core/src/fxge/fx_freetype/fxft2.5.01/src/base/ftsynth.c

   1 /***************************************************************************/
   2 /*                                                                         */
   3 /*  ftsynth.c                                                              */
   4 /*                                                                         */
   5 /*    FreeType synthesizing code for emboldening and slanting (body).      */
   6 /*                                                                         */
   7 /*  Copyright 2000-2006, 2010, 2012 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 "../../include/ft2build.h"
  20 #include "../../include/freetype/ftsynth.h"
  21 #include "../../include/freetype/internal/ftdebug.h"
  22 #include "../../include/freetype/internal/ftobjs.h"
  23 #include "../../include/freetype/ftoutln.h"
  24 #include "../../include/freetype/ftbitmap.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   /****                                                                 ****/
  40   /****   EXPERIMENTAL OBLIQUING SUPPORT                                ****/
  41   /****                                                                 ****/
  42   /*************************************************************************/
  43   /*************************************************************************/
  44
  45   /* documentation is in ftsynth.h */
  46
  47   FT_EXPORT_DEF( void )
  48   FT_GlyphSlot_Oblique( FT_GlyphSlot  slot )
  49   {
  50     FT_Matrix    transform;
  51     FT_Outline*  outline = &slot->outline;
  52
  53
  54     /* only oblique outline glyphs */
  55     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
  56       return;
  57
  58     /* we don't touch the advance width */
  59
  60     /* For italic, simply apply a shear transform, with an angle */
  61     /* of about 12 degrees.                                      */
  62
  63     transform.xx = 0x10000L;
  64     transform.yx = 0x00000L;
  65
  66     transform.xy = 0x0366AL;
  67     transform.yy = 0x10000L;
  68
  69     FT_Outline_Transform( outline, &transform );
  70   }
  71
  72
  73   /*************************************************************************/
  74   /*************************************************************************/
  75   /****                                                                 ****/
  76   /****   EXPERIMENTAL EMBOLDENING SUPPORT                              ****/
  77   /****                                                                 ****/
  78   /*************************************************************************/
  79   /*************************************************************************/
  80
  81
  82   /* documentation is in ftsynth.h */
  83
  84   FT_EXPORT_DEF( void )
  85   FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
  86   {
  87     FT_Library  library = slot->library;
  88     FT_Face     face    = slot->face;
  89     FT_Error    error;
  90     FT_Pos      xstr, ystr;
  91
  92
  93     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE &&
  94          slot->format != FT_GLYPH_FORMAT_BITMAP  )
  95       return;
  96
  97     /* some reasonable strength */
  98     xstr = FT_MulFix( face->units_per_EM,
  99                       face->size->metrics.y_scale ) / 24;
 100     ystr = xstr;
 101
 102     if ( slot->format == FT_GLYPH_FORMAT_OUTLINE )
 103     {
 104       /* ignore error */
 105       (void)FT_Outline_EmboldenXY( &slot->outline, xstr, ystr );
 106     }
 107     else /* slot->format == FT_GLYPH_FORMAT_BITMAP */
 108     {
 109       /* round to full pixels */
 110       xstr &= ~63;
 111       if ( xstr == 0 )
 112         xstr = 1 << 6;
 113       ystr &= ~63;
 114
 115       /*
 116        * XXX: overflow check for 16-bit system, for compatibility
 117        *      with FT_GlyphSlot_Embolden() since freetype-2.1.10.
 118        *      unfortunately, this function return no informations
 119        *      about the cause of error.
 120        */
 121       if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN )
 122       {
 123         FT_TRACE1(( "FT_GlyphSlot_Embolden:" ));
 124         FT_TRACE1(( "too strong embolding parameter ystr=%d\n", ystr ));
 125         return;
 126       }
 127       error = FT_GlyphSlot_Own_Bitmap( slot );
 128       if ( error )
 129         return;
 130
 131       error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr );
 132       if ( error )
 133         return;
 134     }
 135
 136     if ( slot->advance.x )
 137       slot->advance.x += xstr;
 138
 139     if ( slot->advance.y )
 140       slot->advance.y += ystr;
 141
 142     slot->metrics.width       += xstr;
 143     slot->metrics.height      += ystr;
 144     slot->metrics.horiAdvance += xstr;
 145     slot->metrics.vertAdvance += ystr;
 146
 147     /* XXX: 16-bit overflow case must be excluded before here */
 148     if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
 149       slot->bitmap_top += (FT_Int)( ystr >> 6 );
 150   }
 151
 152
 153 /* END */