1 /* 2 * Copyright (c) 2007, 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.pisces; 27 28 import java.util.Map; 29 import java.util.concurrent.ConcurrentHashMap; 30 31 import sun.java2d.pipe.AATileGenerator; 32 33 final class PiscesTileGenerator implements AATileGenerator { 34 public static final int TILE_SIZE = PiscesCache.TILE_SIZE; 35 36 // perhaps we should be using weak references here, but right now 37 // that's not necessary. The way the renderer is, this map will 38 // never contain more than one element - the one with key 64, since 39 // we only do 8x8 supersampling. 40 private static final Map<Integer, byte[]> alphaMapsCache = new 41 ConcurrentHashMap<Integer, byte[]>(); 42 43 PiscesCache cache; 44 int x, y; 45 final int maxalpha; 46 private final int maxTileAlphaSum; 47 48 // The alpha map used by this object (taken out of our map cache) to convert 49 // pixel coverage counts gotten from PiscesCache (which are in the range 50 // [0, maxalpha]) into alpha values, which are in [0,256). 51 byte alphaMap[]; 52 53 public PiscesTileGenerator(Renderer r, int maxalpha) { 54 this.cache = r.getCache(); 55 this.x = cache.bboxX0; 56 this.y = cache.bboxY0; 57 this.alphaMap = getAlphaMap(maxalpha); 58 this.maxalpha = maxalpha; 59 this.maxTileAlphaSum = TILE_SIZE*TILE_SIZE*maxalpha; 60 } 61 62 private static byte[] buildAlphaMap(int maxalpha) { 63 byte[] alMap = new byte[maxalpha+1]; 64 int halfmaxalpha = maxalpha>>2; 65 for (int i = 0; i <= maxalpha; i++) { 66 alMap[i] = (byte) ((i * 255 + halfmaxalpha) / maxalpha); 67 } 68 return alMap; 69 } 70 71 public static byte[] getAlphaMap(int maxalpha) { 72 if (!alphaMapsCache.containsKey(maxalpha)) { 73 alphaMapsCache.put(maxalpha, buildAlphaMap(maxalpha)); 74 } 75 return alphaMapsCache.get(maxalpha); 76 } 77 78 public void getBbox(int bbox[]) { 79 bbox[0] = cache.bboxX0; 80 bbox[1] = cache.bboxY0; 81 bbox[2] = cache.bboxX1; 82 bbox[3] = cache.bboxY1; 83 //System.out.println("bbox["+bbox[0]+", "+bbox[1]+" => "+bbox[2]+", "+bbox[3]+"]"); 84 } 85 86 /** 87 * Gets the width of the tiles that the generator batches output into. 88 * @return the width of the standard alpha tile 89 */ 90 public int getTileWidth() { 91 return TILE_SIZE; 92 } 93 94 /** 95 * Gets the height of the tiles that the generator batches output into. 96 * @return the height of the standard alpha tile 97 */ 98 public int getTileHeight() { 99 return TILE_SIZE; 100 } 101 102 /** 103 * Gets the typical alpha value that will characterize the current 104 * tile. 105 * The answer may be 0x00 to indicate that the current tile has 106 * no coverage in any of its pixels, or it may be 0xff to indicate 107 * that the current tile is completely covered by the path, or any 108 * other value to indicate non-trivial coverage cases. 109 * @return 0x00 for no coverage, 0xff for total coverage, or any other 110 * value for partial coverage of the tile 111 */ 112 public int getTypicalAlpha() { 113 int al = cache.alphaSumInTile(x, y); 114 // Note: if we have a filled rectangle that doesn't end on a tile 115 // border, we could still return 0xff, even though al!=maxTileAlphaSum 116 // This is because if we return 0xff, our users will fill a rectangle 117 // starting at x,y that has width = Math.min(TILE_SIZE, bboxX1-x), 118 // and height min(TILE_SIZE,bboxY1-y), which is what should happen. 119 // However, to support this, we would have to use 2 Math.min's 120 // and 2 multiplications per tile, instead of just 2 multiplications 121 // to compute maxTileAlphaSum. The savings offered would probably 122 // not be worth it, considering how rare this case is. 123 // Note: I have not tested this, so in the future if it is determined 124 // that it is worth it, it should be implemented. Perhaps this method's 125 // interface should be changed to take arguments the width and height 126 // of the current tile. This would eliminate the 2 Math.min calls that 127 // would be needed here, since our caller needs to compute these 2 128 // values anyway. 129 return (al == 0x00 ? 0x00 : 130 (al == maxTileAlphaSum ? 0xff : 0x80)); 131 } 132 133 /** 134 * Skips the current tile and moves on to the next tile. 135 * Either this method, or the getAlpha() method should be called 136 * once per tile, but not both. 137 */ 138 public void nextTile() { 139 if ((x += TILE_SIZE) >= cache.bboxX1) { 140 x = cache.bboxX0; 141 y += TILE_SIZE; 142 } 143 } 144 145 /** 146 * Gets the alpha coverage values for the current tile. 147 * Either this method, or the nextTile() method should be called 148 * once per tile, but not both. 149 */ 150 public void getAlpha(byte tile[], int offset, int rowstride) { 151 // Decode run-length encoded alpha mask data 152 // The data for row j begins at cache.rowOffsetsRLE[j] 153 // and is encoded as a set of 2-byte pairs (val, runLen) 154 // terminated by a (0, 0) pair. 155 156 int x0 = this.x; 157 int x1 = x0 + TILE_SIZE; 158 int y0 = this.y; 159 int y1 = y0 + TILE_SIZE; 160 if (x1 > cache.bboxX1) x1 = cache.bboxX1; 161 if (y1 > cache.bboxY1) y1 = cache.bboxY1; 162 y0 -= cache.bboxY0; 163 y1 -= cache.bboxY0; 164 165 int idx = offset; 166 for (int cy = y0; cy < y1; cy++) { 167 int[] row = cache.rowAARLE[cy]; 168 assert row != null; 169 int cx = cache.minTouched(cy); 170 if (cx > x1) cx = x1; 171 172 for (int i = x0; i < cx; i++) { 173 tile[idx++] = 0x00; 174 } 175 176 int pos = 2; 177 while (cx < x1 && pos < row[1]) { 178 byte val; 179 int runLen = 0; 180 assert row[1] > 2; 181 try { 182 val = alphaMap[row[pos]]; 183 runLen = row[pos + 1]; 184 assert runLen > 0; 185 } catch (RuntimeException e0) { 186 System.out.println("maxalpha = "+maxalpha); 187 System.out.println("tile["+x0+", "+y0+ 188 " => "+x1+", "+y1+"]"); 189 System.out.println("cx = "+cx+", cy = "+cy); 190 System.out.println("idx = "+idx+", pos = "+pos); 191 System.out.println("len = "+runLen); 192 System.out.print(cache.toString()); 193 e0.printStackTrace(); 194 throw e0; 195 } 196 197 int rx0 = cx; 198 cx += runLen; 199 int rx1 = cx; 200 if (rx0 < x0) rx0 = x0; 201 if (rx1 > x1) rx1 = x1; 202 runLen = rx1 - rx0; 203 //System.out.println("M["+runLen+"]"); 204 while (--runLen >= 0) { 205 try { 206 tile[idx++] = val; 207 } catch (RuntimeException e) { 208 System.out.println("maxalpha = "+maxalpha); 209 System.out.println("tile["+x0+", "+y0+ 210 " => "+x1+", "+y1+"]"); 211 System.out.println("cx = "+cx+", cy = "+cy); 212 System.out.println("idx = "+idx+", pos = "+pos); 213 System.out.println("rx0 = "+rx0+", rx1 = "+rx1); 214 System.out.println("len = "+runLen); 215 System.out.print(cache.toString()); 216 e.printStackTrace(); 217 throw e; 218 } 219 } 220 pos += 2; 221 } 222 if (cx < x0) { cx = x0; } 223 while (cx < x1) { 224 tile[idx++] = 0x00; 225 cx++; 226 } 227 /* 228 for (int i = idx - (x1-x0); i < idx; i++) { 229 System.out.print(hex(tile[i], 2)); 230 } 231 System.out.println(); 232 */ 233 idx += (rowstride - (x1-x0)); 234 } 235 nextTile(); 236 } 237 238 static String hex(int v, int d) { 239 String s = Integer.toHexString(v); 240 while (s.length() < d) { 241 s = "0"+s; 242 } 243 return s.substring(0, d); 244 } 245 246 /** 247 * Disposes this tile generator. 248 * No further calls will be made on this instance. 249 */ 250 public void dispose() {} 251 } 252