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package org.apache.batik.ext.awt.image.rendered;


import java.util.List;
import java.util.ArrayList;

This class is responsible for breaking up a block of tiles into a set of smaller requests that are as large as possible without rerequesting significant numbers of tiles that are already available.
Version:$Id: TileBlock.java 1831630 2018-05-15 12:56:55Z ssteiner $
/** * This class is responsible for breaking up a block of tiles into * a set of smaller requests that are as large as possible without * rerequesting significant numbers of tiles that are already * available. * * @version $Id: TileBlock.java 1831630 2018-05-15 12:56:55Z ssteiner $ */
public class TileBlock { int occX, occY, occW, occH; int xOff, yOff, w, h, benefit; boolean [] occupied;
Construct a tile block this represents a block of contigous tiles.
Params:
  • xOff – The x index of left edge of the tile block.
  • yOff – The y index of top edge of the tile block.
  • w – The number of tiles across in the block
  • h – The number of tiles down the block
  • occupied – Which entries in the block are already computed.
/** * Construct a tile block this represents a block of contigous * tiles. * @param xOff The x index of left edge of the tile block. * @param yOff The y index of top edge of the tile block. * @param w The number of tiles across in the block * @param h The number of tiles down the block * @param occupied Which entries in the block are already * computed. */
TileBlock(int occX, int occY, int occW, int occH, boolean [] occupied, int xOff, int yOff, int w, int h) { this.occX = occX; this.occY = occY; this.occW = occW; this.occH = occH; this.xOff = xOff; this.yOff = yOff; this.w = w ; this.h = h ; this.occupied = occupied; // System.out.println("Block: [" + // xloc + "," + yloc + "," + // w + "," + h + "]"); for (int y=0; y<h; y++) for (int x=0; x<w; x++) if (!occupied[x+xOff+occW*(y+yOff)]) benefit++; }
Really nice to string that outlines what tiles are filled and what region this block covers. Really useful for debugging the TileBlock stuff.
/** * Really nice to string that outlines what tiles are filled * and what region this block covers. Really useful for * debugging the TileBlock stuff. */
public String toString() { String ret = ""; for (int y=0; y<occH; y++) { for (int x=0; x<occW+1; x++) { if ((x==xOff) || (x==xOff+w)) { if ((y==yOff) || (y==yOff+h-1)) ret += "+"; else if ((y>yOff) && (y<yOff+h-1)) ret += "|"; else ret += " "; } else if ((y==yOff) && (x> xOff) && (x < xOff+w)) ret += "-"; else if ((y==yOff+h-1) && (x> xOff) && (x < xOff+w)) ret += "_"; else ret += " "; if (x== occW) continue; if (occupied[x+y*occW]) ret += "*"; else ret += "."; } ret += "\n"; } return ret; }
Return the x location of this block of tiles
/** * Return the x location of this block of tiles */
int getXLoc() { return occX+xOff; }
Return the y location of this block of tiles
/** * Return the y location of this block of tiles */
int getYLoc() { return occY+yOff; }
Return the width of this block of tiles
/** * Return the width of this block of tiles */
int getWidth() { return w; }
Return the height of this block of tiles
/** * Return the height of this block of tiles */
int getHeight() { return h; }
Return the number of new tiles computed.
/** * Return the number of new tiles computed. */
int getBenefit() { return benefit; }
Return the approximate amount of work required to compute those tiles.
/** * Return the approximate amount of work required to compute * those tiles. */
int getWork() { return w*h+1; }
Returns the total amount of work for the array of tile blocks
/** * Returns the total amount of work for the array of tile blocks */
static int getWork(TileBlock [] blocks) { int ret=0; for (TileBlock block : blocks) ret += block.getWork(); return ret; }
Returnes an optimized list of TileBlocks to generate that tries to minimize the work to benefit ratio, for the set of blocks defined by this block.
/** * Returnes an optimized list of TileBlocks to generate that * tries to minimize the work to benefit ratio, for the set of * blocks defined by this block. */
TileBlock [] getBestSplit() { if (simplify()) return null; // Optimal split already... if (benefit == w*h) return new TileBlock [] { this }; return splitOneGo(); } public TileBlock [] splitOneGo() { boolean [] filled = occupied.clone(); List items = new ArrayList(); for (int y=yOff; y<yOff+h; y++) for (int x=xOff; x<xOff+w; x++) { if (!filled[x+y*occW]) { // We have an unfilled tile slot, so first we // figure out how long the slot is in this row. int cw = xOff+w-x; for (int cx=x; cx<x+cw; cx++) if (filled[cx+y*occW]) cw = cx-x; else filled[cx+y*occW] = true; // fill as we go.. // Then we check the next rows until we hit // a row that doesn't have this slot all free. // at which point we stop... int ch=1; for (int cy=y+1; cy<yOff+h; cy++) { int cx=x; for (; cx<x+cw; cx++) if (filled[cx+cy*occW]) break; // Partial row so bail (we'll get it later..) if (cx != x+cw) break; // Fill in the slot since we will use it... for (cx=x; cx<x+cw; cx++) filled[cx+cy*occW] = true; ch++; } items.add(new TileBlock(occX, occY, occW, occH, occupied, x, y, cw, ch)); x+=(cw-1); } } TileBlock [] ret = new TileBlock[items.size()]; items.toArray( ret ); return ret; } public boolean simplify() { boolean[] workOccupied = occupied; // local is cheaper for (int y=0; y<h; y++) { int x; for (x=0; x<w; x++) if (!workOccupied[x+xOff+occW*(y+yOff)]) break; if (x!=w) break; // Fully occupied row so remove it. yOff++; y--; h--; } // return true if we were simplified out of existance. if (h==0) return true; // If we make it past here we must have at least one good block. for (int y=h-1; y>=0; y--) { int x; for (x=0; x<w; x++) if (!workOccupied[x+xOff+occW*(y+yOff)]) break; if (x!=w) break; // Fully occupied row so remove it. h--; } for (int x=0; x<w; x++) { int y; for (y=0; y<h; y++) if (!workOccupied[x+xOff+occW*(y+yOff)]) break; if (y!=h) break; // Fully occupied Col so remove it. xOff++; x--; w--; } for (int x=w-1; x>=0; x--) { int y; for (y=0; y<h; y++) if (!workOccupied[x+xOff+occW*(y+yOff)]) break; if (y!=h) break; // Fully occupied Col so remove it. w--; } return false; } }