misc/libfreetype/src/base/ftsynth.c
changeset 9372 915436ff64ab
parent 9371 f3840de881bd
child 9373 b769a8e38cbd
equal deleted inserted replaced
9371:f3840de881bd 9372:915436ff64ab
     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, 2010 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_DEBUG_H
       
    22 #include FT_INTERNAL_OBJECTS_H
       
    23 #include FT_OUTLINE_H
       
    24 #include FT_BITMAP_H
       
    25 
       
    26 
       
    27   /*************************************************************************/
       
    28   /*                                                                       */
       
    29   /* The macro FT_COMPONENT is used in trace mode.  It is an implicit      */
       
    30   /* parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log  */
       
    31   /* messages during execution.                                            */
       
    32   /*                                                                       */
       
    33 #undef  FT_COMPONENT
       
    34 #define FT_COMPONENT  trace_synth
       
    35 
       
    36   /*************************************************************************/
       
    37   /*************************************************************************/
       
    38   /****                                                                 ****/
       
    39   /****   EXPERIMENTAL OBLIQUING SUPPORT                                ****/
       
    40   /****                                                                 ****/
       
    41   /*************************************************************************/
       
    42   /*************************************************************************/
       
    43 
       
    44   /* documentation is in ftsynth.h */
       
    45 
       
    46   FT_EXPORT_DEF( void )
       
    47   FT_GlyphSlot_Oblique( FT_GlyphSlot  slot )
       
    48   {
       
    49     FT_Matrix    transform;
       
    50     FT_Outline*  outline = &slot->outline;
       
    51 
       
    52 
       
    53     /* only oblique outline glyphs */
       
    54     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
       
    55       return;
       
    56 
       
    57     /* we don't touch the advance width */
       
    58 
       
    59     /* For italic, simply apply a shear transform, with an angle */
       
    60     /* of about 12 degrees.                                      */
       
    61 
       
    62     transform.xx = 0x10000L;
       
    63     transform.yx = 0x00000L;
       
    64 
       
    65     transform.xy = 0x06000L;
       
    66     transform.yy = 0x10000L;
       
    67 
       
    68     FT_Outline_Transform( outline, &transform );
       
    69   }
       
    70 
       
    71 
       
    72   /*************************************************************************/
       
    73   /*************************************************************************/
       
    74   /****                                                                 ****/
       
    75   /****   EXPERIMENTAL EMBOLDENING/OUTLINING SUPPORT                    ****/
       
    76   /****                                                                 ****/
       
    77   /*************************************************************************/
       
    78   /*************************************************************************/
       
    79 
       
    80 
       
    81   /* documentation is in ftsynth.h */
       
    82 
       
    83   FT_EXPORT_DEF( void )
       
    84   FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
       
    85   {
       
    86     FT_Library  library = slot->library;
       
    87     FT_Face     face    = slot->face;
       
    88     FT_Error    error;
       
    89     FT_Pos      xstr, ystr;
       
    90 
       
    91 
       
    92     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE &&
       
    93          slot->format != FT_GLYPH_FORMAT_BITMAP  )
       
    94       return;
       
    95 
       
    96     /* some reasonable strength */
       
    97     xstr = FT_MulFix( face->units_per_EM,
       
    98                       face->size->metrics.y_scale ) / 24;
       
    99     ystr = xstr;
       
   100 
       
   101     if ( slot->format == FT_GLYPH_FORMAT_OUTLINE )
       
   102     {
       
   103       /* ignore error */
       
   104       (void)FT_Outline_Embolden( &slot->outline, xstr );
       
   105 
       
   106       /* this is more than enough for most glyphs; if you need accurate */
       
   107       /* values, you have to call FT_Outline_Get_CBox                   */
       
   108       xstr = xstr * 2;
       
   109       ystr = xstr;
       
   110     }
       
   111     else /* slot->format == FT_GLYPH_FORMAT_BITMAP */
       
   112     {
       
   113       /* round to full pixels */
       
   114       xstr &= ~63;
       
   115       if ( xstr == 0 )
       
   116         xstr = 1 << 6;
       
   117       ystr &= ~63;
       
   118 
       
   119       /*
       
   120        * XXX: overflow check for 16-bit system, for compatibility
       
   121        *      with FT_GlyphSlot_Embolden() since freetype-2.1.10.
       
   122        *      unfortunately, this function return no informations
       
   123        *      about the cause of error.
       
   124        */
       
   125       if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN )
       
   126       {
       
   127         FT_TRACE1(( "FT_GlyphSlot_Embolden:" ));
       
   128         FT_TRACE1(( "too strong embolding parameter ystr=%d\n", ystr ));
       
   129         return;
       
   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     /* XXX: 16-bit overflow case must be excluded before here */
       
   155     if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
       
   156       slot->bitmap_top += (FT_Int)( ystr >> 6 );
       
   157   }
       
   158 
       
   159 
       
   160 /* END */