text: /***************************************************************************/
  /*                                                                         */
  /*  ftsynth.c                                                              */
  /*                                                                         */
  /*    FreeType synthesizing code for emboldening and slanting (body).      */
  /*                                                                         */
  /*  Copyright 2000-2017 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 <ft2build.h>
  #include FT_SYNTHESIS_H
  #include FT_INTERNAL_DEBUG_H
  #include FT_INTERNAL_OBJECTS_H
  #include FT_OUTLINE_H
  #include FT_BITMAP_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_synth
  
  
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****   EXPERIMENTAL OBLIQUING SUPPORT                                ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
  
    /* documentation is in ftsynth.h */
  
    FT_EXPORT_DEF( void )
    FT_GlyphSlot_Oblique( FT_GlyphSlot  slot )
    {
      FT_Matrix    transform;
      FT_Outline*  outline;
  
  
      if ( !slot )
        return;
  
      outline = &slot->outline;
  
      /* only oblique outline glyphs */
      if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
        return;
  
      /* we don't touch the advance width */
  
      /* For italic, simply apply a shear transform, with an angle */
      /* of about 12 degrees.                                      */
  
      transform.xx = 0x10000L;
      transform.yx = 0x00000L;
  
      transform.xy = 0x0366AL;
      transform.yy = 0x10000L;
  
      FT_Outline_Transform( outline, &transform );
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****   EXPERIMENTAL EMBOLDENING SUPPORT                              ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /* documentation is in ftsynth.h */
  
    FT_EXPORT_DEF( void )
    FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
    {
      FT_Library  library;
      FT_Face     face;
      FT_Error    error;
      FT_Pos      xstr, ystr;
  
  
      if ( !slot )
        return;
  
      library = slot->library;
      face    = slot->face;
  
      if ( slot->format != FT_GLYPH_FORMAT_OUTLINE &&
           slot->format != FT_GLYPH_FORMAT_BITMAP  )
        return;
  
      /* some reasonable strength */
      xstr = FT_MulFix( face->units_per_EM,
                        face->size->metrics.y_scale ) / 24;
      ystr = xstr;
  
      if ( slot->format == FT_GLYPH_FORMAT_OUTLINE )
        FT_Outline_EmboldenXY( &slot->outline, xstr, ystr );
  
      else /* slot->format == FT_GLYPH_FORMAT_BITMAP */
      {
        /* round to full pixels */
        xstr &= ~63;
        if ( xstr == 0 )
          xstr = 1 << 6;
        ystr &= ~63;
  
        /*
         * XXX: overflow check for 16-bit system, for compatibility
         *      with FT_GlyphSlot_Embolden() since freetype-2.1.10.
         *      unfortunately, this function return no informations
         *      about the cause of error.
         */
        if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN )
        {
          FT_TRACE1(( "FT_GlyphSlot_Embolden:" ));
          FT_TRACE1(( "too strong emboldening parameter ystr=%d\n", ystr ));
          return;
        }
        error = FT_GlyphSlot_Own_Bitmap( slot );
        if ( error )
          return;
  
        error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr );
        if ( error )
          return;
      }
  
      if ( slot->advance.x )
        slot->advance.x += xstr;
  
      if ( slot->advance.y )
        slot->advance.y += ystr;
  
      slot->metrics.width        += xstr;
      slot->metrics.height       += ystr;
      slot->metrics.horiAdvance  += xstr;
      slot->metrics.vertAdvance  += ystr;
      slot->metrics.horiBearingY += ystr;
  
      /* XXX: 16-bit overflow case must be excluded before here */
      if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
        slot->bitmap_top += (FT_Int)( ystr >> 6 );
    }
  
  
  /* END */
  