bundles/org.simantics.diagram.connection/src/org/simantics/diagram/connection/rendering/ConnectionCrossings.java

   1 /*******************************************************************************
   2  * Copyright (c) 2020 Association for Decentralized Information Management in
   3  * Industry THTH ry.
   4  * All rights reserved. This program and the accompanying materials
   5  * are made available under the terms of the Eclipse Public License v1.0
   6  * which accompanies this distribution, and is available at
   7  * http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  * Contributors:
  10  *     Semantum Oy - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.diagram.connection.rendering;
  13
  14 import java.awt.geom.Arc2D;
  15 import java.awt.geom.Path2D;
  16 import java.awt.geom.PathIterator;
  17 import java.awt.geom.Point2D;
  18 import java.util.ArrayList;
  19 import java.util.Collections;
  20 import java.util.List;
  21
  22 public class ConnectionCrossings implements PathModifier {
  23     public enum Type {
  24         NONE,
  25         GAP,
  26         ARC,
  27         SQUARE
  28     }
  29
  30     private List<Segment> segments = new ArrayList<>();
  31     private double width;
  32     private double widthd2;
  33     private Type type;
  34     private boolean keepLines = false;
  35
  36
  37     public void setWidth(double gapWidth) {
  38         this.width = gapWidth;
  39         this.widthd2 = width * 0.5;
  40     }
  41
  42     public double getWidth() {
  43         return width;
  44     }
  45
  46     public void setType(Type type) {
  47         this.type = type;
  48     }
  49
  50     public Type getType() {
  51         return type;
  52     }
  53
  54     /**
  55      * When keep lines is enabled, we keep short lines in the start and end of a line segment, instead of removing them completely with gaps.
  56      * @return
  57      */
  58     public boolean isKeepLines() {
  59         return keepLines;
  60     }
  61
  62     public void setKeepLines(boolean keepLines) {
  63         this.keepLines = keepLines;
  64     }
  65
  66     static class Segment {
  67         public double x1, y1, x2, y2;
  68
  69         public Segment(double x1, double y1, double x2, double y2) {
  70             this.x1 = x1;
  71             this.y1 = y1;
  72             this.x2 = x2;
  73             this.y2 = y2;
  74         }
  75     };
  76
  77     public void reset() {
  78         segments.clear();
  79     }
  80
  81     static Double lineLineIntersection(Segment l1, Segment l2) {
  82         double epsilon = 0.001;
  83
  84         double d = (l1.x1 - l1.x2) * (l2.y1 - l2.y2) - (l1.y1 - l1.y2) * (l2.x1 - l2.x2);
  85         if (d == 0.0) return null;
  86         double s = ((l1.x1 - l2.x1) * (l2.y1 - l2.y2) - (l1.y1 - l2.y1) * (l2.x1 - l2.x2)) / d;
  87         if ((s > epsilon) && (s < 1 - epsilon)) {
  88             double t = -((l1.x1 - l1.x2) * (l1.y1 - l2.y1) - (l1.y1 - l1.y2) * (l1.x1 - l2.x1)) / d;
  89             if ((t > epsilon) && (t < 1 - epsilon)) {
  90                 return t;
  91             }
  92         }
  93         return null;
  94     }
  95
  96     public Path2D modify(Path2D path) {
  97         Path2D.Double path2 = new Path2D.Double();
  98         PathIterator iter = path.getPathIterator(null);
  99         if (!isKeepLines()) {
 100             while (!iter.isDone()) {
 101
 102                 double c[] = new double[6];
 103                 int i = iter.currentSegment(c);
 104                 switch (i) {
 105                 case PathIterator.SEG_MOVETO:
 106                     path2.moveTo(c[0], c[1]);
 107                     break;
 108                 case PathIterator.SEG_LINETO:
 109                     Segment l = new Segment(path2.getCurrentPoint().getX(), path2.getCurrentPoint().getY(), c[0], c[1]);
 110
 111                     List<Double> gaps = new ArrayList<>();
 112                     for (Segment old : segments) {
 113                         Double t = lineLineIntersection(old, l);
 114                         if (t != null) {
 115                             gaps.add(t);
 116                         }
 117                     }
 118
 119                     if (gaps.isEmpty()) {
 120                         path2.lineTo(c[0], c[1]);
 121                     } else {
 122                         Collections.sort(gaps);
 123                         double dx = l.x2 - l.x1;
 124                         double dy = l.y2 - l.y1;
 125
 126                         double pos = 0.0;
 127                         double len = Math.sqrt(dx * dx + dy * dy);
 128                         double len1 = 1.0 / len;
 129
 130                         boolean finish = true;
 131                         Point2D prevGapEnd = null;
 132                         for (Double gapCenter : gaps) {
 133                             double pos2 = gapCenter - widthd2 * len1;
 134                             double pos3 = gapCenter + widthd2 * len1;
 135                             if (pos2 > pos) {
 136                                 handleGap(path2, prevGapEnd);
 137                                 prevGapEnd = null;
 138                                 path2.lineTo(l.x1 + pos2 * dx, l.y1 + pos2 * dy);
 139                             }
 140                             if (pos3 < 1.0) {
 141                                 double x = l.x1 + pos3 * dx;
 142                                 double y = l.y1 + pos3 * dy;
 143                                 prevGapEnd = new Point2D.Double(x, y);
 144                             } else {
 145                                 finish = false;
 146                             }
 147                             pos = pos3;
 148                         }
 149
 150                         if (finish) {
 151                             handleGap(path2, prevGapEnd);
 152                             path2.lineTo(l.x2, l.y2);
 153                         } else {
 154                             prevGapEnd = new Point2D.Double(l.x2, l.y2);
 155                             handleGap(path2, prevGapEnd);
 156                         }
 157                     }
 158                     segments.add(l);
 159
 160                     break;
 161                 case PathIterator.SEG_QUADTO:
 162                     // TODO: implement gaps
 163                     path2.quadTo(c[0], c[1], c[2], c[3]);
 164                     break;
 165                 case PathIterator.SEG_CUBICTO:
 166                     // TODO: implement gaps
 167                     path2.curveTo(c[0], c[1], c[2], c[3], c[4], c[5]);
 168                     break;
 169                 case PathIterator.SEG_CLOSE:
 170                     // TODO: implement gaps
 171                     path2.closePath();
 172                     break;
 173                 default:
 174                     throw new RuntimeException("Unexpected segment type " + i);
 175                 }
 176                 iter.next();
 177             }
 178         } else {
 179             while (!iter.isDone()) {
 180
 181                 double c[] = new double[6];
 182                 int i = iter.currentSegment(c);
 183                 switch (i) {
 184                 case PathIterator.SEG_MOVETO:
 185                     path2.moveTo(c[0], c[1]);
 186                     break;
 187                 case PathIterator.SEG_LINETO:
 188                     Segment l = new Segment(path2.getCurrentPoint().getX(), path2.getCurrentPoint().getY(), c[0], c[1]);
 189
 190                     List<Double> gaps = new ArrayList<>();
 191                     for (Segment old : segments) {
 192                         Double t = lineLineIntersection(old, l);
 193                         if (t != null) {
 194                             gaps.add(t);
 195                         }
 196                     }
 197
 198                     if (gaps.isEmpty()) {
 199                         path2.lineTo(c[0], c[1]);
 200                     } else {
 201                         Collections.sort(gaps);
 202                         double dx = l.x2 - l.x1;
 203                         double dy = l.y2 - l.y1;
 204
 205                         double pos = 0.0;
 206                         double len = Math.sqrt(dx * dx + dy * dy);
 207                         double len1 = 1.0 / len;
 208
 209                         boolean finish = true;
 210                         Point2D prevGapEnd = null;
 211                         for (int j = 0; j < gaps.size(); j++) {
 212                             Double gapCenter = gaps.get(j);
 213                             double gc = gapCenter * len;
 214                             double pos2 = gc - widthd2;
 215                             double pos3 = gc + widthd2;
 216                             if (j == 0) {
 217                                 if (pos2 < widthd2)
 218                                     pos2 += (widthd2 - pos2) * 0.5;
 219                             }
 220                             if (j == gaps.size() - 1) {
 221                                 double d = len - pos3;
 222                                 if (d < widthd2)
 223                                     pos3 -= (widthd2 - d) * 0.5;
 224                             }
 225                             if (pos2 > pos) {
 226                                 handleGap(path2, prevGapEnd);
 227                                 prevGapEnd = null;
 228                                 pos2 *= len1;
 229                                 path2.lineTo(l.x1 + pos2 * dx, l.y1 + pos2 * dy);
 230                             }
 231                             if (pos3 < len) {
 232                                 pos3 *= len1;
 233                                 double x = l.x1 + pos3 * dx;
 234                                 double y = l.y1 + pos3 * dy;
 235                                 prevGapEnd = new Point2D.Double(x, y);
 236                             } else {
 237                                 finish = false;
 238                             }
 239                             pos = pos3;
 240                         }
 241
 242                         if (finish) {
 243                             handleGap(path2, prevGapEnd);
 244                             path2.lineTo(l.x2, l.y2);
 245                         } else {
 246                             prevGapEnd = new Point2D.Double(l.x2, l.y2);
 247                             handleGap(path2, prevGapEnd);
 248                         }
 249                     }
 250                     segments.add(l);
 251
 252                     break;
 253                 case PathIterator.SEG_QUADTO:
 254                     // TODO: implement gaps
 255                     path2.quadTo(c[0], c[1], c[2], c[3]);
 256                     break;
 257                 case PathIterator.SEG_CUBICTO:
 258                     // TODO: implement gaps
 259                     path2.curveTo(c[0], c[1], c[2], c[3], c[4], c[5]);
 260                     break;
 261                 case PathIterator.SEG_CLOSE:
 262                     // TODO: implement gaps
 263                     path2.closePath();
 264                     break;
 265                 default:
 266                     throw new RuntimeException("Unexpected segment type " + i);
 267                 }
 268                 iter.next();
 269             }
 270         }
 271         return path2;
 272     }
 273
 274     private void handleGap(Path2D path, Point2D prevGapEnd) {
 275         if (prevGapEnd != null) {
 276             switch (type) {
 277             case ARC:
 278                 arcTo(path, prevGapEnd.getX(), prevGapEnd.getY());
 279                 break;
 280             case SQUARE:
 281                 squareTo(path, prevGapEnd.getX(), prevGapEnd.getY(), width);
 282                 break;
 283             case GAP:
 284                 path.moveTo(prevGapEnd.getX(), prevGapEnd.getY());
 285                 break;
 286             case NONE:
 287                 break;
 288             }
 289         }
 290     }
 291
 292     private static void arcTo(Path2D path, double x2, double y2) {
 293         Arc2D arc = new Arc2D.Double();
 294         double x1 = path.getCurrentPoint().getX();
 295         double y1 = path.getCurrentPoint().getY();
 296         double dx = x2 - x1;
 297         double dy = y2 - y1;
 298         double r = Math.sqrt(dx * dx + dy * dy) / 2;
 299         double angle = Math.atan2(dx,  dy) * 180 / Math.PI + 90;
 300         double span = (angle > 225 || angle < 45) ? 180 : -180;
 301         arc.setArcByCenter((x1 + x2) / 2, (y1 + y2) / 2, r, angle, span, Arc2D.OPEN);
 302         path.append(arc, true);
 303     }
 304
 305     private static void squareTo(Path2D path, double x2, double y2, double width) {
 306         double x1 = path.getCurrentPoint().getX();
 307         double y1 = path.getCurrentPoint().getY();
 308         double dx = x2 - x1;
 309         double dy = y2 - y1;
 310         double l = Math.sqrt(dx * dx + dy* dy);
 311         if (l > 0) {
 312             double nx = -dy / l;
 313             double ny = dx / l;
 314             if (nx - ny < 0) {
 315                 nx = -nx;
 316                 ny = -ny;
 317             }
 318             path.lineTo(x1 + nx * width / 2, y1 + ny * width / 2);
 319             path.lineTo(x2 + nx * width / 2, y2 + ny * width / 2);
 320             path.lineTo(x2, y2);
 321         }
 322     }
 323
 324 }