/****************************************************************************
*
* 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 )
{
FT_GlyphSlot_Slant( slot, 0x0366A );
}
/* documentation is in ftsynth.h */
FT_EXPORT_DEF( void )
FT_GlyphSlot_Slant( FT_GlyphSlot slot,
FT_Fixed slant )
{
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 = 0x00000L;
transform.xy = slant;
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 */
