1 /*
   2  * Copyright (c) 2007, 2017, Oracle and/or its affiliates. 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.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.marlin;
  27 
  28 import com.sun.javafx.geom.Path2D;
  29 import com.sun.javafx.geom.transform.BaseTransform;
  30 import com.sun.marlin.DHelpers.IndexStack;
  31 import com.sun.marlin.DHelpers.PolyStack;
  32 
  33 public final class DTransformingPathConsumer2D {
  34 
  35     private final DRendererContext rdrCtx;
  36 
  37     // recycled ClosedPathDetector instance from detectClosedPath()
  38     private final ClosedPathDetector   cpDetector;
  39 
  40     // recycled PathClipFilter instance from pathClipper()
  41     private final PathClipFilter       pathClipper;
  42 
  43     // recycled DPathConsumer2D instance from wrapPath2D()
  44     private final Path2DWrapper        wp_Path2DWrapper        = new Path2DWrapper();
  45 
  46     // recycled DPathConsumer2D instances from deltaTransformConsumer()
  47     private final DeltaScaleFilter     dt_DeltaScaleFilter     = new DeltaScaleFilter();
  48     private final DeltaTransformFilter dt_DeltaTransformFilter = new DeltaTransformFilter();
  49 
  50     // recycled DPathConsumer2D instances from inverseDeltaTransformConsumer()
  51     private final DeltaScaleFilter     iv_DeltaScaleFilter     = new DeltaScaleFilter();
  52     private final DeltaTransformFilter iv_DeltaTransformFilter = new DeltaTransformFilter();
  53 
  54     // recycled PathTracer instances from tracer...() methods
  55     private final PathTracer tracerInput      = new PathTracer("[Input]");
  56     private final PathTracer tracerCPDetector = new PathTracer("ClosedPathDetector");
  57     private final PathTracer tracerFiller     = new PathTracer("Filler");
  58     private final PathTracer tracerStroker    = new PathTracer("Stroker");
  59 
  60     DTransformingPathConsumer2D(final DRendererContext rdrCtx) {
  61         // used by RendererContext
  62         this.rdrCtx = rdrCtx;
  63         this.cpDetector = new ClosedPathDetector(rdrCtx);
  64         this.pathClipper = new PathClipFilter(rdrCtx);
  65     }
  66 
  67     public DPathConsumer2D wrapPath2D(Path2D p2d) {
  68         return wp_Path2DWrapper.init(p2d);
  69     }
  70 
  71     public DPathConsumer2D traceInput(DPathConsumer2D out) {
  72         return tracerInput.init(out);
  73     }
  74 
  75     public DPathConsumer2D traceClosedPathDetector(DPathConsumer2D out) {
  76         return tracerCPDetector.init(out);
  77     }
  78 
  79     public DPathConsumer2D traceFiller(DPathConsumer2D out) {
  80         return tracerFiller.init(out);
  81     }
  82 
  83     public DPathConsumer2D traceStroker(DPathConsumer2D out) {
  84         return tracerStroker.init(out);
  85     }
  86 
  87     public DPathConsumer2D detectClosedPath(DPathConsumer2D out) {
  88         return cpDetector.init(out);
  89     }
  90 
  91     public DPathConsumer2D pathClipper(DPathConsumer2D out,
  92                                        final double rdrOffX,
  93                                        final double rdrOffY)
  94     {
  95         return pathClipper.init(out, rdrOffX, rdrOffY);
  96     }
  97 
  98     public DPathConsumer2D deltaTransformConsumer(DPathConsumer2D out,
  99                                                   BaseTransform at,
 100                                                   final double rdrOffX,
 101                                                   final double rdrOffY)
 102     {
 103         if (at == null) {
 104             return out;
 105         }
 106         final double mxx = at.getMxx();
 107         final double mxy = at.getMxy();
 108         final double myx = at.getMyx();
 109         final double myy = at.getMyy();
 110 
 111         if (mxy == 0.0d && myx == 0.0d) {
 112             if (mxx == 1.0d && myy == 1.0d) {
 113                 return out;
 114             } else {
 115                 // Scale only
 116                 if (rdrCtx.doClip) {
 117                     // adjust clip rectangle (ymin, ymax, xmin, xmax):
 118                     adjustClipOffset(rdrCtx.clipRect, rdrOffX, rdrOffY);
 119                     adjustClipScale(rdrCtx.clipRect, mxx, myy);
 120                 }
 121                 return dt_DeltaScaleFilter.init(out, mxx, myy);
 122             }
 123         } else {
 124             if (rdrCtx.doClip) {
 125                 // adjust clip rectangle (ymin, ymax, xmin, xmax):
 126                 adjustClipOffset(rdrCtx.clipRect, rdrOffX, rdrOffY);
 127                 adjustClipInverseDelta(rdrCtx.clipRect, mxx, mxy, myx, myy);
 128             }
 129             return dt_DeltaTransformFilter.init(out, mxx, mxy, myx, myy);
 130         }
 131     }
 132 
 133     private static void adjustClipOffset(final double[] clipRect,
 134                                          final double rdrOffX,
 135                                          final double rdrOffY)
 136     {
 137         clipRect[0] += rdrOffY;
 138         clipRect[1] += rdrOffY;
 139         clipRect[2] += rdrOffX;
 140         clipRect[3] += rdrOffX;
 141     }
 142 
 143     private static void adjustClipScale(final double[] clipRect,
 144                                         final double mxx, final double myy)
 145     {
 146         // Adjust the clipping rectangle (iv_DeltaScaleFilter):
 147         clipRect[0] /= myy;
 148         clipRect[1] /= myy;
 149         clipRect[2] /= mxx;
 150         clipRect[3] /= mxx;
 151     }
 152 
 153     private static void adjustClipInverseDelta(final double[] clipRect,
 154                                                final double mxx, final double mxy,
 155                                                final double myx, final double myy)
 156     {
 157         // Adjust the clipping rectangle (iv_DeltaTransformFilter):
 158         final double det = mxx * myy - mxy * myx;
 159         final double imxx =  myy / det;
 160         final double imxy = -mxy / det;
 161         final double imyx = -myx / det;
 162         final double imyy =  mxx / det;
 163 
 164         double xmin, xmax, ymin, ymax;
 165         double x, y;
 166         // xmin, ymin:
 167         x = clipRect[2] * imxx + clipRect[0] * imxy;
 168         y = clipRect[2] * imyx + clipRect[0] * imyy;
 169 
 170         xmin = xmax = x;
 171         ymin = ymax = y;
 172 
 173         // xmax, ymin:
 174         x = clipRect[3] * imxx + clipRect[0] * imxy;
 175         y = clipRect[3] * imyx + clipRect[0] * imyy;
 176 
 177         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 178         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 179 
 180         // xmin, ymax:
 181         x = clipRect[2] * imxx + clipRect[1] * imxy;
 182         y = clipRect[2] * imyx + clipRect[1] * imyy;
 183 
 184         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 185         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 186 
 187         // xmax, ymax:
 188         x = clipRect[3] * imxx + clipRect[1] * imxy;
 189         y = clipRect[3] * imyx + clipRect[1] * imyy;
 190 
 191         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 192         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 193 
 194         clipRect[0] = ymin;
 195         clipRect[1] = ymax;
 196         clipRect[2] = xmin;
 197         clipRect[3] = xmax;
 198     }
 199 
 200     public DPathConsumer2D inverseDeltaTransformConsumer(DPathConsumer2D out,
 201                                                         BaseTransform at)
 202     {
 203         if (at == null) {
 204             return out;
 205         }
 206         double mxx = at.getMxx();
 207         double mxy = at.getMxy();
 208         double myx = at.getMyx();
 209         double myy = at.getMyy();
 210 
 211         if (mxy == 0.0d && myx == 0.0d) {
 212             if (mxx == 1.0d && myy == 1.0d) {
 213                 return out;
 214             } else {
 215                 return iv_DeltaScaleFilter.init(out, 1.0d/mxx, 1.0d/myy);
 216             }
 217         } else {
 218             final double det = mxx * myy - mxy * myx;
 219             return iv_DeltaTransformFilter.init(out,
 220                                                 myy / det,
 221                                                -mxy / det,
 222                                                -myx / det,
 223                                                 mxx / det);
 224         }
 225     }
 226 
 227     static final class DeltaScaleFilter implements DPathConsumer2D {
 228         private DPathConsumer2D out;
 229         private double sx, sy;
 230 
 231         DeltaScaleFilter() {}
 232 
 233         DeltaScaleFilter init(DPathConsumer2D out,
 234                               double mxx, double myy)
 235         {
 236             this.out = out;
 237             sx = mxx;
 238             sy = myy;
 239             return this; // fluent API
 240         }
 241 
 242         @Override
 243         public void moveTo(double x0, double y0) {
 244             out.moveTo(x0 * sx, y0 * sy);
 245         }
 246 
 247         @Override
 248         public void lineTo(double x1, double y1) {
 249             out.lineTo(x1 * sx, y1 * sy);
 250         }
 251 
 252         @Override
 253         public void quadTo(double x1, double y1,
 254                            double x2, double y2)
 255         {
 256             out.quadTo(x1 * sx, y1 * sy,
 257                        x2 * sx, y2 * sy);
 258         }
 259 
 260         @Override
 261         public void curveTo(double x1, double y1,
 262                             double x2, double y2,
 263                             double x3, double y3)
 264         {
 265             out.curveTo(x1 * sx, y1 * sy,
 266                         x2 * sx, y2 * sy,
 267                         x3 * sx, y3 * sy);
 268         }
 269 
 270         @Override
 271         public void closePath() {
 272             out.closePath();
 273         }
 274 
 275         @Override
 276         public void pathDone() {
 277             out.pathDone();
 278         }
 279     }
 280 
 281     static final class DeltaTransformFilter implements DPathConsumer2D {
 282         private DPathConsumer2D out;
 283         private double mxx, mxy, myx, myy;
 284 
 285         DeltaTransformFilter() {}
 286 
 287         DeltaTransformFilter init(DPathConsumer2D out,
 288                                   double mxx, double mxy,
 289                                   double myx, double myy)
 290         {
 291             this.out = out;
 292             this.mxx = mxx;
 293             this.mxy = mxy;
 294             this.myx = myx;
 295             this.myy = myy;
 296             return this; // fluent API
 297         }
 298 
 299         @Override
 300         public void moveTo(double x0, double y0) {
 301             out.moveTo(x0 * mxx + y0 * mxy,
 302                        x0 * myx + y0 * myy);
 303         }
 304 
 305         @Override
 306         public void lineTo(double x1, double y1) {
 307             out.lineTo(x1 * mxx + y1 * mxy,
 308                        x1 * myx + y1 * myy);
 309         }
 310 
 311         @Override
 312         public void quadTo(double x1, double y1,
 313                            double x2, double y2)
 314         {
 315             out.quadTo(x1 * mxx + y1 * mxy,
 316                        x1 * myx + y1 * myy,
 317                        x2 * mxx + y2 * mxy,
 318                        x2 * myx + y2 * myy);
 319         }
 320 
 321         @Override
 322         public void curveTo(double x1, double y1,
 323                             double x2, double y2,
 324                             double x3, double y3)
 325         {
 326             out.curveTo(x1 * mxx + y1 * mxy,
 327                         x1 * myx + y1 * myy,
 328                         x2 * mxx + y2 * mxy,
 329                         x2 * myx + y2 * myy,
 330                         x3 * mxx + y3 * mxy,
 331                         x3 * myx + y3 * myy);
 332         }
 333 
 334         @Override
 335         public void closePath() {
 336             out.closePath();
 337         }
 338 
 339         @Override
 340         public void pathDone() {
 341             out.pathDone();
 342         }
 343     }
 344 
 345     static final class Path2DWrapper implements DPathConsumer2D {
 346         private Path2D p2d;
 347 
 348         Path2DWrapper() {}
 349 
 350         Path2DWrapper init(Path2D p2d) {
 351             this.p2d = p2d;
 352             return this;
 353         }
 354 
 355         @Override
 356         public void moveTo(double x0, double y0) {
 357             p2d.moveTo((float)x0, (float)y0);
 358         }
 359 
 360         @Override
 361         public void lineTo(double x1, double y1) {
 362             p2d.lineTo((float)x1, (float)y1);
 363         }
 364 
 365         @Override
 366         public void closePath() {
 367             p2d.closePath();
 368         }
 369 
 370         @Override
 371         public void pathDone() {}
 372 
 373         @Override
 374         public void curveTo(double x1, double y1,
 375                             double x2, double y2,
 376                             double x3, double y3)
 377         {
 378             p2d.curveTo((float)x1, (float)y1, (float)x2, (float)y2,
 379                     (float)x3, (float)y3);
 380         }
 381 
 382         @Override
 383         public void quadTo(double x1, double y1, double x2, double y2) {
 384             p2d.quadTo((float)x1, (float)y1, (float)x2, (float)y2);
 385         }
 386     }
 387 
 388     static final class ClosedPathDetector implements DPathConsumer2D {
 389 
 390         private final DRendererContext rdrCtx;
 391         private final PolyStack stack;
 392 
 393         private DPathConsumer2D out;
 394 
 395         ClosedPathDetector(final DRendererContext rdrCtx) {
 396             this.rdrCtx = rdrCtx;
 397             this.stack = (rdrCtx.stats != null) ?
 398                 new PolyStack(rdrCtx,
 399                         rdrCtx.stats.stat_cpd_polystack_types,
 400                         rdrCtx.stats.stat_cpd_polystack_curves,
 401                         rdrCtx.stats.hist_cpd_polystack_curves,
 402                         rdrCtx.stats.stat_array_cpd_polystack_curves,
 403                         rdrCtx.stats.stat_array_cpd_polystack_types)
 404                 : new PolyStack(rdrCtx);
 405         }
 406 
 407         ClosedPathDetector init(DPathConsumer2D out) {
 408             this.out = out;
 409             return this; // fluent API
 410         }
 411 
 412         /**
 413          * Disposes this instance:
 414          * clean up before reusing this instance
 415          */
 416         void dispose() {
 417             stack.dispose();
 418         }
 419 
 420         @Override
 421         public void pathDone() {
 422             // previous path is not closed:
 423             finish(false);
 424             out.pathDone();
 425 
 426             // TODO: fix possible leak if exception happened
 427             // Dispose this instance:
 428             dispose();
 429         }
 430 
 431         @Override
 432         public void closePath() {
 433             // path is closed
 434             finish(true);
 435             out.closePath();
 436         }
 437 
 438         @Override
 439         public void moveTo(double x0, double y0) {
 440             // previous path is not closed:
 441             finish(false);
 442             out.moveTo(x0, y0);
 443         }
 444 
 445         private void finish(final boolean closed) {
 446             rdrCtx.closedPath = closed;
 447             stack.pullAll(out);
 448         }
 449 
 450         @Override
 451         public void lineTo(double x1, double y1) {
 452             stack.pushLine(x1, y1);
 453         }
 454 
 455         @Override
 456         public void curveTo(double x3, double y3,
 457                             double x2, double y2,
 458                             double x1, double y1)
 459         {
 460             stack.pushCubic(x1, y1, x2, y2, x3, y3);
 461         }
 462 
 463         @Override
 464         public void quadTo(double x2, double y2, double x1, double y1) {
 465             stack.pushQuad(x1, y1, x2, y2);
 466         }
 467     }
 468 
 469     static final class PathClipFilter implements DPathConsumer2D {
 470 
 471         private DPathConsumer2D out;
 472 
 473         // Bounds of the drawing region, at pixel precision.
 474         private final double[] clipRect;
 475 
 476         private final double[] corners = new double[8];
 477         private boolean init_corners = false;
 478 
 479         private final IndexStack stack;
 480 
 481         // the current outcode of the current sub path
 482         private int cOutCode = 0;
 483 
 484         // the cumulated (and) outcode of the complete path
 485         private int gOutCode = MarlinConst.OUTCODE_MASK_T_B_L_R;
 486 
 487         private boolean outside = false;
 488 
 489         // The current point OUTSIDE
 490         private double cx0, cy0;
 491 
 492         PathClipFilter(final DRendererContext rdrCtx) {
 493             this.clipRect = rdrCtx.clipRect;
 494             this.stack = (rdrCtx.stats != null) ?
 495                 new IndexStack(rdrCtx,
 496                         rdrCtx.stats.stat_pcf_idxstack_indices,
 497                         rdrCtx.stats.hist_pcf_idxstack_indices,
 498                         rdrCtx.stats.stat_array_pcf_idxstack_indices)
 499                 : new IndexStack(rdrCtx);
 500         }
 501 
 502         PathClipFilter init(final DPathConsumer2D out,
 503                             final double rdrOffX,
 504                             final double rdrOffY)
 505         {
 506             this.out = out;
 507 
 508             // add a small rounding error:
 509             final double margin = 1e-3d;
 510 
 511             final double[] _clipRect = this.clipRect;
 512             // Adjust the clipping rectangle with the renderer offsets
 513             _clipRect[0] -= margin - rdrOffY;
 514             _clipRect[1] += margin + rdrOffY;
 515             _clipRect[2] -= margin - rdrOffX;
 516             _clipRect[3] += margin + rdrOffX;
 517 
 518             this.init_corners = true;
 519             this.gOutCode = MarlinConst.OUTCODE_MASK_T_B_L_R;
 520 
 521             return this; // fluent API
 522         }
 523 
 524         /**
 525          * Disposes this instance:
 526          * clean up before reusing this instance
 527          */
 528         void dispose() {
 529             stack.dispose();
 530         }
 531 
 532         private void finishPath() {
 533             if (outside) {
 534                 // criteria: inside or totally outside ?
 535                 if (gOutCode == 0) {
 536                     finish();
 537                 } else {
 538                     this.outside = false;
 539                     stack.reset();
 540                 }
 541             }
 542         }
 543 
 544         private void finish() {
 545             this.outside = false;
 546 
 547             if (!stack.isEmpty()) {
 548                 if (init_corners) {
 549                     init_corners = false;
 550 
 551                     final double[] _corners = corners;
 552                     final double[] _clipRect = clipRect;
 553                     // Top Left (0):
 554                     _corners[0] = _clipRect[2];
 555                     _corners[1] = _clipRect[0];
 556                     // Bottom Left (1):
 557                     _corners[2] = _clipRect[2];
 558                     _corners[3] = _clipRect[1];
 559                     // Top right (2):
 560                     _corners[4] = _clipRect[3];
 561                     _corners[5] = _clipRect[0];
 562                     // Bottom Right (3):
 563                     _corners[6] = _clipRect[3];
 564                     _corners[7] = _clipRect[1];
 565                 }
 566                 stack.pullAll(corners, out);
 567             }
 568             out.lineTo(cx0, cy0);
 569         }
 570 
 571         @Override
 572         public void pathDone() {
 573             finishPath();
 574 
 575             out.pathDone();
 576 
 577             // TODO: fix possible leak if exception happened
 578             // Dispose this instance:
 579             dispose();
 580         }
 581 
 582         @Override
 583         public void closePath() {
 584             finishPath();
 585 
 586             out.closePath();
 587         }
 588 
 589         @Override
 590         public void moveTo(final double x0, final double y0) {
 591             finishPath();
 592 
 593             final int outcode = DHelpers.outcode(x0, y0, clipRect);
 594             this.cOutCode = outcode;
 595             this.outside = false;
 596             out.moveTo(x0, y0);
 597         }
 598 
 599         @Override
 600         public void lineTo(final double xe, final double ye) {
 601             final int outcode0 = this.cOutCode;
 602             final int outcode1 = DHelpers.outcode(xe, ye, clipRect);
 603             this.cOutCode = outcode1;
 604 
 605             final int sideCode = (outcode0 & outcode1);
 606 
 607             // basic rejection criteria:
 608             if (sideCode == 0) {
 609                 this.gOutCode = 0;
 610             } else {
 611                 this.gOutCode &= sideCode;
 612                 // keep last point coordinate before entering the clip again:
 613                 this.outside = true;
 614                 this.cx0 = xe;
 615                 this.cy0 = ye;
 616 
 617                 clip(sideCode, outcode0, outcode1);
 618                 return;
 619             }
 620             if (outside) {
 621                 finish();
 622             }
 623             // clipping disabled:
 624             out.lineTo(xe, ye);
 625         }
 626 
 627         private void clip(final int sideCode,
 628                           final int outcode0,
 629                           final int outcode1)
 630         {
 631             // corner or cross-boundary on left or right side:
 632             if ((outcode0 != outcode1)
 633                     && ((sideCode & MarlinConst.OUTCODE_MASK_L_R) != 0))
 634             {
 635                 // combine outcodes:
 636                 final int mergeCode = (outcode0 | outcode1);
 637                 final int tbCode = mergeCode & MarlinConst.OUTCODE_MASK_T_B;
 638                 final int lrCode = mergeCode & MarlinConst.OUTCODE_MASK_L_R;
 639                 final int off = (lrCode == MarlinConst.OUTCODE_LEFT) ? 0 : 2;
 640 
 641                 // add corners to outside stack:
 642                 switch (tbCode) {
 643                     case MarlinConst.OUTCODE_TOP:
 644 // System.out.println("TOP "+ ((off == 0) ? "LEFT" : "RIGHT"));
 645                         stack.push(off); // top
 646                         return;
 647                     case MarlinConst.OUTCODE_BOTTOM:
 648 // System.out.println("BOTTOM "+ ((off == 0) ? "LEFT" : "RIGHT"));
 649                         stack.push(off + 1); // bottom
 650                         return;
 651                     default:
 652                         // both TOP / BOTTOM:
 653                         if ((outcode0 & MarlinConst.OUTCODE_TOP) != 0) {
 654 // System.out.println("TOP + BOTTOM "+ ((off == 0) ? "LEFT" : "RIGHT"));
 655                             // top to bottom
 656                             stack.push(off); // top
 657                             stack.push(off + 1); // bottom
 658                         } else {
 659 // System.out.println("BOTTOM + TOP "+ ((off == 0) ? "LEFT" : "RIGHT"));
 660                             // bottom to top
 661                             stack.push(off + 1); // bottom
 662                             stack.push(off); // top
 663                         }
 664                 }
 665             }
 666         }
 667 
 668         @Override
 669         public void curveTo(final double x1, final double y1,
 670                             final double x2, final double y2,
 671                             final double xe, final double ye)
 672         {
 673             final int outcode0 = this.cOutCode;
 674             final int outcode3 = DHelpers.outcode(xe, ye, clipRect);
 675             this.cOutCode = outcode3;
 676 
 677             int sideCode = outcode0 & outcode3;
 678 
 679             if (sideCode == 0) {
 680                 this.gOutCode = 0;
 681             } else {
 682                 sideCode &= DHelpers.outcode(x1, y1, clipRect);
 683                 sideCode &= DHelpers.outcode(x2, y2, clipRect);
 684                 this.gOutCode &= sideCode;
 685 
 686                 // basic rejection criteria:
 687                 if (sideCode != 0) {
 688                     // keep last point coordinate before entering the clip again:
 689                     this.outside = true;
 690                     this.cx0 = xe;
 691                     this.cy0 = ye;
 692 
 693                     clip(sideCode, outcode0, outcode3);
 694                     return;
 695                 }
 696             }
 697             if (outside) {
 698                 finish();
 699             }
 700             // clipping disabled:
 701             out.curveTo(x1, y1, x2, y2, xe, ye);
 702         }
 703 
 704         @Override
 705         public void quadTo(final double x1, final double y1,
 706                            final double xe, final double ye)
 707         {
 708             final int outcode0 = this.cOutCode;
 709             final int outcode2 = DHelpers.outcode(xe, ye, clipRect);
 710             this.cOutCode = outcode2;
 711 
 712             int sideCode = outcode0 & outcode2;
 713 
 714             if (sideCode == 0) {
 715                 this.gOutCode = 0;
 716             } else {
 717                 sideCode &= DHelpers.outcode(x1, y1, clipRect);
 718                 this.gOutCode &= sideCode;
 719 
 720                 // basic rejection criteria:
 721                 if (sideCode != 0) {
 722                     // keep last point coordinate before entering the clip again:
 723                     this.outside = true;
 724                     this.cx0 = xe;
 725                     this.cy0 = ye;
 726 
 727                     clip(sideCode, outcode0, outcode2);
 728                     return;
 729                 }
 730             }
 731             if (outside) {
 732                 finish();
 733             }
 734             // clipping disabled:
 735             out.quadTo(x1, y1, xe, ye);
 736         }
 737     }
 738 
 739     static final class PathTracer implements DPathConsumer2D {
 740         private final String prefix;
 741         private DPathConsumer2D out;
 742 
 743         PathTracer(String name) {
 744             this.prefix = name + ": ";
 745         }
 746 
 747         PathTracer init(DPathConsumer2D out) {
 748             this.out = out;
 749             return this; // fluent API
 750         }
 751 
 752         @Override
 753         public void moveTo(double x0, double y0) {
 754             log("moveTo (" + x0 + ", " + y0 + ')');
 755             out.moveTo(x0, y0);
 756         }
 757 
 758         @Override
 759         public void lineTo(double x1, double y1) {
 760             log("lineTo (" + x1 + ", " + y1 + ')');
 761             out.lineTo(x1, y1);
 762         }
 763 
 764         @Override
 765         public void curveTo(double x1, double y1,
 766                             double x2, double y2,
 767                             double x3, double y3)
 768         {
 769             log("curveTo P1(" + x1 + ", " + y1 + ") P2(" + x2 + ", " + y2  + ") P3(" + x3 + ", " + y3 + ')');
 770             out.curveTo(x1, y1, x2, y2, x3, y3);
 771         }
 772 
 773         @Override
 774         public void quadTo(double x1, double y1, double x2, double y2) {
 775             log("quadTo P1(" + x1 + ", " + y1 + ") P2(" + x2 + ", " + y2  + ')');
 776             out.quadTo(x1, y1, x2, y2);
 777         }
 778 
 779         @Override
 780         public void closePath() {
 781             log("closePath");
 782             out.closePath();
 783         }
 784 
 785         @Override
 786         public void pathDone() {
 787             log("pathDone");
 788             out.pathDone();
 789         }
 790 
 791         private void log(final String message) {
 792             System.out.println(prefix + message);
 793         }
 794     }
 795 }