( axis->segments, new_max ) )
+          goto Exit;
+        ft_memcpy( axis->segments, axis->embedded.segments,
+                   sizeof ( axis->embedded.segments ) );
+      }
+      else
+      {
+        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, */
+  /* without initializing the edge itself.                 */
+
+  FT_LOCAL( FT_Error )
+  af_axis_hints_new_edge( AF_AxisHints  axis,
+                          FT_Int        fpos,
+                          AF_Direction  dir,
+                          FT_Bool       top_to_bottom_hinting,
+                          FT_Memory     memory,
+                          AF_Edge      *anedge )
+  {
+    FT_Error  error = FT_Err_Ok;
+    AF_Edge   edge  = NULL;
+    AF_Edge   edges;
+
+
+    if ( axis->num_edges < AF_EDGES_EMBEDDED )
+    {
+      if ( !axis->edges )
+      {
+        axis->edges     = axis->embedded.edges;
+        axis->max_edges = AF_EDGES_EMBEDDED;
+      }
+    }
+    else 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 ( axis->edges == axis->embedded.edges )
+      {
+        if ( FT_NEW_ARRAY( axis->edges, new_max ) )
+          goto Exit;
+        ft_memcpy( axis->edges, axis->embedded.edges,
+                   sizeof ( axis->embedded.edges ) );
+      }
+      else
+      {
+        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 ( top_to_bottom_hinting ? ( edge[-1].fpos > fpos )
+                                 : ( 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++;
+
+  Exit:
+    *anedge = edge;
+    return error;
+  }
+
+
+  /* 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 do not differ enough       */
+    /* (value 14 is heuristic, corresponding to approx. 4.1 degrees) */
+    /* the long arm is never negative                                */
+    if ( ll <= 14 * FT_ABS( ss ) )
+      dir = AF_DIR_NONE;
+
+    return dir;
+  }
+
+
+  FT_LOCAL_DEF( void )
+  af_glyph_hints_init( AF_GlyphHints  hints,
+                       FT_Memory      memory )
+  {
+    /* no need to initialize the embedded items */
+    FT_MEM_ZERO( hints, sizeof ( *hints ) - sizeof ( hints->embedded ) );
+    hints->memory = memory;
+  }
+
+
+  FT_LOCAL_DEF( void )
+  af_glyph_hints_done( AF_GlyphHints  hints )
+  {
+    FT_Memory  memory;
+    int        dim;
+
+
+    if ( !( hints && hints->memory ) )
+      return;
+
+    memory = hints->memory;
+
+    /*
+     *  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;
+      if ( axis->segments != axis->embedded.segments )
+        FT_FREE( axis->segments );
+
+      axis->num_edges = 0;
+      axis->max_edges = 0;
+      if ( axis->edges != axis->embedded.edges )
+        FT_FREE( axis->edges );
+    }
+
+    if ( hints->contours != hints->embedded.contours )
+      FT_FREE( hints->contours );
+    hints->max_contours = 0;
+    hints->num_contours = 0;
+
+    if ( hints->points != hints->embedded.points )
+      FT_FREE( hints->points );
+    hints->max_points = 0;
+    hints->num_points = 0;
+
+    hints->memory = NULL;
+  }
+
+
+  /* Reset metrics. */
+
+  FT_LOCAL_DEF( void )
+  af_glyph_hints_rescale( AF_GlyphHints    hints,
+                          AF_StyleMetrics  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 = (FT_UInt)hints->max_contours;
+
+    if ( new_max <= AF_CONTOURS_EMBEDDED )
+    {
+      if ( !hints->contours )
+      {
+        hints->contours     = hints->embedded.contours;
+        hints->max_contours = AF_CONTOURS_EMBEDDED;
+      }
+    }
+    else if ( new_max > old_max )
+    {
+      if ( hints->contours == hints->embedded.contours )
+        hints->contours = NULL;
+
+      new_max = ( new_max + 3 ) & ~3U; /* round up to a multiple of 4 */
+
+      if ( FT_RENEW_ARRAY( hints->contours, old_max, new_max ) )
+        goto Exit;
+
+      hints->max_contours = (FT_Int)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 = (FT_UInt)hints->max_points;
+
+    if ( new_max <= AF_POINTS_EMBEDDED )
+    {
+      if ( !hints->points )
+      {
+        hints->points     = hints->embedded.points;
+        hints->max_points = AF_POINTS_EMBEDDED;
+      }
+    }
+    else if ( new_max > old_max )
+    {
+      if ( hints->points == hints->embedded.points )
+        hints->points = NULL;
+
+      new_max = ( new_max + 2 + 7 ) & ~7U; /* round up to a multiple of 8 */
+
+      if ( FT_RENEW_ARRAY( hints->points, old_max, new_max ) )
+        goto Exit;
+
+      hints->max_points = (FT_Int)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;
+
+      /* value 20 in `near_limit' is heuristic */
+      FT_UInt  units_per_em = hints->metrics->scaler.face->units_per_EM;
+      FT_Int   near_limit   = 20 * units_per_em / 2048;
+
+
+      /* compute coordinates & Bezier flags, next and prev */
+      {
+        FT_Vector*  vec           = outline->points;
+        char*       tag           = outline->tags;
+        FT_Short    endpoint      = outline->contours[0];
+        AF_Point    end           = points + endpoint;
+        AF_Point    prev          = end;
+        FT_Int      contour_index = 0;
+
+
+        for ( point = points; point < point_limit; point++, vec++, tag++ )
+        {
+          FT_Pos  out_x, out_y;
+
+
+          point->in_dir  = (FT_Char)AF_DIR_NONE;
+          point->out_dir = (FT_Char)AF_DIR_NONE;
+
+          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;
+
+          end->fx = (FT_Short)outline->points[endpoint].x;
+          end->fy = (FT_Short)outline->points[endpoint].y;
+
+          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;
+          }
+
+          out_x = point->fx - prev->fx;
+          out_y = point->fy - prev->fy;
+
+          if ( FT_ABS( out_x ) + FT_ABS( out_y ) < near_limit )
+            prev->flags |= AF_FLAG_NEAR;
+
+          point->prev = prev;
+          prev->next  = point;
+          prev        = point;
+
+          if ( point == end )
+          {
+            if ( ++contour_index < outline->n_contours )
+            {
+              endpoint = outline->contours[contour_index];
+              end      = points + endpoint;
+              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' and `out' vectors.
+         *
+         *  Note that distances between points that are very near to each
+         *  other are accumulated.  In other words, the auto-hinter either
+         *  prepends the small vectors between near points to the first
+         *  non-near vector, or the sum of small vector lengths exceeds a
+         *  threshold, thus `grouping' the small vectors.  All intermediate
+         *  points are tagged as weak; the directions are adjusted also to
+         *  be equal to the accumulated one.
+         */
+
+        FT_Int  near_limit2 = 2 * near_limit - 1;
+
+        AF_Point*  contour;
+        AF_Point*  contour_limit = hints->contours + hints->num_contours;
+
+
+        for ( contour = hints->contours; contour < contour_limit; contour++ )
+        {
+          AF_Point  first = *contour;
+          AF_Point  next, prev, curr;
+
+          FT_Pos  out_x, out_y;
+
+
+          /* since the first point of a contour could be part of a */
+          /* series of near points, go backwards to find the first */
+          /* non-near point and adjust `first'                     */
+
+          point = first;
+          prev  = first->prev;
+
+          while ( prev != first )
+          {
+            out_x = point->fx - prev->fx;
+            out_y = point->fy - prev->fy;
+
+            /*
+             *  We use Taxicab metrics to measure the vector length.
+             *
+             *  Note that the accumulated distances so far could have the
+             *  opposite direction of the distance measured here.  For this
+             *  reason we use `near_limit2' for the comparison to get a
+             *  non-near point even in the worst case.
+             */
+            if ( FT_ABS( out_x ) + FT_ABS( out_y ) >= near_limit2 )
+              break;
+
+            point = prev;
+            prev  = prev->prev;
+          }
+
+          /* adjust first point */
+          first = point;
+
+          /* now loop over all points of the contour to get */
+          /* `in' and `out' vector directions               */
+
+          curr = first;
+
+          /*
+           *  We abuse the `u' and `v' fields to store index deltas to the
+           *  next and previous non-near point, respectively.
+           *
+           *  To avoid problems with not having non-near points, we point to
+           *  `first' by default as the next non-near point.
+           *
+           */
+          curr->u  = (FT_Pos)( first - curr );
+          first->v = -curr->u;
+
+          out_x = 0;
+          out_y = 0;
+
+          next = first;
+          do
+          {
+            AF_Direction  out_dir;
+
+
+            point = next;
+            next  = point->next;
+
+            out_x += next->fx - point->fx;
+            out_y += next->fy - point->fy;
+
+            if ( FT_ABS( out_x ) + FT_ABS( out_y ) < near_limit )
+            {
+              next->flags |= AF_FLAG_WEAK_INTERPOLATION;
+              continue;
+            }
+
+            curr->u = (FT_Pos)( next - curr );
+            next->v = -curr->u;
+
+            out_dir = af_direction_compute( out_x, out_y );
+
+            /* adjust directions for all points inbetween; */
+            /* the loop also updates position of `curr'    */
+            curr->out_dir = (FT_Char)out_dir;
+            for ( curr = curr->next; curr != next; curr = curr->next )
+            {
+              curr->in_dir  = (FT_Char)out_dir;
+              curr->out_dir = (FT_Char)out_dir;
+            }
+            next->in_dir = (FT_Char)out_dir;
+
+            curr->u  = (FT_Pos)( first - curr );
+            first->v = -curr->u;
+
+            out_x = 0;
+            out_y = 0;
+
+          } while ( next != first );
+        }
+
+        /*
+         *  The next step is to `simplify' an outline's topology so that we
+         *  can identify local extrema more reliably: A series of
+         *  non-horizontal or non-vertical vectors pointing into the same
+         *  quadrant are handled as a single, long vector.  From a
+         *  topological point of the view, the intermediate points are of no
+         *  interest and thus tagged as weak.
+         */
+
+        for ( point = points; point < point_limit; point++ )
+        {
+          if ( point->flags & AF_FLAG_WEAK_INTERPOLATION )
+            continue;
+
+          if ( point->in_dir  == AF_DIR_NONE &&
+               point->out_dir == AF_DIR_NONE )
+          {
+            /* check whether both vectors point into the same quadrant */
+
+            FT_Pos  in_x, in_y;
+            FT_Pos  out_x, out_y;
+
+            AF_Point  next_u = point + point->u;
+            AF_Point  prev_v = point + point->v;
+
+
+            in_x = point->fx - prev_v->fx;
+            in_y = point->fy - prev_v->fy;
+
+            out_x = next_u->fx - point->fx;
+            out_y = next_u->fy - point->fy;
+
+            if ( ( in_x ^ out_x ) >= 0 && ( in_y ^ out_y ) >= 0 )
+            {
+              /* yes, so tag current point as weak */
+              /* and update index deltas           */
+
+              point->flags |= AF_FLAG_WEAK_INTERPOLATION;
+
+              prev_v->u = (FT_Pos)( next_u - prev_v );
+              next_u->v = -prev_v->u;
+            }
+          }
+        }
+
+        /*
+         *  Finally, check for remaining weak points.  Everything else not
+         *  collected in edges so far is then implicitly classified as strong
+         *  points.
+         */
+
+        for ( point = points; point < point_limit; point++ )
+        {
+          if ( point->flags & AF_FLAG_WEAK_INTERPOLATION )
+            continue;
+
+          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;
+            }
+
+            {
+              AF_Point  next_u = point + point->u;
+              AF_Point  prev_v = point + point->v;
+
+
+              if ( ft_corner_is_flat( point->fx  - prev_v->fx,
+                                      point->fy  - prev_v->fy,
+                                      next_u->fx - point->fx,
+                                      next_u->fy - point->fy ) )
+              {
+                /* either the `in' or the `out' vector is much more  */
+                /* dominant than the other one, so tag current point */
+                /* as weak and update index deltas                   */
+
+                prev_v->u = (FT_Pos)( next_u - prev_v );
+                next_u->v = -prev_v->u;
+
+                goto Is_Weak_Point;
+              }
+            }
+          }
+          else if ( point->in_dir == -point->out_dir )
+          {
+            /* current point forms a spike */
+            goto Is_Weak_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 )
+          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 )
+          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;
+    FT_UInt       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 ) )
+          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, v1, v2, u1, u2, d1, d2;
+
+
+    if ( p1 > p2 )
+      return;
+
+    if ( ref1->v > ref2->v )
+    {
+      p    = ref1;
+      ref1 = ref2;
+      ref2 = p;
+    }
+
+    v1 = ref1->v;
+    v2 = ref2->v;
+    u1 = ref1->u;
+    u2 = ref2->u;
+    d1 = u1 - v1;
+    d2 = u2 - v2;
+
+    if ( u1 == u2 || v1 == v2 )
+    {
+      for ( p = p1; p <= p2; p++ )
+      {
+        u = p->v;
+
+        if ( u <= v1 )
+          u += d1;
+        else if ( u >= v2 )
+          u += d2;
+        else
+          u = u1;
+
+        p->u = u;
+      }
+    }
+    else
+    {
+      FT_Fixed  scale = FT_DivFix( u2 - u1, v2 - v1 );
+
+
+      for ( p = p1; p <= p2; p++ )
+      {
+        u = p->v;
+
+        if ( u <= v1 )
+          u += d1;
+        else if ( u >= v2 )
+          u += d2;
+        else
+          u = u1 + FT_MulFix( u - v1, scale );
+
+        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;
+    FT_UInt    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;
+      }
+    }
+
+    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;
+
+      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 */