From f875fc71179b1e742d6f782b8c99b0cc031c9467 Mon Sep 17 00:00:00 2001 From: Alexei Podtelezhnikov Date: Mon, 28 May 2012 22:34:58 +0200 Subject: [PATCH] New function FT_Outline_EmboldenXY. * include/freetype/ftoutln.h (FT_Outline_EmboldenXY): Define it. * src/base/ftoutln.c (FT_Outline_EmboldenXY): Implement it, using a simplified embolding algorithm. (FT_Outline_Embolden): Make it a special case of `FT_Outline_EmboldenXY' --- ChangeLog | 11 ++++++ include/freetype/ftoutln.h | 18 +++++++++ src/base/ftoutln.c | 76 ++++++++++++++++++++++---------------- 3 files changed, 73 insertions(+), 32 deletions(-) diff --git a/ChangeLog b/ChangeLog index 96dba1c7a..f9db415c9 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,14 @@ +2012-05-28 Alexei Podtelezhnikov + + New function FT_Outline_EmboldenXY. + + * include/freetype/ftoutln.h (FT_Outline_EmboldenXY): Define it. + + * src/base/ftoutln.c (FT_Outline_EmboldenXY): Implement it, using a + simplified embolding algorithm. + (FT_Outline_Embolden): Make it a special case of + `FT_Outline_EmboldenXY' + 2012-05-07 Werner Lemberg [type1] Fix Savannah bug #36386. diff --git a/include/freetype/ftoutln.h b/include/freetype/ftoutln.h index 89b55e7e7..e733f391e 100644 --- a/include/freetype/ftoutln.h +++ b/include/freetype/ftoutln.h @@ -59,6 +59,7 @@ FT_BEGIN_HEADER /* FT_Outline_Translate */ /* FT_Outline_Transform */ /* FT_Outline_Embolden */ + /* FT_Outline_EmboldenXY */ /* FT_Outline_Reverse */ /* FT_Outline_Check */ /* */ @@ -350,6 +351,23 @@ FT_BEGIN_HEADER FT_Pos strength ); + /*************************************************************************/ + /* */ + /* */ + /* FT_Outline_EmboldenXY */ + /* */ + /* */ + /* Embolden an outline. The new outline will be `xstrength' pixels */ + /* wider and `ystrength' pixels higher. Otherwise, it is similar to */ + /* @FT_Outline_Embolden, which uses the same strength in both */ + /* directions. */ + /* */ + FT_EXPORT( FT_Error ) + FT_Outline_EmboldenXY( FT_Outline* outline, + FT_Pos xstrength, + FT_Pos ystrength ); + + /*************************************************************************/ /* */ /* */ diff --git a/src/base/ftoutln.c b/src/base/ftoutln.c index 9ae276d08..9fcb32aca 100644 --- a/src/base/ftoutln.c +++ b/src/base/ftoutln.c @@ -881,10 +881,20 @@ FT_EXPORT_DEF( FT_Error ) FT_Outline_Embolden( FT_Outline* outline, FT_Pos strength ) + { + return FT_Outline_EmboldenXY( outline, strength, strength ); + } + + + /* documentation is in ftoutln.h */ + + FT_EXPORT_DEF( FT_Error ) + FT_Outline_EmboldenXY( FT_Outline* outline, + FT_Pos xstrength, + FT_Pos ystrength ) { FT_Vector* points; FT_Vector v_prev, v_first, v_next, v_cur; - FT_Angle rotate, angle_in, angle_out; FT_Int c, n, first; FT_Int orientation; @@ -892,8 +902,9 @@ if ( !outline ) return FT_Err_Invalid_Argument; - strength /= 2; - if ( strength == 0 ) + xstrength /= 2; + ystrength /= 2; + if ( xstrength == 0 && ystrength == 0 ) return FT_Err_Ok; orientation = FT_Outline_Get_Orientation( outline ); @@ -905,62 +916,63 @@ return FT_Err_Ok; } - if ( orientation == FT_ORIENTATION_TRUETYPE ) - rotate = -FT_ANGLE_PI2; - else - rotate = FT_ANGLE_PI2; - points = outline->points; first = 0; for ( c = 0; c < outline->n_contours; c++ ) { - int last = outline->contours[c]; + FT_Vector in, out, shift; + FT_Fixed l_in, l_out, d; + int last = outline->contours[c]; v_first = points[first]; v_prev = points[last]; v_cur = v_first; + /* compute the incoming vector and its length */ + in.x = v_cur.x - v_prev.x; + in.y = v_cur.y - v_prev.y; + l_in = FT_Vector_Length( &in ); + for ( n = first; n <= last; n++ ) { - FT_Vector in, out; - FT_Angle angle_diff; - FT_Pos d; - FT_Fixed scale; - - 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; - + /* compute the outgoing vector and its length */ out.x = v_next.x - v_cur.x; out.y = v_next.y - v_cur.y; + l_out = FT_Vector_Length( &out ); - 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 ); + d = l_in * l_out + in.x * out.x + in.y * out.y; - if ( scale < 0x4000L && scale > -0x4000L ) - in.x = in.y = 0; - else + /* shift only if turn is less then ~160 degrees */ + if ( 16 * d > l_in * l_out ) { - d = FT_DivFix( strength, scale ); + /* shift components are rotated */ + shift.x = FT_DivFix( l_out * in.y + l_in * out.y, d ); + shift.y = FT_DivFix( l_out * in.x + l_in * out.x, d ); - FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate ); + if ( orientation == FT_ORIENTATION_TRUETYPE ) + shift.x = -shift.x; + else + shift.y = -shift.y; + + shift.x = FT_MulFix( xstrength, shift.x ); + shift.y = FT_MulFix( ystrength, shift.y ); } + else + shift.x = shift.y = 0; - outline->points[n].x = v_cur.x + strength + in.x; - outline->points[n].y = v_cur.y + strength + in.y; + outline->points[n].x = v_cur.x + xstrength + shift.x; + outline->points[n].y = v_cur.y + ystrength + shift.y; - v_prev = v_cur; - v_cur = v_next; + in = out; + l_in = l_out; + v_cur = v_next; } first = last + 1;