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 ) FT_GlyphSlot_Oblique(FT_GlyphSlot slot)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 ) FT_GlyphSlot_Embolden(FT_GlyphSlot slot)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 */ 161