1 /*
2 * Copyright (c) 2007, 2018, 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 import sun.java2d.marlin.TransformingPathConsumer2D.CurveBasicMonotonizer;
31 import sun.java2d.marlin.TransformingPathConsumer2D.CurveClipSplitter;
32
33 /**
34 * The <code>Dasher</code> class takes a series of linear commands
35 * (<code>moveTo</code>, <code>lineTo</code>, <code>close</code> and
36 * <code>end</code>) and breaks them into smaller segments according to a
37 * dash pattern array and a starting dash phase.
38 *
39 * <p> Issues: in J2Se, a zero length dash segment as drawn as a very
40 * short dash, whereas Pisces does not draw anything. The PostScript
41 * semantics are unclear.
42 *
43 */
44 final class Dasher implements PathConsumer2D, MarlinConst {
45
46 /* huge circle with radius ~ 2E9 only needs 12 subdivision levels */
47 static final int REC_LIMIT = 16;
48 static final float CURVE_LEN_ERR = MarlinProperties.getCurveLengthError(); // 0.01
49 static final float MIN_T_INC = 1.0f / (1 << REC_LIMIT);
50
51 static final float EPS = 1e-6f;
52
53 // More than 24 bits of mantissa means we can no longer accurately
54 // measure the number of times cycled through the dash array so we
55 // punt and override the phase to just be 0 past that point.
56 static final float MAX_CYCLES = 16000000.0f;
57
58 private PathConsumer2D out;
59 private float[] dash;
60 private int dashLen;
61 private float startPhase;
62 private boolean startDashOn;
63 private int startIdx;
64
65 private boolean starting;
66 private boolean needsMoveTo;
67
68 private int idx;
69 private boolean dashOn;
70 private float phase;
71
72 // The starting point of the path
73 private float sx0, sy0;
74 // the current point
75 private float cx0, cy0;
76
77 // temporary storage for the current curve
78 private final float[] curCurvepts;
79
80 // per-thread renderer context
81 final RendererContext rdrCtx;
82
83 // flag to recycle dash array copy
84 boolean recycleDashes;
85
86 // We don't emit the first dash right away. If we did, caps would be
87 // drawn on it, but we need joins to be drawn if there's a closePath()
88 // So, we store the path elements that make up the first dash in the
89 // buffer below.
90 private float[] firstSegmentsBuffer; // dynamic array
91 private int firstSegidx;
92
93 // dashes ref (dirty)
94 final FloatArrayCache.Reference dashes_ref;
95 // firstSegmentsBuffer ref (dirty)
96 final FloatArrayCache.Reference firstSegmentsBuffer_ref;
97
98 // Bounds of the drawing region, at pixel precision.
99 private float[] clipRect;
100
101 // the outcode of the current point
102 private int cOutCode = 0;
103
104 private boolean subdivide = DO_CLIP_SUBDIVIDER;
105
106 private final LengthIterator li = new LengthIterator();
107
108 private final CurveClipSplitter curveSplitter;
109
110 private float cycleLen;
111 private boolean outside;
112 private float totalSkipLen;
113
114 /**
115 * Constructs a <code>Dasher</code>.
116 * @param rdrCtx per-thread renderer context
117 */
118 Dasher(final RendererContext rdrCtx) {
119 this.rdrCtx = rdrCtx;
120
121 dashes_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
122
123 firstSegmentsBuffer_ref = rdrCtx.newDirtyFloatArrayRef(INITIAL_ARRAY); // 1K
124 firstSegmentsBuffer = firstSegmentsBuffer_ref.initial;
125
126 // we need curCurvepts to be able to contain 2 curves because when
127 // dashing curves, we need to subdivide it
128 curCurvepts = new float[8 * 2];
129
130 this.curveSplitter = rdrCtx.curveClipSplitter;
131 }
132
133 /**
134 * Initialize the <code>Dasher</code>.
135 *
136 * @param out an output <code>PathConsumer2D</code>.
137 * @param dash an array of <code>float</code>s containing the dash pattern
138 * @param dashLen length of the given dash array
139 * @param phase a <code>float</code> containing the dash phase
140 * @param recycleDashes true to indicate to recycle the given dash array
141 * @return this instance
142 */
143 Dasher init(final PathConsumer2D out, final float[] dash, final int dashLen,
144 float phase, final boolean recycleDashes)
145 {
146 this.out = out;
147
148 // Normalize so 0 <= phase < dash[0]
149 int sidx = 0;
150 dashOn = true;
151
152 // note: BasicStroke constructor checks dash elements and sum > 0
153 float sum = 0.0f;
154 for (int i = 0; i < dashLen; i++) {
155 sum += dash[i];
156 }
157 this.cycleLen = sum;
158
159 float cycles = phase / sum;
160 if (phase < 0.0f) {
161 if (-cycles >= MAX_CYCLES) {
162 phase = 0.0f;
163 } else {
164 int fullcycles = FloatMath.floor_int(-cycles);
165 if ((fullcycles & dashLen & 1) != 0) {
166 dashOn = !dashOn;
167 }
168 phase += fullcycles * sum;
169 while (phase < 0.0f) {
170 if (--sidx < 0) {
171 sidx = dashLen - 1;
172 }
173 phase += dash[sidx];
174 dashOn = !dashOn;
175 }
176 }
177 } else if (phase > 0.0f) {
178 if (cycles >= MAX_CYCLES) {
179 phase = 0.0f;
180 } else {
181 int fullcycles = FloatMath.floor_int(cycles);
182 if ((fullcycles & dashLen & 1) != 0) {
183 dashOn = !dashOn;
184 }
185 phase -= fullcycles * sum;
186 float d;
187 while (phase >= (d = dash[sidx])) {
188 phase -= d;
189 sidx = (sidx + 1) % dashLen;
190 dashOn = !dashOn;
191 }
192 }
193 }
194
195 this.dash = dash;
196 this.dashLen = dashLen;
197 this.phase = phase;
198 this.startPhase = phase;
199 this.startDashOn = dashOn;
200 this.startIdx = sidx;
201 this.starting = true;
202 this.needsMoveTo = false;
203 this.firstSegidx = 0;
204
205 this.recycleDashes = recycleDashes;
206
207 if (rdrCtx.doClip) {
208 this.clipRect = rdrCtx.clipRect;
209 } else {
210 this.clipRect = null;
211 this.cOutCode = 0;
212 }
213 return this; // fluent API
214 }
215
216 /**
217 * Disposes this dasher:
218 * clean up before reusing this instance
219 */
220 void dispose() {
221 if (DO_CLEAN_DIRTY) {
222 // Force zero-fill dirty arrays:
223 Arrays.fill(curCurvepts, 0.0f);
224 }
225 // Return arrays:
226 if (recycleDashes) {
227 dash = dashes_ref.putArray(dash);
228 }
229 firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer);
230 }
231
232 float[] copyDashArray(final float[] dashes) {
233 final int len = dashes.length;
234 final float[] newDashes;
235 if (len <= MarlinConst.INITIAL_ARRAY) {
236 newDashes = dashes_ref.initial;
237 } else {
238 if (DO_STATS) {
239 rdrCtx.stats.stat_array_dasher_dasher.add(len);
240 }
241 newDashes = dashes_ref.getArray(len);
242 }
243 System.arraycopy(dashes, 0, newDashes, 0, len);
244 return newDashes;
245 }
246
247 @Override
248 public void moveTo(final float x0, final float y0) {
249 if (firstSegidx != 0) {
250 out.moveTo(sx0, sy0);
251 emitFirstSegments();
252 }
253 this.needsMoveTo = true;
254 this.idx = startIdx;
255 this.dashOn = this.startDashOn;
256 this.phase = this.startPhase;
257 this.cx0 = x0;
258 this.cy0 = y0;
259
260 // update starting point:
261 this.sx0 = x0;
262 this.sy0 = y0;
263 this.starting = true;
264
265 if (clipRect != null) {
266 final int outcode = Helpers.outcode(x0, y0, clipRect);
267 this.cOutCode = outcode;
268 this.outside = false;
269 this.totalSkipLen = 0.0f;
270 }
271 }
272
273 private void emitSeg(float[] buf, int off, int type) {
274 switch (type) {
275 case 4:
276 out.lineTo(buf[off], buf[off + 1]);
277 return;
278 case 8:
279 out.curveTo(buf[off ], buf[off + 1],
280 buf[off + 2], buf[off + 3],
281 buf[off + 4], buf[off + 5]);
282 return;
283 case 6:
284 out.quadTo(buf[off ], buf[off + 1],
285 buf[off + 2], buf[off + 3]);
286 return;
287 default:
288 }
289 }
290
291 private void emitFirstSegments() {
292 final float[] fSegBuf = firstSegmentsBuffer;
293
294 for (int i = 0, len = firstSegidx; i < len; ) {
295 int type = (int)fSegBuf[i];
296 emitSeg(fSegBuf, i + 1, type);
297 i += (type - 1);
298 }
299 firstSegidx = 0;
300 }
301
302 // precondition: pts must be in relative coordinates (relative to x0,y0)
303 private void goTo(final float[] pts, final int off, final int type,
304 final boolean on)
305 {
306 final int index = off + type;
307 final float x = pts[index - 4];
308 final float y = pts[index - 3];
309
310 if (on) {
311 if (starting) {
312 goTo_starting(pts, off, type);
313 } else {
314 if (needsMoveTo) {
315 needsMoveTo = false;
316 out.moveTo(cx0, cy0);
317 }
318 emitSeg(pts, off, type);
319 }
320 } else {
321 if (starting) {
322 // low probability test (hotspot)
323 starting = false;
324 }
325 needsMoveTo = true;
326 }
327 this.cx0 = x;
328 this.cy0 = y;
329 }
330
331 private void goTo_starting(final float[] pts, final int off, final int type) {
332 int len = type - 1; // - 2 + 1
333 int segIdx = firstSegidx;
334 float[] buf = firstSegmentsBuffer;
335
336 if (segIdx + len > buf.length) {
337 if (DO_STATS) {
338 rdrCtx.stats.stat_array_dasher_firstSegmentsBuffer
339 .add(segIdx + len);
340 }
341 firstSegmentsBuffer = buf
342 = firstSegmentsBuffer_ref.widenArray(buf, segIdx,
343 segIdx + len);
344 }
345 buf[segIdx++] = type;
346 len--;
347 // small arraycopy (2, 4 or 6) but with offset:
348 System.arraycopy(pts, off, buf, segIdx, len);
349 firstSegidx = segIdx + len;
350 }
351
352 @Override
353 public void lineTo(final float x1, final float y1) {
354 final int outcode0 = this.cOutCode;
355
356 if (clipRect != null) {
357 final int outcode1 = Helpers.outcode(x1, y1, clipRect);
358
359 // Should clip
360 final int orCode = (outcode0 | outcode1);
361
362 if (orCode != 0) {
363 final int sideCode = outcode0 & outcode1;
364
365 // basic rejection criteria:
366 if (sideCode == 0) {
367 // overlap clip:
368 if (subdivide) {
369 // avoid reentrance
370 subdivide = false;
371 // subdivide curve => callback with subdivided parts:
372 boolean ret = curveSplitter.splitLine(cx0, cy0, x1, y1,
373 orCode, this);
374 // reentrance is done:
375 subdivide = true;
376 if (ret) {
377 return;
378 }
379 }
380 // already subdivided so render it
381 } else {
382 this.cOutCode = outcode1;
383 skipLineTo(x1, y1);
384 return;
385 }
386 }
387
388 this.cOutCode = outcode1;
389
390 if (this.outside) {
391 this.outside = false;
392 // Adjust current index, phase & dash:
393 skipLen();
394 }
395 }
396 _lineTo(x1, y1);
397 }
398
399 private void _lineTo(final float x1, final float y1) {
400 final float dx = x1 - cx0;
401 final float dy = y1 - cy0;
402
403 float len = dx * dx + dy * dy;
404 if (len == 0.0f) {
405 return;
406 }
407 len = (float) Math.sqrt(len);
408
409 // The scaling factors needed to get the dx and dy of the
410 // transformed dash segments.
411 final float cx = dx / len;
412 final float cy = dy / len;
413
414 final float[] _curCurvepts = curCurvepts;
415 final float[] _dash = dash;
416 final int _dashLen = this.dashLen;
417
418 int _idx = idx;
419 boolean _dashOn = dashOn;
420 float _phase = phase;
421
422 float leftInThisDashSegment, rem;
423
424 while (true) {
425 leftInThisDashSegment = _dash[_idx] - _phase;
426 rem = len - leftInThisDashSegment;
427
428 if (rem <= EPS) {
429 _curCurvepts[0] = x1;
430 _curCurvepts[1] = y1;
431
432 goTo(_curCurvepts, 0, 4, _dashOn);
433
434 // Advance phase within current dash segment
435 _phase += len;
436
437 // compare values using epsilon:
438 if (Math.abs(rem) <= EPS) {
439 _phase = 0.0f;
440 _idx = (_idx + 1) % _dashLen;
441 _dashOn = !_dashOn;
442 }
443 break;
444 }
445
446 _curCurvepts[0] = cx0 + leftInThisDashSegment * cx;
447 _curCurvepts[1] = cy0 + leftInThisDashSegment * cy;
448
449 goTo(_curCurvepts, 0, 4, _dashOn);
450
451 len = rem;
452 // Advance to next dash segment
453 _idx = (_idx + 1) % _dashLen;
454 _dashOn = !_dashOn;
455 _phase = 0.0f;
456 }
457 // Save local state:
458 idx = _idx;
459 dashOn = _dashOn;
460 phase = _phase;
461 }
462
463 private void skipLineTo(final float x1, final float y1) {
464 final float dx = x1 - cx0;
465 final float dy = y1 - cy0;
466
467 float len = dx * dx + dy * dy;
468 if (len != 0.0f) {
469 len = (float)Math.sqrt(len);
470 }
471
472 // Accumulate skipped length:
473 this.outside = true;
474 this.totalSkipLen += len;
475
476 // Fix initial move:
477 this.needsMoveTo = true;
478 this.starting = false;
479
480 this.cx0 = x1;
481 this.cy0 = y1;
482 }
483
484 public void skipLen() {
485 float len = this.totalSkipLen;
486 this.totalSkipLen = 0.0f;
487
488 final float[] _dash = dash;
489 final int _dashLen = this.dashLen;
490
491 int _idx = idx;
492 boolean _dashOn = dashOn;
493 float _phase = phase;
494
495 // -2 to ensure having 2 iterations of the post-loop
496 // to compensate the remaining phase
497 final long fullcycles = (long)Math.floor(len / cycleLen) - 2L;
498
499 if (fullcycles > 0L) {
500 len -= cycleLen * fullcycles;
501
502 final long iterations = fullcycles * _dashLen;
503 _idx = (int) (iterations + _idx) % _dashLen;
504 _dashOn = (iterations + (_dashOn ? 1L : 0L) & 1L) == 1L;
505 }
506
507 float leftInThisDashSegment, rem;
508
509 while (true) {
510 leftInThisDashSegment = _dash[_idx] - _phase;
511 rem = len - leftInThisDashSegment;
512
513 if (rem <= EPS) {
514 // Advance phase within current dash segment
515 _phase += len;
516
517 // compare values using epsilon:
518 if (Math.abs(rem) <= EPS) {
519 _phase = 0.0f;
520 _idx = (_idx + 1) % _dashLen;
521 _dashOn = !_dashOn;
522 }
523 break;
524 }
525
526 len = rem;
527 // Advance to next dash segment
528 _idx = (_idx + 1) % _dashLen;
529 _dashOn = !_dashOn;
530 _phase = 0.0f;
531 }
532 // Save local state:
533 idx = _idx;
534 dashOn = _dashOn;
535 phase = _phase;
536 }
537
538 // preconditions: curCurvepts must be an array of length at least 2 * type,
539 // that contains the curve we want to dash in the first type elements
540 private void somethingTo(final int type) {
541 final float[] _curCurvepts = curCurvepts;
542 if (pointCurve(_curCurvepts, type)) {
543 return;
544 }
545 final LengthIterator _li = li;
546 final float[] _dash = dash;
547 final int _dashLen = this.dashLen;
548
549 _li.initializeIterationOnCurve(_curCurvepts, type);
550
551 int _idx = idx;
552 boolean _dashOn = dashOn;
553 float _phase = phase;
554
555 // initially the current curve is at curCurvepts[0...type]
556 int curCurveoff = 0;
557 float prevT = 0.0f;
558 float t;
559 float leftInThisDashSegment = _dash[_idx] - _phase;
560
561 while ((t = _li.next(leftInThisDashSegment)) < 1.0f) {
562 if (t != 0.0f) {
563 Helpers.subdivideAt((t - prevT) / (1.0f - prevT),
564 _curCurvepts, curCurveoff,
565 _curCurvepts, 0, type);
566 prevT = t;
567 goTo(_curCurvepts, 2, type, _dashOn);
568 curCurveoff = type;
569 }
570 // Advance to next dash segment
571 _idx = (_idx + 1) % _dashLen;
572 _dashOn = !_dashOn;
573 _phase = 0.0f;
574 leftInThisDashSegment = _dash[_idx];
575 }
576
577 goTo(_curCurvepts, curCurveoff + 2, type, _dashOn);
578
579 _phase += _li.lastSegLen();
580
581 // compare values using epsilon:
582 if (_phase + EPS >= _dash[_idx]) {
583 _phase = 0.0f;
584 _idx = (_idx + 1) % _dashLen;
585 _dashOn = !_dashOn;
586 }
587 // Save local state:
588 idx = _idx;
589 dashOn = _dashOn;
590 phase = _phase;
591
592 // reset LengthIterator:
593 _li.reset();
594 }
595
596 private void skipSomethingTo(final int type) {
597 final float[] _curCurvepts = curCurvepts;
598 if (pointCurve(_curCurvepts, type)) {
599 return;
600 }
601 final LengthIterator _li = li;
602
603 _li.initializeIterationOnCurve(_curCurvepts, type);
604
605 // In contrary to somethingTo(),
606 // just estimate properly the curve length:
607 final float len = _li.totalLength();
608
609 // Accumulate skipped length:
610 this.outside = true;
611 this.totalSkipLen += len;
612
613 // Fix initial move:
614 this.needsMoveTo = true;
615 this.starting = false;
616 }
617
618 private static boolean pointCurve(final float[] curve, final int type) {
619 for (int i = 2; i < type; i++) {
620 if (curve[i] != curve[i-2]) {
621 return false;
622 }
623 }
624 return true;
625 }
626
627 // Objects of this class are used to iterate through curves. They return
628 // t values where the left side of the curve has a specified length.
629 // It does this by subdividing the input curve until a certain error
630 // condition has been met. A recursive subdivision procedure would
631 // return as many as 1<<limit curves, but this is an iterator and we
632 // don't need all the curves all at once, so what we carry out a
633 // lazy inorder traversal of the recursion tree (meaning we only move
634 // through the tree when we need the next subdivided curve). This saves
635 // us a lot of memory because at any one time we only need to store
636 // limit+1 curves - one for each level of the tree + 1.
637 // NOTE: the way we do things here is not enough to traverse a general
638 // tree; however, the trees we are interested in have the property that
639 // every non leaf node has exactly 2 children
640 static final class LengthIterator {
641 // Holds the curves at various levels of the recursion. The root
642 // (i.e. the original curve) is at recCurveStack[0] (but then it
643 // gets subdivided, the left half is put at 1, so most of the time
644 // only the right half of the original curve is at 0)
645 private final float[][] recCurveStack; // dirty
646 // sidesRight[i] indicates whether the node at level i+1 in the path from
647 // the root to the current leaf is a left or right child of its parent.
648 private final boolean[] sidesRight; // dirty
649 private int curveType;
650 // lastT and nextT delimit the current leaf.
651 private float nextT;
652 private float lenAtNextT;
653 private float lastT;
654 private float lenAtLastT;
655 private float lenAtLastSplit;
656 private float lastSegLen;
657 // the current level in the recursion tree. 0 is the root. limit
658 // is the deepest possible leaf.
659 private int recLevel;
660 private boolean done;
661
662 // the lengths of the lines of the control polygon. Only its first
663 // curveType/2 - 1 elements are valid. This is an optimization. See
664 // next() for more detail.
665 private final float[] curLeafCtrlPolyLengths = new float[3];
666
667 LengthIterator() {
668 this.recCurveStack = new float[REC_LIMIT + 1][8];
669 this.sidesRight = new boolean[REC_LIMIT];
670 // if any methods are called without first initializing this object
671 // on a curve, we want it to fail ASAP.
672 this.nextT = Float.MAX_VALUE;
673 this.lenAtNextT = Float.MAX_VALUE;
674 this.lenAtLastSplit = Float.MIN_VALUE;
675 this.recLevel = Integer.MIN_VALUE;
676 this.lastSegLen = Float.MAX_VALUE;
677 this.done = true;
678 }
679
680 /**
681 * Reset this LengthIterator.
682 */
683 void reset() {
684 // keep data dirty
685 // as it appears not useful to reset data:
686 if (DO_CLEAN_DIRTY) {
687 final int recLimit = recCurveStack.length - 1;
688 for (int i = recLimit; i >= 0; i--) {
689 Arrays.fill(recCurveStack[i], 0.0f);
690 }
691 Arrays.fill(sidesRight, false);
692 Arrays.fill(curLeafCtrlPolyLengths, 0.0f);
693 Arrays.fill(nextRoots, 0.0f);
694 Arrays.fill(flatLeafCoefCache, 0.0f);
695 flatLeafCoefCache[2] = -1.0f;
696 }
697 }
698
699 void initializeIterationOnCurve(final float[] pts, final int type) {
700 // optimize arraycopy (8 values faster than 6 = type):
701 System.arraycopy(pts, 0, recCurveStack[0], 0, 8);
702 this.curveType = type;
703 this.recLevel = 0;
704 this.lastT = 0.0f;
705 this.lenAtLastT = 0.0f;
706 this.nextT = 0.0f;
707 this.lenAtNextT = 0.0f;
708 goLeft(); // initializes nextT and lenAtNextT properly
709 this.lenAtLastSplit = 0.0f;
710 if (recLevel > 0) {
711 this.sidesRight[0] = false;
712 this.done = false;
713 } else {
714 // the root of the tree is a leaf so we're done.
715 this.sidesRight[0] = true;
716 this.done = true;
717 }
718 this.lastSegLen = 0.0f;
719 }
720
721 // 0 == false, 1 == true, -1 == invalid cached value.
722 private int cachedHaveLowAcceleration = -1;
723
724 private boolean haveLowAcceleration(final float err) {
725 if (cachedHaveLowAcceleration == -1) {
726 final float len1 = curLeafCtrlPolyLengths[0];
727 final float len2 = curLeafCtrlPolyLengths[1];
728 // the test below is equivalent to !within(len1/len2, 1, err).
729 // It is using a multiplication instead of a division, so it
730 // should be a bit faster.
731 if (!Helpers.within(len1, len2, err * len2)) {
732 cachedHaveLowAcceleration = 0;
733 return false;
734 }
735 if (curveType == 8) {
736 final float len3 = curLeafCtrlPolyLengths[2];
737 // if len1 is close to 2 and 2 is close to 3, that probably
738 // means 1 is close to 3 so the second part of this test might
739 // not be needed, but it doesn't hurt to include it.
740 final float errLen3 = err * len3;
741 if (!(Helpers.within(len2, len3, errLen3) &&
742 Helpers.within(len1, len3, errLen3))) {
743 cachedHaveLowAcceleration = 0;
744 return false;
745 }
746 }
747 cachedHaveLowAcceleration = 1;
748 return true;
749 }
750
751 return (cachedHaveLowAcceleration == 1);
752 }
753
754 // we want to avoid allocations/gc so we keep this array so we
755 // can put roots in it,
756 private final float[] nextRoots = new float[4];
757
758 // caches the coefficients of the current leaf in its flattened
759 // form (see inside next() for what that means). The cache is
760 // invalid when it's third element is negative, since in any
761 // valid flattened curve, this would be >= 0.
762 private final float[] flatLeafCoefCache = new float[]{0.0f, 0.0f, -1.0f, 0.0f};
763
764 // returns the t value where the remaining curve should be split in
765 // order for the left subdivided curve to have length len. If len
766 // is >= than the length of the uniterated curve, it returns 1.
767 float next(final float len) {
768 final float targetLength = lenAtLastSplit + len;
769 while (lenAtNextT < targetLength) {
770 if (done) {
771 lastSegLen = lenAtNextT - lenAtLastSplit;
772 return 1.0f;
773 }
774 goToNextLeaf();
775 }
776 lenAtLastSplit = targetLength;
777 final float leaflen = lenAtNextT - lenAtLastT;
778 float t = (targetLength - lenAtLastT) / leaflen;
779
780 // cubicRootsInAB is a fairly expensive call, so we just don't do it
781 // if the acceleration in this section of the curve is small enough.
782 if (!haveLowAcceleration(0.05f)) {
783 // We flatten the current leaf along the x axis, so that we're
784 // left with a, b, c which define a 1D Bezier curve. We then
785 // solve this to get the parameter of the original leaf that
786 // gives us the desired length.
787 final float[] _flatLeafCoefCache = flatLeafCoefCache;
788
789 if (_flatLeafCoefCache[2] < 0.0f) {
790 float x = curLeafCtrlPolyLengths[0],
791 y = x + curLeafCtrlPolyLengths[1];
792 if (curveType == 8) {
793 float z = y + curLeafCtrlPolyLengths[2];
794 _flatLeafCoefCache[0] = 3.0f * (x - y) + z;
795 _flatLeafCoefCache[1] = 3.0f * (y - 2.0f * x);
796 _flatLeafCoefCache[2] = 3.0f * x;
797 _flatLeafCoefCache[3] = -z;
798 } else if (curveType == 6) {
799 _flatLeafCoefCache[0] = 0.0f;
800 _flatLeafCoefCache[1] = y - 2.0f * x;
801 _flatLeafCoefCache[2] = 2.0f * x;
802 _flatLeafCoefCache[3] = -y;
803 }
804 }
805 float a = _flatLeafCoefCache[0];
806 float b = _flatLeafCoefCache[1];
807 float c = _flatLeafCoefCache[2];
808 float d = t * _flatLeafCoefCache[3];
809
810 // we use cubicRootsInAB here, because we want only roots in 0, 1,
811 // and our quadratic root finder doesn't filter, so it's just a
812 // matter of convenience.
813 final int n = Helpers.cubicRootsInAB(a, b, c, d, nextRoots, 0, 0.0f, 1.0f);
814 if (n == 1 && !Float.isNaN(nextRoots[0])) {
815 t = nextRoots[0];
816 }
817 }
818 // t is relative to the current leaf, so we must make it a valid parameter
819 // of the original curve.
820 t = t * (nextT - lastT) + lastT;
821 if (t >= 1.0f) {
822 t = 1.0f;
823 done = true;
824 }
825 // even if done = true, if we're here, that means targetLength
826 // is equal to, or very, very close to the total length of the
827 // curve, so lastSegLen won't be too high. In cases where len
828 // overshoots the curve, this method will exit in the while
829 // loop, and lastSegLen will still be set to the right value.
830 lastSegLen = len;
831 return t;
832 }
833
834 float totalLength() {
835 while (!done) {
836 goToNextLeaf();
837 }
838 // reset LengthIterator:
839 reset();
840
841 return lenAtNextT;
842 }
843
844 float lastSegLen() {
845 return lastSegLen;
846 }
847
848 // go to the next leaf (in an inorder traversal) in the recursion tree
849 // preconditions: must be on a leaf, and that leaf must not be the root.
850 private void goToNextLeaf() {
851 // We must go to the first ancestor node that has an unvisited
852 // right child.
853 final boolean[] _sides = sidesRight;
854 int _recLevel = recLevel;
855 _recLevel--;
856
857 while(_sides[_recLevel]) {
858 if (_recLevel == 0) {
859 recLevel = 0;
860 done = true;
861 return;
862 }
863 _recLevel--;
864 }
865
866 _sides[_recLevel] = true;
867 // optimize arraycopy (8 values faster than 6 = type):
868 System.arraycopy(recCurveStack[_recLevel++], 0,
869 recCurveStack[_recLevel], 0, 8);
870 recLevel = _recLevel;
871 goLeft();
872 }
873
874 // go to the leftmost node from the current node. Return its length.
875 private void goLeft() {
876 final float len = onLeaf();
877 if (len >= 0.0f) {
878 lastT = nextT;
879 lenAtLastT = lenAtNextT;
880 nextT += (1 << (REC_LIMIT - recLevel)) * MIN_T_INC;
881 lenAtNextT += len;
882 // invalidate caches
883 flatLeafCoefCache[2] = -1.0f;
884 cachedHaveLowAcceleration = -1;
885 } else {
886 Helpers.subdivide(recCurveStack[recLevel],
887 recCurveStack[recLevel + 1],
888 recCurveStack[recLevel], curveType);
889
890 sidesRight[recLevel] = false;
891 recLevel++;
892 goLeft();
893 }
894 }
895
896 // this is a bit of a hack. It returns -1 if we're not on a leaf, and
897 // the length of the leaf if we are on a leaf.
898 private float onLeaf() {
899 final float[] curve = recCurveStack[recLevel];
900 final int _curveType = curveType;
901 float polyLen = 0.0f;
902
903 float x0 = curve[0], y0 = curve[1];
904 for (int i = 2; i < _curveType; i += 2) {
905 final float x1 = curve[i], y1 = curve[i + 1];
906 final float len = Helpers.linelen(x0, y0, x1, y1);
907 polyLen += len;
908 curLeafCtrlPolyLengths[(i >> 1) - 1] = len;
909 x0 = x1;
910 y0 = y1;
911 }
912
913 final float lineLen = Helpers.linelen(curve[0], curve[1], x0, y0);
914
915 if ((polyLen - lineLen) < CURVE_LEN_ERR || recLevel == REC_LIMIT) {
916 return (polyLen + lineLen) / 2.0f;
917 }
918 return -1.0f;
919 }
920 }
921
922 @Override
923 public void curveTo(final float x1, final float y1,
924 final float x2, final float y2,
925 final float x3, final float y3)
926 {
927 final int outcode0 = this.cOutCode;
928
929 if (clipRect != null) {
930 final int outcode1 = Helpers.outcode(x1, y1, clipRect);
931 final int outcode2 = Helpers.outcode(x2, y2, clipRect);
932 final int outcode3 = Helpers.outcode(x3, y3, clipRect);
933
934 // Should clip
935 final int orCode = (outcode0 | outcode1 | outcode2 | outcode3);
936 if (orCode != 0) {
937 final int sideCode = outcode0 & outcode1 & outcode2 & outcode3;
938
939 // basic rejection criteria:
940 if (sideCode == 0) {
941 // overlap clip:
942 if (subdivide) {
943 // avoid reentrance
944 subdivide = false;
945 // subdivide curve => callback with subdivided parts:
946 boolean ret = curveSplitter.splitCurve(cx0, cy0, x1, y1, x2, y2, x3, y3,
947 orCode, this);
948 // reentrance is done:
949 subdivide = true;
950 if (ret) {
951 return;
952 }
953 }
954 // already subdivided so render it
955 } else {
956 this.cOutCode = outcode3;
957 skipCurveTo(x1, y1, x2, y2, x3, y3);
958 return;
959 }
960 }
961
962 this.cOutCode = outcode3;
963
964 if (this.outside) {
965 this.outside = false;
966 // Adjust current index, phase & dash:
967 skipLen();
968 }
969 }
970 _curveTo(x1, y1, x2, y2, x3, y3);
971 }
972
973 private void _curveTo(final float x1, final float y1,
974 final float x2, final float y2,
975 final float x3, final float y3)
976 {
977 final float[] _curCurvepts = curCurvepts;
978
979 // monotonize curve:
980 final CurveBasicMonotonizer monotonizer
981 = rdrCtx.monotonizer.curve(cx0, cy0, x1, y1, x2, y2, x3, y3);
982
983 final int nSplits = monotonizer.nbSplits;
984 final float[] mid = monotonizer.middle;
985
986 for (int i = 0, off = 0; i <= nSplits; i++, off += 6) {
987 // optimize arraycopy (8 values faster than 6 = type):
988 System.arraycopy(mid, off, _curCurvepts, 0, 8);
989
990 somethingTo(8);
991 }
992 }
993
994 private void skipCurveTo(final float x1, final float y1,
995 final float x2, final float y2,
996 final float x3, final float y3)
997 {
998 final float[] _curCurvepts = curCurvepts;
999 _curCurvepts[0] = cx0; _curCurvepts[1] = cy0;
1000 _curCurvepts[2] = x1; _curCurvepts[3] = y1;
1001 _curCurvepts[4] = x2; _curCurvepts[5] = y2;
1002 _curCurvepts[6] = x3; _curCurvepts[7] = y3;
1003
1004 skipSomethingTo(8);
1005
1006 this.cx0 = x3;
1007 this.cy0 = y3;
1008 }
1009
1010 @Override
1011 public void quadTo(final float x1, final float y1,
1012 final float x2, final float y2)
1013 {
1014 final int outcode0 = this.cOutCode;
1015
1016 if (clipRect != null) {
1017 final int outcode1 = Helpers.outcode(x1, y1, clipRect);
1018 final int outcode2 = Helpers.outcode(x2, y2, clipRect);
1019
1020 // Should clip
1021 final int orCode = (outcode0 | outcode1 | outcode2);
1022 if (orCode != 0) {
1023 final int sideCode = outcode0 & outcode1 & outcode2;
1024
1025 // basic rejection criteria:
1026 if (sideCode == 0) {
1027 // overlap clip:
1028 if (subdivide) {
1029 // avoid reentrance
1030 subdivide = false;
1031 // subdivide curve => call lineTo() with subdivided curves:
1032 boolean ret = curveSplitter.splitQuad(cx0, cy0, x1, y1,
1033 x2, y2, orCode, this);
1034 // reentrance is done:
1035 subdivide = true;
1036 if (ret) {
1037 return;
1038 }
1039 }
1040 // already subdivided so render it
1041 } else {
1042 this.cOutCode = outcode2;
1043 skipQuadTo(x1, y1, x2, y2);
1044 return;
1045 }
1046 }
1047
1048 this.cOutCode = outcode2;
1049
1050 if (this.outside) {
1051 this.outside = false;
1052 // Adjust current index, phase & dash:
1053 skipLen();
1054 }
1055 }
1056 _quadTo(x1, y1, x2, y2);
1057 }
1058
1059 private void _quadTo(final float x1, final float y1,
1060 final float x2, final float y2)
1061 {
1062 final float[] _curCurvepts = curCurvepts;
1063
1064 // monotonize quad:
1065 final CurveBasicMonotonizer monotonizer
1066 = rdrCtx.monotonizer.quad(cx0, cy0, x1, y1, x2, y2);
1067
1068 final int nSplits = monotonizer.nbSplits;
1069 final float[] mid = monotonizer.middle;
1070
1071 for (int i = 0, off = 0; i <= nSplits; i++, off += 4) {
1072 // optimize arraycopy (8 values faster than 6 = type):
1073 System.arraycopy(mid, off, _curCurvepts, 0, 8);
1074
1075 somethingTo(6);
1076 }
1077 }
1078
1079 private void skipQuadTo(final float x1, final float y1,
1080 final float x2, final float y2)
1081 {
1082 final float[] _curCurvepts = curCurvepts;
1083 _curCurvepts[0] = cx0; _curCurvepts[1] = cy0;
1084 _curCurvepts[2] = x1; _curCurvepts[3] = y1;
1085 _curCurvepts[4] = x2; _curCurvepts[5] = y2;
1086
1087 skipSomethingTo(6);
1088
1089 this.cx0 = x2;
1090 this.cy0 = y2;
1091 }
1092
1093 @Override
1094 public void closePath() {
1095 if (cx0 != sx0 || cy0 != sy0) {
1096 lineTo(sx0, sy0);
1097 }
1098 if (firstSegidx != 0) {
1099 if (!dashOn || needsMoveTo) {
1100 out.moveTo(sx0, sy0);
1101 }
1102 emitFirstSegments();
1103 }
1104 moveTo(sx0, sy0);
1105 }
1106
1107 @Override
1108 public void pathDone() {
1109 if (firstSegidx != 0) {
1110 out.moveTo(sx0, sy0);
1111 emitFirstSegments();
1112 }
1113 out.pathDone();
1114
1115 // Dispose this instance:
1116 dispose();
1117 }
1118
1119 @Override
1120 public long getNativeConsumer() {
1121 throw new InternalError("Dasher does not use a native consumer");
1122 }
1123 }
1124