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;
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],
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
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.
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;
|
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.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 PathConsumer2D, MarlinConst {
43
44 static final int REC_LIMIT = 4;
45 static final float ERR = 0.01f;
46 static final float MIN_T_INC = 1.0f / (1 << REC_LIMIT);
47
48 // More than 24 bits of mantissa means we can no longer accurately
49 // measure the number of times cycled through the dash array so we
50 // punt and override the phase to just be 0 past that point.
51 static final float MAX_CYCLES = 16000000.0f;
52
53 private PathConsumer2D out;
54 private float[] dash;
55 private int dashLen;
56 private float startPhase;
57 private boolean startDashOn;
58 private int startIdx;
59
60 private boolean starting;
61 private boolean needsMoveTo;
62
63 private int idx;
64 private boolean dashOn;
65 private float phase;
66
67 private float sx, sy;
68 private float x0, y0;
69
70 // temporary storage for the current curve
71 private final float[] curCurvepts;
94 firstSegmentsBuffer = firstSegmentsBuffer_ref.initial;
95
96 // we need curCurvepts to be able to contain 2 curves because when
97 // dashing curves, we need to subdivide it
98 curCurvepts = new float[8 * 2];
99 }
100
101 /**
102 * Initialize the <code>Dasher</code>.
103 *
104 * @param out an output <code>PathConsumer2D</code>.
105 * @param dash an array of <code>float</code>s containing the dash pattern
106 * @param dashLen length of the given dash array
107 * @param phase a <code>float</code> containing the dash phase
108 * @param recycleDashes true to indicate to recycle the given dash array
109 * @return this instance
110 */
111 Dasher init(final PathConsumer2D out, float[] dash, int dashLen,
112 float phase, boolean recycleDashes)
113 {
114 this.out = out;
115
116 // Normalize so 0 <= phase < dash[0]
117 int sidx = 0;
118 dashOn = true;
119 float sum = 0.0f;
120 for (float d : dash) {
121 sum += d;
122 }
123 float cycles = phase / sum;
124 if (phase < 0.0f) {
125 if (-cycles >= MAX_CYCLES) {
126 phase = 0.0f;
127 } else {
128 int fullcycles = FloatMath.floor_int(-cycles);
129 if ((fullcycles & dash.length & 1) != 0) {
130 dashOn = !dashOn;
131 }
132 phase += fullcycles * sum;
133 while (phase < 0.0f) {
134 if (--sidx < 0) {
135 sidx = dash.length - 1;
136 }
137 phase += dash[sidx];
138 dashOn = !dashOn;
139 }
140 }
141 } else if (phase > 0) {
142 if (cycles >= MAX_CYCLES) {
143 phase = 0.0f;
144 } else {
145 int fullcycles = FloatMath.floor_int(cycles);
146 if ((fullcycles & dash.length & 1) != 0) {
147 dashOn = !dashOn;
148 }
149 phase -= fullcycles * sum;
150 float d;
151 while (phase >= (d = dash[sidx])) {
152 phase -= d;
153 sidx = (sidx + 1) % dash.length;
154 dashOn = !dashOn;
155 }
156 }
157 }
158
159 this.dash = dash;
160 this.dashLen = dashLen;
161 this.startPhase = this.phase = phase;
162 this.startDashOn = dashOn;
163 this.startIdx = sidx;
164 this.starting = true;
165 needsMoveTo = false;
166 firstSegidx = 0;
167
168 this.recycleDashes = recycleDashes;
169
170 return this; // fluent API
171 }
172
173 /**
174 * Disposes this dasher:
175 * clean up before reusing this instance
176 */
177 void dispose() {
178 if (DO_CLEAN_DIRTY) {
179 // Force zero-fill dirty arrays:
180 Arrays.fill(curCurvepts, 0.0f);
181 }
182 // Return arrays:
183 if (recycleDashes) {
184 dash = dashes_ref.putArray(dash);
185 }
186 firstSegmentsBuffer = firstSegmentsBuffer_ref.putArray(firstSegmentsBuffer);
187 }
188
189 float[] copyDashArray(final float[] dashes) {
190 final int len = dashes.length;
191 final float[] newDashes;
192 if (len <= MarlinConst.INITIAL_ARRAY) {
193 newDashes = dashes_ref.initial;
194 } else {
195 if (DO_STATS) {
196 rdrCtx.stats.stat_array_dasher_dasher.add(len);
197 }
198 newDashes = dashes_ref.getArray(len);
199 }
200 System.arraycopy(dashes, 0, newDashes, 0, len);
201 return newDashes;
202 }
203
204 @Override
205 public void moveTo(float x0, float y0) {
206 if (firstSegidx > 0) {
207 out.moveTo(sx, sy);
208 emitFirstSegments();
209 }
210 needsMoveTo = true;
211 this.idx = startIdx;
212 this.dashOn = this.startDashOn;
213 this.phase = this.startPhase;
214 this.sx = this.x0 = x0;
215 this.sy = this.y0 = y0;
216 this.starting = true;
217 }
218
219 private void emitSeg(float[] buf, int off, int type) {
220 switch (type) {
221 case 8:
222 out.curveTo(buf[off+0], buf[off+1],
223 buf[off+2], buf[off+3],
235 }
236
237 private void emitFirstSegments() {
238 final float[] fSegBuf = firstSegmentsBuffer;
239
240 for (int i = 0; i < firstSegidx; ) {
241 int type = (int)fSegBuf[i];
242 emitSeg(fSegBuf, i + 1, type);
243 i += (type - 1);
244 }
245 firstSegidx = 0;
246 }
247 // We don't emit the first dash right away. If we did, caps would be
248 // drawn on it, but we need joins to be drawn if there's a closePath()
249 // So, we store the path elements that make up the first dash in the
250 // buffer below.
251 private float[] firstSegmentsBuffer; // dynamic array
252 private int firstSegidx;
253
254 // precondition: pts must be in relative coordinates (relative to x0,y0)
255 private void goTo(float[] pts, int off, final int type) {
256 float x = pts[off + type - 4];
257 float y = pts[off + type - 3];
258 if (dashOn) {
259 if (starting) {
260 int len = type - 1; // - 2 + 1
261 int segIdx = firstSegidx;
262 float[] buf = firstSegmentsBuffer;
263 if (segIdx + len > buf.length) {
264 if (DO_STATS) {
265 rdrCtx.stats.stat_array_dasher_firstSegmentsBuffer
266 .add(segIdx + len);
267 }
268 firstSegmentsBuffer = buf
269 = firstSegmentsBuffer_ref.widenArray(buf, segIdx,
270 segIdx + len);
271 }
272 buf[segIdx++] = type;
273 len--;
274 // small arraycopy (2, 4 or 6) but with offset:
275 System.arraycopy(pts, off, buf, segIdx, len);
276 segIdx += len;
277 firstSegidx = segIdx;
278 } else {
279 if (needsMoveTo) {
280 out.moveTo(x0, y0);
281 needsMoveTo = false;
282 }
283 emitSeg(pts, off, type);
284 }
285 } else {
286 starting = false;
287 needsMoveTo = true;
288 }
289 this.x0 = x;
290 this.y0 = y;
291 }
292
293 @Override
294 public void lineTo(float x1, float y1) {
295 float dx = x1 - x0;
296 float dy = y1 - y0;
297
298 float len = dx*dx + dy*dy;
299 if (len == 0.0f) {
300 return;
301 }
302 len = (float) Math.sqrt(len);
303
304 // The scaling factors needed to get the dx and dy of the
305 // transformed dash segments.
306 final float cx = dx / len;
307 final float cy = dy / len;
308
309 final float[] _curCurvepts = curCurvepts;
310 final float[] _dash = dash;
311
312 float leftInThisDashSegment;
313 float dashdx, dashdy, p;
314
315 while (true) {
316 leftInThisDashSegment = _dash[idx] - phase;
317
318 if (len <= leftInThisDashSegment) {
319 _curCurvepts[0] = x1;
320 _curCurvepts[1] = y1;
321 goTo(_curCurvepts, 0, 4);
322
323 // Advance phase within current dash segment
324 phase += len;
325 // TODO: compare float values using epsilon:
326 if (len == leftInThisDashSegment) {
327 phase = 0.0f;
328 idx = (idx + 1) % dashLen;
329 dashOn = !dashOn;
330 }
331 return;
332 }
333
334 dashdx = _dash[idx] * cx;
335 dashdy = _dash[idx] * cy;
336
337 if (phase == 0.0f) {
338 _curCurvepts[0] = x0 + dashdx;
339 _curCurvepts[1] = y0 + dashdy;
340 } else {
341 p = leftInThisDashSegment / _dash[idx];
342 _curCurvepts[0] = x0 + p * dashdx;
343 _curCurvepts[1] = y0 + p * dashdy;
344 }
345
346 goTo(_curCurvepts, 0, 4);
347
348 len -= leftInThisDashSegment;
349 // Advance to next dash segment
350 idx = (idx + 1) % dashLen;
351 dashOn = !dashOn;
352 phase = 0.0f;
353 }
354 }
355
356 // shared instance in Dasher
357 private final LengthIterator li = new LengthIterator();
358
359 // preconditions: curCurvepts must be an array of length at least 2 * type,
360 // that contains the curve we want to dash in the first type elements
361 private void somethingTo(int type) {
362 if (pointCurve(curCurvepts, type)) {
363 return;
364 }
365 li.initializeIterationOnCurve(curCurvepts, type);
366
367 // initially the current curve is at curCurvepts[0...type]
368 int curCurveoff = 0;
369 float lastSplitT = 0.0f;
370 float t;
371 float leftInThisDashSegment = dash[idx] - phase;
372
373 while ((t = li.next(leftInThisDashSegment)) < 1.0f) {
374 if (t != 0.0f) {
375 Helpers.subdivideAt((t - lastSplitT) / (1.0f - lastSplitT),
376 curCurvepts, curCurveoff,
377 curCurvepts, 0,
378 curCurvepts, type, type);
379 lastSplitT = t;
380 goTo(curCurvepts, 2, type);
381 curCurveoff = type;
382 }
383 // Advance to next dash segment
384 idx = (idx + 1) % dashLen;
385 dashOn = !dashOn;
386 phase = 0.0f;
387 leftInThisDashSegment = dash[idx];
388 }
389 goTo(curCurvepts, curCurveoff+2, type);
390 phase += li.lastSegLen();
391 if (phase >= dash[idx]) {
392 phase = 0.0f;
393 idx = (idx + 1) % dashLen;
394 dashOn = !dashOn;
395 }
396 // reset LengthIterator:
397 li.reset();
398 }
399
400 private static boolean pointCurve(float[] curve, int type) {
401 for (int i = 2; i < type; i++) {
402 if (curve[i] != curve[i-2]) {
403 return false;
404 }
405 }
406 return true;
407 }
408
409 // Objects of this class are used to iterate through curves. They return
410 // t values where the left side of the curve has a specified length.
411 // It does this by subdividing the input curve until a certain error
412 // condition has been met. A recursive subdivision procedure would
427 // only the right half of the original curve is at 0)
428 private final float[][] recCurveStack; // dirty
429 // sides[i] indicates whether the node at level i+1 in the path from
430 // the root to the current leaf is a left or right child of its parent.
431 private final Side[] sides; // dirty
432 private int curveType;
433 // lastT and nextT delimit the current leaf.
434 private float nextT;
435 private float lenAtNextT;
436 private float lastT;
437 private float lenAtLastT;
438 private float lenAtLastSplit;
439 private float lastSegLen;
440 // the current level in the recursion tree. 0 is the root. limit
441 // is the deepest possible leaf.
442 private int recLevel;
443 private boolean done;
444
445 // the lengths of the lines of the control polygon. Only its first
446 // curveType/2 - 1 elements are valid. This is an optimization. See
447 // next() for more detail.
448 private final float[] curLeafCtrlPolyLengths = new float[3];
449
450 LengthIterator() {
451 this.recCurveStack = new float[REC_LIMIT + 1][8];
452 this.sides = new Side[REC_LIMIT];
453 // if any methods are called without first initializing this object
454 // on a curve, we want it to fail ASAP.
455 this.nextT = Float.MAX_VALUE;
456 this.lenAtNextT = Float.MAX_VALUE;
457 this.lenAtLastSplit = Float.MIN_VALUE;
458 this.recLevel = Integer.MIN_VALUE;
459 this.lastSegLen = Float.MAX_VALUE;
460 this.done = true;
461 }
462
463 /**
464 * Reset this LengthIterator.
465 */
466 void reset() {
467 // keep data dirty
468 // as it appears not useful to reset data:
469 if (DO_CLEAN_DIRTY) {
470 final int recLimit = recCurveStack.length - 1;
471 for (int i = recLimit; i >= 0; i--) {
472 Arrays.fill(recCurveStack[i], 0.0f);
473 }
474 Arrays.fill(sides, Side.LEFT);
475 Arrays.fill(curLeafCtrlPolyLengths, 0.0f);
476 Arrays.fill(nextRoots, 0.0f);
477 Arrays.fill(flatLeafCoefCache, 0.0f);
478 flatLeafCoefCache[2] = -1.0f;
479 }
480 }
481
482 void initializeIterationOnCurve(float[] pts, int type) {
483 // optimize arraycopy (8 values faster than 6 = type):
484 System.arraycopy(pts, 0, recCurveStack[0], 0, 8);
485 this.curveType = type;
486 this.recLevel = 0;
487 this.lastT = 0.0f;
488 this.lenAtLastT = 0.0f;
489 this.nextT = 0.0f;
490 this.lenAtNextT = 0.0f;
491 goLeft(); // initializes nextT and lenAtNextT properly
492 this.lenAtLastSplit = 0.0f;
493 if (recLevel > 0) {
494 this.sides[0] = Side.LEFT;
495 this.done = false;
496 } else {
497 // the root of the tree is a leaf so we're done.
498 this.sides[0] = Side.RIGHT;
499 this.done = true;
500 }
501 this.lastSegLen = 0.0f;
502 }
503
504 // 0 == false, 1 == true, -1 == invalid cached value.
505 private int cachedHaveLowAcceleration = -1;
506
507 private boolean haveLowAcceleration(float err) {
508 if (cachedHaveLowAcceleration == -1) {
509 final float len1 = curLeafCtrlPolyLengths[0];
510 final float len2 = curLeafCtrlPolyLengths[1];
511 // the test below is equivalent to !within(len1/len2, 1, err).
512 // It is using a multiplication instead of a division, so it
513 // should be a bit faster.
514 if (!Helpers.within(len1, len2, err * len2)) {
515 cachedHaveLowAcceleration = 0;
516 return false;
517 }
518 if (curveType == 8) {
519 final float len3 = curLeafCtrlPolyLengths[2];
520 // if len1 is close to 2 and 2 is close to 3, that probably
521 // means 1 is close to 3 so the second part of this test might
522 // not be needed, but it doesn't hurt to include it.
523 final float errLen3 = err * len3;
524 if (!(Helpers.within(len2, len3, errLen3) &&
525 Helpers.within(len1, len3, errLen3))) {
526 cachedHaveLowAcceleration = 0;
527 return false;
528 }
529 }
530 cachedHaveLowAcceleration = 1;
531 return true;
532 }
533
534 return (cachedHaveLowAcceleration == 1);
535 }
536
537 // we want to avoid allocations/gc so we keep this array so we
538 // can put roots in it,
539 private final float[] nextRoots = new float[4];
540
541 // caches the coefficients of the current leaf in its flattened
542 // form (see inside next() for what that means). The cache is
543 // invalid when it's third element is negative, since in any
544 // valid flattened curve, this would be >= 0.
545 private final float[] flatLeafCoefCache = new float[]{0.0f, 0.0f, -1.0f, 0.0f};
546
547 // returns the t value where the remaining curve should be split in
548 // order for the left subdivided curve to have length len. If len
549 // is >= than the length of the uniterated curve, it returns 1.
550 float next(final float len) {
551 final float targetLength = lenAtLastSplit + len;
552 while (lenAtNextT < targetLength) {
553 if (done) {
554 lastSegLen = lenAtNextT - lenAtLastSplit;
555 return 1.0f;
556 }
557 goToNextLeaf();
558 }
559 lenAtLastSplit = targetLength;
560 final float leaflen = lenAtNextT - lenAtLastT;
561 float t = (targetLength - lenAtLastT) / leaflen;
562
563 // cubicRootsInAB is a fairly expensive call, so we just don't do it
564 // if the acceleration in this section of the curve is small enough.
565 if (!haveLowAcceleration(0.05f)) {
566 // We flatten the current leaf along the x axis, so that we're
567 // left with a, b, c which define a 1D Bezier curve. We then
568 // solve this to get the parameter of the original leaf that
569 // gives us the desired length.
570 final float[] _flatLeafCoefCache = flatLeafCoefCache;
571
572 if (_flatLeafCoefCache[2] < 0.0f) {
573 float x = curLeafCtrlPolyLengths[0],
574 y = x + curLeafCtrlPolyLengths[1];
575 if (curveType == 8) {
576 float z = y + curLeafCtrlPolyLengths[2];
577 _flatLeafCoefCache[0] = 3.0f * (x - y) + z;
578 _flatLeafCoefCache[1] = 3.0f * (y - 2.0f * x);
579 _flatLeafCoefCache[2] = 3.0f * x;
580 _flatLeafCoefCache[3] = -z;
581 } else if (curveType == 6) {
582 _flatLeafCoefCache[0] = 0.0f;
583 _flatLeafCoefCache[1] = y - 2.0f * x;
584 _flatLeafCoefCache[2] = 2.0f * x;
585 _flatLeafCoefCache[3] = -y;
586 }
587 }
588 float a = _flatLeafCoefCache[0];
589 float b = _flatLeafCoefCache[1];
590 float c = _flatLeafCoefCache[2];
591 float d = t * _flatLeafCoefCache[3];
592
593 // we use cubicRootsInAB here, because we want only roots in 0, 1,
594 // and our quadratic root finder doesn't filter, so it's just a
595 // matter of convenience.
596 int n = Helpers.cubicRootsInAB(a, b, c, d, nextRoots, 0, 0.0f, 1.0f);
597 if (n == 1 && !Float.isNaN(nextRoots[0])) {
598 t = nextRoots[0];
599 }
600 }
601 // t is relative to the current leaf, so we must make it a valid parameter
602 // of the original curve.
603 t = t * (nextT - lastT) + lastT;
604 if (t >= 1.0f) {
605 t = 1.0f;
606 done = true;
607 }
608 // even if done = true, if we're here, that means targetLength
609 // is equal to, or very, very close to the total length of the
610 // curve, so lastSegLen won't be too high. In cases where len
611 // overshoots the curve, this method will exit in the while
612 // loop, and lastSegLen will still be set to the right value.
613 lastSegLen = len;
614 return t;
615 }
616
617 float lastSegLen() {
618 return lastSegLen;
619 }
620
621 // go to the next leaf (in an inorder traversal) in the recursion tree
622 // preconditions: must be on a leaf, and that leaf must not be the root.
623 private void goToNextLeaf() {
624 // We must go to the first ancestor node that has an unvisited
625 // right child.
632 recLevel = 0;
633 done = true;
634 return;
635 }
636 _recLevel--;
637 }
638
639 _sides[_recLevel] = Side.RIGHT;
640 // optimize arraycopy (8 values faster than 6 = type):
641 System.arraycopy(recCurveStack[_recLevel], 0,
642 recCurveStack[_recLevel+1], 0, 8);
643 _recLevel++;
644
645 recLevel = _recLevel;
646 goLeft();
647 }
648
649 // go to the leftmost node from the current node. Return its length.
650 private void goLeft() {
651 float len = onLeaf();
652 if (len >= 0.0f) {
653 lastT = nextT;
654 lenAtLastT = lenAtNextT;
655 nextT += (1 << (REC_LIMIT - recLevel)) * MIN_T_INC;
656 lenAtNextT += len;
657 // invalidate caches
658 flatLeafCoefCache[2] = -1.0f;
659 cachedHaveLowAcceleration = -1;
660 } else {
661 Helpers.subdivide(recCurveStack[recLevel], 0,
662 recCurveStack[recLevel+1], 0,
663 recCurveStack[recLevel], 0, curveType);
664 sides[recLevel] = Side.LEFT;
665 recLevel++;
666 goLeft();
667 }
668 }
669
670 // this is a bit of a hack. It returns -1 if we're not on a leaf, and
671 // the length of the leaf if we are on a leaf.
672 private float onLeaf() {
673 float[] curve = recCurveStack[recLevel];
674 float polyLen = 0.0f;
675
676 float x0 = curve[0], y0 = curve[1];
677 for (int i = 2; i < curveType; i += 2) {
678 final float x1 = curve[i], y1 = curve[i+1];
679 final float len = Helpers.linelen(x0, y0, x1, y1);
680 polyLen += len;
681 curLeafCtrlPolyLengths[i/2 - 1] = len;
682 x0 = x1;
683 y0 = y1;
684 }
685
686 final float lineLen = Helpers.linelen(curve[0], curve[1],
687 curve[curveType-2],
688 curve[curveType-1]);
689 if ((polyLen - lineLen) < ERR || recLevel == REC_LIMIT) {
690 return (polyLen + lineLen) / 2.0f;
691 }
692 return -1.0f;
693 }
694 }
695
696 @Override
697 public void curveTo(float x1, float y1,
698 float x2, float y2,
699 float x3, float y3)
700 {
701 final float[] _curCurvepts = curCurvepts;
702 _curCurvepts[0] = x0; _curCurvepts[1] = y0;
703 _curCurvepts[2] = x1; _curCurvepts[3] = y1;
704 _curCurvepts[4] = x2; _curCurvepts[5] = y2;
705 _curCurvepts[6] = x3; _curCurvepts[7] = y3;
706 somethingTo(8);
707 }
708
709 @Override
710 public void quadTo(float x1, float y1, float x2, float y2) {
711 final float[] _curCurvepts = curCurvepts;
712 _curCurvepts[0] = x0; _curCurvepts[1] = y0;
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