165 lines
5.3 KiB
C
165 lines
5.3 KiB
C
/***************************************************************************/
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/* */
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/* ftsynth.c */
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/* */
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/* FreeType synthesizing code for emboldening and slanting (body). */
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/* */
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/* Copyright 2000-2001, 2002, 2003, 2004 by */
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/* David Turner, Robert Wilhelm, and Werner Lemberg. */
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/* */
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/* This file is part of the FreeType project, and may only be used, */
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/* modified, and distributed under the terms of the FreeType project */
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/* license, LICENSE.TXT. By continuing to use, modify, or distribute */
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/* this file you indicate that you have read the license and */
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/* understand and accept it fully. */
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/* */
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/***************************************************************************/
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#include <ft2build.h>
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#include FT_INTERNAL_OBJECTS_H
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#include FT_INTERNAL_CALC_H
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#include FT_OUTLINE_H
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#include FT_TRIGONOMETRY_H
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#include FT_SYNTHESIS_H
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#define FT_BOLD_THRESHOLD 0x0100
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/*************************************************************************/
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/*************************************************************************/
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/**** ****/
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/**** EXPERIMENTAL OBLIQUING SUPPORT ****/
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/**** ****/
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/*************************************************************************/
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/*************************************************************************/
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/* documentation is in ftsynth.h */
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FT_EXPORT_DEF( void )
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FT_GlyphSlot_Oblique( FT_GlyphSlot slot )
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{
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FT_Matrix transform;
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FT_Outline* outline = &slot->outline;
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/* only oblique outline glyphs */
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if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
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return;
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/* we don't touch the advance width */
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/* For italic, simply apply a shear transform, with an angle */
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/* of about 12 degrees. */
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transform.xx = 0x10000L;
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transform.yx = 0x00000L;
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transform.xy = 0x06000L;
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transform.yy = 0x10000L;
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FT_Outline_Transform( outline, &transform );
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}
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/*************************************************************************/
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/*************************************************************************/
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/**** ****/
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/**** EXPERIMENTAL EMBOLDENING/OUTLINING SUPPORT ****/
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/**** ****/
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/*************************************************************************/
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/*************************************************************************/
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/* documentation is in ftsynth.h */
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FT_EXPORT_DEF( void )
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FT_GlyphSlot_Embolden( FT_GlyphSlot slot )
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{
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FT_Vector* points;
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FT_Vector v_prev, v_first, v_next, v_cur;
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FT_Pos distance;
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FT_Outline* outline = &slot->outline;
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FT_Face face = FT_SLOT_FACE( slot );
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FT_Angle rotate, angle_in, angle_out;
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FT_Int c, n, first;
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/* only embolden outline glyph images */
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if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
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return;
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/* compute control distance */
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distance = FT_MulFix( face->units_per_EM / 60,
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face->size->metrics.y_scale );
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if ( FT_Outline_Get_Orientation( outline ) == FT_ORIENTATION_TRUETYPE )
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rotate = -FT_ANGLE_PI2;
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else
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rotate = FT_ANGLE_PI2;
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points = outline->points;
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first = 0;
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for ( c = 0; c < outline->n_contours; c++ )
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{
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int last = outline->contours[c];
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v_first = points[first];
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v_prev = points[last];
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v_cur = v_first;
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for ( n = first; n <= last; n++ )
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{
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FT_Pos d;
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FT_Vector in, out;
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FT_Fixed scale;
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FT_Angle angle_diff;
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if ( n < last ) v_next = points[n + 1];
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else v_next = v_first;
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/* compute the in and out vectors */
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in.x = v_cur.x - v_prev.x;
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in.y = v_cur.y - v_prev.y;
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out.x = v_next.x - v_cur.x;
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out.y = v_next.y - v_cur.y;
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angle_in = FT_Atan2( in.x, in.y );
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angle_out = FT_Atan2( out.x, out.y );
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angle_diff = FT_Angle_Diff( angle_in, angle_out );
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scale = FT_Cos( angle_diff/2 );
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if ( scale < 0x400L && scale > -0x400L )
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{
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if ( scale >= 0 )
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scale = 0x400L;
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else
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scale = -0x400L;
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}
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d = FT_DivFix( distance, scale );
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FT_Vector_From_Polar( &in, d, angle_in + angle_diff/2 - rotate );
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outline->points[n].x = v_cur.x + distance + in.x;
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outline->points[n].y = v_cur.y + distance + in.y;
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v_prev = v_cur;
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v_cur = v_next;
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}
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first = last + 1;
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}
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slot->metrics.horiAdvance =
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( slot->metrics.horiAdvance + distance*4 ) & ~63;
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}
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/* END */
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