1 /*
2 * Copyright (c) 2007, 2011, 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 cache.getBBox(bbox);
80 //System.out.println("bbox["+bbox[0]+", "+bbox[1]+" => "+bbox[2]+", "+bbox[3]+"]");
81 }
82
83 /**
84 * Gets the width of the tiles that the generator batches output into.
85 * @return the width of the standard alpha tile
86 */
87 public int getTileWidth() {
88 return TILE_SIZE;
89 }
90
91 /**
92 * Gets the height of the tiles that the generator batches output into.
93 * @return the height of the standard alpha tile
94 */
95 public int getTileHeight() {
96 return TILE_SIZE;
97 }
98
99 /**
100 * Gets the typical alpha value that will characterize the current
101 * tile.
102 * The answer may be 0x00 to indicate that the current tile has
103 * no coverage in any of its pixels, or it may be 0xff to indicate
104 * that the current tile is completely covered by the path, or any
105 * other value to indicate non-trivial coverage cases.
106 * @return 0x00 for no coverage, 0xff for total coverage, or any other
107 * value for partial coverage of the tile
108 */
109 public int getTypicalAlpha() {
110 int al = cache.alphaSumInTile(x, y);
111 // Note: if we have a filled rectangle that doesn't end on a tile
112 // border, we could still return 0xff, even though al!=maxTileAlphaSum
113 // This is because if we return 0xff, our users will fill a rectangle
114 // starting at x,y that has width = Math.min(TILE_SIZE, bboxX1-x),
115 // and height min(TILE_SIZE,bboxY1-y), which is what should happen.
116 // However, to support this, we would have to use 2 Math.min's
117 // and 2 multiplications per tile, instead of just 2 multiplications
118 // to compute maxTileAlphaSum. The savings offered would probably
119 // not be worth it, considering how rare this case is.
120 // Note: I have not tested this, so in the future if it is determined
121 // that it is worth it, it should be implemented. Perhaps this method's
122 // interface should be changed to take arguments the width and height
123 // of the current tile. This would eliminate the 2 Math.min calls that
124 // would be needed here, since our caller needs to compute these 2
125 // values anyway.
126 return (al == 0x00 ? 0x00 :
127 (al == maxTileAlphaSum ? 0xff : 0x80));
128 }
129
130 /**
131 * Skips the current tile and moves on to the next tile.
132 * Either this method, or the getAlpha() method should be called
133 * once per tile, but not both.
134 */
135 public void nextTile() {
136 if ((x += TILE_SIZE) >= cache.bboxX1) {
137 x = cache.bboxX0;
138 y += TILE_SIZE;
139 }
140 }
141
142 /**
143 * Gets the alpha coverage values for the current tile.
144 * Either this method, or the nextTile() method should be called
145 * once per tile, but not both.
146 */
147 public void getAlpha(byte tile[], int offset, int rowstride) {
148 // Decode run-length encoded alpha mask data
149 // The data for row j begins at cache.rowOffsetsRLE[j]
150 // and is encoded as a set of 2-byte pairs (val, runLen)
151 // terminated by a (0, 0) pair.
152
153 int x0 = this.x;
154 int x1 = x0 + TILE_SIZE;
155 int y0 = this.y;
156 int y1 = y0 + TILE_SIZE;
157 if (x1 > cache.bboxX1) x1 = cache.bboxX1;
158 if (y1 > cache.bboxY1) y1 = cache.bboxY1;
159 y0 -= cache.bboxY0;
160 y1 -= cache.bboxY0;
161
162 int idx = offset;
163 for (int cy = y0; cy < y1; cy++) {
164 int[] row = cache.rowAARLE[cy];
165 assert row != null;
166 int cx = cache.minTouched(cy);
167 if (cx > x1) cx = x1;
168
169 for (int i = x0; i < cx; i++) {
170 tile[idx++] = 0x00;
171 }
172
173 int pos = 2;
174 while (cx < x1 && pos < row[1]) {
175 byte val;
176 int runLen = 0;
177 assert row[1] > 2;
178 try {
179 val = alphaMap[row[pos]];
180 runLen = row[pos + 1];
181 assert runLen > 0;
182 } catch (RuntimeException e0) {
183 System.out.println("maxalpha = "+maxalpha);
184 System.out.println("tile["+x0+", "+y0+
185 " => "+x1+", "+y1+"]");
186 System.out.println("cx = "+cx+", cy = "+cy);
187 System.out.println("idx = "+idx+", pos = "+pos);
188 System.out.println("len = "+runLen);
189 System.out.print(cache.toString());
190 e0.printStackTrace();
191 throw e0;
192 }
193
194 int rx0 = cx;
195 cx += runLen;
196 int rx1 = cx;
197 if (rx0 < x0) rx0 = x0;
198 if (rx1 > x1) rx1 = x1;
199 runLen = rx1 - rx0;
200 //System.out.println("M["+runLen+"]");
201 while (--runLen >= 0) {
202 try {
203 tile[idx++] = val;
204 } catch (RuntimeException e) {
205 System.out.println("maxalpha = "+maxalpha);
206 System.out.println("tile["+x0+", "+y0+
207 " => "+x1+", "+y1+"]");
208 System.out.println("cx = "+cx+", cy = "+cy);
209 System.out.println("idx = "+idx+", pos = "+pos);
210 System.out.println("rx0 = "+rx0+", rx1 = "+rx1);
211 System.out.println("len = "+runLen);
212 System.out.print(cache.toString());
213 e.printStackTrace();
214 throw e;
215 }
216 }
217 pos += 2;
218 }
219 if (cx < x0) { cx = x0; }
220 while (cx < x1) {
221 tile[idx++] = 0x00;
222 cx++;
223 }
224 /*
225 for (int i = idx - (x1-x0); i < idx; i++) {
226 System.out.print(hex(tile[i], 2));
227 }
228 System.out.println();
229 */
230 idx += (rowstride - (x1-x0));
231 }
232 nextTile();
233 }
234
235 static String hex(int v, int d) {
236 String s = Integer.toHexString(v);
237 while (s.length() < d) {
238 s = "0"+s;
239 }
240 return s.substring(0, d);
241 }
242
243 /**
244 * Disposes this tile generator.
245 * No further calls will be made on this instance.
246 */
247 public void dispose() {}
248 }
249