FT_Outline_Embolden( FT_Outline* outline,
FT_Pos strength )
{
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;
if ( !outline )
return FT_Err_Invalid_Argument;
strength /= 2;
if ( strength == 0 )
return FT_Err_Ok;
orientation = FT_Outline_Get_Orientation( outline );
if ( orientation == FT_ORIENTATION_NONE )
{
if ( outline->n_contours )
return FT_Err_Invalid_Argument;
else
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];
v_first = points[first];
v_prev = points[last];
v_cur = v_first;
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;
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 < 0x4000L && scale > -0x4000L )
in.x = in.y = 0;
else
{
d = FT_DivFix( strength, scale );
FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate );
}
outline->points[n].x = v_cur.x + strength + in.x;
outline->points[n].y = v_cur.y + strength + in.y;
v_prev = v_cur;
v_cur = v_next;
}
first = last + 1;
}
return FT_Err_Ok;
}
static void GK_Outline_Embolden(FT_Outline* outline,FT_Pos strength,int* x_left,int* x_right,int* y_bottom,int* y_top)
{
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 = 0;
FT_Int orientation;
FT_Int min_x = 35565, max_x = -35565, min_y = 35565, max_y = -35565;
FT_Int new_min_x = 35565, new_max_x = -35565, new_min_y = 35565, new_max_y = -35565;
if (!outline) return;
strength /= 2;
if ( strength == 0 ) return;
orientation = FT_Outline_Get_Orientation(outline);
if (orientation == FT_ORIENTATION_NONE) return;
#ifdef GLYPH_LOG
if (glyph_log) { fprintf(glyph_log," Emboldening the outline by %ld:\n",strength); }
#endif
if (orientation == FT_ORIENTATION_TRUETYPE) rotate = -FT_ANGLE_PI2;
else rotate = FT_ANGLE_PI2;
points = outline->points;
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_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;
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 < 0x4000L && scale > -0x4000L ) in.x = in.y = 0;
else
{
d = FT_DivFix( strength, scale );
FT_Vector_From_Polar( &in, d, angle_in + angle_diff / 2 - rotate );
}
outline->points[n].x = v_cur.x + strength + in.x;
outline->points[n].y = v_cur.y + strength + in.y;
if (v_cur.x < min_x) min_x = v_cur.x;
if (v_cur.x > max_x) max_x = v_cur.x;
if (v_cur.y < min_y) min_y = v_cur.y;
if (v_cur.y > max_y) max_y = v_cur.y;
if (outline->points[n].x < new_min_x) new_min_x = outline->points[n].x;
if (outline->points[n].x > new_max_x) new_max_x = outline->points[n].x;
if (outline->points[n].y < new_min_y) new_min_y = outline->points[n].y;
if (outline->points[n].y > new_max_y) new_max_y = outline->points[n].y;
v_prev = v_cur;
v_cur = v_next;
}
first = last + 1;
}
*x_left = min_x - new_min_x;
*x_right = new_max_x - max_x;
*y_top = new_max_y - max_y;
*y_bottom = min_y - new_min_y;
#ifdef GLYPH_LOG
if (glyph_log)
{
fprintf(glyph_log," (%d..%d x %d..%d) -> (%d..%d x %d..%d)\n",
min_x,max_x,min_y,max_y,new_min_x,new_max_x,new_min_y,new_max_y);
}
#endif
}