misc/libfreetype/src/autofit/afloader.c
author koda
Sun, 29 Jan 2012 18:52:01 +0100
changeset 6613 c7bf3b7c49dd
parent 5172 88f2e05288ba
permissions -rw-r--r--
disabling the discovery of SDL13+ on desktop. SDL13 has become SDL2 with a completely different ABI and will require a new FindSDL2 module for Cmake to be found; for current sdl development installations, hedgewars will either use the compatibility layer (present in sdl1.3 but not in sdl2) or just fail to build (in case sdl2 is installed but sdl1.2.* is not). whew

/***************************************************************************/
/*                                                                         */
/*  afloader.c                                                             */
/*                                                                         */
/*    Auto-fitter glyph loading routines (body).                           */
/*                                                                         */
/*  Copyright 2003-2009, 2011 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 "afloader.h"
#include "afhints.h"
#include "afglobal.h"
#include "aferrors.h"


  /* Initialize glyph loader. */

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

    af_glyph_hints_init( &loader->hints, memory );
#ifdef FT_DEBUG_AUTOFIT
    _af_debug_hints = &loader->hints;
#endif
    return FT_GlyphLoader_New( memory, &loader->gloader );
  }


  /* Reset glyph loader and compute globals if necessary. */

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


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

    FT_GlyphLoader_Rewind( loader->gloader );

    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;
  }


  /* Finalize glyph loader. */

  FT_LOCAL_DEF( void )
  af_loader_done( AF_Loader  loader )
  {
    af_glyph_hints_done( &loader->hints );

    loader->face    = NULL;
    loader->globals = NULL;

#ifdef FT_DEBUG_AUTOFIT
    _af_debug_hints = NULL;
#endif
    FT_GlyphLoader_Done( loader->gloader );
    loader->gloader = NULL;
  }


  /* Load a single glyph component.  This routine calls itself */
  /* recursively, if necessary, and does the main work of      */
  /* `af_loader_load_glyph.'                                   */

  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;
    FT_Face           face     = loader->face;
    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_Outline_Translate( &slot->outline,
                              loader->trans_delta.x,
                              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_CHECK_POINTS( gloader,
                                           slot->outline.n_points + 4,
                                           slot->outline.n_contours );
      if ( error )
        goto Exit;

      FT_ARRAY_COPY( gloader->current.outline.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 horizontal phantom points (and ignore */
      /* vertical ones)                                         */
      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                                 */
      if ( metrics->clazz->script_hints_apply )
        metrics->clazz->script_hints_apply( hints,
                                            &gloader->current.outline,
                                            metrics );

      /* we now need to adjust the metrics according to the change in */
      /* width/positioning that occurred during the hinting process   */
      if ( scaler->render_mode != FT_RENDER_MODE_LIGHT )
      {
        FT_Pos        old_rsb, old_lsb, new_lsb;
        FT_Pos        pp1x_uh, pp2x_uh;
        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 */


        if ( axis->num_edges > 1 && AF_HINTS_DO_ADVANCE( hints ) )
        {
          old_rsb = loader->pp2.x - edge2->opos;
          old_lsb = edge1->opos;
          new_lsb = edge1->pos;

          /* remember unhinted values to later account */
          /* for rounding errors                       */

          pp1x_uh = new_lsb    - old_lsb;
          pp2x_uh = edge2->pos + old_rsb;

          /* prefer too much space over too little space */
          /* for very small sizes                        */

          if ( old_lsb < 24 )
            pp1x_uh -= 8;

          if ( old_rsb < 24 )
            pp2x_uh += 8;

          loader->pp1.x = FT_PIX_ROUND( pp1x_uh );
          loader->pp2.x = FT_PIX_ROUND( pp2x_uh );

          if ( loader->pp1.x >= new_lsb && old_lsb > 0 )
            loader->pp1.x -= 64;

          if ( loader->pp2.x <= edge2->pos && old_rsb > 0 )
            loader->pp2.x += 64;

          slot->lsb_delta = loader->pp1.x - pp1x_uh;
          slot->rsb_delta = loader->pp2.x - pp2x_uh;
        }
        else
        {
          FT_Pos  pp1x = loader->pp1.x;
          FT_Pos  pp2x = loader->pp2.x;


          loader->pp1.x = FT_PIX_ROUND( pp1x );
          loader->pp2.x = FT_PIX_ROUND( pp2x );

          slot->lsb_delta = loader->pp1.x - pp1x;
          slot->rsb_delta = loader->pp2.x - pp2x;
        }
      }
      else
      {
        FT_Pos  pp1x = loader->pp1.x;
        FT_Pos  pp2x = loader->pp2.x;


        loader->pp1.x = FT_PIX_ROUND( pp1x + hints->xmin_delta );
        loader->pp2.x = FT_PIX_ROUND( pp2x + hints->xmax_delta );

        slot->lsb_delta = loader->pp1.x - pp1x;
        slot->rsb_delta = loader->pp2.x - pp2x;
      }

      /* 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 transformation 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*  limit = cur + num_new_points;


            for ( ; cur < limit; cur++ )
              FT_Vector_Transform( cur, &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 = AF_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 = AF_Err_Unimplemented_Feature;
    }

  Hint_Metrics:
    if ( depth == 0 )
    {
      FT_BBox    bbox;
      FT_Vector  vvector;


      vvector.x = slot->metrics.vertBearingX - slot->metrics.horiBearingX;
      vvector.y = slot->metrics.vertBearingY - slot->metrics.horiBearingY;
      vvector.x = FT_MulFix( vvector.x, metrics->scaler.x_scale );
      vvector.y = FT_MulFix( vvector.y, metrics->scaler.y_scale );

      /* transform the hinted outline if needed */
      if ( loader->transformed )
      {
        FT_Outline_Transform( &gloader->base.outline, &loader->trans_matrix );
        FT_Vector_Transform( &vvector, &loader->trans_matrix );
      }
#if 1
      /* 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 );
#endif
      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;

      slot->metrics.vertBearingX = FT_PIX_FLOOR( bbox.xMin + vvector.x );
      slot->metrics.vertBearingY = FT_PIX_FLOOR( bbox.yMax + vvector.y );

      /* for mono-width fonts (like Andale, Courier, etc.) we need */
      /* to keep the original rounded advance width; ditto for     */
      /* digits if all have the same 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
      if ( FT_IS_FIXED_WIDTH( slot->face )                              ||
           ( af_face_globals_is_digit( loader->globals, glyph_index ) &&
             metrics->digits_have_same_width                          ) )
      {
        slot->metrics.horiAdvance = FT_MulFix( slot->metrics.horiAdvance,
                                               metrics->scaler.x_scale );

        /* Set delta values to 0.  Otherwise code that uses them is */
        /* going to ruin the fixed advance width.                   */
        slot->lsb_delta = 0;
        slot->rsb_delta = 0;
      }
      else
      {
        /* non-spacing glyphs must stay as-is */
        if ( slot->metrics.horiAdvance )
          slot->metrics.horiAdvance = loader->pp2.x - loader->pp1.x;
      }
#endif

      slot->metrics.vertAdvance = FT_MulFix( slot->metrics.vertAdvance,
                                             metrics->scaler.y_scale );

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

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

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

  Exit:
    return error;
  }


  /* Load a glyph. */

  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 AF_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;
      FT_UInt           options = 0;


#ifdef FT_OPTION_AUTOFIT2
      /* XXX: undocumented hook to activate the latin2 hinter */
      if ( load_flags & ( 1UL << 20 ) )
        options = 2;
#endif

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

        if ( metrics->clazz->script_metrics_scale )
          metrics->clazz->script_metrics_scale( metrics, &scaler );
        else
          metrics->scaler = scaler;

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

        if ( metrics->clazz->script_hints_init )
        {
          error = metrics->clazz->script_hints_init( &loader->hints,
                                                     metrics );
          if ( error )
            goto Exit;
        }

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


/* END */