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 sun.java2d.marlin;
  27 
  28 import java.awt.geom.AffineTransform;
  29 import java.awt.geom.Path2D;
  30 import sun.java2d.marlin.DHelpers.IndexStack;
  31 import sun.java2d.marlin.DHelpers.PolyStack;
  32 
  33 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     DPathConsumer2D wrapPath2D(Path2D.Double p2d) {
  68         return wp_Path2DWrapper.init(p2d);
  69     }
  70 
  71     DPathConsumer2D traceInput(DPathConsumer2D out) {
  72         return tracerInput.init(out);
  73     }
  74 
  75     DPathConsumer2D traceClosedPathDetector(DPathConsumer2D out) {
  76         return tracerCPDetector.init(out);
  77     }
  78 
  79     DPathConsumer2D traceFiller(DPathConsumer2D out) {
  80         return tracerFiller.init(out);
  81     }
  82 
  83     DPathConsumer2D traceStroker(DPathConsumer2D out) {
  84         return tracerStroker.init(out);
  85     }
  86 
  87     DPathConsumer2D detectClosedPath(DPathConsumer2D out) {
  88         return cpDetector.init(out);
  89     }
  90 
  91     DPathConsumer2D pathClipper(DPathConsumer2D out) {
  92         return pathClipper.init(out);
  93     }
  94 
  95     DPathConsumer2D deltaTransformConsumer(DPathConsumer2D out,
  96                                           AffineTransform at)
  97     {
  98         if (at == null) {
  99             return out;
 100         }
 101         final double mxx = at.getScaleX();
 102         final double mxy = at.getShearX();
 103         final double myx = at.getShearY();
 104         final double myy = at.getScaleY();
 105 
 106         if (mxy == 0.0d && myx == 0.0d) {
 107             if (mxx == 1.0d && myy == 1.0d) {
 108                 return out;
 109             } else {
 110                 // Scale only
 111                 if (rdrCtx.doClip) {
 112                     // adjust clip rectangle (ymin, ymax, xmin, xmax):
 113                     adjustClipScale(rdrCtx.clipRect, mxx, myy);
 114                 }
 115                 return dt_DeltaScaleFilter.init(out, mxx, myy);
 116             }
 117         } else {
 118             if (rdrCtx.doClip) {
 119                 // adjust clip rectangle (ymin, ymax, xmin, xmax):
 120                 adjustClipInverseDelta(rdrCtx.clipRect, mxx, mxy, myx, myy);
 121             }
 122             return dt_DeltaTransformFilter.init(out, mxx, mxy, myx, myy);
 123         }
 124     }
 125 
 126     private static void adjustClipOffset(final double[] clipRect) {
 127         clipRect[0] += Renderer.RDR_OFFSET_Y;
 128         clipRect[1] += Renderer.RDR_OFFSET_Y;
 129         clipRect[2] += Renderer.RDR_OFFSET_X;
 130         clipRect[3] += Renderer.RDR_OFFSET_X;
 131     }
 132 
 133     private static void adjustClipScale(final double[] clipRect,
 134                                         final double mxx, final double myy)
 135     {
 136         adjustClipOffset(clipRect);
 137 
 138         // Adjust the clipping rectangle (iv_DeltaScaleFilter):
 139         clipRect[0] /= myy;
 140         clipRect[1] /= myy;
 141         clipRect[2] /= mxx;
 142         clipRect[3] /= mxx;
 143     }
 144 
 145     private static void adjustClipInverseDelta(final double[] clipRect,
 146                                                final double mxx, final double mxy,
 147                                                final double myx, final double myy)
 148     {
 149         adjustClipOffset(clipRect);
 150 
 151         // Adjust the clipping rectangle (iv_DeltaTransformFilter):
 152         final double det = mxx * myy - mxy * myx;
 153         final double imxx =  myy / det;
 154         final double imxy = -mxy / det;
 155         final double imyx = -myx / det;
 156         final double imyy =  mxx / det;
 157 
 158         double xmin, xmax, ymin, ymax;
 159         double x, y;
 160         // xmin, ymin:
 161         x = clipRect[2] * imxx + clipRect[0] * imxy;
 162         y = clipRect[2] * imyx + clipRect[0] * imyy;
 163 
 164         xmin = xmax = x;
 165         ymin = ymax = y;
 166 
 167         // xmax, ymin:
 168         x = clipRect[3] * imxx + clipRect[0] * imxy;
 169         y = clipRect[3] * imyx + clipRect[0] * imyy;
 170 
 171         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 172         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 173 
 174         // xmin, ymax:
 175         x = clipRect[2] * imxx + clipRect[1] * imxy;
 176         y = clipRect[2] * imyx + clipRect[1] * imyy;
 177 
 178         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 179         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 180 
 181         // xmax, ymax:
 182         x = clipRect[3] * imxx + clipRect[1] * imxy;
 183         y = clipRect[3] * imyx + clipRect[1] * imyy;
 184 
 185         if (x < xmin) { xmin = x; } else if (x > xmax) { xmax = x; }
 186         if (y < ymin) { ymin = y; } else if (y > ymax) { ymax = y; }
 187 
 188         clipRect[0] = ymin;
 189         clipRect[1] = ymax;
 190         clipRect[2] = xmin;
 191         clipRect[3] = xmax;
 192     }
 193 
 194     DPathConsumer2D inverseDeltaTransformConsumer(DPathConsumer2D out,
 195                                                  AffineTransform at)
 196     {
 197         if (at == null) {
 198             return out;
 199         }
 200         double mxx = at.getScaleX();
 201         double mxy = at.getShearX();
 202         double myx = at.getShearY();
 203         double myy = at.getScaleY();
 204 
 205         if (mxy == 0.0d && myx == 0.0d) {
 206             if (mxx == 1.0d && myy == 1.0d) {
 207                 return out;
 208             } else {
 209                 return iv_DeltaScaleFilter.init(out, 1.0d/mxx, 1.0d/myy);
 210             }
 211         } else {
 212             final double det = mxx * myy - mxy * myx;
 213             return iv_DeltaTransformFilter.init(out,
 214                                                 myy / det,
 215                                                -mxy / det,
 216                                                -myx / det,
 217                                                 mxx / det);
 218         }
 219     }
 220 
 221     static final class DeltaScaleFilter implements DPathConsumer2D {
 222         private DPathConsumer2D out;
 223         private double sx, sy;
 224 
 225         DeltaScaleFilter() {}
 226 
 227         DeltaScaleFilter init(DPathConsumer2D out,
 228                               double mxx, double myy)
 229         {
 230             this.out = out;
 231             sx = mxx;
 232             sy = myy;
 233             return this; // fluent API
 234         }
 235 
 236         @Override
 237         public void moveTo(double x0, double y0) {
 238             out.moveTo(x0 * sx, y0 * sy);
 239         }
 240 
 241         @Override
 242         public void lineTo(double x1, double y1) {
 243             out.lineTo(x1 * sx, y1 * sy);
 244         }
 245 
 246         @Override
 247         public void quadTo(double x1, double y1,
 248                            double x2, double y2)
 249         {
 250             out.quadTo(x1 * sx, y1 * sy,
 251                        x2 * sx, y2 * sy);
 252         }
 253 
 254         @Override
 255         public void curveTo(double x1, double y1,
 256                             double x2, double y2,
 257                             double x3, double y3)
 258         {
 259             out.curveTo(x1 * sx, y1 * sy,
 260                         x2 * sx, y2 * sy,
 261                         x3 * sx, y3 * sy);
 262         }
 263 
 264         @Override
 265         public void closePath() {
 266             out.closePath();
 267         }
 268 
 269         @Override
 270         public void pathDone() {
 271             out.pathDone();
 272         }
 273 
 274         @Override
 275         public long getNativeConsumer() {
 276             return 0;
 277         }
 278     }
 279 
 280     static final class DeltaTransformFilter implements DPathConsumer2D {
 281         private DPathConsumer2D out;
 282         private double mxx, mxy, myx, myy;
 283 
 284         DeltaTransformFilter() {}
 285 
 286         DeltaTransformFilter init(DPathConsumer2D out,
 287                                   double mxx, double mxy,
 288                                   double myx, double myy)
 289         {
 290             this.out = out;
 291             this.mxx = mxx;
 292             this.mxy = mxy;
 293             this.myx = myx;
 294             this.myy = myy;
 295             return this; // fluent API
 296         }
 297 
 298         @Override
 299         public void moveTo(double x0, double y0) {
 300             out.moveTo(x0 * mxx + y0 * mxy,
 301                        x0 * myx + y0 * myy);
 302         }
 303 
 304         @Override
 305         public void lineTo(double x1, double y1) {
 306             out.lineTo(x1 * mxx + y1 * mxy,
 307                        x1 * myx + y1 * myy);
 308         }
 309 
 310         @Override
 311         public void quadTo(double x1, double y1,
 312                            double x2, double y2)
 313         {
 314             out.quadTo(x1 * mxx + y1 * mxy,
 315                        x1 * myx + y1 * myy,
 316                        x2 * mxx + y2 * mxy,
 317                        x2 * myx + y2 * myy);
 318         }
 319 
 320         @Override
 321         public void curveTo(double x1, double y1,
 322                             double x2, double y2,
 323                             double x3, double y3)
 324         {
 325             out.curveTo(x1 * mxx + y1 * mxy,
 326                         x1 * myx + y1 * myy,
 327                         x2 * mxx + y2 * mxy,
 328                         x2 * myx + y2 * myy,
 329                         x3 * mxx + y3 * mxy,
 330                         x3 * myx + y3 * myy);
 331         }
 332 
 333         @Override
 334         public void closePath() {
 335             out.closePath();
 336         }
 337 
 338         @Override
 339         public void pathDone() {
 340             out.pathDone();
 341         }
 342 
 343         @Override
 344         public long getNativeConsumer() {
 345             return 0;
 346         }
 347     }
 348 
 349     static final class Path2DWrapper implements DPathConsumer2D {
 350         private Path2D.Double p2d;
 351 
 352         Path2DWrapper() {}
 353 
 354         Path2DWrapper init(Path2D.Double p2d) {
 355             this.p2d = p2d;
 356             return this;
 357         }
 358 
 359         @Override
 360         public void moveTo(double x0, double y0) {
 361             p2d.moveTo(x0, y0);
 362         }
 363 
 364         @Override
 365         public void lineTo(double x1, double y1) {
 366             p2d.lineTo(x1, y1);
 367         }
 368 
 369         @Override
 370         public void closePath() {
 371             p2d.closePath();
 372         }
 373 
 374         @Override
 375         public void pathDone() {}
 376 
 377         @Override
 378         public void curveTo(double x1, double y1,
 379                             double x2, double y2,
 380                             double x3, double y3)
 381         {
 382             p2d.curveTo(x1, y1, x2, y2, x3, y3);
 383         }
 384 
 385         @Override
 386         public void quadTo(double x1, double y1, double x2, double y2) {
 387             p2d.quadTo(x1, y1, x2, y2);
 388         }
 389 
 390         @Override
 391         public long getNativeConsumer() {
 392             throw new InternalError("Not using a native peer");
 393         }
 394     }
 395 
 396     static final class ClosedPathDetector implements DPathConsumer2D {
 397 
 398         private final DRendererContext rdrCtx;
 399         private final PolyStack stack;
 400 
 401         private DPathConsumer2D out;
 402 
 403         ClosedPathDetector(final DRendererContext rdrCtx) {
 404             this.rdrCtx = rdrCtx;
 405             this.stack = (rdrCtx.stats != null) ?
 406                 new PolyStack(rdrCtx,
 407                         rdrCtx.stats.stat_cpd_polystack_types,
 408                         rdrCtx.stats.stat_cpd_polystack_curves,
 409                         rdrCtx.stats.hist_cpd_polystack_curves,
 410                         rdrCtx.stats.stat_array_cpd_polystack_curves,
 411                         rdrCtx.stats.stat_array_cpd_polystack_types)
 412                 : new PolyStack(rdrCtx);
 413         }
 414 
 415         ClosedPathDetector init(DPathConsumer2D out) {
 416             this.out = out;
 417             return this; // fluent API
 418         }
 419 
 420         /**
 421          * Disposes this instance:
 422          * clean up before reusing this instance
 423          */
 424         void dispose() {
 425             stack.dispose();
 426         }
 427 
 428         @Override
 429         public void pathDone() {
 430             // previous path is not closed:
 431             finish(false);
 432             out.pathDone();
 433 
 434             // TODO: fix possible leak if exception happened
 435             // Dispose this instance:
 436             dispose();
 437         }
 438 
 439         @Override
 440         public void closePath() {
 441             // path is closed
 442             finish(true);
 443             out.closePath();
 444         }
 445 
 446         @Override
 447         public void moveTo(double x0, double y0) {
 448             // previous path is not closed:
 449             finish(false);
 450             out.moveTo(x0, y0);
 451         }
 452 
 453         private void finish(final boolean closed) {
 454             rdrCtx.closedPath = closed;
 455             stack.pullAll(out);
 456         }
 457 
 458         @Override
 459         public void lineTo(double x1, double y1) {
 460             stack.pushLine(x1, y1);
 461         }
 462 
 463         @Override
 464         public void curveTo(double x3, double y3,
 465                             double x2, double y2,
 466                             double x1, double y1)
 467         {
 468             stack.pushCubic(x1, y1, x2, y2, x3, y3);
 469         }
 470 
 471         @Override
 472         public void quadTo(double x2, double y2, double x1, double y1) {
 473             stack.pushQuad(x1, y1, x2, y2);
 474         }
 475 
 476         @Override
 477         public long getNativeConsumer() {
 478             throw new InternalError("Not using a native peer");
 479         }
 480     }
 481 
 482     static final class PathClipFilter implements DPathConsumer2D {
 483 
 484         private DPathConsumer2D out;
 485 
 486         // Bounds of the drawing region, at pixel precision.
 487         private final double[] clipRect;
 488 
 489         private final double[] corners = new double[8];
 490         private boolean init_corners = false;
 491 
 492         private final IndexStack stack;
 493 
 494         // the current outcode of the current sub path
 495         private int cOutCode = 0;
 496 
 497         // the cumulated (and) outcode of the complete path
 498         private int gOutCode = MarlinConst.OUTCODE_MASK_T_B_L_R;
 499 
 500         private boolean outside = false;
 501 
 502         // The current point OUTSIDE
 503         private double cx0, cy0;
 504 
 505         PathClipFilter(final DRendererContext rdrCtx) {
 506             this.clipRect = rdrCtx.clipRect;
 507             this.stack = (rdrCtx.stats != null) ?
 508                 new IndexStack(rdrCtx,
 509                         rdrCtx.stats.stat_pcf_idxstack_indices,
 510                         rdrCtx.stats.hist_pcf_idxstack_indices,
 511                         rdrCtx.stats.stat_array_pcf_idxstack_indices)
 512                 : new IndexStack(rdrCtx);
 513         }
 514 
 515         PathClipFilter init(final DPathConsumer2D out) {
 516             this.out = out;
 517 
 518             // Adjust the clipping rectangle with the renderer offsets
 519             final double rdrOffX = DRenderer.RDR_OFFSET_X;
 520             final double rdrOffY = DRenderer.RDR_OFFSET_Y;
 521 
 522             // add a small rounding error:
 523             final double margin = 1e-3d;
 524 
 525             final double[] _clipRect = this.clipRect;
 526             _clipRect[0] -= margin - rdrOffY;
 527             _clipRect[1] += margin + rdrOffY;
 528             _clipRect[2] -= margin - rdrOffX;
 529             _clipRect[3] += margin + rdrOffX;
 530 
 531             this.init_corners = true;
 532             this.gOutCode = MarlinConst.OUTCODE_MASK_T_B_L_R;
 533 
 534             return this; // fluent API
 535         }
 536 
 537         /**
 538          * Disposes this instance:
 539          * clean up before reusing this instance
 540          */
 541         void dispose() {
 542             stack.dispose();
 543         }
 544 
 545         private void finishPath() {
 546             if (outside) {
 547                 // criteria: inside or totally outside ?
 548                 if (gOutCode == 0) {
 549                     finish();
 550                 } else {
 551                     this.outside = false;
 552                     stack.reset();
 553                 }
 554             }
 555         }
 556 
 557         private void finish() {
 558             this.outside = false;
 559 
 560             if (!stack.isEmpty()) {
 561                 if (init_corners) {
 562                     init_corners = false;
 563 
 564                     final double[] _corners = corners;
 565                     final double[] _clipRect = clipRect;
 566                     // Top Left (0):
 567                     _corners[0] = _clipRect[2];
 568                     _corners[1] = _clipRect[0];
 569                     // Bottom Left (1):
 570                     _corners[2] = _clipRect[2];
 571                     _corners[3] = _clipRect[1];
 572                     // Top right (2):
 573                     _corners[4] = _clipRect[3];
 574                     _corners[5] = _clipRect[0];
 575                     // Bottom Right (3):
 576                     _corners[6] = _clipRect[3];
 577                     _corners[7] = _clipRect[1];
 578                 }
 579                 stack.pullAll(corners, out);
 580             }
 581             out.lineTo(cx0, cy0);
 582         }
 583 
 584         @Override
 585         public void pathDone() {
 586             finishPath();
 587 
 588             out.pathDone();
 589 
 590             // TODO: fix possible leak if exception happened
 591             // Dispose this instance:
 592             dispose();
 593         }
 594 
 595         @Override
 596         public void closePath() {
 597             finishPath();
 598 
 599             out.closePath();
 600         }
 601 
 602         @Override
 603         public void moveTo(final double x0, final double y0) {
 604             finishPath();
 605 
 606             final int outcode = DHelpers.outcode(x0, y0, clipRect);
 607             this.cOutCode = outcode;
 608             this.outside = false;
 609             out.moveTo(x0, y0);
 610         }
 611 
 612         @Override
 613         public void lineTo(final double xe, final double ye) {
 614             final int outcode0 = this.cOutCode;
 615             final int outcode1 = DHelpers.outcode(xe, ye, clipRect);
 616             this.cOutCode = outcode1;
 617 
 618             final int sideCode = (outcode0 & outcode1);
 619 
 620             // basic rejection criteria:
 621             if (sideCode == 0) {
 622                 this.gOutCode = 0;
 623             } else {
 624                 this.gOutCode &= sideCode;
 625                 // keep last point coordinate before entering the clip again:
 626                 this.outside = true;
 627                 this.cx0 = xe;
 628                 this.cy0 = ye;
 629 
 630                 clip(sideCode, outcode0, outcode1);
 631                 return;
 632             }
 633             if (outside) {
 634                 finish();
 635             }
 636             // clipping disabled:
 637             out.lineTo(xe, ye);
 638         }
 639 
 640         private void clip(final int sideCode,
 641                           final int outcode0,
 642                           final int outcode1)
 643         {
 644             // corner or cross-boundary on left or right side:
 645             if ((outcode0 != outcode1)
 646                     && ((sideCode & MarlinConst.OUTCODE_MASK_L_R) != 0))
 647             {
 648                 // combine outcodes:
 649                 final int mergeCode = (outcode0 | outcode1);
 650                 final int tbCode = mergeCode & MarlinConst.OUTCODE_MASK_T_B;
 651                 final int lrCode = mergeCode & MarlinConst.OUTCODE_MASK_L_R;
 652                 final int off = (lrCode == MarlinConst.OUTCODE_LEFT) ? 0 : 2;
 653 
 654                 // add corners to outside stack:
 655                 switch (tbCode) {
 656                     case MarlinConst.OUTCODE_TOP:
 657 // System.out.println("TOP "+ ((off == 0) ? "LEFT" : "RIGHT"));
 658                         stack.push(off); // top
 659                         return;
 660                     case MarlinConst.OUTCODE_BOTTOM:
 661 // System.out.println("BOTTOM "+ ((off == 0) ? "LEFT" : "RIGHT"));
 662                         stack.push(off + 1); // bottom
 663                         return;
 664                     default:
 665                         // both TOP / BOTTOM:
 666                         if ((outcode0 & MarlinConst.OUTCODE_TOP) != 0) {
 667 // System.out.println("TOP + BOTTOM "+ ((off == 0) ? "LEFT" : "RIGHT"));
 668                             // top to bottom
 669                             stack.push(off); // top
 670                             stack.push(off + 1); // bottom
 671                         } else {
 672 // System.out.println("BOTTOM + TOP "+ ((off == 0) ? "LEFT" : "RIGHT"));
 673                             // bottom to top
 674                             stack.push(off + 1); // bottom
 675                             stack.push(off); // top
 676                         }
 677                 }
 678             }
 679         }
 680 
 681         @Override
 682         public void curveTo(final double x1, final double y1,
 683                             final double x2, final double y2,
 684                             final double xe, final double ye)
 685         {
 686             final int outcode0 = this.cOutCode;
 687             final int outcode3 = DHelpers.outcode(xe, ye, clipRect);
 688             this.cOutCode = outcode3;
 689 
 690             int sideCode = outcode0 & outcode3;
 691 
 692             if (sideCode == 0) {
 693                 this.gOutCode = 0;
 694             } else {
 695                 sideCode &= DHelpers.outcode(x1, y1, clipRect);
 696                 sideCode &= DHelpers.outcode(x2, y2, clipRect);
 697                 this.gOutCode &= sideCode;
 698 
 699                 // basic rejection criteria:
 700                 if (sideCode != 0) {
 701                     // keep last point coordinate before entering the clip again:
 702                     this.outside = true;
 703                     this.cx0 = xe;
 704                     this.cy0 = ye;
 705 
 706                     clip(sideCode, outcode0, outcode3);
 707                     return;
 708                 }
 709             }
 710             if (outside) {
 711                 finish();
 712             }
 713             // clipping disabled:
 714             out.curveTo(x1, y1, x2, y2, xe, ye);
 715         }
 716 
 717         @Override
 718         public void quadTo(final double x1, final double y1,
 719                            final double xe, final double ye)
 720         {
 721             final int outcode0 = this.cOutCode;
 722             final int outcode2 = DHelpers.outcode(xe, ye, clipRect);
 723             this.cOutCode = outcode2;
 724 
 725             int sideCode = outcode0 & outcode2;
 726 
 727             if (sideCode == 0) {
 728                 this.gOutCode = 0;
 729             } else {
 730                 sideCode &= DHelpers.outcode(x1, y1, clipRect);
 731                 this.gOutCode &= sideCode;
 732 
 733                 // basic rejection criteria:
 734                 if (sideCode != 0) {
 735                     // keep last point coordinate before entering the clip again:
 736                     this.outside = true;
 737                     this.cx0 = xe;
 738                     this.cy0 = ye;
 739 
 740                     clip(sideCode, outcode0, outcode2);
 741                     return;
 742                 }
 743             }
 744             if (outside) {
 745                 finish();
 746             }
 747             // clipping disabled:
 748             out.quadTo(x1, y1, xe, ye);
 749         }
 750 
 751         @Override
 752         public long getNativeConsumer() {
 753             throw new InternalError("Not using a native peer");
 754         }
 755     }
 756 
 757     static final class PathTracer implements DPathConsumer2D {
 758         private final String prefix;
 759         private DPathConsumer2D out;
 760 
 761         PathTracer(String name) {
 762             this.prefix = name + ": ";
 763         }
 764 
 765         PathTracer init(DPathConsumer2D out) {
 766             this.out = out;
 767             return this; // fluent API
 768         }
 769 
 770         @Override
 771         public void moveTo(double x0, double y0) {
 772             log("moveTo (" + x0 + ", " + y0 + ')');
 773             out.moveTo(x0, y0);
 774         }
 775 
 776         @Override
 777         public void lineTo(double x1, double y1) {
 778             log("lineTo (" + x1 + ", " + y1 + ')');
 779             out.lineTo(x1, y1);
 780         }
 781 
 782         @Override
 783         public void curveTo(double x1, double y1,
 784                             double x2, double y2,
 785                             double x3, double y3)
 786         {
 787             log("curveTo P1(" + x1 + ", " + y1 + ") P2(" + x2 + ", " + y2  + ") P3(" + x3 + ", " + y3 + ')');
 788             out.curveTo(x1, y1, x2, y2, x3, y3);
 789         }
 790 
 791         @Override
 792         public void quadTo(double x1, double y1, double x2, double y2) {
 793             log("quadTo P1(" + x1 + ", " + y1 + ") P2(" + x2 + ", " + y2  + ')');
 794             out.quadTo(x1, y1, x2, y2);
 795         }
 796 
 797         @Override
 798         public void closePath() {
 799             log("closePath");
 800             out.closePath();
 801         }
 802 
 803         @Override
 804         public void pathDone() {
 805             log("pathDone");
 806             out.pathDone();
 807         }
 808 
 809         private void log(final String message) {
 810             System.out.println(prefix + message);
 811         }
 812 
 813         @Override
 814         public long getNativeConsumer() {
 815             throw new InternalError("Not using a native peer");
 816         }
 817     }
 818 }