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Diffstat (limited to 'modules/freetype2/src/base/ftsynth.c')
| -rw-r--r-- | modules/freetype2/src/base/ftsynth.c | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/modules/freetype2/src/base/ftsynth.c b/modules/freetype2/src/base/ftsynth.c new file mode 100644 index 0000000000..6ec25e13e4 --- /dev/null +++ b/modules/freetype2/src/base/ftsynth.c @@ -0,0 +1,172 @@ +/**************************************************************************** + * + * ftsynth.c + * + * FreeType synthesizing code for emboldening and slanting (body). + * + * Copyright (C) 2000-2023 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 ) + { + /* Value '0x0366A' corresponds to a shear angle of about 12 degrees. */ + FT_GlyphSlot_Slant( slot, 0x0366A, 0 ); + } + + + /* documentation is in ftsynth.h */ + + FT_EXPORT_DEF( void ) + FT_GlyphSlot_Slant( FT_GlyphSlot slot, + FT_Fixed xslant, + FT_Fixed yslant ) + { + 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 */ + transform.xx = 0x10000L; + transform.yx = -yslant; + + transform.xy = xslant; + 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 */ |