J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1998 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.awt.geom; |
| 27 | |
| 28 | final class ChainEnd { |
| 29 | CurveLink head; |
| 30 | CurveLink tail; |
| 31 | ChainEnd partner; |
| 32 | int etag; |
| 33 | |
| 34 | public ChainEnd(CurveLink first, ChainEnd partner) { |
| 35 | this.head = first; |
| 36 | this.tail = first; |
| 37 | this.partner = partner; |
| 38 | this.etag = first.getEdgeTag(); |
| 39 | } |
| 40 | |
| 41 | public CurveLink getChain() { |
| 42 | return head; |
| 43 | } |
| 44 | |
| 45 | public void setOtherEnd(ChainEnd partner) { |
| 46 | this.partner = partner; |
| 47 | } |
| 48 | |
| 49 | public ChainEnd getPartner() { |
| 50 | return partner; |
| 51 | } |
| 52 | |
| 53 | /* |
| 54 | * Returns head of a complete chain to be added to subcurves |
| 55 | * or null if the links did not complete such a chain. |
| 56 | */ |
| 57 | public CurveLink linkTo(ChainEnd that) { |
| 58 | if (etag == AreaOp.ETAG_IGNORE || |
| 59 | that.etag == AreaOp.ETAG_IGNORE) |
| 60 | { |
| 61 | throw new InternalError("ChainEnd linked more than once!"); |
| 62 | } |
| 63 | if (etag == that.etag) { |
| 64 | throw new InternalError("Linking chains of the same type!"); |
| 65 | } |
| 66 | ChainEnd enter, exit; |
| 67 | // assert(partner.etag != that.partner.etag); |
| 68 | if (etag == AreaOp.ETAG_ENTER) { |
| 69 | enter = this; |
| 70 | exit = that; |
| 71 | } else { |
| 72 | enter = that; |
| 73 | exit = this; |
| 74 | } |
| 75 | // Now make sure these ChainEnds are not linked to any others... |
| 76 | etag = AreaOp.ETAG_IGNORE; |
| 77 | that.etag = AreaOp.ETAG_IGNORE; |
| 78 | // Now link everything up... |
| 79 | enter.tail.setNext(exit.head); |
| 80 | enter.tail = exit.tail; |
| 81 | if (partner == that) { |
| 82 | // Curve has closed on itself... |
| 83 | return enter.head; |
| 84 | } |
| 85 | // Link this chain into one end of the chain formed by the partners |
| 86 | ChainEnd otherenter = exit.partner; |
| 87 | ChainEnd otherexit = enter.partner; |
| 88 | otherenter.partner = otherexit; |
| 89 | otherexit.partner = otherenter; |
| 90 | if (enter.head.getYTop() < otherenter.head.getYTop()) { |
| 91 | enter.tail.setNext(otherenter.head); |
| 92 | otherenter.head = enter.head; |
| 93 | } else { |
| 94 | otherexit.tail.setNext(enter.head); |
| 95 | otherexit.tail = enter.tail; |
| 96 | } |
| 97 | return null; |
| 98 | } |
| 99 | |
| 100 | public void addLink(CurveLink newlink) { |
| 101 | if (etag == AreaOp.ETAG_ENTER) { |
| 102 | tail.setNext(newlink); |
| 103 | tail = newlink; |
| 104 | } else { |
| 105 | newlink.setNext(head); |
| 106 | head = newlink; |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | public double getX() { |
| 111 | if (etag == AreaOp.ETAG_ENTER) { |
| 112 | return tail.getXBot(); |
| 113 | } else { |
| 114 | return head.getXBot(); |
| 115 | } |
| 116 | } |
| 117 | } |