1 /*
   2  * Copyright (c) 2007, 2016, 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.util.Arrays;
  29 import sun.awt.geom.PathConsumer2D;
  30 
  31 /**
  32  * The <code>Dasher</code> class takes a series of linear commands
  33  * (<code>moveTo</code>, <code>lineTo</code>, <code>close</code> and
  34  * <code>end</code>) and breaks them into smaller segments according to a
  35  * dash pattern array and a starting dash phase.
  36  *
  37  * <p> Issues: in J2Se, a zero length dash segment as drawn as a very
  38  * short dash, whereas Pisces does not draw anything.  The PostScript
  39  * semantics are unclear.
  40  *
  41  */
  42 final class Dasher implements sun.awt.geom.PathConsumer2D, MarlinConst {
  43 
  44     static final int REC_LIMIT = 4;
  45     static final float ERR = 0.01f;
  46     static final float MIN_T_INC = 1f / (1 << REC_LIMIT);
  47 
  48     private PathConsumer2D out;
  49     private float[] dash;
  50     private int dashLen;
  51     private float startPhase;
  52     private boolean startDashOn;
  53     private int startIdx;
  54 
  55     private boolean starting;
  56     private boolean needsMoveTo;
  57 
  58     private int idx;
  59     private boolean dashOn;
  60     private float phase;
  61 
  62     private float sx, sy;
  63     private float x0, y0;
  64 
  65     // temporary storage for the current curve
  66     private final float[] curCurvepts;
  67 
  68     // per-thread renderer context
  69     final RendererContext rdrCtx;
  70 
  71     // flag to recycle dash array copy
  72     boolean recycleDashes;
  73 
  74     // dashes ref (dirty)
  75     final FloatArrayCache.Reference dashes_ref;
  76     // firstSegmentsBuffer ref (dirty)
  77     final FloatArrayCache.Reference firstSegmentsBuffer_ref;
  78 
  79     /**
  80      * Constructs a <code>Dasher</code>.
  81      * @param rdrCtx per-thread renderer context
  82      */
  83     Dasher(final RendererContext rdrCtx) {
  84         this.rdrCtx = rdrCtx;
  85 
  86         dashes_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
  87 
  88         firstSegmentsBuffer_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
  89         firstSegmentsBuffer     = firstSegmentsBuffer_ref.initial;
  90 
  91         // we need curCurvepts to be able to contain 2 curves because when
  92         // dashing curves, we need to subdivide it
  93         curCurvepts = new float[8 * 2];
  94     }
  95 
  96     /**
  97      * Initialize the <code>Dasher</code>.
  98      *
  99      * @param out an output <code>PathConsumer2D</code>.
 100      * @param dash an array of <code>float</code>s containing the dash pattern
 101      * @param dashLen length of the given dash array
 102      * @param phase a <code>float</code> containing the dash phase
 103      * @param recycleDashes true to indicate to recycle the given dash array
 104      * @return this instance
 105      */
 106     Dasher init(final PathConsumer2D out, float[] dash, int dashLen,
 107                 float phase, boolean recycleDashes)
 108     {
 109         if (phase < 0f) {
 110             throw new IllegalArgumentException("phase < 0 !");
 111         }
 112         this.out = out;
 113 
 114         // Normalize so 0 <= phase < dash[0]
 115         int idx = 0;
 116         dashOn = true;
 117         float d;
 118         while (phase >= (d = dash[idx])) {
 119             phase -= d;
 120             idx = (idx + 1) % dashLen;
 121             dashOn = !dashOn;
 122         }
 123 
 124         this.dash = dash;
 125         this.dashLen = dashLen;
 126         this.startPhase = this.phase = phase;
 127         this.startDashOn = dashOn;
 128         this.startIdx = idx;
 129         this.starting = true;
 130         needsMoveTo = false;
 131         firstSegidx = 0;
 132 
 133         this.recycleDashes = recycleDashes;
 134 
 135         return this; // fluent API
 136     }
 137 
 138     /**
 139      * Disposes this dasher:
 140      * clean up before reusing this instance
 141      */
 142     void dispose() {
 143         if (DO_CLEAN_DIRTY) {
 144             // Force zero-fill dirty arrays:
 145             Arrays.fill(curCurvepts, 0f);
 146         }
 147         // Return arrays:
 148         if (recycleDashes) {
 149             dash = dashes_ref.putArray(dash);
 150         }
 151         firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer);
 152     }
 153 
 154     @Override
 155     public void moveTo(float x0, float y0) {
 156         if (firstSegidx > 0) {
 157             out.moveTo(sx, sy);
 158             emitFirstSegments();
 159         }
 160         needsMoveTo = true;
 161         this.idx = startIdx;
 162         this.dashOn = this.startDashOn;
 163         this.phase = this.startPhase;
 164         this.sx = this.x0 = x0;
 165         this.sy = this.y0 = y0;
 166         this.starting = true;
 167     }
 168 
 169     private void emitSeg(float[] buf, int off, int type) {
 170         switch (type) {
 171         case 8:
 172             out.curveTo(buf[off+0], buf[off+1],
 173                         buf[off+2], buf[off+3],
 174                         buf[off+4], buf[off+5]);
 175             return;
 176         case 6:
 177             out.quadTo(buf[off+0], buf[off+1],
 178                        buf[off+2], buf[off+3]);
 179             return;
 180         case 4:
 181             out.lineTo(buf[off], buf[off+1]);
 182             return;
 183         default:
 184         }
 185     }
 186 
 187     private void emitFirstSegments() {
 188         final float[] fSegBuf = firstSegmentsBuffer;
 189 
 190         for (int i = 0; i < firstSegidx; ) {
 191             int type = (int)fSegBuf[i];
 192             emitSeg(fSegBuf, i + 1, type);
 193             i += (type - 1);
 194         }
 195         firstSegidx = 0;
 196     }
 197     // We don't emit the first dash right away. If we did, caps would be
 198     // drawn on it, but we need joins to be drawn if there's a closePath()
 199     // So, we store the path elements that make up the first dash in the
 200     // buffer below.
 201     private float[] firstSegmentsBuffer; // dynamic array
 202     private int firstSegidx;
 203 
 204     // precondition: pts must be in relative coordinates (relative to x0,y0)
 205     // fullCurve is true iff the curve in pts has not been split.
 206     private void goTo(float[] pts, int off, final int type) {
 207         float x = pts[off + type - 4];
 208         float y = pts[off + type - 3];
 209         if (dashOn) {
 210             if (starting) {
 211                 int len = type - 2 + 1;
 212                 int segIdx = firstSegidx;
 213                 float[] buf = firstSegmentsBuffer;
 214                 if (segIdx + len  > buf.length) {
 215                     if (DO_STATS) {
 216                         rdrCtx.stats.stat_array_dasher_firstSegmentsBuffer
 217                             .add(segIdx + len);
 218                     }
 219                     firstSegmentsBuffer = buf
 220                         = firstSegmentsBuffer_ref.widenArray(buf, segIdx,
 221                                                              segIdx + len);
 222                 }
 223                 buf[segIdx++] = type;
 224                 len--;
 225                 // small arraycopy (2, 4 or 6) but with offset:
 226                 System.arraycopy(pts, off, buf, segIdx, len);
 227                 segIdx += len;
 228                 firstSegidx = segIdx;
 229             } else {
 230                 if (needsMoveTo) {
 231                     out.moveTo(x0, y0);
 232                     needsMoveTo = false;
 233                 }
 234                 emitSeg(pts, off, type);
 235             }
 236         } else {
 237             starting = false;
 238             needsMoveTo = true;
 239         }
 240         this.x0 = x;
 241         this.y0 = y;
 242     }
 243 
 244     @Override
 245     public void lineTo(float x1, float y1) {
 246         float dx = x1 - x0;
 247         float dy = y1 - y0;
 248 
 249         float len = dx*dx + dy*dy;
 250         if (len == 0f) {
 251             return;
 252         }
 253         len = (float) Math.sqrt(len);
 254 
 255         // The scaling factors needed to get the dx and dy of the
 256         // transformed dash segments.
 257         final float cx = dx / len;
 258         final float cy = dy / len;
 259 
 260         final float[] _curCurvepts = curCurvepts;
 261         final float[] _dash = dash;
 262 
 263         float leftInThisDashSegment;
 264         float dashdx, dashdy, p;
 265 
 266         while (true) {
 267             leftInThisDashSegment = _dash[idx] - phase;
 268 
 269             if (len <= leftInThisDashSegment) {
 270                 _curCurvepts[0] = x1;
 271                 _curCurvepts[1] = y1;
 272                 goTo(_curCurvepts, 0, 4);
 273 
 274                 // Advance phase within current dash segment
 275                 phase += len;
 276                 // TODO: compare float values using epsilon:
 277                 if (len == leftInThisDashSegment) {
 278                     phase = 0f;
 279                     idx = (idx + 1) % dashLen;
 280                     dashOn = !dashOn;
 281                 }
 282                 return;
 283             }
 284 
 285             dashdx = _dash[idx] * cx;
 286             dashdy = _dash[idx] * cy;
 287 
 288             if (phase == 0f) {
 289                 _curCurvepts[0] = x0 + dashdx;
 290                 _curCurvepts[1] = y0 + dashdy;
 291             } else {
 292                 p = leftInThisDashSegment / _dash[idx];
 293                 _curCurvepts[0] = x0 + p * dashdx;
 294                 _curCurvepts[1] = y0 + p * dashdy;
 295             }
 296 
 297             goTo(_curCurvepts, 0, 4);
 298 
 299             len -= leftInThisDashSegment;
 300             // Advance to next dash segment
 301             idx = (idx + 1) % dashLen;
 302             dashOn = !dashOn;
 303             phase = 0f;
 304         }
 305     }
 306 
 307     // shared instance in Dasher
 308     private final LengthIterator li = new LengthIterator();
 309 
 310     // preconditions: curCurvepts must be an array of length at least 2 * type,
 311     // that contains the curve we want to dash in the first type elements
 312     private void somethingTo(int type) {
 313         if (pointCurve(curCurvepts, type)) {
 314             return;
 315         }
 316         li.initializeIterationOnCurve(curCurvepts, type);
 317 
 318         // initially the current curve is at curCurvepts[0...type]
 319         int curCurveoff = 0;
 320         float lastSplitT = 0f;
 321         float t;
 322         float leftInThisDashSegment = dash[idx] - phase;
 323 
 324         while ((t = li.next(leftInThisDashSegment)) < 1f) {
 325             if (t != 0f) {
 326                 Helpers.subdivideAt((t - lastSplitT) / (1f - lastSplitT),
 327                                     curCurvepts, curCurveoff,
 328                                     curCurvepts, 0,
 329                                     curCurvepts, type, type);
 330                 lastSplitT = t;
 331                 goTo(curCurvepts, 2, type);
 332                 curCurveoff = type;
 333             }
 334             // Advance to next dash segment
 335             idx = (idx + 1) % dashLen;
 336             dashOn = !dashOn;
 337             phase = 0f;
 338             leftInThisDashSegment = dash[idx];
 339         }
 340         goTo(curCurvepts, curCurveoff+2, type);
 341         phase += li.lastSegLen();
 342         if (phase >= dash[idx]) {
 343             phase = 0f;
 344             idx = (idx + 1) % dashLen;
 345             dashOn = !dashOn;
 346         }
 347         // reset LengthIterator:
 348         li.reset();
 349     }
 350 
 351     private static boolean pointCurve(float[] curve, int type) {
 352         for (int i = 2; i < type; i++) {
 353             if (curve[i] != curve[i-2]) {
 354                 return false;
 355             }
 356         }
 357         return true;
 358     }
 359 
 360     // Objects of this class are used to iterate through curves. They return
 361     // t values where the left side of the curve has a specified length.
 362     // It does this by subdividing the input curve until a certain error
 363     // condition has been met. A recursive subdivision procedure would
 364     // return as many as 1<<limit curves, but this is an iterator and we
 365     // don't need all the curves all at once, so what we carry out a
 366     // lazy inorder traversal of the recursion tree (meaning we only move
 367     // through the tree when we need the next subdivided curve). This saves
 368     // us a lot of memory because at any one time we only need to store
 369     // limit+1 curves - one for each level of the tree + 1.
 370     // NOTE: the way we do things here is not enough to traverse a general
 371     // tree; however, the trees we are interested in have the property that
 372     // every non leaf node has exactly 2 children
 373     static final class LengthIterator {
 374         private enum Side {LEFT, RIGHT};
 375         // Holds the curves at various levels of the recursion. The root
 376         // (i.e. the original curve) is at recCurveStack[0] (but then it
 377         // gets subdivided, the left half is put at 1, so most of the time
 378         // only the right half of the original curve is at 0)
 379         private final float[][] recCurveStack; // dirty
 380         // sides[i] indicates whether the node at level i+1 in the path from
 381         // the root to the current leaf is a left or right child of its parent.
 382         private final Side[] sides; // dirty
 383         private int curveType;
 384         // lastT and nextT delimit the current leaf.
 385         private float nextT;
 386         private float lenAtNextT;
 387         private float lastT;
 388         private float lenAtLastT;
 389         private float lenAtLastSplit;
 390         private float lastSegLen;
 391         // the current level in the recursion tree. 0 is the root. limit
 392         // is the deepest possible leaf.
 393         private int recLevel;
 394         private boolean done;
 395 
 396         // the lengths of the lines of the control polygon. Only its first
 397         // curveType/2 - 1 elements are valid. This is an optimization. See
 398         // next(float) for more detail.
 399         private final float[] curLeafCtrlPolyLengths = new float[3];
 400 
 401         LengthIterator() {
 402             this.recCurveStack = new float[REC_LIMIT + 1][8];
 403             this.sides = new Side[REC_LIMIT];
 404             // if any methods are called without first initializing this object
 405             // on a curve, we want it to fail ASAP.
 406             this.nextT = Float.MAX_VALUE;
 407             this.lenAtNextT = Float.MAX_VALUE;
 408             this.lenAtLastSplit = Float.MIN_VALUE;
 409             this.recLevel = Integer.MIN_VALUE;
 410             this.lastSegLen = Float.MAX_VALUE;
 411             this.done = true;
 412         }
 413 
 414         /**
 415          * Reset this LengthIterator.
 416          */
 417         void reset() {
 418             // keep data dirty
 419             // as it appears not useful to reset data:
 420             if (DO_CLEAN_DIRTY) {
 421                 final int recLimit = recCurveStack.length - 1;
 422                 for (int i = recLimit; i >= 0; i--) {
 423                     Arrays.fill(recCurveStack[i], 0f);
 424                 }
 425                 Arrays.fill(sides, Side.LEFT);
 426                 Arrays.fill(curLeafCtrlPolyLengths, 0f);
 427                 Arrays.fill(nextRoots, 0f);
 428                 Arrays.fill(flatLeafCoefCache, 0f);
 429                 flatLeafCoefCache[2] = -1f;
 430             }
 431         }
 432 
 433         void initializeIterationOnCurve(float[] pts, int type) {
 434             // optimize arraycopy (8 values faster than 6 = type):
 435             System.arraycopy(pts, 0, recCurveStack[0], 0, 8);
 436             this.curveType = type;
 437             this.recLevel = 0;
 438             this.lastT = 0f;
 439             this.lenAtLastT = 0f;
 440             this.nextT = 0f;
 441             this.lenAtNextT = 0f;
 442             goLeft(); // initializes nextT and lenAtNextT properly
 443             this.lenAtLastSplit = 0f;
 444             if (recLevel > 0) {
 445                 this.sides[0] = Side.LEFT;
 446                 this.done = false;
 447             } else {
 448                 // the root of the tree is a leaf so we're done.
 449                 this.sides[0] = Side.RIGHT;
 450                 this.done = true;
 451             }
 452             this.lastSegLen = 0f;
 453         }
 454 
 455         // 0 == false, 1 == true, -1 == invalid cached value.
 456         private int cachedHaveLowAcceleration = -1;
 457 
 458         private boolean haveLowAcceleration(float err) {
 459             if (cachedHaveLowAcceleration == -1) {
 460                 final float len1 = curLeafCtrlPolyLengths[0];
 461                 final float len2 = curLeafCtrlPolyLengths[1];
 462                 // the test below is equivalent to !within(len1/len2, 1, err).
 463                 // It is using a multiplication instead of a division, so it
 464                 // should be a bit faster.
 465                 if (!Helpers.within(len1, len2, err*len2)) {
 466                     cachedHaveLowAcceleration = 0;
 467                     return false;
 468                 }
 469                 if (curveType == 8) {
 470                     final float len3 = curLeafCtrlPolyLengths[2];
 471                     // if len1 is close to 2 and 2 is close to 3, that probably
 472                     // means 1 is close to 3 so the second part of this test might
 473                     // not be needed, but it doesn't hurt to include it.
 474                     final float errLen3 = err * len3;
 475                     if (!(Helpers.within(len2, len3, errLen3) &&
 476                           Helpers.within(len1, len3, errLen3))) {
 477                         cachedHaveLowAcceleration = 0;
 478                         return false;
 479                     }
 480                 }
 481                 cachedHaveLowAcceleration = 1;
 482                 return true;
 483             }
 484 
 485             return (cachedHaveLowAcceleration == 1);
 486         }
 487 
 488         // we want to avoid allocations/gc so we keep this array so we
 489         // can put roots in it,
 490         private final float[] nextRoots = new float[4];
 491 
 492         // caches the coefficients of the current leaf in its flattened
 493         // form (see inside next() for what that means). The cache is
 494         // invalid when it's third element is negative, since in any
 495         // valid flattened curve, this would be >= 0.
 496         private final float[] flatLeafCoefCache = new float[]{0f, 0f, -1f, 0f};
 497 
 498         // returns the t value where the remaining curve should be split in
 499         // order for the left subdivided curve to have length len. If len
 500         // is >= than the length of the uniterated curve, it returns 1.
 501         float next(final float len) {
 502             final float targetLength = lenAtLastSplit + len;
 503             while (lenAtNextT < targetLength) {
 504                 if (done) {
 505                     lastSegLen = lenAtNextT - lenAtLastSplit;
 506                     return 1f;
 507                 }
 508                 goToNextLeaf();
 509             }
 510             lenAtLastSplit = targetLength;
 511             final float leaflen = lenAtNextT - lenAtLastT;
 512             float t = (targetLength - lenAtLastT) / leaflen;
 513 
 514             // cubicRootsInAB is a fairly expensive call, so we just don't do it
 515             // if the acceleration in this section of the curve is small enough.
 516             if (!haveLowAcceleration(0.05f)) {
 517                 // We flatten the current leaf along the x axis, so that we're
 518                 // left with a, b, c which define a 1D Bezier curve. We then
 519                 // solve this to get the parameter of the original leaf that
 520                 // gives us the desired length.
 521                 final float[] _flatLeafCoefCache = flatLeafCoefCache;
 522 
 523                 if (_flatLeafCoefCache[2] < 0) {
 524                     float x = 0f + curLeafCtrlPolyLengths[0],
 525                           y = x  + curLeafCtrlPolyLengths[1];
 526                     if (curveType == 8) {
 527                         float z = y + curLeafCtrlPolyLengths[2];
 528                         _flatLeafCoefCache[0] = 3f * (x - y) + z;
 529                         _flatLeafCoefCache[1] = 3f * (y - 2f * x);
 530                         _flatLeafCoefCache[2] = 3f * x;
 531                         _flatLeafCoefCache[3] = -z;
 532                     } else if (curveType == 6) {
 533                         _flatLeafCoefCache[0] = 0f;
 534                         _flatLeafCoefCache[1] = y - 2f * x;
 535                         _flatLeafCoefCache[2] = 2f * x;
 536                         _flatLeafCoefCache[3] = -y;
 537                     }
 538                 }
 539                 float a = _flatLeafCoefCache[0];
 540                 float b = _flatLeafCoefCache[1];
 541                 float c = _flatLeafCoefCache[2];
 542                 float d = t * _flatLeafCoefCache[3];
 543 
 544                 // we use cubicRootsInAB here, because we want only roots in 0, 1,
 545                 // and our quadratic root finder doesn't filter, so it's just a
 546                 // matter of convenience.
 547                 int n = Helpers.cubicRootsInAB(a, b, c, d, nextRoots, 0, 0, 1);
 548                 if (n == 1 && !Float.isNaN(nextRoots[0])) {
 549                     t = nextRoots[0];
 550                 }
 551             }
 552             // t is relative to the current leaf, so we must make it a valid parameter
 553             // of the original curve.
 554             t = t * (nextT - lastT) + lastT;
 555             if (t >= 1f) {
 556                 t = 1f;
 557                 done = true;
 558             }
 559             // even if done = true, if we're here, that means targetLength
 560             // is equal to, or very, very close to the total length of the
 561             // curve, so lastSegLen won't be too high. In cases where len
 562             // overshoots the curve, this method will exit in the while
 563             // loop, and lastSegLen will still be set to the right value.
 564             lastSegLen = len;
 565             return t;
 566         }
 567 
 568         float lastSegLen() {
 569             return lastSegLen;
 570         }
 571 
 572         // go to the next leaf (in an inorder traversal) in the recursion tree
 573         // preconditions: must be on a leaf, and that leaf must not be the root.
 574         private void goToNextLeaf() {
 575             // We must go to the first ancestor node that has an unvisited
 576             // right child.
 577             int _recLevel = recLevel;
 578             final Side[] _sides = sides;
 579 
 580             _recLevel--;
 581             while(_sides[_recLevel] == Side.RIGHT) {
 582                 if (_recLevel == 0) {
 583                     recLevel = 0;
 584                     done = true;
 585                     return;
 586                 }
 587                 _recLevel--;
 588             }
 589 
 590             _sides[_recLevel] = Side.RIGHT;
 591             // optimize arraycopy (8 values faster than 6 = type):
 592             System.arraycopy(recCurveStack[_recLevel], 0,
 593                              recCurveStack[_recLevel+1], 0, 8);
 594             _recLevel++;
 595 
 596             recLevel = _recLevel;
 597             goLeft();
 598         }
 599 
 600         // go to the leftmost node from the current node. Return its length.
 601         private void goLeft() {
 602             float len = onLeaf();
 603             if (len >= 0f) {
 604                 lastT = nextT;
 605                 lenAtLastT = lenAtNextT;
 606                 nextT += (1 << (REC_LIMIT - recLevel)) * MIN_T_INC;
 607                 lenAtNextT += len;
 608                 // invalidate caches
 609                 flatLeafCoefCache[2] = -1f;
 610                 cachedHaveLowAcceleration = -1;
 611             } else {
 612                 Helpers.subdivide(recCurveStack[recLevel], 0,
 613                                   recCurveStack[recLevel+1], 0,
 614                                   recCurveStack[recLevel], 0, curveType);
 615                 sides[recLevel] = Side.LEFT;
 616                 recLevel++;
 617                 goLeft();
 618             }
 619         }
 620 
 621         // this is a bit of a hack. It returns -1 if we're not on a leaf, and
 622         // the length of the leaf if we are on a leaf.
 623         private float onLeaf() {
 624             float[] curve = recCurveStack[recLevel];
 625             float polyLen = 0f;
 626 
 627             float x0 = curve[0], y0 = curve[1];
 628             for (int i = 2; i < curveType; i += 2) {
 629                 final float x1 = curve[i], y1 = curve[i+1];
 630                 final float len = Helpers.linelen(x0, y0, x1, y1);
 631                 polyLen += len;
 632                 curLeafCtrlPolyLengths[i/2 - 1] = len;
 633                 x0 = x1;
 634                 y0 = y1;
 635             }
 636 
 637             final float lineLen = Helpers.linelen(curve[0], curve[1],
 638                                                   curve[curveType-2],
 639                                                   curve[curveType-1]);
 640             if ((polyLen - lineLen) < ERR || recLevel == REC_LIMIT) {
 641                 return (polyLen + lineLen) / 2f;
 642             }
 643             return -1f;
 644         }
 645     }
 646 
 647     @Override
 648     public void curveTo(float x1, float y1,
 649                         float x2, float y2,
 650                         float x3, float y3)
 651     {
 652         final float[] _curCurvepts = curCurvepts;
 653         _curCurvepts[0] = x0;        _curCurvepts[1] = y0;
 654         _curCurvepts[2] = x1;        _curCurvepts[3] = y1;
 655         _curCurvepts[4] = x2;        _curCurvepts[5] = y2;
 656         _curCurvepts[6] = x3;        _curCurvepts[7] = y3;
 657         somethingTo(8);
 658     }
 659 
 660     @Override
 661     public void quadTo(float x1, float y1, float x2, float y2) {
 662         final float[] _curCurvepts = curCurvepts;
 663         _curCurvepts[0] = x0;        _curCurvepts[1] = y0;
 664         _curCurvepts[2] = x1;        _curCurvepts[3] = y1;
 665         _curCurvepts[4] = x2;        _curCurvepts[5] = y2;
 666         somethingTo(6);
 667     }
 668 
 669     @Override
 670     public void closePath() {
 671         lineTo(sx, sy);
 672         if (firstSegidx > 0) {
 673             if (!dashOn || needsMoveTo) {
 674                 out.moveTo(sx, sy);
 675             }
 676             emitFirstSegments();
 677         }
 678         moveTo(sx, sy);
 679     }
 680 
 681     @Override
 682     public void pathDone() {
 683         if (firstSegidx > 0) {
 684             out.moveTo(sx, sy);
 685             emitFirstSegments();
 686         }
 687         out.pathDone();
 688 
 689         // Dispose this instance:
 690         dispose();
 691     }
 692 
 693     @Override
 694     public long getNativeConsumer() {
 695         throw new InternalError("Dasher does not use a native consumer");
 696     }
 697 }
 698