lib/3rdparty/freetype/src/base/ftsynth.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftsynth.c                                                              */
   4 /*                                                                         */
   5 /*    FreeType synthesizing code for emboldening and slanting (body).      */
   6 /*                                                                         */
   7 /*  Copyright 2000-2001, 2002, 2003, 2004, 2005, 2006 by                   */
   8 /*  David Turner, Robert Wilhelm, and Werner Lemberg.                      */
   9 /*                                                                         */
  10 /*  This file is part of the FreeType project, and may only be used,       */
  11 /*  modified, and distributed under the terms of the FreeType project      */
  12 /*  license, LICENSE.TXT.  By continuing to use, modify, or distribute     */
  13 /*  this file you indicate that you have read the license and              */
  14 /*  understand and accept it fully.                                        */
  15 /*                                                                         */
  16 /***************************************************************************/
  17
  18
  19 #include <ft2build.h>
  20 #include FT_SYNTHESIS_H
  21 #include FT_INTERNAL_OBJECTS_H
  22 #include FT_OUTLINE_H
  23 #include FT_BITMAP_H
  24
  25
  26   /*************************************************************************/
  27   /*************************************************************************/
  28   /****                                                                 ****/
  29   /****   EXPERIMENTAL OBLIQUING SUPPORT                                ****/
  30   /****                                                                 ****/
  31   /*************************************************************************/
  32   /*************************************************************************/
  33
  34   /* documentation is in ftsynth.h */
  35
  36   FT_EXPORT_DEF( void )
  37   FT_GlyphSlot_Oblique( FT_GlyphSlot  slot )
  38   {
  39     FT_Matrix    transform;
  40     FT_Outline*  outline = &slot->outline;
  41
  42
  43     /* only oblique outline glyphs */
  44     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
  45       return;
  46
  47     /* we don't touch the advance width */
  48
  49     /* For italic, simply apply a shear transform, with an angle */
  50     /* of about 12 degrees.                                      */
  51
  52     transform.xx = 0x10000L;
  53     transform.yx = 0x00000L;
  54
  55     transform.xy = 0x06000L;
  56     transform.yy = 0x10000L;
  57
  58     FT_Outline_Transform( outline, &transform );
  59   }
  60
  61
  62   /*************************************************************************/
  63   /*************************************************************************/
  64   /****                                                                 ****/
  65   /****   EXPERIMENTAL EMBOLDENING/OUTLINING SUPPORT                    ****/
  66   /****                                                                 ****/
  67   /*************************************************************************/
  68   /*************************************************************************/
  69
  70
  71   FT_EXPORT_DEF( FT_Error )
  72   FT_GlyphSlot_Own_Bitmap( FT_GlyphSlot  slot )
  73   {
  74     if ( slot && slot->format == FT_GLYPH_FORMAT_BITMAP   &&
  75          !( slot->internal->flags & FT_GLYPH_OWN_BITMAP ) )
  76     {
  77       FT_Bitmap  bitmap;
  78       FT_Error   error;
  79
  80
  81       FT_Bitmap_New( &bitmap );
  82       error = FT_Bitmap_Copy( slot->library, &slot->bitmap, &bitmap );
  83       if ( error )
  84         return error;
  85
  86       slot->bitmap = bitmap;
  87       slot->internal->flags |= FT_GLYPH_OWN_BITMAP;
  88     }
  89
  90     return FT_Err_Ok;
  91   }
  92
  93
  94   /* documentation is in ftsynth.h */
  95
  96   FT_EXPORT_DEF( void )
  97   FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
  98   {
  99     FT_Library  library = slot->library;
 100     FT_Face     face    = FT_SLOT_FACE( slot );
 101     FT_Error    error;
 102     FT_Pos      xstr, ystr;
 103
 104
 105     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE &&
 106          slot->format != FT_GLYPH_FORMAT_BITMAP )
 107       return;
 108
 109     /* some reasonable strength */
 110     xstr = FT_MulFix( face->units_per_EM,
 111                       face->size->metrics.y_scale ) / 24;
 112     ystr = xstr;
 113
 114     if ( slot->format == FT_GLYPH_FORMAT_OUTLINE )
 115     {
 116       error = FT_Outline_Embolden( &slot->outline, xstr );
 117       /* ignore error */
 118
 119       /* this is more than enough for most glyphs; if you need accurate */
 120       /* values, you have to call FT_Outline_Get_CBox                   */
 121       xstr = xstr * 2;
 122       ystr = xstr;
 123     }
 124     else if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
 125     {
 126       xstr = FT_PIX_FLOOR( xstr );
 127       if ( xstr == 0 )
 128         xstr = 1 << 6;
 129       ystr = FT_PIX_FLOOR( ystr );
 130
 131       error = FT_GlyphSlot_Own_Bitmap( slot );
 132       if ( error )
 133         return;
 134
 135       error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr );
 136       if ( error )
 137         return;
 138     }
 139
 140     if ( slot->advance.x )
 141       slot->advance.x += xstr;
 142
 143     if ( slot->advance.y )
 144       slot->advance.y += ystr;
 145
 146     slot->metrics.width        += xstr;
 147     slot->metrics.height       += ystr;
 148     slot->metrics.horiBearingY += ystr;
 149     slot->metrics.horiAdvance  += xstr;
 150     slot->metrics.vertBearingX -= xstr / 2;
 151     slot->metrics.vertBearingY += ystr;
 152     slot->metrics.vertAdvance  += ystr;
 153
 154     if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
 155       slot->bitmap_top += ystr >> 6;
 156   }
 157
 158
 159 /* END */