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	/*
	* Copyright (c) 2007, 2011, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package sun.java2d.pisces;

	import java.util.Map;
	import java.util.concurrent.ConcurrentHashMap;

	import sun.java2d.pipe.AATileGenerator;

	final class PiscesTileGenerator implements AATileGenerator {
	public static final int TILE_SIZE = PiscesCache.TILE_SIZE;

	// perhaps we should be using weak references here, but right now
	// that's not necessary. The way the renderer is, this map will
	// never contain more than one element - the one with key 64, since
	// we only do 8x8 supersampling.
	private static final Map<Integer, byte[]> alphaMapsCache = new
	ConcurrentHashMap<Integer, byte[]>();

	PiscesCache cache;
	int x, y;
	final int maxalpha;
	private final int maxTileAlphaSum;

	// The alpha map used by this object (taken out of our map cache) to convert
	// pixel coverage counts gotten from PiscesCache (which are in the range
	// [0, maxalpha]) into alpha values, which are in [0,256).
	byte alphaMap[];

	public PiscesTileGenerator(Renderer r, int maxalpha) {
	this.cache = r.getCache();
	this.x = cache.bboxX0;
	this.y = cache.bboxY0;
	this.alphaMap = getAlphaMap(maxalpha);
	this.maxalpha = maxalpha;
	this.maxTileAlphaSum = TILE_SIZETILE_SIZEmaxalpha;
	}

	private static byte[] buildAlphaMap(int maxalpha) {
	byte[] alMap = new byte[maxalpha+1];
	int halfmaxalpha = maxalpha>>2;
	for (int i = 0; i <= maxalpha; i++) {
	alMap[i] = (byte) ((i * 255 + halfmaxalpha) / maxalpha);
	}
	return alMap;
	}

	public static byte[] getAlphaMap(int maxalpha) {
	if (!alphaMapsCache.containsKey(maxalpha)) {
	alphaMapsCache.put(maxalpha, buildAlphaMap(maxalpha));
	}
	return alphaMapsCache.get(maxalpha);
	}

	public void getBbox(int bbox[]) {
	bbox[0] = cache.bboxX0;
	bbox[1] = cache.bboxY0;
	bbox[2] = cache.bboxX1;
	bbox[3] = cache.bboxY1;
	//System.out.println("bbox["+bbox[0]+", "+bbox[1]+" => "+bbox[2]+", "+bbox[3]+"]");
	}

	/**
	* Gets the width of the tiles that the generator batches output into.
	* @return the width of the standard alpha tile
	*/
	public int getTileWidth() {
	return TILE_SIZE;
	}

	/**
	* Gets the height of the tiles that the generator batches output into.
	* @return the height of the standard alpha tile
	*/
	public int getTileHeight() {
	return TILE_SIZE;
	}

	/**
	* Gets the typical alpha value that will characterize the current
	* tile.
	* The answer may be 0x00 to indicate that the current tile has
	* no coverage in any of its pixels, or it may be 0xff to indicate
	* that the current tile is completely covered by the path, or any
	* other value to indicate non-trivial coverage cases.
	* @return 0x00 for no coverage, 0xff for total coverage, or any other
	* value for partial coverage of the tile
	*/
	public int getTypicalAlpha() {
	int al = cache.alphaSumInTile(x, y);
	// Note: if we have a filled rectangle that doesn't end on a tile
	// border, we could still return 0xff, even though al!=maxTileAlphaSum
	// This is because if we return 0xff, our users will fill a rectangle
	// starting at x,y that has width = Math.min(TILE_SIZE, bboxX1-x),
	// and height min(TILE_SIZE,bboxY1-y), which is what should happen.
	// However, to support this, we would have to use 2 Math.min's
	// and 2 multiplications per tile, instead of just 2 multiplications
	// to compute maxTileAlphaSum. The savings offered would probably
	// not be worth it, considering how rare this case is.
	// Note: I have not tested this, so in the future if it is determined
	// that it is worth it, it should be implemented. Perhaps this method's
	// interface should be changed to take arguments the width and height
	// of the current tile. This would eliminate the 2 Math.min calls that
	// would be needed here, since our caller needs to compute these 2
	// values anyway.
	return (al == 0x00 ? 0x00 :
	(al == maxTileAlphaSum ? 0xff : 0x80));
	}

	/**
	* Skips the current tile and moves on to the next tile.
	* Either this method, or the getAlpha() method should be called
	* once per tile, but not both.
	*/
	public void nextTile() {
	if ((x += TILE_SIZE) >= cache.bboxX1) {
	x = cache.bboxX0;
	y += TILE_SIZE;
	}
	}

	/**
	* Gets the alpha coverage values for the current tile.
	* Either this method, or the nextTile() method should be called
	* once per tile, but not both.
	*/
	public void getAlpha(byte tile[], int offset, int rowstride) {
	// Decode run-length encoded alpha mask data
	// The data for row j begins at cache.rowOffsetsRLE[j]
	// and is encoded as a set of 2-byte pairs (val, runLen)
	// terminated by a (0, 0) pair.

	int x0 = this.x;
	int x1 = x0 + TILE_SIZE;
	int y0 = this.y;
	int y1 = y0 + TILE_SIZE;
	if (x1 > cache.bboxX1) x1 = cache.bboxX1;
	if (y1 > cache.bboxY1) y1 = cache.bboxY1;
	y0 -= cache.bboxY0;
	y1 -= cache.bboxY0;

	int idx = offset;
	for (int cy = y0; cy < y1; cy++) {
	int[] row = cache.rowAARLE[cy];
	assert row != null;
	int cx = cache.minTouched(cy);
	if (cx > x1) cx = x1;

	for (int i = x0; i < cx; i++) {
	tile[idx++] = 0x00;
	}

	int pos = 2;
	while (cx < x1 && pos < row[1]) {
	byte val;
	int runLen = 0;
	assert row[1] > 2;
	try {
	val = alphaMap[row[pos]];
	runLen = row[pos + 1];
	assert runLen > 0;
	} catch (RuntimeException e0) {
	System.out.println("maxalpha = "+maxalpha);
	System.out.println("tile["+x0+", "+y0+
	" => "+x1+", "+y1+"]");
	System.out.println("cx = "+cx+", cy = "+cy);
	System.out.println("idx = "+idx+", pos = "+pos);
	System.out.println("len = "+runLen);
	System.out.print(cache.toString());
	e0.printStackTrace();
	throw e0;
	}

	int rx0 = cx;
	cx += runLen;
	int rx1 = cx;
	if (rx0 < x0) rx0 = x0;
	if (rx1 > x1) rx1 = x1;
	runLen = rx1 - rx0;
	//System.out.println("M["+runLen+"]");
	while (--runLen >= 0) {
	try {
	tile[idx++] = val;
	} catch (RuntimeException e) {
	System.out.println("maxalpha = "+maxalpha);
	System.out.println("tile["+x0+", "+y0+
	" => "+x1+", "+y1+"]");
	System.out.println("cx = "+cx+", cy = "+cy);
	System.out.println("idx = "+idx+", pos = "+pos);
	System.out.println("rx0 = "+rx0+", rx1 = "+rx1);
	System.out.println("len = "+runLen);
	System.out.print(cache.toString());
	e.printStackTrace();
	throw e;
	}
	}
	pos += 2;
	}
	if (cx < x0) { cx = x0; }
	while (cx < x1) {
	tile[idx++] = 0x00;
	cx++;
	}
	/*
	for (int i = idx - (x1-x0); i < idx; i++) {
	System.out.print(hex(tile[i], 2));
	}
	System.out.println();
	*/
	idx += (rowstride - (x1-x0));
	}
	nextTile();
	}

	static String hex(int v, int d) {
	String s = Integer.toHexString(v);
	while (s.length() < d) {
	s = "0"+s;
	}
	return s.substring(0, d);
	}

	/**
	* Disposes this tile generator.
	* No further calls will be made on this instance.
	*/
	public void dispose() {}
	}

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