| /**************************************************************************** |
| * |
| * ftsynth.c |
| * |
| * FreeType synthesizing code for emboldening and slanting (body). |
| * |
| * Copyright (C) 2000-2020 by |
| * David Turner, Robert Wilhelm, and Werner Lemberg. |
| * |
| * This file is part of the FreeType project, and may only be used, |
| * modified, and distributed under the terms of the FreeType project |
| * license, LICENSE.TXT. By continuing to use, modify, or distribute |
| * this file you indicate that you have read the license and |
| * understand and accept it fully. |
| * |
| */ |
| |
| |
| #include <freetype/ftsynth.h> |
| #include <freetype/internal/ftdebug.h> |
| #include <freetype/internal/ftobjs.h> |
| #include <freetype/ftoutln.h> |
| #include <freetype/ftbitmap.h> |
| |
| |
| /************************************************************************** |
| * |
| * The macro FT_COMPONENT is used in trace mode. It is an implicit |
| * parameter of the FT_TRACE() and FT_ERROR() macros, used to print/log |
| * messages during execution. |
| */ |
| #undef FT_COMPONENT |
| #define FT_COMPONENT synth |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** EXPERIMENTAL OBLIQUING SUPPORT ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| /* documentation is in ftsynth.h */ |
| |
| FT_EXPORT_DEF( void ) |
| FT_GlyphSlot_Oblique( FT_GlyphSlot slot ) |
| { |
| FT_Matrix transform; |
| FT_Outline* outline; |
| |
| |
| if ( !slot ) |
| return; |
| |
| outline = &slot->outline; |
| |
| /* only oblique outline glyphs */ |
| if ( slot->format != FT_GLYPH_FORMAT_OUTLINE ) |
| return; |
| |
| /* we don't touch the advance width */ |
| |
| /* For italic, simply apply a shear transform, with an angle */ |
| /* of about 12 degrees. */ |
| |
| transform.xx = 0x10000L; |
| transform.yx = 0x00000L; |
| |
| transform.xy = 0x0366AL; |
| transform.yy = 0x10000L; |
| |
| FT_Outline_Transform( outline, &transform ); |
| } |
| |
| |
| /*************************************************************************/ |
| /*************************************************************************/ |
| /**** ****/ |
| /**** EXPERIMENTAL EMBOLDENING SUPPORT ****/ |
| /**** ****/ |
| /*************************************************************************/ |
| /*************************************************************************/ |
| |
| |
| /* documentation is in ftsynth.h */ |
| |
| FT_EXPORT_DEF( void ) |
| FT_GlyphSlot_Embolden( FT_GlyphSlot slot ) |
| { |
| FT_Library library; |
| FT_Face face; |
| FT_Error error; |
| FT_Pos xstr, ystr; |
| |
| |
| if ( !slot ) |
| return; |
| |
| library = slot->library; |
| face = slot->face; |
| |
| if ( slot->format != FT_GLYPH_FORMAT_OUTLINE && |
| slot->format != FT_GLYPH_FORMAT_BITMAP ) |
| return; |
| |
| /* some reasonable strength */ |
| xstr = FT_MulFix( face->units_per_EM, |
| face->size->metrics.y_scale ) / 24; |
| ystr = xstr; |
| |
| if ( slot->format == FT_GLYPH_FORMAT_OUTLINE ) |
| FT_Outline_EmboldenXY( &slot->outline, xstr, ystr ); |
| |
| else /* slot->format == FT_GLYPH_FORMAT_BITMAP */ |
| { |
| /* round to full pixels */ |
| xstr &= ~63; |
| if ( xstr == 0 ) |
| xstr = 1 << 6; |
| ystr &= ~63; |
| |
| /* |
| * XXX: overflow check for 16-bit system, for compatibility |
| * with FT_GlyphSlot_Embolden() since FreeType 2.1.10. |
| * unfortunately, this function return no informations |
| * about the cause of error. |
| */ |
| if ( ( ystr >> 6 ) > FT_INT_MAX || ( ystr >> 6 ) < FT_INT_MIN ) |
| { |
| FT_TRACE1(( "FT_GlyphSlot_Embolden:" )); |
| FT_TRACE1(( "too strong emboldening parameter ystr=%ld\n", ystr )); |
| return; |
| } |
| error = FT_GlyphSlot_Own_Bitmap( slot ); |
| if ( error ) |
| return; |
| |
| error = FT_Bitmap_Embolden( library, &slot->bitmap, xstr, ystr ); |
| if ( error ) |
| return; |
| } |
| |
| if ( slot->advance.x ) |
| slot->advance.x += xstr; |
| |
| if ( slot->advance.y ) |
| slot->advance.y += ystr; |
| |
| slot->metrics.width += xstr; |
| slot->metrics.height += ystr; |
| slot->metrics.horiAdvance += xstr; |
| slot->metrics.vertAdvance += ystr; |
| slot->metrics.horiBearingY += ystr; |
| |
| /* XXX: 16-bit overflow case must be excluded before here */ |
| if ( slot->format == FT_GLYPH_FORMAT_BITMAP ) |
| slot->bitmap_top += (FT_Int)( ystr >> 6 ); |
| } |
| |
| |
| /* END */ |