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 jdk.internal.misc.Unsafe;
29
30 /**
31 * An object used to cache pre-rendered complex paths.
32 *
33 * @see Renderer
34 */
35 public final class MarlinCache implements MarlinConst {
36
37 static final boolean FORCE_RLE = MarlinProperties.isForceRLE();
38 static final boolean FORCE_NO_RLE = MarlinProperties.isForceNoRLE();
39 // minimum width to try using RLE encoding:
40 static final int RLE_MIN_WIDTH
41 = Math.max(BLOCK_SIZE, MarlinProperties.getRLEMinWidth());
42 // maximum width for RLE encoding:
43 // values are stored as int [x|alpha] where alpha is 8 bits
44 static final int RLE_MAX_WIDTH = 1 << (24 - 1);
45
46 // 2048 (pixelSize) alpha values (width) x 32 rows (tile) = 64K bytes
47 // x1 instead of 4 bytes (RLE) ie 1/4 capacity or average good RLE compression
48 static final long INITIAL_CHUNK_ARRAY = TILE_SIZE * INITIAL_PIXEL_DIM; // 64K
49
50 // The alpha map used by this object (taken out of our map cache) to convert
51 // pixel coverage counts gotten from MarlinCache (which are in the range
52 // [0, maxalpha]) into alpha values, which are in [0,256).
53 static final byte[] ALPHA_MAP;
54
55 static final OffHeapArray ALPHA_MAP_UNSAFE;
56
57 static {
58 final byte[] _ALPHA_MAP = buildAlphaMap(MAX_AA_ALPHA);
59
60 ALPHA_MAP_UNSAFE = new OffHeapArray(_ALPHA_MAP, _ALPHA_MAP.length); // 1K
61 ALPHA_MAP =_ALPHA_MAP;
62
63 final Unsafe _unsafe = OffHeapArray.UNSAFE;
64 final long addr = ALPHA_MAP_UNSAFE.address;
65
66 for (int i = 0; i < _ALPHA_MAP.length; i++) {
67 _unsafe.putByte(addr + i, _ALPHA_MAP[i]);
68 }
69 }
70
71 int bboxX0, bboxY0, bboxX1, bboxY1;
72
73 // 1D dirty arrays
74 // row index in rowAAChunk[]
75 final long[] rowAAChunkIndex = new long[TILE_SIZE];
76 // first pixel (inclusive) for each row
77 final int[] rowAAx0 = new int[TILE_SIZE];
78 // last pixel (exclusive) for each row
79 final int[] rowAAx1 = new int[TILE_SIZE];
80 // encoding mode (0=raw, 1=RLE encoding) for each row
81 final int[] rowAAEnc = new int[TILE_SIZE];
82 // coded length (RLE encoding) for each row
83 final long[] rowAALen = new long[TILE_SIZE];
84 // last position in RLE decoding for each row (getAlpha):
85 final long[] rowAAPos = new long[TILE_SIZE];
86
87 // dirty off-heap array containing pixel coverages for (32) rows (packed)
88 // if encoding=raw, it contains alpha coverage values (val) as integer
89 // if encoding=RLE, it contains tuples (val, last x-coordinate exclusive)
90 // use rowAAx0/rowAAx1 to get row indices within this chunk
91 final OffHeapArray rowAAChunk;
92
93 // current position in rowAAChunk array
94 long rowAAChunkPos;
95
96 // touchedTile[i] is the sum of all the alphas in the tile with
97 // x=j*TILE_SIZE+bboxX0.
98 int[] touchedTile;
99
100 // per-thread renderer context
101 final RendererContext rdrCtx;
102
103 // touchedTile ref (clean)
104 private final IntArrayCache.Reference touchedTile_ref;
105
106 int tileMin, tileMax;
107
108 boolean useRLE = false;
109
110 MarlinCache(final RendererContext rdrCtx) {
111 this.rdrCtx = rdrCtx;
112
113 rowAAChunk = rdrCtx.newOffHeapArray(INITIAL_CHUNK_ARRAY); // 64K
114
115 touchedTile_ref = rdrCtx.newCleanIntArrayRef(INITIAL_ARRAY); // 1K = 1 tile line
116 touchedTile = touchedTile_ref.initial;
117
118 // tile used marks:
119 tileMin = Integer.MAX_VALUE;
120 tileMax = Integer.MIN_VALUE;
121 }
122
123 void init(int minx, int miny, int maxx, int maxy, int edgeSumDeltaY)
124 {
125 // assert maxy >= miny && maxx >= minx;
126 bboxX0 = minx;
127 bboxY0 = miny;
128 bboxX1 = maxx;
129 bboxY1 = maxy;
130
131 final int width = (maxx - minx);
132
133 if (FORCE_NO_RLE) {
134 useRLE = false;
135 } else if (FORCE_RLE) {
136 useRLE = true;
137 } else {
138 // heuristics: use both bbox area and complexity
139 // ie number of primitives:
140
141 // fast check min and max width (maxx < 23bits):
142 if (width <= RLE_MIN_WIDTH || width >= RLE_MAX_WIDTH) {
143 useRLE = false;
144 } else {
145 // perimeter approach: how fit the total length into given height:
146
147 // if stroking: meanCrossings /= 2 => divide edgeSumDeltaY by 2
148 final int heightSubPixel
149 = (((maxy - miny) << SUBPIXEL_LG_POSITIONS_Y) << rdrCtx.stroking);
150
151 // check meanDist > block size:
152 // check width / (meanCrossings - 1) >= RLE_THRESHOLD
153
154 // fast case: (meanCrossingPerPixel <= 2) means 1 span only
155 useRLE = (edgeSumDeltaY <= (heightSubPixel << 1))
156 // note: already checked (meanCrossingPerPixel <= 2)
157 // rewritten to avoid division:
158 || (width * heightSubPixel) >
159 ((edgeSumDeltaY - heightSubPixel) << BLOCK_SIZE_LG);
160
161 if (DO_TRACE && !useRLE) {
162 final float meanCrossings
163 = ((float) edgeSumDeltaY) / heightSubPixel;
164 final float meanDist = width / (meanCrossings - 1);
165
166 System.out.println("High complexity: "
167 + " for bbox[width = " + width
168 + " height = " + (maxy - miny)
169 + "] edgeSumDeltaY = " + edgeSumDeltaY
170 + " heightSubPixel = " + heightSubPixel
171 + " meanCrossings = "+ meanCrossings
172 + " meanDist = " + meanDist
173 + " width = " + (width * heightSubPixel)
174 + " <= criteria: " + ((edgeSumDeltaY - heightSubPixel) << BLOCK_SIZE_LG)
175 );
176 }
177 }
178 }
179
180 // the ceiling of (maxy - miny + 1) / TILE_SIZE;
181 final int nxTiles = (width + TILE_SIZE) >> TILE_SIZE_LG;
182
183 if (nxTiles > INITIAL_ARRAY) {
184 if (DO_STATS) {
185 rdrCtx.stats.stat_array_marlincache_touchedTile.add(nxTiles);
186 }
187 touchedTile = touchedTile_ref.getArray(nxTiles);
188 }
189 }
190
191 /**
192 * Disposes this cache:
193 * clean up before reusing this instance
194 */
195 void dispose() {
196 // Reset touchedTile if needed:
197 resetTileLine(0);
198
199 if (DO_STATS) {
200 rdrCtx.stats.totalOffHeap += rowAAChunk.length;
201 }
202
203 // Return arrays:
204 touchedTile = touchedTile_ref.putArray(touchedTile, 0, 0); // already zero filled
205
206 // At last: resize back off-heap rowAA to initial size
207 if (rowAAChunk.length != INITIAL_CHUNK_ARRAY) {
208 // note: may throw OOME:
209 rowAAChunk.resize(INITIAL_CHUNK_ARRAY);
210 }
211 if (DO_CLEAN_DIRTY) {
212 // Force zero-fill dirty arrays:
213 rowAAChunk.fill(BYTE_0);
214 }
215 }
216
217 void resetTileLine(final int pminY) {
218 // update bboxY0 to process a complete tile line [0 - 32]
219 bboxY0 = pminY;
220
221 // reset current pos
222 if (DO_STATS) {
223 rdrCtx.stats.stat_cache_rowAAChunk.add(rowAAChunkPos);
224 }
225 rowAAChunkPos = 0L;
226
227 // Reset touchedTile:
228 if (tileMin != Integer.MAX_VALUE) {
229 if (DO_STATS) {
230 rdrCtx.stats.stat_cache_tiles.add(tileMax - tileMin);
231 }
232 // clean only dirty touchedTile:
233 if (tileMax == 1) {
234 touchedTile[0] = 0;
235 } else {
236 IntArrayCache.fill(touchedTile, tileMin, tileMax, 0);
237 }
238 // reset tile used marks:
239 tileMin = Integer.MAX_VALUE;
240 tileMax = Integer.MIN_VALUE;
241 }
242
243 if (DO_CLEAN_DIRTY) {
244 // Force zero-fill dirty arrays:
245 rowAAChunk.fill(BYTE_0);
246 }
247 }
248
249 void clearAARow(final int y) {
250 // process tile line [0 - 32]
251 final int row = y - bboxY0;
252
253 // update pixel range:
254 rowAAx0[row] = 0; // first pixel inclusive
255 rowAAx1[row] = 0; // last pixel exclusive
256 rowAAEnc[row] = 0; // raw encoding
257
258 // note: leave rowAAChunkIndex[row] undefined
259 // and rowAALen[row] & rowAAPos[row] (RLE)
260 }
261
262 /**
263 * Copy the given alpha data into the rowAA cache
264 * @param alphaRow alpha data to copy from
265 * @param y y pixel coordinate
266 * @param px0 first pixel inclusive x0
267 * @param px1 last pixel exclusive x1
268 */
269 void copyAARowNoRLE(final int[] alphaRow, final int y,
270 final int px0, final int px1)
271 {
272 if (DO_MONITORS) {
273 rdrCtx.stats.mon_rdr_copyAARow.start();
274 }
275
276 // skip useless pixels above boundary
277 final int px_bbox1 = FloatMath.min(px1, bboxX1);
278
279 if (DO_LOG_BOUNDS) {
280 MarlinUtils.logInfo("row = [" + px0 + " ... " + px_bbox1
281 + " (" + px1 + ") [ for y=" + y);
282 }
283
284 final int row = y - bboxY0;
285
286 // update pixel range:
287 rowAAx0[row] = px0; // first pixel inclusive
288 rowAAx1[row] = px_bbox1; // last pixel exclusive
289 rowAAEnc[row] = 0; // raw encoding
290
291 // get current position (bytes):
292 final long pos = rowAAChunkPos;
293 // update row index to current position:
294 rowAAChunkIndex[row] = pos;
295
296 // determine need array size:
297 // for RLE encoding, position must be aligned to 4 bytes (int):
298 // align - 1 = 3 so add +3 and round-off by mask ~3 = -4
299 final long needSize = pos + ((px_bbox1 - px0 + 3) & -4);
300
301 // update next position (bytes):
302 rowAAChunkPos = needSize;
303
304 // update row data:
305 final OffHeapArray _rowAAChunk = rowAAChunk;
306 // ensure rowAAChunk capacity:
307 if (_rowAAChunk.length < needSize) {
308 expandRowAAChunk(needSize);
309 }
310 if (DO_STATS) {
311 rdrCtx.stats.stat_cache_rowAA.add(px_bbox1 - px0);
312 }
313
314 // rowAA contains only alpha values for range[x0; x1[
315 final int[] _touchedTile = touchedTile;
316 final int _TILE_SIZE_LG = TILE_SIZE_LG;
317
318 final int from = px0 - bboxX0; // first pixel inclusive
319 final int to = px_bbox1 - bboxX0; // last pixel exclusive
320
321 final Unsafe _unsafe = OffHeapArray.UNSAFE;
322 final long SIZE_BYTE = 1L;
323 final long addr_alpha = ALPHA_MAP_UNSAFE.address;
324 long addr_off = _rowAAChunk.address + pos;
325
326 // compute alpha sum into rowAA:
327 for (int x = from, val = 0; x < to; x++) {
328 // alphaRow is in [0; MAX_COVERAGE]
329 val += alphaRow[x]; // [from; to[
330
331 // ensure values are in [0; MAX_AA_ALPHA] range
332 if (DO_AA_RANGE_CHECK) {
333 if (val < 0) {
334 System.out.println("Invalid coverage = " + val);
335 val = 0;
336 }
337 if (val > MAX_AA_ALPHA) {
338 System.out.println("Invalid coverage = " + val);
339 val = MAX_AA_ALPHA;
340 }
341 }
342
343 // store alpha sum (as byte):
344 if (val == 0) {
345 _unsafe.putByte(addr_off, (byte)0); // [0..255]
346 } else {
347 _unsafe.putByte(addr_off, _unsafe.getByte(addr_alpha + val)); // [0..255]
348
349 // update touchedTile
350 _touchedTile[x >> _TILE_SIZE_LG] += val;
351 }
352 addr_off += SIZE_BYTE;
353 }
354
355 // update tile used marks:
356 int tx = from >> _TILE_SIZE_LG; // inclusive
357 if (tx < tileMin) {
358 tileMin = tx;
359 }
360
361 tx = ((to - 1) >> _TILE_SIZE_LG) + 1; // exclusive (+1 to be sure)
362 if (tx > tileMax) {
363 tileMax = tx;
364 }
365
366 if (DO_LOG_BOUNDS) {
367 MarlinUtils.logInfo("clear = [" + from + " ... " + to + "[");
368 }
369
370 // Clear alpha row for reuse:
371 IntArrayCache.fill(alphaRow, from, px1 - bboxX0, 0);
372
373 if (DO_MONITORS) {
374 rdrCtx.stats.mon_rdr_copyAARow.stop();
375 }
376 }
377
378 void copyAARowRLE_WithBlockFlags(final int[] blkFlags, final int[] alphaRow,
379 final int y, final int px0, final int px1)
380 {
381 if (DO_MONITORS) {
382 rdrCtx.stats.mon_rdr_copyAARow.start();
383 }
384
385 // Copy rowAA data into the piscesCache if one is present
386 final int _bboxX0 = bboxX0;
387
388 // process tile line [0 - 32]
389 final int row = y - bboxY0;
390 final int from = px0 - _bboxX0; // first pixel inclusive
391
392 // skip useless pixels above boundary
393 final int px_bbox1 = FloatMath.min(px1, bboxX1);
394 final int to = px_bbox1 - _bboxX0; // last pixel exclusive
395
396 if (DO_LOG_BOUNDS) {
397 MarlinUtils.logInfo("row = [" + px0 + " ... " + px_bbox1
398 + " (" + px1 + ") [ for y=" + y);
399 }
400
401 // get current position:
402 final long initialPos = startRLERow(row, px0, px_bbox1);
403
404 // determine need array size:
405 // pessimistic: max needed size = deltaX x 4 (1 int)
406 final long needSize = initialPos + ((to - from) << 2);
407
408 // update row data:
409 OffHeapArray _rowAAChunk = rowAAChunk;
410 // ensure rowAAChunk capacity:
411 if (_rowAAChunk.length < needSize) {
412 expandRowAAChunk(needSize);
413 }
414
415 final Unsafe _unsafe = OffHeapArray.UNSAFE;
416 final long SIZE_INT = 4L;
417 final long addr_alpha = ALPHA_MAP_UNSAFE.address;
418 long addr_off = _rowAAChunk.address + initialPos;
419
420 final int[] _touchedTile = touchedTile;
421 final int _TILE_SIZE_LG = TILE_SIZE_LG;
422 final int _BLK_SIZE_LG = BLOCK_SIZE_LG;
423
424 // traverse flagged blocks:
425 final int blkW = (from >> _BLK_SIZE_LG);
426 final int blkE = (to >> _BLK_SIZE_LG) + 1;
427
428 // Perform run-length encoding and store results in the piscesCache
429 int val = 0;
430 int cx0 = from;
431 int runLen;
432
433 final int _MAX_VALUE = Integer.MAX_VALUE;
434 int last_t0 = _MAX_VALUE;
435
436 int skip = 0;
437
438 for (int t = blkW, blk_x0, blk_x1, cx, delta; t <= blkE; t++) {
439 if (blkFlags[t] != 0) {
440 blkFlags[t] = 0;
441
442 if (last_t0 == _MAX_VALUE) {
443 last_t0 = t;
444 }
445 continue;
446 }
447 if (last_t0 != _MAX_VALUE) {
448 // emit blocks:
449 blk_x0 = FloatMath.max(last_t0 << _BLK_SIZE_LG, from);
450 last_t0 = _MAX_VALUE;
451
452 // (last block pixel+1) inclusive => +1
453 blk_x1 = FloatMath.min((t << _BLK_SIZE_LG) + 1, to);
454
455 for (cx = blk_x0; cx < blk_x1; cx++) {
456 if ((delta = alphaRow[cx]) != 0) {
457 alphaRow[cx] = 0;
458
459 // not first rle entry:
460 if (cx != cx0) {
461 runLen = cx - cx0;
462
463 // store alpha coverage (ensure within bounds):
464 // as [absX|val] where:
465 // absX is the absolute x-coordinate:
466 // note: last pixel exclusive (>= 0)
467 // note: it should check X is smaller than 23bits (overflow)!
468
469 // check address alignment to 4 bytes:
470 if (DO_CHECK_UNSAFE) {
471 if ((addr_off & 3) != 0) {
472 MarlinUtils.logInfo("Misaligned Unsafe address: " + addr_off);
473 }
474 }
475
476 // special case to encode entries into a single int:
477 if (val == 0) {
478 _unsafe.putInt(addr_off,
479 ((_bboxX0 + cx) << 8)
480 );
481 } else {
482 _unsafe.putInt(addr_off,
483 ((_bboxX0 + cx) << 8)
484 | (((int) _unsafe.getByte(addr_alpha + val)) & 0xFF) // [0..255]
485 );
486
487 if (runLen == 1) {
488 _touchedTile[cx0 >> _TILE_SIZE_LG] += val;
489 } else {
490 touchTile(cx0, val, cx, runLen, _touchedTile);
491 }
492 }
493 addr_off += SIZE_INT;
494
495 if (DO_STATS) {
496 rdrCtx.stats.hist_tile_generator_encoding_runLen
497 .add(runLen);
498 }
499 cx0 = cx;
500 }
501
502 // alpha value = running sum of coverage delta:
503 val += delta;
504
505 // ensure values are in [0; MAX_AA_ALPHA] range
506 if (DO_AA_RANGE_CHECK) {
507 if (val < 0) {
508 System.out.println("Invalid coverage = " + val);
509 val = 0;
510 }
511 if (val > MAX_AA_ALPHA) {
512 System.out.println("Invalid coverage = " + val);
513 val = MAX_AA_ALPHA;
514 }
515 }
516 }
517 }
518 } else if (DO_STATS) {
519 skip++;
520 }
521 }
522
523 // Process remaining RLE run:
524 runLen = to - cx0;
525
526 // store alpha coverage (ensure within bounds):
527 // as (int)[absX|val] where:
528 // absX is the absolute x-coordinate in bits 31 to 8 and val in bits 0..7
529 // note: last pixel exclusive (>= 0)
530 // note: it should check X is smaller than 23bits (overflow)!
531
532 // check address alignment to 4 bytes:
533 if (DO_CHECK_UNSAFE) {
534 if ((addr_off & 3) != 0) {
535 MarlinUtils.logInfo("Misaligned Unsafe address: " + addr_off);
536 }
537 }
538
539 // special case to encode entries into a single int:
540 if (val == 0) {
541 _unsafe.putInt(addr_off,
542 ((_bboxX0 + to) << 8)
543 );
544 } else {
545 _unsafe.putInt(addr_off,
546 ((_bboxX0 + to) << 8)
547 | (((int) _unsafe.getByte(addr_alpha + val)) & 0xFF) // [0..255]
548 );
549
550 if (runLen == 1) {
551 _touchedTile[cx0 >> _TILE_SIZE_LG] += val;
552 } else {
553 touchTile(cx0, val, to, runLen, _touchedTile);
554 }
555 }
556 addr_off += SIZE_INT;
557
558 if (DO_STATS) {
559 rdrCtx.stats.hist_tile_generator_encoding_runLen.add(runLen);
560 }
561
562 long len = (addr_off - _rowAAChunk.address);
563
564 // update coded length as bytes:
565 rowAALen[row] = (len - initialPos);
566
567 // update current position:
568 rowAAChunkPos = len;
569
570 if (DO_STATS) {
571 rdrCtx.stats.stat_cache_rowAA.add(rowAALen[row]);
572 rdrCtx.stats.hist_tile_generator_encoding_ratio.add(
573 (100 * skip) / (blkE - blkW)
574 );
575 }
576
577 // update tile used marks:
578 int tx = from >> _TILE_SIZE_LG; // inclusive
579 if (tx < tileMin) {
580 tileMin = tx;
581 }
582
583 tx = ((to - 1) >> _TILE_SIZE_LG) + 1; // exclusive (+1 to be sure)
584 if (tx > tileMax) {
585 tileMax = tx;
586 }
587
588 // Clear alpha row for reuse:
589 if (px1 > bboxX1) {
590 alphaRow[to ] = 0;
591 alphaRow[to + 1] = 0;
592 }
593 if (DO_CHECKS) {
594 IntArrayCache.check(blkFlags, blkW, blkE, 0);
595 IntArrayCache.check(alphaRow, from, px1 - bboxX0, 0);
596 }
597
598 if (DO_MONITORS) {
599 rdrCtx.stats.mon_rdr_copyAARow.stop();
600 }
601 }
602
603 long startRLERow(final int row, final int x0, final int x1) {
604 // rows are supposed to be added by increasing y.
605 rowAAx0[row] = x0; // first pixel inclusive
606 rowAAx1[row] = x1; // last pixel exclusive
607 rowAAEnc[row] = 1; // RLE encoding
608 rowAAPos[row] = 0L; // position = 0
609
610 // update row index to current position:
611 return (rowAAChunkIndex[row] = rowAAChunkPos);
612 }
613
614 private void expandRowAAChunk(final long needSize) {
615 if (DO_STATS) {
616 rdrCtx.stats.stat_array_marlincache_rowAAChunk.add(needSize);
617 }
618
619 // note: throw IOOB if neededSize > 2Gb:
620 final long newSize = ArrayCacheConst.getNewLargeSize(rowAAChunk.length,
621 needSize);
622
623 rowAAChunk.resize(newSize);
624 }
625
626 private void touchTile(final int x0, final int val, final int x1,
627 final int runLen,
628 final int[] _touchedTile)
629 {
630 // the x and y of the current row, minus bboxX0, bboxY0
631 // process tile line [0 - 32]
632 final int _TILE_SIZE_LG = TILE_SIZE_LG;
633
634 // update touchedTile
635 int tx = (x0 >> _TILE_SIZE_LG);
636
637 // handle trivial case: same tile (x0, x0+runLen)
638 if (tx == (x1 >> _TILE_SIZE_LG)) {
639 // same tile:
640 _touchedTile[tx] += val * runLen;
641 return;
642 }
643
644 final int tx1 = (x1 - 1) >> _TILE_SIZE_LG;
645
646 if (tx <= tx1) {
647 final int nextTileXCoord = (tx + 1) << _TILE_SIZE_LG;
648 _touchedTile[tx++] += val * (nextTileXCoord - x0);
649 }
650 if (tx < tx1) {
651 // don't go all the way to tx1 - we need to handle the last
652 // tile as a special case (just like we did with the first
653 final int tileVal = (val << _TILE_SIZE_LG);
654 for (; tx < tx1; tx++) {
655 _touchedTile[tx] += tileVal;
656 }
657 }
658 // they will be equal unless x0 >> TILE_SIZE_LG == tx1
659 if (tx == tx1) {
660 final int txXCoord = tx << _TILE_SIZE_LG;
661 final int nextTileXCoord = (tx + 1) << _TILE_SIZE_LG;
662
663 final int lastXCoord = (nextTileXCoord <= x1) ? nextTileXCoord : x1;
664 _touchedTile[tx] += val * (lastXCoord - txXCoord);
665 }
666 }
667
668 int alphaSumInTile(final int x) {
669 return touchedTile[(x - bboxX0) >> TILE_SIZE_LG];
670 }
671
672 @Override
673 public String toString() {
674 return "bbox = ["
675 + bboxX0 + ", " + bboxY0 + " => "
676 + bboxX1 + ", " + bboxY1 + "]\n";
677 }
678
679 private static byte[] buildAlphaMap(final int maxalpha) {
680 // double size !
681 final byte[] alMap = new byte[maxalpha << 1];
682 final int halfmaxalpha = maxalpha >> 2;
683 for (int i = 0; i <= maxalpha; i++) {
684 alMap[i] = (byte) ((i * 255 + halfmaxalpha) / maxalpha);
685 // System.out.println("alphaMap[" + i + "] = "
686 // + Byte.toUnsignedInt(alMap[i]));
687 }
688 return alMap;
689 }
690 }