1 /* Segment.java -- Abstract segment used for BasicStroke
2 Copyright (C) 2006 Free Software Foundation, Inc.
4 This file is part of GNU Classpath.
6 GNU Classpath is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2, or (at your option)
11 GNU Classpath is distributed in the hope that it will be useful, but
12 WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with GNU Classpath; see the file COPYING. If not, write to the
18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
21 Linking this library statically or dynamically with other modules is
22 making a combined work based on this library. Thus, the terms and
23 conditions of the GNU General Public License cover the whole
26 As a special exception, the copyright holders of this library give you
27 permission to link this library with independent modules to produce an
28 executable, regardless of the license terms of these independent
29 modules, and to copy and distribute the resulting executable under
30 terms of your choice, provided that you also meet, for each linked
31 independent module, the terms and conditions of the license of that
32 module. An independent module is a module which is not derived from
33 or based on this library. If you modify this library, you may extend
34 this exception to your version of the library, but you are not
35 obligated to do so. If you do not wish to do so, delete this
36 exception statement from your version. */
39 package gnu
.java
.awt
.java2d
;
41 import java
.awt
.geom
.Point2D
;
43 public abstract class Segment
implements Cloneable
45 // segment type, PathIterator segment types are used.
50 protected double radius
;
59 public void add(Segment newsegment
)
61 last
.next
= newsegment
;
66 * Reverses the orientation of the whole polygon
68 public void reverseAll()
72 Segment former
= this;
79 Segment oldnext
= v
.next
;
83 v
= oldnext
; // move to the next in list
87 public String
toString()
89 return "Segment:"+P1
+", "+P2
;
93 * Get the normal vector to the slope of the line.
94 * Returns: 0.5*width*(norm of derivative of the (x0,y0)-(x1,y1) vector)
96 protected double[] normal(double x0
, double y0
, double x1
, double y1
)
98 double dx
= (x1
- x0
);
99 double dy
= (y1
- y0
);
102 dy
= radius
* ((dx
> 0)?
1:-1);
107 dx
= radius
* ((dy
> 0)?
-1:1);
112 double N
= Math
.sqrt(dx
* dx
+ dy
* dy
);
114 dx
= -radius
* dy
/ N
;
115 dy
= radius
* odx
/ N
;
117 return new double[]{ dx
, dy
};
120 public abstract void reverse();
123 * Get the "top" and "bottom" segments of a segment.
124 * First array element is p0 + normal, second is p0 - normal.
126 public abstract Segment
[] getDisplacedSegments(double radius
);
128 public abstract double[] first();
129 public abstract double[] last();