kc3-lang/freetype/src/base/ftsynth.c

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• Hash : ece8b20e
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  Date : 2004-12-13T23:16:59
  

  Documentation updates, whitespace.

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• src/base/ftsynth.c

• /***************************************************************************/
  /*                                                                         */
  /*  ftsynth.c                                                              */
  /*                                                                         */
  /*    FreeType synthesizing code for emboldening and slanting (body).      */
  /*                                                                         */
  /*  Copyright 2000-2001, 2002, 2003, 2004 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_INTERNAL_OBJECTS_H
  #include FT_INTERNAL_CALC_H
  #include FT_OUTLINE_H
  #include FT_TRIGONOMETRY_H
  #include FT_SYNTHESIS_H
  
  
  #define FT_BOLD_THRESHOLD  0x0100
  
  
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****   EXPERIMENTAL OBLIQUING SUPPORT                                ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
  
    /* documentation is in ftsynth.h */
  
    FT_EXPORT_DEF( void )
    FT_GlyphSlot_Oblique( FT_GlyphSlot  slot )
    {
      FT_Matrix    transform;
      FT_Outline*  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 = 0x06000L;
      transform.yy = 0x10000L;
  
      FT_Outline_Transform( outline, &transform );
    }
  
  
    /*************************************************************************/
    /*************************************************************************/
    /****                                                                 ****/
    /****   EXPERIMENTAL EMBOLDENING/OUTLINING SUPPORT                    ****/
    /****                                                                 ****/
    /*************************************************************************/
    /*************************************************************************/
  
  
    /* documentation is in ftsynth.h */
  
    FT_EXPORT_DEF( void )
    FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
    {
      FT_Vector*   points;
      FT_Vector    v_prev, v_first, v_next, v_cur;
      FT_Pos       distance;
      FT_Outline*  outline = &slot->outline;
      FT_Face      face = FT_SLOT_FACE( slot );
      FT_Angle     rotate, angle_in, angle_out;
      FT_Int       c, n, first;
  
  
      /* only embolden outline glyph images */
      if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
        return;
  
      /* compute control distance */
      distance = FT_MulFix( face->units_per_EM / 60,
                            face->size->metrics.y_scale );
  
      if ( FT_Outline_Get_Orientation( outline ) == FT_ORIENTATION_TRUETYPE )
        rotate = -FT_ANGLE_PI2;
      else
        rotate = FT_ANGLE_PI2;
  
      points = outline->points;
  
      first = 0;
      for ( c = 0; c < outline->n_contours; c++ )
      {
        int  last = outline->contours[c];
  
  
        v_first = points[first];
        v_prev  = points[last];
        v_cur   = v_first;
  
        for ( n = first; n <= last; n++ )
        {
          FT_Pos     d;
          FT_Vector  in, out;
          FT_Fixed   scale;
          FT_Angle   angle_diff;
  
  
          if ( n < last ) v_next = points[n + 1];
          else            v_next = v_first;
  
          /* compute the in and out vectors */
          in.x  = v_cur.x - v_prev.x;
          in.y  = v_cur.y - v_prev.y;
  
          out.x = v_next.x - v_cur.x;
          out.y = v_next.y - v_cur.y;
  
          angle_in   = FT_Atan2( in.x, in.y );
          angle_out  = FT_Atan2( out.x, out.y );
          angle_diff = FT_Angle_Diff( angle_in, angle_out );
          scale      = FT_Cos( angle_diff/2 );
  
          if ( scale < 0x400L && scale > -0x400L )
          {
            if ( scale >= 0 )
              scale = 0x400L;
            else
              scale = -0x400L;
          }
  
          d = FT_DivFix( distance, scale );
  
          FT_Vector_From_Polar( &in, d, angle_in + angle_diff/2 - rotate );
  
          outline->points[n].x = v_cur.x + distance + in.x;
          outline->points[n].y = v_cur.y + distance + in.y;
  
          v_prev = v_cur;
          v_cur  = v_next;
        }
  
        first = last + 1;
      }
  
      slot->metrics.horiAdvance =
        ( slot->metrics.horiAdvance + distance*4 ) & ~63;
    }
  
  
  /* END */
  

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