kc3-lang/freetype/src/autohint/ahhint.c

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• Hash : 54e75749
  Author :
  Date : 2000-11-04T02:52:02
  

  defining new types to hold "internal" fields of public objects: FT_Face_Internal, FT_Size_Internal, FT_Slot_Internal these contain some fields that may change between releases of FreeType, without affecting the size of FT_FaceRec, FT_SizeRec, FT_GlyphSlotRec, etc.., which means that drivers wouldn't need to be recompiled if we only add new fields to an internal structure.. I plan to hack a few things related to the auto-hinter and I need this move to ensure that we will not break binary compatibility between 2.0 and 2.1 :-) - David

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• src/autohint/ahhint.c

• /***************************************************************************/
  /*                                                                         */
  /*  ahhint.c                                                               */
  /*                                                                         */
  /*    Glyph hinter (body).                                                 */
  /*                                                                         */
  /*  Copyright 2000 Catharon Productions Inc.                               */
  /*  Author: David Turner                                                   */
  /*                                                                         */
  /*  This file is part of the Catharon Typography Project and shall only    */
  /*  be used, modified, and distributed under the terms of the Catharon     */
  /*  Open Source License that should come with this file under the name     */
  /*  `CatharonLicense.txt'.  By continuing to use, modify, or distribute    */
  /*  this file you indicate that you have read the license and              */
  /*  understand and accept it fully.                                        */
  /*                                                                         */
  /*  Note that this license is compatible with the FreeType license.        */
  /*                                                                         */
  /***************************************************************************/
  
  
  #ifdef FT_FLAT_COMPILE
  
  #include "ahhint.h"
  #include "ahglyph.h"
  #include "ahangles.h"
  
  #else
  
  #include <autohint/ahhint.h>
  #include <autohint/ahglyph.h>
  #include <autohint/ahangles.h>
  
  #endif
  
  #include <freetype/ftoutln.h>
  
  
  #define FACE_GLOBALS( face )  ((AH_Face_Globals*)(face)->autohint.data)
  
  #define AH_USE_IUP
  
  
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****   Hinting routines                                              ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
  
  
    static int  disable_horz_edges = 0;
    static int  disable_vert_edges = 0;
  
  
    /* snap a given width in scaled coordinates to one of the */
    /* current standard widths                                */
    static
    FT_Pos  ah_snap_width( FT_Pos*  widths,
                           FT_Int   count,
                           FT_Pos   width )
    {
      int     n;
      FT_Pos  best      = 64 + 32 + 2;
      FT_Pos  reference = width;
  
  
      for ( n = 0; n < count; n++ )
      {
        FT_Pos  w;
        FT_Pos  dist;
  
  
        w = widths[n];
        dist = width - w;
        if ( dist < 0 )
          dist = -dist;
        if ( dist < best )
        {
          best      = dist;
          reference = w;
        }
      }
  
      if ( width >= reference )
      {
        width -= 0x21;
        if ( width < reference )
          width = reference;
      }
      else
      {
        width += 0x21;
        if ( width > reference )
          width = reference;
      }
  
      return width;
    }
  
  
    /* align one stem edge relative to the previous stem edge */
    static
    void  ah_align_linked_edge( AH_Hinter*  hinter,
                                AH_Edge*    base_edge,
                                AH_Edge*    stem_edge,
                                int         vertical )
    {
      FT_Pos       dist    = stem_edge->opos - base_edge->opos;
      AH_Globals*  globals = &hinter->globals->scaled;
      FT_Pos       sign    = 1;
  
  
      if ( dist < 0 )
      {
        dist = -dist;
        sign = -1;
      }
  
      if ( vertical )
      {
        dist = ah_snap_width( globals->heights, globals->num_heights, dist );
  
        /* in the case of vertical hinting, always round */
        /* the stem heights to integer pixels            */
        if ( dist >= 64 )
          dist = ( dist + 16 ) & -64;
        else
          dist = 64;
      }
      else
      {
        dist = ah_snap_width( globals->widths,  globals->num_widths, dist );
  
        if ( hinter->flags & ah_hinter_monochrome )
        {
          /* monochrome horizontal hinting: snap widths to integer pixels */
          /* with a different threshold                                   */
          if ( dist < 64 )
            dist = 64;
          else
            dist = ( dist + 32 ) & -64;
        }
        else
        {
          /* for horizontal anti-aliased hinting, we adopt a more subtle */
          /* approach: we strengthen small stems, round stems whose size */
          /* is between 1 and 2 pixels to an integer, otherwise nothing  */
          if ( dist < 48 )
            dist = ( dist + 64 ) >> 1;
  
          else if ( dist < 128 )
            dist = ( dist + 42 ) & -64;
        }
      }
  
      stem_edge->pos = base_edge->pos + sign * dist;
    }
  
  
    static
    void  ah_align_serif_edge( AH_Hinter*  hinter,
                               AH_Edge*    base,
                               AH_Edge*    serif )
    {
      FT_Pos  dist;
      FT_Pos  sign = 1;
  
      UNUSED( hinter );
  
  
      dist = serif->opos - base->opos;
      if ( dist < 0 )
      {
        dist = -dist;
        sign = -1;
      }
  
      /* do not strengthen serifs */
      if ( base->flags & ah_edge_done )
      {
        if ( dist > 64 )
          dist = ( dist + 16 ) & -64;
  
        else if ( dist <= 32 )
          dist = ( dist + 33 ) >> 1;
      }
  
      serif->pos = base->pos + sign * dist;
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****       E D G E   H I N T I N G                                   ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /* Another alternative edge hinting algorithm */
    static
    void  ah_hint_edges_3( AH_Hinter*  hinter )
    {
      AH_Edge*     edges;
      AH_Edge*     edge_limit;
      AH_Outline*  outline = hinter->glyph;
      FT_Int       dimension;
  
  
      edges      = outline->horz_edges;
      edge_limit = edges + outline->num_hedges;
  
      for ( dimension = 1; dimension >= 0; dimension-- )
      {
        AH_Edge*  edge;
        AH_Edge*  before = 0;
        AH_Edge*  after  = 0;
        AH_Edge*  anchor = 0;
        int       has_serifs = 0;
  
  
        if ( disable_vert_edges && !dimension )
          goto Next_Dimension;
  
        if ( disable_horz_edges && dimension )
          goto Next_Dimension;
  
        /* we begin by aligning all stems relative to the blue zone */
        /* if needed -- that's only for horizontal edges            */
        if ( dimension )
        {
          for ( edge = edges; edge < edge_limit; edge++ )
          {
            FT_Pos*  blue;
            AH_Edge  *edge1, *edge2;
  
  
            if ( edge->flags & ah_edge_done )
              continue;
  
            blue  = edge->blue_edge;
            edge1 = 0;
            edge2 = edge->link;
  
            if ( blue )
            {
              edge1 = edge;
            }
            else if (edge2 && edge2->blue_edge)
            {
              blue  = edge2->blue_edge;
              edge1 = edge2;
              edge2 = edge;
            }
  
            if ( !edge1 )
              continue;
  
            edge1->pos    = blue[0];
            edge1->flags |= ah_edge_done;
  
            if ( edge2 && !edge2->blue_edge )
            {
              ah_align_linked_edge( hinter, edge1, edge2, dimension );
              edge2->flags |= ah_edge_done;
            }
  
            if ( !anchor )
              anchor = edge;
           }
         }
  
        /* now, we will align all stem edges, trying to maintain the */
        /* relative order of stems in the glyph..                    */
        before = 0;
        after  = 0;
        for ( edge = edges; edge < edge_limit; edge++ )
        {
          AH_Edge  *edge2;
  
  
          if ( edge->flags & ah_edge_done )
            continue;
  
          /* skip all non-stem edges */
          edge2 = edge->link;
          if ( !edge2 )
          {
            has_serifs++;
            continue;
          }
  
          /* now, align the stem */
  
          /* this should not happen, but it's better to be safe.. */
          if ( edge2->blue_edge || edge2 < edge )
          {
  
  #if 0
            printf( "strange blue alignement, edge %d to %d\n",
                    edge - edges, edge2 - edges );
  #endif
  
            ah_align_linked_edge( hinter, edge2, edge, dimension );
            edge->flags |= ah_edge_done;
            continue;
          }
  
          {
            FT_Bool  min = 0;
            FT_Pos   delta;
  
            if ( !anchor )
            {
              edge->pos = ( edge->opos + 32 ) & -64;
              anchor    = edge;
            }
            else
              edge->pos = anchor->pos +
                          ( ( edge->opos - anchor->opos + 32 ) & -64 );
  
            edge->flags |= ah_edge_done;
  
            if ( edge > edges && edge->pos < edge[-1].pos )
            {
              edge->pos = edge[-1].pos;
              min       = 1;
            }
  
            ah_align_linked_edge( hinter, edge, edge2, dimension );
            delta = 0;
            if ( edge2 + 1 < edge_limit        &&
                 edge2[1].flags & ah_edge_done )
              delta = edge2[1].pos - edge2->pos;
  
            if ( delta < 0 )
            {
              edge2->pos += delta;
              if ( !min )
                edge->pos += delta;
            }
            edge2->flags |= ah_edge_done;
          }
        }
  
        if ( !has_serifs )
          goto Next_Dimension;
  
        /* now, hint the remaining edges (serifs and single) in order */
        /* to complete our processing                                 */
        for ( edge = edges; edge < edge_limit; edge++ )
        {
          if ( edge->flags & ah_edge_done )
            continue;
  
          if ( edge->serif )
          {
            ah_align_serif_edge( hinter, edge->serif, edge );
          }
          else if ( !anchor )
          {
            edge->pos = ( edge->opos + 32 ) & -64;
            anchor    = edge;
          }
          else
            edge->pos = anchor->pos +
                        ( ( edge->opos-anchor->opos + 32 ) & -64 );
  
          edge->flags |= ah_edge_done;
  
          if ( edge > edges && edge->pos < edge[-1].pos )
            edge->pos = edge[-1].pos;
  
          if ( edge + 1 < edge_limit        &&
               edge[1].flags & ah_edge_done &&
               edge->pos > edge[1].pos      )
            edge->pos = edge[1].pos;
        }
  
      Next_Dimension:
        edges      = outline->vert_edges;
        edge_limit = edges + outline->num_vedges;
      }
    }
  
  
    FT_LOCAL_DEF
    void  ah_hinter_hint_edges( AH_Hinter*  hinter,
                                int         no_horz_edges,
                                int         no_vert_edges )
    {
      disable_horz_edges = no_horz_edges;
      disable_vert_edges = no_vert_edges;
  
      /* AH_Interpolate_Blue_Edges( hinter ); -- doesn't seem to help      */
      /* reduce the problem of the disappearing eye in the `e' of Times... */
      /* also, creates some artifacts near the blue zones?                 */
      {
        ah_hint_edges_3( hinter );
  
  #if 0
        /* outline optimizer removed temporarily */
        if ( hinter->flags & ah_hinter_optimize )
        {
          AH_Optimizer  opt;
  
  
          if ( !AH_Optimizer_Init( &opt, hinter->glyph, hinter->memory ) )
          {
            AH_Optimizer_Compute( &opt );
            AH_Optimizer_Done( &opt );
          }
        }
  #endif
  
      }
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****       P O I N T   H I N T I N G                                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
    static
    void  ah_hinter_align_edge_points( AH_Hinter*  hinter )
    {
      AH_Outline*  outline = hinter->glyph;
      AH_Edge*     edges;
      AH_Edge*     edge_limit;
      FT_Int       dimension;
  
  
      edges      = outline->horz_edges;
      edge_limit = edges + outline->num_hedges;
  
      for ( dimension = 1; dimension >= 0; dimension-- )
      {
        AH_Edge*   edge;
        AH_Edge*   before;
        AH_Edge*   after;
  
  
        before = 0;
        after  = 0;
  
        edge = edges;
        for ( ; edge < edge_limit; edge++ )
        {
          /* move the points of each segment     */
          /* in each edge to the edge's position */
          AH_Segment*  seg = edge->first;
  
  
          do
          {
            AH_Point*  point = seg->first;
  
  
            for (;;)
            {
              if ( dimension )
              {
                point->y      = edge->pos;
                point->flags |= ah_flah_touch_y;
              }
              else
              {
                point->x      = edge->pos;
                point->flags |= ah_flah_touch_x;
              }
  
              if ( point == seg->last )
                break;
  
              point = point->next;
            }
  
            seg = seg->edge_next;
  
          } while ( seg != edge->first );
        }
  
        edges      = outline->vert_edges;
        edge_limit = edges + outline->num_vedges;
      }
    }
  
  
    /* hint the strong points -- this is equivalent to the TrueType `IP' */
    static
    void  ah_hinter_align_strong_points( AH_Hinter*  hinter )
    {
      AH_Outline*  outline = hinter->glyph;
      FT_Int       dimension;
      AH_Edge*     edges;
      AH_Edge*     edge_limit;
      AH_Point*    points;
      AH_Point*    point_limit;
      AH_Flags     touch_flag;
  
  
      points      = outline->points;
      point_limit = points + outline->num_points;
  
      edges       = outline->horz_edges;
      edge_limit  = edges + outline->num_hedges;
      touch_flag  = ah_flah_touch_y;
  
      for ( dimension = 1; dimension >= 0; dimension-- )
      {
        AH_Point*  point;
        AH_Edge*   edge;
  
  
        if ( edges < edge_limit )
          for ( point = points; point < point_limit; point++ )
          {
            FT_Pos  u, ou, fu;  /* point position */
            FT_Pos  delta;
  
  
            if ( point->flags & touch_flag )
              continue;
  
  #ifndef AH_OPTION_NO_WEAK_INTERPOLATION
            /* if this point is candidate to weak interpolation, we will  */
            /* interpolate it after all strong points have been processed */
            if ( point->flags & ah_flah_weak_interpolation )
              continue;
  #endif
  
            if ( dimension )
            {
              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;
            }
  
            /* otherwise, interpolate the point in between */
            {
              AH_Edge*  before = 0;
              AH_Edge*  after  = 0;
  
  
              for ( edge = edges; edge < edge_limit; edge++ )
              {
                if ( u == edge->fpos )
                {
                  u = edge->pos;
                  goto Store_Point;
                }
                if ( u < edge->fpos )
                  break;
                before = edge;
              }
  
              for ( edge = edge_limit - 1; edge >= edges; edge-- )
              {
                if ( u == edge->fpos )
                {
                  u = edge->pos;
                  goto Store_Point;
                }
                if ( u > edge->fpos )
                  break;
                after = edge;
              }
  
              /* assert( before && after && before != after ) */
              u = before->pos + FT_MulDiv( fu - before->fpos,
                                           after->pos - before->pos,
                                           after->fpos - before->fpos );
            }
  
          Store_Point:
  
            /* save the point position */
            if ( dimension )
              point->y = u;
            else
              point->x = u;
  
            point->flags |= touch_flag;
          }
  
        edges      = outline->vert_edges;
        edge_limit = edges + outline->num_vedges;
        touch_flag = ah_flah_touch_x;
      }
    }
  
  
  #ifndef AH_OPTION_NO_WEAK_INTERPOLATION
  
    static
    void  ah_iup_shift( AH_Point*  p1,
                        AH_Point*  p2,
                        AH_Point*  ref )
    {
      AH_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  ah_iup_interp( AH_Point*  p1,
                         AH_Point*  p2,
                         AH_Point*  ref1,
                         AH_Point*  ref2 )
    {
      AH_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;
        }
      }
    }
  
  
    /* interpolate weak points -- this is equivalent to the TrueType `IUP' */
    static
    void  ah_hinter_align_weak_points( AH_Hinter*  hinter )
    {
      AH_Outline*  outline = hinter->glyph;
      FT_Int       dimension;
      AH_Edge*     edges;
      AH_Edge*     edge_limit;
      AH_Point*    points;
      AH_Point*    point_limit;
      AH_Point**   contour_limit;
      AH_Flags     touch_flag;
  
  
      points      = outline->points;
      point_limit = points + outline->num_points;
  
      /* PASS 1: Move segment points to edge positions */
  
      edges      = outline->horz_edges;
      edge_limit = edges + outline->num_hedges;
      touch_flag = ah_flah_touch_y;
  
      contour_limit = outline->contours + outline->num_contours;
  
      ah_setup_uv( outline, ah_uv_oy );
  
      for ( dimension = 1; dimension >= 0; dimension-- )
      {
        AH_Point*   point;
        AH_Point*   end_point;
        AH_Point*   first_point;
        AH_Point**  contour;
  
  
        point   = points;
        contour = outline->contours;
  
        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 )
          {
            AH_Point*  first_touched = point;
            AH_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                        */
                ah_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           */
              ah_iup_shift( first_point, end_point, cur_touched );
            }
            else
            {
              /* now interpolate after the last touched point to the end */
              /* of the contour                                          */
              ah_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 )
                ah_iup_interp( first_point, first_touched - 1,
                               cur_touched, first_touched );
            }
          }
        }
  
        /* now save the interpolated values back to x/y */
        if ( dimension )
        {
          for ( point = points; point < point_limit; point++ )
            point->y = point->u;
  
          touch_flag = ah_flah_touch_x;
          ah_setup_uv( outline, ah_uv_ox );
        }
        else
        {
          for ( point = points; point < point_limit; point++ )
            point->x = point->u;
  
          break;  /* exit loop */
        }
      }
    }
  
  #endif /* !AH_OPTION_NO_WEAK_INTERPOLATION */
  
  
    FT_LOCAL_DEF
    void  ah_hinter_align_points( AH_Hinter*  hinter )
    {
      ah_hinter_align_edge_points( hinter );
  
  #ifndef AH_OPTION_NO_STRONG_INTERPOLATION
      ah_hinter_align_strong_points( hinter );
  #endif
  
  #ifndef AH_OPTION_NO_WEAK_INTERPOLATION
      ah_hinter_align_weak_points( hinter );
  #endif
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****       H I N T E R   O B J E C T   M E T H O D S                 ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /* scale and fit the global metrics */
    static
    void  ah_hinter_scale_globals( AH_Hinter*  hinter,
                                   FT_Fixed    x_scale,
                                   FT_Fixed    y_scale )
    {
      FT_Int            n;
      AH_Face_Globals*  globals = hinter->globals;
      AH_Globals*       design = &globals->design;
      AH_Globals*       scaled = &globals->scaled;
  
  
      /* copy content */
      *scaled = *design;
  
      /* scale the standard widths & heights */
      for ( n = 0; n < design->num_widths; n++ )
        scaled->widths[n] = FT_MulFix( design->widths[n], x_scale );
  
      for ( n = 0; n < design->num_heights; n++ )
        scaled->heights[n] = FT_MulFix( design->heights[n], y_scale );
  
      /* scale the blue zones */
      for ( n = 0; n < ah_blue_max; n++ )
      {
        FT_Pos  delta, delta2;
  
  
        delta = design->blue_shoots[n] - design->blue_refs[n];
        delta2 = delta;
        if ( delta < 0 )
          delta2 = -delta2;
        delta2 = FT_MulFix( delta2, y_scale );
  
        if ( delta2 < 32 )
          delta2 = 0;
        else if ( delta2 < 64 )
          delta2 = 32 + ( ( ( delta2 - 32 ) + 16 ) & -32 );
        else
          delta2 = ( delta2 + 32 ) & -64;
  
        if ( delta < 0 )
          delta2 = -delta2;
  
        scaled->blue_refs[n] =
          ( FT_MulFix( design->blue_refs[n], y_scale ) + 32 ) & -64;
        scaled->blue_shoots[n] = scaled->blue_refs[n] + delta2;
      }
  
      globals->x_scale = x_scale;
      globals->y_scale = y_scale;
    }
  
  
    static
    void  ah_hinter_align( AH_Hinter*  hinter )
    {
      ah_hinter_align_edge_points( hinter );
      ah_hinter_align_points( hinter );
    }
  
  
    /* finalize a hinter object */
    FT_LOCAL_DEF
    void ah_hinter_done( AH_Hinter*  hinter )
    {
      if ( hinter )
      {
        FT_Memory  memory = hinter->memory;
  
  
        ah_loader_done( hinter->loader );
        ah_outline_done( hinter->glyph );
  
        /* note: the `globals' pointer is _not_ owned by the hinter */
        /*       but by the current face object, we don't need to   */
        /*       release it                                         */
        hinter->globals = 0;
        hinter->face    = 0;
  
        FREE( hinter );
      }
    }
  
  
    /* create a new empty hinter object */
    FT_LOCAL_DEF
    FT_Error  ah_hinter_new( FT_Library   library,
                             AH_Hinter**  ahinter )
    {
      AH_Hinter*  hinter = 0;
      FT_Memory   memory = library->memory;
      FT_Error    error;
  
  
      *ahinter = 0;
  
      /* allocate object */
      if ( ALLOC( hinter, sizeof ( *hinter ) ) )
        goto Exit;
  
      hinter->memory = memory;
      hinter->flags  = 0;
  
      /* allocate outline and loader */
      error = ah_outline_new( memory, &hinter->glyph )  ||
              ah_loader_new ( memory, &hinter->loader ) ||
              ah_loader_create_extra( hinter->loader );
      if ( error )
        goto Exit;
  
      *ahinter = hinter;
  
    Exit:
      if ( error )
        ah_hinter_done( hinter );
  
      return error;
    }
  
  
    /* create a face's autohint globals */
    FT_LOCAL_DEF
    FT_Error  ah_hinter_new_face_globals( AH_Hinter*   hinter,
                                          FT_Face      face,
                                          AH_Globals*  globals )
    {
      FT_Error          error;
      FT_Memory         memory = hinter->memory;
      AH_Face_Globals*  face_globals;
  
  
      if ( ALLOC( face_globals, sizeof ( *face_globals ) ) )
        goto Exit;
  
      hinter->face    = face;
      hinter->globals = face_globals;
  
      if ( globals )
        face_globals->design = *globals;
      else
        ah_hinter_compute_globals( hinter );
  
      face->autohint.data      = face_globals;
      face->autohint.finalizer = (FT_Generic_Finalizer)
                                   ah_hinter_done_face_globals;
      face_globals->face       = face;
  
    Exit:
      return error;
    }
  
  
    /* discard a face's autohint globals */
    FT_LOCAL_DEF
    void  ah_hinter_done_face_globals( AH_Face_Globals*  globals )
    {
      FT_Face    face   = globals->face;
      FT_Memory  memory = face->memory;
  
  
      FREE( globals );
    }
  
  
    static
    FT_Error  ah_hinter_load( AH_Hinter*  hinter,
                              FT_UInt     glyph_index,
                              FT_UInt     load_flags,
                              FT_UInt     depth )
    {
      FT_Face           face    = hinter->face;
      FT_GlyphSlot      slot    = face->glyph;
      FT_Fixed          x_scale = face->size->metrics.x_scale;
      FT_Fixed          y_scale = face->size->metrics.y_scale;
      FT_Glyph_Metrics  metrics;  /* temporary metrics */
      FT_Error          error;
      AH_Outline*       outline = hinter->glyph;
      AH_Loader*        gloader = hinter->loader;
      FT_Bool           no_horz_hints =
                          ( load_flags & AH_HINT_NO_HORZ_EDGES ) != 0;
      FT_Bool           no_vert_hints =
                          ( load_flags & AH_HINT_NO_VERT_EDGES ) != 0;
  
  
      /* load the glyph */
      error = FT_Load_Glyph( face, glyph_index, load_flags );
      if ( error )
        goto Exit;
  
      /* save current glyph metrics */
      metrics = slot->metrics;
  
      switch ( slot->format )
      {
      case ft_glyph_format_outline:
        /* first of all, copy the outline points in the loader's current  */
        /* extra points, which is used to keep original glyph coordinates */
        error = ah_loader_check_points( gloader, slot->outline.n_points + 2,
                                        slot->outline.n_contours );
        if ( error )
          goto Exit;
  
        MEM_Copy( gloader->current.extra_points, slot->outline.points,
                  slot->outline.n_points * sizeof ( FT_Vector ) );
  
        MEM_Copy( gloader->current.outline.contours, slot->outline.contours,
                  slot->outline.n_contours * sizeof ( short ) );
  
        MEM_Copy( gloader->current.outline.tags, slot->outline.tags,
                  slot->outline.n_points * sizeof ( char ) );
  
        gloader->current.outline.n_points   = slot->outline.n_points;
        gloader->current.outline.n_contours = slot->outline.n_contours;
  
        /* compute original phantom points */
        hinter->pp1.x = 0;
        hinter->pp1.y = 0;
        hinter->pp2.x = FT_MulFix( slot->metrics.horiAdvance, x_scale );
        hinter->pp2.y = 0;
  
        /* be sure to check for spacing glyphs */
        if ( slot->outline.n_points == 0 )
          goto Hint_Metrics;
  
        /* now, load the slot image into the auto-outline, and run the */
        /* automatic hinting process                                   */
        error = ah_outline_load( outline, face );   /* XXX: change to slot */
        if ( error )
          goto Exit;
  
        /* perform feature detection */
        ah_outline_detect_features( outline );
  
        if ( !no_horz_hints )
        {
          ah_outline_compute_blue_edges( outline, hinter->globals );
          ah_outline_scale_blue_edges( outline, hinter->globals );
        }
  
        /* perform alignment control */
        ah_hinter_hint_edges( hinter, no_horz_hints, no_vert_hints );
        ah_hinter_align( hinter );
  
        /* now save the current outline into the loader's current table */
        ah_outline_save( outline, gloader );
  
        /* we now need to hint the metrics according to the change in */
        /* width/positioning that occured during the hinting process  */
        {
          FT_Pos    old_width, new_width;
          FT_Pos    old_advance, new_advance;
          FT_Pos    old_lsb, new_lsb;
          AH_Edge*  edge1 = outline->vert_edges;     /* leftmost edge  */
          AH_Edge*  edge2 = edge1 +
                            outline->num_vedges - 1; /* rightmost edge */
  
  
          old_width = edge2->opos - edge1->opos;
          new_width = edge2->pos  - edge1->pos;
  
          old_advance = hinter->pp2.x;
          old_lsb     = edge1->opos;
          new_lsb     = edge1->pos;
  
          new_advance = old_advance +
                        ( new_width + new_lsb - old_width - old_lsb );
  
          hinter->pp1.x = ( ( new_lsb - old_lsb ) + 32 ) & -64;
          hinter->pp2.x = ( ( edge2->pos +
                              ( old_advance - edge2->opos ) ) + 32 ) & -64;
        }
  
        /* good, we simply add the glyph to our loader's base */
        ah_loader_add( gloader );
        break;
  
      case ft_glyph_format_composite:
        {
          FT_UInt       nn, num_subglyphs = slot->num_subglyphs;
          FT_UInt       num_base_subgs, start_point, start_contour;
          FT_SubGlyph*  subglyph;
  
  
          start_point   = gloader->base.outline.n_points;
          start_contour = gloader->base.outline.n_contours;
  
          /* first of all, copy the subglyph descriptors in the glyph loader */
          error = ah_loader_check_subglyphs( gloader, num_subglyphs );
          if ( error )
            goto Exit;
  
          MEM_Copy( gloader->current.subglyphs, slot->subglyphs,
                    num_subglyphs * sizeof ( FT_SubGlyph ) );
  
          gloader->current.num_subglyphs = num_subglyphs;
          num_base_subgs = gloader->base.num_subglyphs;
  
          /* now, read each subglyph independently */
          for ( nn = 0; nn < num_subglyphs; nn++ )
          {
            FT_Vector  pp1, pp2;
            FT_Pos     x, y;
            FT_UInt    num_points, num_new_points, num_base_points;
  
  
            /* gloader.current.subglyphs can change during glyph loading due */
            /* to re-allocation -- we must recompute the current subglyph on */
            /* each iteration                                                */
            subglyph = gloader->base.subglyphs + num_base_subgs + nn;
  
            pp1 = hinter->pp1;
            pp2 = hinter->pp2;
  
            num_base_points = gloader->base.outline.n_points;
  
            error = ah_hinter_load( hinter, subglyph->index,
                                    load_flags, depth + 1 );
            if ( error )
              goto Exit;
  
            /* recompute subglyph pointer */
            subglyph = gloader->base.subglyphs + num_base_subgs + nn;
  
            if ( subglyph->flags & FT_SUBGLYPH_FLAG_USE_MY_METRICS )
            {
              pp1 = hinter->pp1;
              pp2 = hinter->pp2;
            }
            else
            {
              hinter->pp1 = pp1;
              hinter->pp2 = pp2;
            }
  
            num_points     = gloader->base.outline.n_points;
            num_new_points = num_points - num_base_points;
  
            /* now perform the transform required for this subglyph */
  
            if ( subglyph->flags & ( FT_SUBGLYPH_FLAG_SCALE    |
                                     FT_SUBGLYPH_FLAG_XY_SCALE |
                                     FT_SUBGLYPH_FLAG_2X2      ) )
            {
              FT_Vector*  cur   = gloader->base.outline.points +
                                  num_base_points;
              FT_Vector*  org   = gloader->base.extra_points +
                                  num_base_points;
              FT_Vector*  limit = cur + num_new_points;
  
  
              for ( ; cur < limit; cur++, org++ )
              {
                FT_Vector_Transform( cur, &subglyph->transform );
                FT_Vector_Transform( org, &subglyph->transform );
              }
            }
  
            /* apply offset */
  
            if ( !( subglyph->flags & FT_SUBGLYPH_FLAG_ARGS_ARE_XY_VALUES ) )
            {
              FT_Int      k = subglyph->arg1;
              FT_UInt     l = subglyph->arg2;
              FT_Vector*  p1;
              FT_Vector*  p2;
  
  
              if ( start_point + k >= num_base_points          ||
                                 l >= (FT_UInt)num_new_points  )
              {
                error = FT_Err_Invalid_Composite;
                goto Exit;
              }
  
              l += num_base_points;
  
              /* for now, only use the current point coordinates     */
              /* we may consider another approach in the near future */
              p1 = gloader->base.outline.points + start_point + k;
              p2 = gloader->base.outline.points + start_point + l;
  
              x = p1->x - p2->x;
              y = p1->y - p2->y;
            }
            else
            {
              x = FT_MulFix( subglyph->arg1, x_scale );
              y = FT_MulFix( subglyph->arg2, y_scale );
  
              x = ( x + 32 ) & -64;
              y = ( y + 32 ) & -64;
            }
  
            {
              FT_Outline  dummy = gloader->base.outline;
  
  
              dummy.points  += num_base_points;
              dummy.n_points = num_new_points;
  
              FT_Outline_Translate( &dummy, x, y );
            }
          }
        }
        break;
  
      default:
        /* we don't support other formats (yet?) */
        error = FT_Err_Unimplemented_Feature;
      }
  
    Hint_Metrics:
      if ( depth == 0 )
      {
        FT_BBox  bbox;
  
  
        /* we must translate our final outline by -pp1.x, and compute */
        /* the new metrics                                            */
        if ( hinter->pp1.x )
          FT_Outline_Translate( &gloader->base.outline, -hinter->pp1.x, 0 );
  
        FT_Outline_Get_CBox( &gloader->base.outline, &bbox );
        bbox.xMin &= -64;
        bbox.yMin &= -64;
        bbox.xMax  = ( bbox.xMax + 63 ) & -64;
        bbox.yMax  = ( bbox.yMax + 63 ) & -64;
  
        slot->metrics.width        = bbox.xMax - bbox.xMin;
        slot->metrics.height       = bbox.yMax - bbox.yMin;
        slot->metrics.horiBearingX = bbox.xMin;
        slot->metrics.horiBearingY = bbox.yMax;
        slot->metrics.horiAdvance  = hinter->pp2.x - hinter->pp1.x;
        /* XXX: TO DO - slot->linearHoriAdvance */
  
        /* now copy outline into glyph slot */
        ah_loader_rewind( slot->internal->loader );
        error = ah_loader_copy_points( slot->internal->loader, gloader );
        if ( error )
          goto Exit;
  
        slot->outline = slot->internal->loader->base.outline;
        slot->format  = ft_glyph_format_outline;
      }
  
    Exit:
      return error;
    }
  
  
    /* load and hint a given glyph */
    FT_LOCAL_DEF
    FT_Error  ah_hinter_load_glyph( AH_Hinter*    hinter,
                                    FT_GlyphSlot  slot,
                                    FT_Size       size,
                                    FT_UInt       glyph_index,
                                    FT_Int        load_flags )
    {
      FT_Face           face         = slot->face;
      FT_Error          error;
      FT_Fixed          x_scale      = size->metrics.x_scale;
      FT_Fixed          y_scale      = size->metrics.y_scale;
      AH_Face_Globals*  face_globals = FACE_GLOBALS( face );
  
  
      /* first of all, we need to check that we're using the correct face and */
      /* global hints to load the glyph                                       */
      if ( hinter->face != face || hinter->globals != face_globals )
      {
        hinter->face = face;
        if ( !face_globals )
        {
          error = ah_hinter_new_face_globals( hinter, face, 0 );
          if ( error )
            goto Exit;
        }
        hinter->globals = FACE_GLOBALS( face );
        face_globals    = FACE_GLOBALS( face );
      }
  
      /* now, we must check the current character pixel size to see if we */
      /* need to rescale the global metrics                               */
      if ( face_globals->x_scale != x_scale ||
           face_globals->y_scale != y_scale )
        ah_hinter_scale_globals( hinter, x_scale, y_scale );
  
      load_flags |= FT_LOAD_NO_SCALE | FT_LOAD_NO_RECURSE;
  
      ah_loader_rewind( hinter->loader );
  
      error = ah_hinter_load( hinter, glyph_index, load_flags, 0 );
  
    Exit:
      return error;
    }
  
  
    /* retrieve a face's autohint globals for client applications */
    FT_LOCAL_DEF
    void  ah_hinter_get_global_hints( AH_Hinter*  hinter,
                                      FT_Face     face,
                                      void**      global_hints,
                                      long*       global_len )
    {
      AH_Globals*  globals = 0;
      FT_Memory    memory  = hinter->memory;
      FT_Error     error;
  
  
      /* allocate new master globals */
      if ( ALLOC( globals, sizeof ( *globals ) ) )
        goto Fail;
  
      /* compute face globals if needed */
      if ( !FACE_GLOBALS( face ) )
      {
        error = ah_hinter_new_face_globals( hinter, face, 0 );
        if ( error )
          goto Fail;
      }
  
      *globals      = FACE_GLOBALS( face )->design;
      *global_hints = globals;
      *global_len   = sizeof( *globals );
  
      return;
  
    Fail:
      FREE( globals );
  
      *global_hints = 0;
      *global_len   = 0;
    }
  
  
    FT_LOCAL_DEF
    void  ah_hinter_done_global_hints( AH_Hinter*  hinter,
                                       void*       global_hints )
    {
      FT_Memory  memory = hinter->memory;
  
  
      FREE( global_hints );
    }
  
  
  /* END */
  

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