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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'
This commit is contained in:
Alexei Podtelezhnikov 2012-05-28 22:34:58 +02:00 committed by Werner Lemberg
parent 8be5d3ac0d
commit f875fc7117
3 changed files with 73 additions and 32 deletions
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11
ChangeLog
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@ -1,3 +1,14 @@
2012-05-28 Alexei Podtelezhnikov <apodtele@gmail.com>
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 <wl@gnu.org>
[type1] Fix Savannah bug #36386.

18
include/freetype/ftoutln.h
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@ -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 );
/*************************************************************************/
/* */
/* <Function> */
/* FT_Outline_EmboldenXY */
/* */
/* <Description> */
/* 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 );
/*************************************************************************/
/* */
/* <Function> */

76
src/base/ftoutln.c
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@ -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;