1/***************************************************************************/
2/*                                                                         */
3/*  ftsynth.c                                                              */
4/*                                                                         */
5/*    FreeType synthesizing code for emboldening and slanting (body).      */
6/*                                                                         */
7/*  Copyright 2000-2006, 2010, 2012, 2013 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  /****                                                                 ****/
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    slot->metrics.horiBearingY += ystr;
147
148    /* XXX: 16-bit overflow case must be excluded before here */
149    if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
150      slot->bitmap_top += (FT_Int)( ystr >> 6 );
151  }
152
153
154/* END */
155