XFA: merge patch from CL 815103002
[pdfium.git] / third_party / freetype / 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, 2012-2014 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;
52
53
54     if ( !slot )
55       return;
56
57     outline = &slot->outline;
58
59     /* only oblique outline glyphs */
60     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
61       return;
62
63     /* we don't touch the advance width */
64
65     /* For italic, simply apply a shear transform, with an angle */
66     /* of about 12 degrees.                                      */
67
68     transform.xx = 0x10000L;
69     transform.yx = 0x00000L;
70
71     transform.xy = 0x0366AL;
72     transform.yy = 0x10000L;
73
74     FT_Outline_Transform( outline, &transform );
75   }
76
77
78   /*************************************************************************/
79   /*************************************************************************/
80   /****                                                                 ****/
81   /****   EXPERIMENTAL EMBOLDENING SUPPORT                              ****/
82   /****                                                                 ****/
83   /*************************************************************************/
84   /*************************************************************************/
85
86
87   /* documentation is in ftsynth.h */
88
89   FT_EXPORT_DEF( void )
90   FT_GlyphSlot_Embolden( FT_GlyphSlot  slot )
91   {
92     FT_Library  library;
93     FT_Face     face;
94     FT_Error    error;
95     FT_Pos      xstr, ystr;
96
97
98     if ( !slot )
99       return;
100
101     library = slot->library;
102     face    = slot->face;
103
104     if ( slot->format != FT_GLYPH_FORMAT_OUTLINE &&
105          slot->format != FT_GLYPH_FORMAT_BITMAP  )
106       return;
107
108     /* some reasonable strength */
109     xstr = FT_MulFix( face->units_per_EM,
110                       face->size->metrics.y_scale ) / 24;
111     ystr = xstr;
112
113     if ( slot->format == FT_GLYPH_FORMAT_OUTLINE )
114       FT_Outline_EmboldenXY( &slot->outline, xstr, ystr );
115
116     else /* slot->format == FT_GLYPH_FORMAT_BITMAP */
117     {
118       /* round to full pixels */
119       xstr &= ~63;
120       if ( xstr == 0 )
121         xstr = 1 << 6;
122       ystr &= ~63;
123
124       /*
125        * XXX: overflow check for 16-bit system, for compatibility
126        *      with FT_GlyphSlot_Embolden() since freetype-2.1.10.
127        *      unfortunately, this function return no informations
128        *      about the cause of error.
129        */
130       if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN )
131       {
132         FT_TRACE1(( "FT_GlyphSlot_Embolden:" ));
133         FT_TRACE1(( "too strong embolding parameter ystr=%d\n", ystr ));
134         return;
135       }
136       error = FT_GlyphSlot_Own_Bitmap( slot );
137       if ( error )
138         return;
139
140       error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr );
141       if ( error )
142         return;
143     }
144
145     if ( slot->advance.x )
146       slot->advance.x += xstr;
147
148     if ( slot->advance.y )
149       slot->advance.y += ystr;
150
151     slot->metrics.width        += xstr;
152     slot->metrics.height       += ystr;
153     slot->metrics.horiAdvance  += xstr;
154     slot->metrics.vertAdvance  += ystr;
155     slot->metrics.horiBearingY += ystr;
156
157     /* XXX: 16-bit overflow case must be excluded before here */
158     if ( slot->format == FT_GLYPH_FORMAT_BITMAP )
159       slot->bitmap_top += (FT_Int)( ystr >> 6 );
160   }
161
162
163 /* END */