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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
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	package sun.java2d.pisces;

	import java.util.Arrays;

	/**
	* An object used to cache pre-rendered complex paths.
	*
	* @see PiscesRenderer#render
	*/
	final class PiscesCache {

	final int bboxX0, bboxY0, bboxX1, bboxY1;

	// rowAARLE[i] holds the encoding of the pixel row with y = bboxY0+i.
	// The format of each of the inner arrays is: rowAARLE[i][0,1] = (x0, n)
	// where x0 is the first x in row i with nonzero alpha, and n is the
	// number of RLE entries in this row. rowAARLE[i][j,j+1] for j>1 is
	// (val,runlen)
	final int[][] rowAARLE;

	// RLE encodings are added in increasing y rows and then in increasing
	// x inside those rows. Therefore, at any one time there is a well
	// defined position (x,y) where a run length is about to be added (or
	// the row terminated). x0,y0 is this (x,y)-(bboxX0,bboxY0). They
	// are used to get indices into the current tile.
	private int x0 = Integer.MIN_VALUE, y0 = Integer.MIN_VALUE;

	// touchedTile[i][j] is the sum of all the alphas in the tile with
	// y=iTILE_SIZE+bboxY0 and x=jTILE_SIZE+bboxX0.
	private final int[][] touchedTile;

	static final int TILE_SIZE_LG = 5;
	static final int TILE_SIZE = 1 << TILE_SIZE_LG; // 32
	private static final int INIT_ROW_SIZE = 8; // enough for 3 run lengths

	PiscesCache(int minx, int miny, int maxx, int maxy) {
	assert maxy >= miny && maxx >= minx;
	bboxX0 = minx;
	bboxY0 = miny;
	bboxX1 = maxx + 1;
	bboxY1 = maxy + 1;
	// we could just leave the inner arrays as null and allocate them
	// lazily (which would be beneficial for shapes with gaps), but we
	// assume there won't be too many of those so we allocate everything
	// up front (which is better for other cases)
	rowAARLE = new int[bboxY1 - bboxY0 + 1][INIT_ROW_SIZE];
	x0 = 0;
	y0 = -1; // -1 makes the first assert in startRow succeed
	// the ceiling of (maxy - miny + 1) / TILE_SIZE;
	int nyTiles = (maxy - miny + TILE_SIZE) >> TILE_SIZE_LG;
	int nxTiles = (maxx - minx + TILE_SIZE) >> TILE_SIZE_LG;

	touchedTile = new int[nyTiles][nxTiles];
	}

	void addRLERun(int val, int runLen) {
	if (runLen > 0) {
	addTupleToRow(y0, val, runLen);
	if (val != 0) {
	// the x and y of the current row, minus bboxX0, bboxY0
	int tx = x0 >> TILE_SIZE_LG;
	int ty = y0 >> TILE_SIZE_LG;
	int tx1 = (x0 + runLen - 1) >> TILE_SIZE_LG;
	// while we forbid rows from starting before bboxx0, our users
	// can still store rows that go beyond bboxx1 (although this
	// shouldn't happen), so it's a good idea to check that i
	// is not going out of bounds in touchedTile[ty]
	if (tx1 >= touchedTile[ty].length) {
	tx1 = touchedTile[ty].length - 1;
	}
	if (tx <= tx1) {
	int nextTileXCoord = (tx + 1) << TILE_SIZE_LG;
	if (nextTileXCoord > x0+runLen) {
	touchedTile[ty][tx] += val * runLen;
	} else {
	touchedTile[ty][tx] += val * (nextTileXCoord - x0);
	}
	tx++;
	}
	// don't go all the way to tx1 - we need to handle the last
	// tile as a special case (just like we did with the first
	for (; tx < tx1; tx++) {
	// try {
	touchedTile[ty][tx] += (val << TILE_SIZE_LG);
	// } catch (RuntimeException e) {
	// System.out.println("x0, y0: " + x0 + ", " + y0);
	// System.out.printf("tx, ty, tx1: %d, %d, %d %n", tx, ty, tx1);
	// System.out.printf("bboxX/Y0/1: %d, %d, %d, %d %n",
	// bboxX0, bboxY0, bboxX1, bboxY1);
	// throw e;
	// }
	}
	// they will be equal unless x0>>TILE_SIZE_LG == tx1
	if (tx == tx1) {
	int lastXCoord = Math.min(x0 + runLen, (tx + 1) << TILE_SIZE_LG);
	int txXCoord = tx << TILE_SIZE_LG;
	touchedTile[ty][tx] += val * (lastXCoord - txXCoord);
	}
	}
	x0 += runLen;
	}
	}

	void startRow(int y, int x) {
	// rows are supposed to be added by increasing y.
	assert y - bboxY0 > y0;
	assert y <= bboxY1; // perhaps this should be < instead of <=

	y0 = y - bboxY0;
	// this should be a new, uninitialized row.
	assert rowAARLE[y0][1] == 0;

	x0 = x - bboxX0;
	assert x0 >= 0 : "Input must not be to the left of bbox bounds";

	// the way addTupleToRow is implemented it would work for this but it's
	// not a good idea to use it because it is meant for adding
	// RLE tuples, not the first tuple (which is special).
	rowAARLE[y0][0] = x;
	rowAARLE[y0][1] = 2;
	}

	int alphaSumInTile(int x, int y) {
	x -= bboxX0;
	y -= bboxY0;
	return touchedTile[y>>TILE_SIZE_LG][x>>TILE_SIZE_LG];
	}

	int minTouched(int rowidx) {
	return rowAARLE[rowidx][0];
	}

	int rowLength(int rowidx) {
	return rowAARLE[rowidx][1];
	}

	private void addTupleToRow(int row, int a, int b) {
	int end = rowAARLE[row][1];
	rowAARLE[row] = Helpers.widenArray(rowAARLE[row], end, 2);
	rowAARLE[row][end++] = a;
	rowAARLE[row][end++] = b;
	rowAARLE[row][1] = end;
	}

	@Override
	public String toString() {
	String ret = "bbox = ["+
	bboxX0+", "+bboxY0+" => "+
	bboxX1+", "+bboxY1+"]\n";
	for (int[] row : rowAARLE) {
	if (row != null) {
	ret += ("minTouchedX=" + row[0] +
	"\tRLE Entries: " + Arrays.toString(
	Arrays.copyOfRange(row, 2, row[1])) + "\n");
	} else {
	ret += "[]\n";
	}
	}
	return ret;
	}
	}

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