freetype/src/autofit/afloader.c

#include "afloader.h"
#include "afhints.h"
#include "afglobal.h"
#include "aflatin.h"

  FT_LOCAL_DEF( FT_Error )
  af_loader_init( AF_Loader  loader,
                  FT_Memory  memory )
  {
    FT_Error  error;

    FT_ZERO( loader );

    af_glyph_hints_init( &loader->hints, memory );

    error = FT_GlyphLoader_New( memory, &loader->gloader );
    if ( !error )
    {
      error = FT_GlyphLoader_CreateExtra( loader->gloader );
      if ( error )
      {
        FT_GlyphLoader_Done( loader->gloader );
        loader->gloader = NULL;
      }
    }
    return error;
  }


  FT_LOCAL_DEF( FT_Error )
  af_loader_reset( AF_Loader   loader,
                   FT_Face     face )
  {
    FT_Error   error = 0;

    loader->face    = face;
    loader->gloader = face->glyph->internal->loader;
    loader->globals = (AF_FaceGlobals) face->autohint.data;

    if ( loader->globals == NULL )
    {
      error = af_face_globals_new( face, &loader->globals );
      if ( !error )
      {
        face->autohint.data      = (FT_Pointer) loader->globals;
        face->autohint.finalizer = (FT_Generic_Finalizer) af_face_globals_free;
      }
    }
    return error;
  }


  FT_LOCAL_DEF( void )
  af_loader_done( AF_Loader   loader )
  {
    loader->face    = NULL;
    loader->globals = NULL;

    FT_GlyphLoader_Done( loader->gloader );
    loader->gloader = NULL;
  }


  static FT_Error
  af_loader_load_g( AF_Loader  loader,
                    AF_Scaler  scaler,
                    FT_UInt    glyph_index,
                    FT_Int32   load_flags,
                    FT_UInt    depth )
  {
    FT_Error          error    = 0;
    FT_Face           face     = loader->face;
    AF_FaceGlobals    globals  = loader->globals;
    FT_GlyphLoader    gloader  = loader->gloader;
    AF_ScriptMetrics  metrics  = loader->metrics;
    AF_GlyphHints     hints    = &loader->hints;
    FT_GlyphSlot      slot     = face->glyph;
    FT_Slot_Internal  internal = slot->internal;

    error = FT_Load_Glyph( face, glyph_index, load_flags );
    if ( error )
      goto Exit;

    loader->transformed = internal->glyph_transformed;
    if ( loader->transformed )
    {
      FT_Matrix  inverse;

      loader->trans_matrix = internal->glyph_matrix;
      loader->trans_delta  = internal->glyph_delta;

      inverse = loader->trans_matrix;
      FT_Matrix_Invert( &inverse );
      FT_Vector_Transform( &loader->trans_delta, &inverse );
    }

    /* set linear metrics */
    slot->linearHoriAdvance = slot->metrics.horiAdvance;
    slot->linearVertAdvance = slot->metrics.vertAdvance;

    switch ( slot->format )
    {
      case FT_GLYPH_FORMAT_OUTLINE:
       /* translate the loaded glyph when an internal transform
        * is needed
        */
        if ( loader->transformed )
        {
          FT_Vector*  point = slot->outline.points;
          FT_Vector*  limit = point + slot->outline.n_points;

          for ( ; point < limit; point++ )
          {
            point->x += loader->trans_delta.x;
            point->y += loader->trans_delta.y;
          }
        }

        /* copy the outline points in the loader's current               */
        /* extra points which is used to keep original glyph coordinates */
        error = FT_GlyphLoader_CheckPoints( gloader,
                                            slot->outline.n_points + 2,
                                            slot->outline.n_contours );
        if ( error )
          goto Exit;

        FT_ARRAY_COPY( gloader->current.extra_points,
                       slot->outline.points,
                       slot->outline.n_points );

        FT_ARRAY_COPY( gloader->current.outline.contours,
                       slot->outline.contours,
                       slot->outline.n_contours );

        FT_ARRAY_COPY( gloader->current.outline.tags,
                       slot->outline.tags,
                       slot->outline.n_points );

        gloader->current.outline.n_points   = slot->outline.n_points;
        gloader->current.outline.n_contours = slot->outline.n_contours;

        /* compute original phantom points */
        loader->pp1.x = hints->x_delta;
        loader->pp1.y = hints->y_delta;
        loader->pp2.x = FT_MulFix( slot->metrics.horiAdvance,
                                   hints->x_scale ) + hints->x_delta;
        loader->pp2.y = hints->y_delta;

        /* 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 = metrics->clazz->script_hints_init( hints,
                                                   &gloader->current.outline,
                                                   metrics );
        if ( error )
          goto Exit;

        /* apply the hints */
        metrics->clazz->script_hints_apply( hints,
                                            &gloader->current.outline,
                                            metrics );
        /* we now need to hint the metrics according to the change in */
        /* width/positioning that occured during the hinting process  */
        {
          FT_Pos        old_advance, old_rsb, old_lsb, new_lsb;
          AF_AxisHints  axis  = &hints->axis[ AF_DIMENSION_HORZ ];
          AF_Edge       edge1 = axis->edges;    /* leftmost edge  */
          AF_Edge       edge2 = edge1 + axis->num_edges - 1; /* rightmost edge */


          old_advance = loader->pp2.x;
          old_rsb     = old_advance - edge2->opos;
          old_lsb     = edge1->opos;
          new_lsb     = edge1->pos;

          loader->pp1.x = FT_PIX_ROUND( new_lsb    - old_lsb );
          loader->pp2.x = FT_PIX_ROUND( edge2->pos + old_rsb );

#if 0
          /* try to fix certain bad advance computations */
          if ( loader->pp2.x + loader->pp1.x == edge2->pos && old_rsb > 4 )
            loader->pp2.x += 64;
#endif
        }

        /* good, we simply add the glyph to our loader's base */
        FT_GlyphLoader_Add( gloader );
        break;

    case FT_GLYPH_FORMAT_COMPOSITE:
      {
        FT_UInt      nn, num_subglyphs = slot->num_subglyphs;
        FT_UInt      num_base_subgs, start_point;
        FT_SubGlyph  subglyph;


        start_point = gloader->base.outline.n_points;

        /* first of all, copy the subglyph descriptors in the glyph loader */
        error = FT_GlyphLoader_CheckSubGlyphs( gloader, num_subglyphs );
        if ( error )
          goto Exit;

        FT_ARRAY_COPY( gloader->current.subglyphs,
                       slot->subglyphs,
                       num_subglyphs );

        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 = loader->pp1;
          pp2 = loader->pp2;

          num_base_points = gloader->base.outline.n_points;

          error = af_loader_load_g( loader, scaler, 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 = loader->pp1;
            pp2 = loader->pp2;
          }
          else
          {
            loader->pp1 = pp1;
            loader->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, hints->x_scale ) + hints->x_delta;
            y = FT_MulFix( subglyph->arg2, hints->y_scale ) + hints->y_delta;

            x = FT_PIX_ROUND(x);
            y = FT_PIX_ROUND(y);
          }

          {
            FT_Outline  dummy = gloader->base.outline;


            dummy.points  += num_base_points;
            dummy.n_points = (short)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;


      /* transform the hinted outline if needed */
      if ( loader->transformed )
        FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );

      /* we must translate our final outline by -pp1.x and compute */
      /* the new metrics                                           */
      if ( loader->pp1.x )
        FT_Outline_Translate( &gloader->base.outline, -loader->pp1.x, 0 );

      FT_Outline_Get_CBox( &gloader->base.outline, &bbox );

      bbox.xMin  = FT_PIX_FLOOR(  bbox.xMin );
      bbox.yMin  = FT_PIX_FLOOR(  bbox.yMin );
      bbox.xMax  = FT_PIX_CEIL( bbox.xMax );
      bbox.yMax  = FT_PIX_CEIL( bbox.yMax );

      slot->metrics.width        = bbox.xMax - bbox.xMin;
      slot->metrics.height       = bbox.yMax - bbox.yMin;
      slot->metrics.horiBearingX = bbox.xMin;
      slot->metrics.horiBearingY = bbox.yMax;

      /* for mono-width fonts (like Andale, Courier, etc.) we need */
      /* to keep the original rounded advance width                */
#if 0
      if ( !FT_IS_FIXED_WIDTH( slot->face ) )
        slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
      else
        slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
                                               x_scale );
#else
      slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
#endif

      slot->metrics.horiAdvance = FT_PIX_ROUND( slot->metrics.horiAdvance );

      /* now copy outline into glyph slot */
      FT_GlyphLoader_Rewind( loader->gloader );
      error = FT_GlyphLoader_CopyPoints( loader->gloader, gloader );
      if ( error )
        goto Exit;

      slot->outline = slot->internal->loader->base.outline;
      slot->format  = FT_GLYPH_FORMAT_OUTLINE;
    }

#ifdef DEBUG_HINTER
    af_debug_hinter = hinter;
#endif

  Exit:
    return error;
  }




  FT_LOCAL_DEF( FT_Error )
  af_loader_load_glyph( AF_Loader  loader,
                        FT_Face    face,
                        FT_UInt    gindex,
                        FT_UInt32  load_flags )
  {
    FT_Error      error;
    FT_Size       size = face->size;
    AF_ScalerRec  scaler;

    if ( !size )
      return FT_Err_Invalid_Argument;

    FT_ZERO( &scaler );

    scaler.face    = face;
    scaler.x_scale = size->metrics.x_scale;
    scaler.x_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */
    scaler.y_scale = size->metrics.y_scale;
    scaler.y_delta = 0;  /* XXX: TODO: add support for sub-pixel hinting */

    scaler.render_mode = FT_LOAD_TARGET_MODE( load_flags );
    scaler.flags       = 0;  /* XXX: fix this */

    error = af_loader_reset( loader, face );
    if ( !error )
    {
      AF_ScriptMetrics  metrics;

      error = af_face_globals_get_metrics( loader->globals, gindex, &metrics );
      if ( !error )
      {
        metrics->clazz->script_metrics_scale( metrics, &scaler );

        load_flags |=  FT_LOAD_NO_SCALE | FT_LOAD_IGNORE_TRANSFORM;
        load_flags &= ~FT_LOAD_RENDER;

        error = af_loader_load_g( loader, &scaler, gindex, load_flags, 0 );
      }
    }
    return error;
  }