--- /dev/null
+/***************************************************************************/
+/* */
+/* ftsynth.c */
+/* */
+/* FreeType synthesizing code for emboldening and slanting (body). */
+/* */
+/* Copyright 2000-2001 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 <ft2build.h>
+#include FT_INTERNAL_OBJECTS_H
+#include FT_INTERNAL_CALC_H
+#include FT_OUTLINE_H
+#include FT_TRIGONOMETRY_H
+#include FT_SYNTHESIS_H
+
+
+#define FT_BOLD_THRESHOLD 0x0100
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /**** ****/
+ /**** EXPERIMENTAL OBLIQUING SUPPORT ****/
+ /**** ****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+ FT_EXPORT_DEF( void )
+ FT_GlyphSlot_Oblique( FT_GlyphSlot slot )
+ {
+ FT_Matrix transform;
+ FT_Outline* 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 = 0x06000L;
+ transform.yy = 0x10000L;
+
+ FT_Outline_Transform( outline, &transform );
+ }
+
+
+ /*************************************************************************/
+ /*************************************************************************/
+ /**** ****/
+ /**** EXPERIMENTAL EMBOLDENING/OUTLINING SUPPORT ****/
+ /**** ****/
+ /*************************************************************************/
+ /*************************************************************************/
+
+
+
+ static int
+ ft_test_extrema( FT_Outline* outline,
+ int n )
+ {
+ FT_Vector *prev, *cur, *next;
+ FT_Pos product;
+ FT_Int c, first, last;
+
+
+ /* we need to compute the `previous' and `next' point */
+ /* for these extrema. */
+ cur = outline->points + n;
+ prev = cur - 1;
+ next = cur + 1;
+
+ first = 0;
+ for ( c = 0; c < outline->n_contours; c++ )
+ {
+ last = outline->contours[c];
+
+ if ( n == first )
+ prev = outline->points + last;
+
+ if ( n == last )
+ next = outline->points + first;
+
+ first = last + 1;
+ }
+
+ product = FT_MulDiv( cur->x - prev->x, /* in.x */
+ next->y - cur->y, /* out.y */
+ 0x40 )
+ -
+ FT_MulDiv( cur->y - prev->y, /* in.y */
+ next->x - cur->x, /* out.x */
+ 0x40 );
+
+ if ( product )
+ product = product > 0 ? 1 : -1;
+
+ return product;
+ }
+
+
+ /* Compute the orientation of path filling. It differs between TrueType */
+ /* and Type1 formats. We could use the `FT_OUTLINE_REVERSE_FILL' flag, */
+ /* but it is better to re-compute it directly (it seems that this flag */
+ /* isn't correctly set for some weird composite glyphs currently). */
+ /* */
+ /* We do this by computing bounding box points, and computing their */
+ /* curvature. */
+ /* */
+ /* The function returns either 1 or -1. */
+ /* */
+ static int
+ ft_get_orientation( FT_Outline* outline )
+ {
+ FT_BBox box;
+ FT_BBox indices;
+ int n, last;
+
+
+ indices.xMin = -1;
+ indices.yMin = -1;
+ indices.xMax = -1;
+ indices.yMax = -1;
+
+ box.xMin = box.yMin = 32767;
+ box.xMax = box.yMax = -32768;
+
+ /* is it empty ? */
+ if ( outline->n_contours < 1 )
+ return 1;
+
+ last = outline->contours[outline->n_contours - 1];
+
+ for ( n = 0; n <= last; n++ )
+ {
+ FT_Pos x, y;
+
+
+ x = outline->points[n].x;
+ if ( x < box.xMin )
+ {
+ box.xMin = x;
+ indices.xMin = n;
+ }
+ if ( x > box.xMax )
+ {
+ box.xMax = x;
+ indices.xMax = n;
+ }
+
+ y = outline->points[n].y;
+ if ( y < box.yMin )
+ {
+ box.yMin = y;
+ indices.yMin = n;
+ }
+ if ( y > box.yMax )
+ {
+ box.yMax = y;
+ indices.yMax = n;
+ }
+ }
+
+ /* test orientation of the xmin */
+ n = ft_test_extrema( outline, indices.xMin );
+ if ( n )
+ goto Exit;
+
+ n = ft_test_extrema( outline, indices.yMin );
+ if ( n )
+ goto Exit;
+
+ n = ft_test_extrema( outline, indices.xMax );
+ if ( n )
+ goto Exit;
+
+ n = ft_test_extrema( outline, indices.yMax );
+ if ( !n )
+ n = 1;
+
+ Exit:
+ return n;
+ }
+
+
+ FT_EXPORT_DEF( void )
+ FT_GlyphSlot_Embolden( FT_GlyphSlot slot )
+ {
+ FT_Vector* points;
+ FT_Vector v_prev, v_first, v_next, v_cur;
+ FT_Pos distance;
+ FT_Outline* outline = &slot->outline;
+ FT_Face face = FT_SLOT_FACE( slot );
+ FT_Angle rotate, angle_in, angle_out;
+ FT_Int c, n, first, orientation;
+
+
+ /* only embolden outline glyph images */
+ if ( slot->format != FT_GLYPH_FORMAT_OUTLINE )
+ return;
+
+ /* compute control distance */
+ distance = FT_MulFix( face->units_per_EM / 60,
+ face->size->metrics.y_scale );
+
+ orientation = ft_get_orientation( outline );
+ rotate = FT_ANGLE_PI2*orientation;
+
+ points = outline->points;
+
+ first = 0;
+ for ( c = 0; c < outline->n_contours; c++ )
+ {
+ int last = outline->contours[c];
+
+
+ v_first = points[first];
+ v_prev = points[last];
+ v_cur = v_first;
+
+ for ( n = first; n <= last; n++ )
+ {
+ FT_Pos d;
+ FT_Vector in, out;
+ FT_Fixed scale;
+ FT_Angle angle_diff;
+
+
+ if ( n < last ) v_next = points[n + 1];
+ else v_next = v_first;
+
+ /* compute the in and out vectors */
+ in.x = v_cur.x - v_prev.x;
+ in.y = v_cur.y - v_prev.y;
+
+ out.x = v_next.x - v_cur.x;
+ out.y = v_next.y - v_cur.y;
+
+ angle_in = FT_Atan2( in.x, in.y );
+ angle_out = FT_Atan2( out.x, out.y );
+ angle_diff = FT_Angle_Diff( angle_in, angle_out );
+ scale = FT_Cos( angle_diff/2 );
+
+ if ( scale < 0x400L && scale > -0x400L )
+ {
+ if ( scale >= 0 )
+ scale = 0x400L;
+ else
+ scale = -0x400L;
+ }
+
+ d = FT_DivFix( distance, scale );
+
+ FT_Vector_From_Polar( &in, d, angle_in + angle_diff/2 - rotate );
+
+ outline->points[n].x = v_cur.x + distance + in.x;
+ outline->points[n].y = v_cur.y + distance + in.y;
+
+ v_prev = v_cur;
+ v_cur = v_next;
+ }
+
+ first = last + 1;
+ }
+
+ slot->metrics.horiAdvance = ( slot->metrics.horiAdvance + distance*4 ) & -64;
+ }
+
+
+/* END */
git://git.jankratochvil.net / reactos.git / blobdiff