1 /**************************************************************************** 2 * 3 * ftsynth.c 4 * 5 * FreeType synthesizing code for emboldening and slanting (body). 6 * 7 * Copyright (C) 2000-2020 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 <freetype/ftsynth.h> 20 #include <freetype/internal/ftdebug.h> 21 #include <freetype/internal/ftobjs.h> 22 #include <freetype/ftoutln.h> 23 #include <freetype/ftbitmap.h> 24 25 26 /************************************************************************** 27 * 28 * The macro FT_COMPONENT is used in trace mode. It is an implicit 29 * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log 30 * messages during execution. 31 */ 32 #undef FT_COMPONENT 33 #define FT_COMPONENT synth 34 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; 51 52 53 if ( !slot ) 54 return; 55 56 outline = &slot->outline; 57 58 /* only oblique outline glyphs */ 59 if ( slot->format != FT_GLYPH_FORMAT_OUTLINE ) 60 return; 61 62 /* we don't touch the advance width */ 63 64 /* For italic, simply apply a shear transform, with an angle */ 65 /* of about 12 degrees. */ 66 67 transform.xx = 0x10000L; 68 transform.yx = 0x00000L; 69 70 transform.xy = 0x0366AL; 71 transform.yy = 0x10000L; 72 73 FT_Outline_Transform( outline, &transform ); 74 } 75 76 77 /*************************************************************************/ 78 /*************************************************************************/ 79 /**** ****/ 80 /**** EXPERIMENTAL EMBOLDENING SUPPORT ****/ 81 /**** ****/ 82 /*************************************************************************/ 83 /*************************************************************************/ 84 85 86 /* documentation is in ftsynth.h */ 87 88 FT_EXPORT_DEF( void ) FT_GlyphSlot_Embolden(FT_GlyphSlot slot)89 FT_GlyphSlot_Embolden( FT_GlyphSlot slot ) 90 { 91 FT_Library library; 92 FT_Face face; 93 FT_Error error; 94 FT_Pos xstr, ystr; 95 96 97 if ( !slot ) 98 return; 99 100 library = slot->library; 101 face = slot->face; 102 103 if ( slot->format != FT_GLYPH_FORMAT_OUTLINE && 104 slot->format != FT_GLYPH_FORMAT_BITMAP ) 105 return; 106 107 /* some reasonable strength */ 108 xstr = FT_MulFix( face->units_per_EM, 109 face->size->metrics.y_scale ) / 24; 110 ystr = xstr; 111 112 if ( slot->format == FT_GLYPH_FORMAT_OUTLINE ) 113 FT_Outline_EmboldenXY( &slot->outline, xstr, ystr ); 114 115 else /* slot->format == FT_GLYPH_FORMAT_BITMAP */ 116 { 117 /* round to full pixels */ 118 xstr &= ~63; 119 if ( xstr == 0 ) 120 xstr = 1 << 6; 121 ystr &= ~63; 122 123 /* 124 * XXX: overflow check for 16-bit system, for compatibility 125 * with FT_GlyphSlot_Embolden() since FreeType 2.1.10. 126 * unfortunately, this function return no informations 127 * about the cause of error. 128 */ 129 if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN ) 130 { 131 FT_TRACE1(( "FT_GlyphSlot_Embolden:" )); 132 FT_TRACE1(( "too strong emboldening parameter ystr=%ld\n", ystr )); 133 return; 134 } 135 error = FT_GlyphSlot_Own_Bitmap( slot ); 136 if ( error ) 137 return; 138 139 error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr ); 140 if ( error ) 141 return; 142 } 143 144 if ( slot->advance.x ) 145 slot->advance.x += xstr; 146 147 if ( slot->advance.y ) 148 slot->advance.y += ystr; 149 150 slot->metrics.width += xstr; 151 slot->metrics.height += ystr; 152 slot->metrics.horiAdvance += xstr; 153 slot->metrics.vertAdvance += ystr; 154 slot->metrics.horiBearingY += ystr; 155 156 /* XXX: 16-bit overflow case must be excluded before here */ 157 if ( slot->format == FT_GLYPH_FORMAT_BITMAP ) 158 slot->bitmap_top += (FT_Int)( ystr >> 6 ); 159 } 160 161 162 /* END */ 163