J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1995-2006 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | /*- |
| 27 | * Reads GIF images from an InputStream and reports the |
| 28 | * image data to an InputStreamImageSource object. |
| 29 | * |
| 30 | * The algorithm is copyright of CompuServe. |
| 31 | */ |
| 32 | package sun.awt.image; |
| 33 | |
| 34 | import java.util.Vector; |
| 35 | import java.util.Hashtable; |
| 36 | import java.io.InputStream; |
| 37 | import java.io.IOException; |
| 38 | import java.awt.image.*; |
| 39 | |
| 40 | /** |
| 41 | * Gif Image converter |
| 42 | * |
| 43 | * @author Arthur van Hoff |
| 44 | * @author Jim Graham |
| 45 | */ |
| 46 | public class GifImageDecoder extends ImageDecoder { |
| 47 | private static final boolean verbose = false; |
| 48 | |
| 49 | private static final int IMAGESEP = 0x2c; |
| 50 | private static final int EXBLOCK = 0x21; |
| 51 | private static final int EX_GRAPHICS_CONTROL= 0xf9; |
| 52 | private static final int EX_COMMENT = 0xfe; |
| 53 | private static final int EX_APPLICATION = 0xff; |
| 54 | private static final int TERMINATOR = 0x3b; |
| 55 | private static final int TRANSPARENCYMASK = 0x01; |
| 56 | private static final int INTERLACEMASK = 0x40; |
| 57 | private static final int COLORMAPMASK = 0x80; |
| 58 | |
| 59 | int num_global_colors; |
| 60 | byte[] global_colormap; |
| 61 | int trans_pixel = -1; |
| 62 | IndexColorModel global_model; |
| 63 | |
| 64 | Hashtable props = new Hashtable(); |
| 65 | |
| 66 | byte[] saved_image; |
| 67 | IndexColorModel saved_model; |
| 68 | |
| 69 | int global_width; |
| 70 | int global_height; |
| 71 | int global_bgpixel; |
| 72 | |
| 73 | GifFrame curframe; |
| 74 | |
| 75 | public GifImageDecoder(InputStreamImageSource src, InputStream is) { |
| 76 | super(src, is); |
| 77 | } |
| 78 | |
| 79 | /** |
| 80 | * An error has occurred. Throw an exception. |
| 81 | */ |
| 82 | private static void error(String s1) throws ImageFormatException { |
| 83 | throw new ImageFormatException(s1); |
| 84 | } |
| 85 | |
| 86 | /** |
| 87 | * Read a number of bytes into a buffer. |
| 88 | * @return number of bytes that were not read due to EOF or error |
| 89 | */ |
| 90 | private int readBytes(byte buf[], int off, int len) { |
| 91 | while (len > 0) { |
| 92 | try { |
| 93 | int n = input.read(buf, off, len); |
| 94 | if (n < 0) { |
| 95 | break; |
| 96 | } |
| 97 | off += n; |
| 98 | len -= n; |
| 99 | } catch (IOException e) { |
| 100 | break; |
| 101 | } |
| 102 | } |
| 103 | return len; |
| 104 | } |
| 105 | |
| 106 | private static final int ExtractByte(byte buf[], int off) { |
| 107 | return (buf[off] & 0xFF); |
| 108 | } |
| 109 | |
| 110 | private static final int ExtractWord(byte buf[], int off) { |
| 111 | return (buf[off] & 0xFF) | ((buf[off + 1] & 0xFF) << 8); |
| 112 | } |
| 113 | |
| 114 | /** |
| 115 | * produce an image from the stream. |
| 116 | */ |
| 117 | public void produceImage() throws IOException, ImageFormatException { |
| 118 | try { |
| 119 | readHeader(); |
| 120 | |
| 121 | int totalframes = 0; |
| 122 | int frameno = 0; |
| 123 | int nloops = -1; |
| 124 | int disposal_method = 0; |
| 125 | int delay = -1; |
| 126 | boolean loopsRead = false; |
| 127 | boolean isAnimation = false; |
| 128 | |
| 129 | while (!aborted) { |
| 130 | int code; |
| 131 | |
| 132 | switch (code = input.read()) { |
| 133 | case EXBLOCK: |
| 134 | switch (code = input.read()) { |
| 135 | case EX_GRAPHICS_CONTROL: { |
| 136 | byte buf[] = new byte[6]; |
| 137 | if (readBytes(buf, 0, 6) != 0) { |
| 138 | return;//error("corrupt GIF file"); |
| 139 | } |
| 140 | if ((buf[0] != 4) || (buf[5] != 0)) { |
| 141 | return;//error("corrupt GIF file (GCE size)"); |
| 142 | } |
| 143 | // Get the index of the transparent color |
| 144 | delay = ExtractWord(buf, 2) * 10; |
| 145 | if (delay > 0 && !isAnimation) { |
| 146 | isAnimation = true; |
| 147 | ImageFetcher.startingAnimation(); |
| 148 | } |
| 149 | disposal_method = (buf[1] >> 2) & 7; |
| 150 | if ((buf[1] & TRANSPARENCYMASK) != 0) { |
| 151 | trans_pixel = ExtractByte(buf, 4); |
| 152 | } else { |
| 153 | trans_pixel = -1; |
| 154 | } |
| 155 | break; |
| 156 | } |
| 157 | |
| 158 | case EX_COMMENT: |
| 159 | case EX_APPLICATION: |
| 160 | default: |
| 161 | boolean loop_tag = false; |
| 162 | String comment = ""; |
| 163 | while (true) { |
| 164 | int n = input.read(); |
| 165 | if (n <= 0) { |
| 166 | break; |
| 167 | } |
| 168 | byte buf[] = new byte[n]; |
| 169 | if (readBytes(buf, 0, n) != 0) { |
| 170 | return;//error("corrupt GIF file"); |
| 171 | } |
| 172 | if (code == EX_COMMENT) { |
| 173 | comment += new String(buf, 0); |
| 174 | } else if (code == EX_APPLICATION) { |
| 175 | if (loop_tag) { |
| 176 | if (n == 3 && buf[0] == 1) { |
| 177 | if (loopsRead) { |
| 178 | ExtractWord(buf, 1); |
| 179 | } |
| 180 | else { |
| 181 | nloops = ExtractWord(buf, 1); |
| 182 | loopsRead = true; |
| 183 | } |
| 184 | } else { |
| 185 | loop_tag = false; |
| 186 | } |
| 187 | } |
| 188 | if ("NETSCAPE2.0".equals(new String(buf, 0))) { |
| 189 | loop_tag = true; |
| 190 | } |
| 191 | } |
| 192 | } |
| 193 | if (code == EX_COMMENT) { |
| 194 | props.put("comment", comment); |
| 195 | } |
| 196 | if (loop_tag && !isAnimation) { |
| 197 | isAnimation = true; |
| 198 | ImageFetcher.startingAnimation(); |
| 199 | } |
| 200 | break; |
| 201 | |
| 202 | case -1: |
| 203 | return; //error("corrupt GIF file"); |
| 204 | } |
| 205 | break; |
| 206 | |
| 207 | case IMAGESEP: |
| 208 | if (!isAnimation) { |
| 209 | input.mark(0); // we don't need the mark buffer |
| 210 | } |
| 211 | try { |
| 212 | if (!readImage(totalframes == 0, |
| 213 | disposal_method, |
| 214 | delay)) { |
| 215 | return; |
| 216 | } |
| 217 | } catch (Exception e) { |
| 218 | if (verbose) { |
| 219 | e.printStackTrace(); |
| 220 | } |
| 221 | return; |
| 222 | } |
| 223 | frameno++; |
| 224 | totalframes++; |
| 225 | break; |
| 226 | |
| 227 | default: |
| 228 | case -1: |
| 229 | if (verbose) { |
| 230 | if (code == -1) { |
| 231 | System.err.println("Premature EOF in GIF file," + |
| 232 | " frame " + frameno); |
| 233 | } else { |
| 234 | System.err.println("corrupt GIF file (parse) [" |
| 235 | + code + "]."); |
| 236 | } |
| 237 | } |
| 238 | if (frameno == 0) { |
| 239 | return; |
| 240 | } |
| 241 | // NOBREAK |
| 242 | |
| 243 | case TERMINATOR: |
| 244 | if (nloops == 0 || nloops-- >= 0) { |
| 245 | try { |
| 246 | if (curframe != null) { |
| 247 | curframe.dispose(); |
| 248 | curframe = null; |
| 249 | } |
| 250 | input.reset(); |
| 251 | saved_image = null; |
| 252 | saved_model = null; |
| 253 | frameno = 0; |
| 254 | break; |
| 255 | } catch (IOException e) { |
| 256 | return; // Unable to reset input buffer |
| 257 | } |
| 258 | } |
| 259 | if (verbose && frameno != 1) { |
| 260 | System.out.println("processing GIF terminator," |
| 261 | + " frames: " + frameno |
| 262 | + " total: " + totalframes); |
| 263 | } |
| 264 | imageComplete(ImageConsumer.STATICIMAGEDONE, true); |
| 265 | return; |
| 266 | } |
| 267 | } |
| 268 | } finally { |
| 269 | close(); |
| 270 | } |
| 271 | } |
| 272 | |
| 273 | /** |
| 274 | * Read Image header |
| 275 | */ |
| 276 | private void readHeader() throws IOException, ImageFormatException { |
| 277 | // Create a buffer |
| 278 | byte buf[] = new byte[13]; |
| 279 | |
| 280 | // Read the header |
| 281 | if (readBytes(buf, 0, 13) != 0) { |
| 282 | throw new IOException(); |
| 283 | } |
| 284 | |
| 285 | // Check header |
| 286 | if ((buf[0] != 'G') || (buf[1] != 'I') || (buf[2] != 'F')) { |
| 287 | error("not a GIF file."); |
| 288 | } |
| 289 | |
| 290 | // Global width&height |
| 291 | global_width = ExtractWord(buf, 6); |
| 292 | global_height = ExtractWord(buf, 8); |
| 293 | |
| 294 | // colormap info |
| 295 | int ch = ExtractByte(buf, 10); |
| 296 | if ((ch & COLORMAPMASK) == 0) { |
| 297 | // no global colormap so make up our own |
| 298 | // If there is a local colormap, it will override what we |
| 299 | // have here. If there is not a local colormap, the rules |
| 300 | // for GIF89 say that we can use whatever colormap we want. |
| 301 | // This means that we should probably put in a full 256 colormap |
| 302 | // at some point. REMIND! |
| 303 | num_global_colors = 2; |
| 304 | global_bgpixel = 0; |
| 305 | global_colormap = new byte[2*3]; |
| 306 | global_colormap[0] = global_colormap[1] = global_colormap[2] = (byte)0; |
| 307 | global_colormap[3] = global_colormap[4] = global_colormap[5] = (byte)255; |
| 308 | |
| 309 | } |
| 310 | else { |
| 311 | num_global_colors = 1 << ((ch & 0x7) + 1); |
| 312 | |
| 313 | global_bgpixel = ExtractByte(buf, 11); |
| 314 | |
| 315 | if (buf[12] != 0) { |
| 316 | props.put("aspectratio", ""+((ExtractByte(buf, 12) + 15) / 64.0)); |
| 317 | } |
| 318 | |
| 319 | // Read colors |
| 320 | global_colormap = new byte[num_global_colors * 3]; |
| 321 | if (readBytes(global_colormap, 0, num_global_colors * 3) != 0) { |
| 322 | throw new IOException(); |
| 323 | } |
| 324 | } |
| 325 | input.mark(Integer.MAX_VALUE); // set this mark in case this is an animated GIF |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * The ImageConsumer hints flag for a non-interlaced GIF image. |
| 330 | */ |
| 331 | private static final int normalflags = |
| 332 | ImageConsumer.TOPDOWNLEFTRIGHT | ImageConsumer.COMPLETESCANLINES | |
| 333 | ImageConsumer.SINGLEPASS | ImageConsumer.SINGLEFRAME; |
| 334 | |
| 335 | /** |
| 336 | * The ImageConsumer hints flag for an interlaced GIF image. |
| 337 | */ |
| 338 | private static final int interlaceflags = |
| 339 | ImageConsumer.RANDOMPIXELORDER | ImageConsumer.COMPLETESCANLINES | |
| 340 | ImageConsumer.SINGLEPASS | ImageConsumer.SINGLEFRAME; |
| 341 | |
| 342 | private short prefix[] = new short[4096]; |
| 343 | private byte suffix[] = new byte[4096]; |
| 344 | private byte outCode[] = new byte[4097]; |
| 345 | |
| 346 | private static native void initIDs(); |
| 347 | |
| 348 | static { |
| 349 | /* ensure that the necessary native libraries are loaded */ |
| 350 | NativeLibLoader.loadLibraries(); |
| 351 | initIDs(); |
| 352 | } |
| 353 | |
| 354 | private native boolean parseImage(int x, int y, int width, int height, |
| 355 | boolean interlace, int initCodeSize, |
| 356 | byte block[], byte rasline[], |
| 357 | IndexColorModel model); |
| 358 | |
| 359 | private int sendPixels(int x, int y, int width, int height, |
| 360 | byte rasline[], ColorModel model) { |
| 361 | int rasbeg, rasend, x2; |
| 362 | if (y < 0) { |
| 363 | height += y; |
| 364 | y = 0; |
| 365 | } |
| 366 | if (y + height > global_height) { |
| 367 | height = global_height - y; |
| 368 | } |
| 369 | if (height <= 0) { |
| 370 | return 1; |
| 371 | } |
| 372 | // rasline[0] == pixel at coordinate (x,y) |
| 373 | // rasline[width] == pixel at coordinate (x+width, y) |
| 374 | if (x < 0) { |
| 375 | rasbeg = -x; |
| 376 | width += x; // same as (width -= rasbeg) |
| 377 | x2 = 0; // same as (x2 = x + rasbeg) |
| 378 | } else { |
| 379 | rasbeg = 0; |
| 380 | // width -= 0; // same as (width -= rasbeg) |
| 381 | x2 = x; // same as (x2 = x + rasbeg) |
| 382 | } |
| 383 | // rasline[rasbeg] == pixel at coordinate (x2,y) |
| 384 | // rasline[width] == pixel at coordinate (x+width, y) |
| 385 | // rasline[rasbeg + width] == pixel at coordinate (x2+width, y) |
| 386 | if (x2 + width > global_width) { |
| 387 | width = global_width - x2; |
| 388 | } |
| 389 | if (width <= 0) { |
| 390 | return 1; |
| 391 | } |
| 392 | rasend = rasbeg + width; |
| 393 | // rasline[rasbeg] == pixel at coordinate (x2,y) |
| 394 | // rasline[rasend] == pixel at coordinate (x2+width, y) |
| 395 | int off = y * global_width + x2; |
| 396 | boolean save = (curframe.disposal_method == GifFrame.DISPOSAL_SAVE); |
| 397 | if (trans_pixel >= 0 && !curframe.initialframe) { |
| 398 | if (saved_image != null && model.equals(saved_model)) { |
| 399 | for (int i = rasbeg; i < rasend; i++, off++) { |
| 400 | byte pixel = rasline[i]; |
| 401 | if ((pixel & 0xff) == trans_pixel) { |
| 402 | rasline[i] = saved_image[off]; |
| 403 | } else if (save) { |
| 404 | saved_image[off] = pixel; |
| 405 | } |
| 406 | } |
| 407 | } else { |
| 408 | // We have to do this the hard way - only transmit |
| 409 | // the non-transparent sections of the line... |
| 410 | // Fix for 6301050: the interlacing is ignored in this case |
| 411 | // in order to avoid artefacts in case of animated images. |
| 412 | int runstart = -1; |
| 413 | int count = 1; |
| 414 | for (int i = rasbeg; i < rasend; i++, off++) { |
| 415 | byte pixel = rasline[i]; |
| 416 | if ((pixel & 0xff) == trans_pixel) { |
| 417 | if (runstart >= 0) { |
| 418 | count = setPixels(x + runstart, y, |
| 419 | i - runstart, 1, |
| 420 | model, rasline, |
| 421 | runstart, 0); |
| 422 | if (count == 0) { |
| 423 | break; |
| 424 | } |
| 425 | } |
| 426 | runstart = -1; |
| 427 | } else { |
| 428 | if (runstart < 0) { |
| 429 | runstart = i; |
| 430 | } |
| 431 | if (save) { |
| 432 | saved_image[off] = pixel; |
| 433 | } |
| 434 | } |
| 435 | } |
| 436 | if (runstart >= 0) { |
| 437 | count = setPixels(x + runstart, y, |
| 438 | rasend - runstart, 1, |
| 439 | model, rasline, |
| 440 | runstart, 0); |
| 441 | } |
| 442 | return count; |
| 443 | } |
| 444 | } else if (save) { |
| 445 | System.arraycopy(rasline, rasbeg, saved_image, off, width); |
| 446 | } |
| 447 | int count = setPixels(x2, y, width, height, model, |
| 448 | rasline, rasbeg, 0); |
| 449 | return count; |
| 450 | } |
| 451 | |
| 452 | /** |
| 453 | * Read Image data |
| 454 | */ |
| 455 | private boolean readImage(boolean first, int disposal_method, int delay) |
| 456 | throws IOException |
| 457 | { |
| 458 | if (curframe != null && !curframe.dispose()) { |
| 459 | abort(); |
| 460 | return false; |
| 461 | } |
| 462 | |
| 463 | long tm = 0; |
| 464 | |
| 465 | if (verbose) { |
| 466 | tm = System.currentTimeMillis(); |
| 467 | } |
| 468 | |
| 469 | // Allocate the buffer |
| 470 | byte block[] = new byte[256 + 3]; |
| 471 | |
| 472 | // Read the image descriptor |
| 473 | if (readBytes(block, 0, 10) != 0) { |
| 474 | throw new IOException(); |
| 475 | } |
| 476 | int x = ExtractWord(block, 0); |
| 477 | int y = ExtractWord(block, 2); |
| 478 | int width = ExtractWord(block, 4); |
| 479 | int height = ExtractWord(block, 6); |
| 480 | |
| 481 | /* |
| 482 | * Majority of gif images have |
| 483 | * same logical screen and frame dimensions. |
| 484 | * Also, Photoshop and Mozilla seem to use the logical |
| 485 | * screen dimension (from the global stream header) |
| 486 | * if frame dimension is invalid. |
| 487 | * |
| 488 | * We use similar heuristic and trying to recover |
| 489 | * frame width from logical screen dimension and |
| 490 | * frame offset. |
| 491 | */ |
| 492 | if (width == 0 && global_width != 0) { |
| 493 | width = global_width - x; |
| 494 | } |
| 495 | if (height == 0 && global_height != 0) { |
| 496 | height = global_height - y; |
| 497 | } |
| 498 | |
| 499 | boolean interlace = (block[8] & INTERLACEMASK) != 0; |
| 500 | |
| 501 | IndexColorModel model = global_model; |
| 502 | |
| 503 | if ((block[8] & COLORMAPMASK) != 0) { |
| 504 | // We read one extra byte above so now when we must |
| 505 | // transfer that byte as the first colormap byte |
| 506 | // and manually read the code size when we are done |
| 507 | int num_local_colors = 1 << ((block[8] & 0x7) + 1); |
| 508 | |
| 509 | // Read local colors |
| 510 | byte[] local_colormap = new byte[num_local_colors * 3]; |
| 511 | local_colormap[0] = block[9]; |
| 512 | if (readBytes(local_colormap, 1, num_local_colors * 3 - 1) != 0) { |
| 513 | throw new IOException(); |
| 514 | } |
| 515 | |
| 516 | // Now read the "real" code size byte which follows |
| 517 | // the local color table |
| 518 | if (readBytes(block, 9, 1) != 0) { |
| 519 | throw new IOException(); |
| 520 | } |
| 521 | if (trans_pixel >= num_local_colors) { |
| 522 | // Fix for 4233748: extend colormap to contain transparent pixel |
| 523 | num_local_colors = trans_pixel + 1; |
| 524 | local_colormap = grow_colormap(local_colormap, num_local_colors); |
| 525 | } |
| 526 | model = new IndexColorModel(8, num_local_colors, local_colormap, |
| 527 | 0, false, trans_pixel); |
| 528 | } else if (model == null |
| 529 | || trans_pixel != model.getTransparentPixel()) { |
| 530 | if (trans_pixel >= num_global_colors) { |
| 531 | // Fix for 4233748: extend colormap to contain transparent pixel |
| 532 | num_global_colors = trans_pixel + 1; |
| 533 | global_colormap = grow_colormap(global_colormap, num_global_colors); |
| 534 | } |
| 535 | model = new IndexColorModel(8, num_global_colors, global_colormap, |
| 536 | 0, false, trans_pixel); |
| 537 | global_model = model; |
| 538 | } |
| 539 | |
| 540 | // Notify the consumers |
| 541 | if (first) { |
| 542 | if (global_width == 0) global_width = width; |
| 543 | if (global_height == 0) global_height = height; |
| 544 | |
| 545 | setDimensions(global_width, global_height); |
| 546 | setProperties(props); |
| 547 | setColorModel(model); |
| 548 | headerComplete(); |
| 549 | } |
| 550 | |
| 551 | if (disposal_method == GifFrame.DISPOSAL_SAVE && saved_image == null) { |
| 552 | saved_image = new byte[global_width * global_height]; |
| 553 | /* |
| 554 | * If height of current image is smaller than the global height, |
| 555 | * fill the gap with transparent pixels. |
| 556 | */ |
| 557 | if ((height < global_height) && (model != null)) { |
| 558 | byte tpix = (byte)model.getTransparentPixel(); |
| 559 | if (tpix >= 0) { |
| 560 | byte trans_rasline[] = new byte[global_width]; |
| 561 | for (int i=0; i<global_width;i++) { |
| 562 | trans_rasline[i] = tpix; |
| 563 | } |
| 564 | |
| 565 | setPixels(0, 0, global_width, y, |
| 566 | model, trans_rasline, 0, 0); |
| 567 | setPixels(0, y+height, global_width, |
| 568 | global_height-height-y, model, trans_rasline, |
| 569 | 0, 0); |
| 570 | } |
| 571 | } |
| 572 | } |
| 573 | |
| 574 | int hints = (interlace ? interlaceflags : normalflags); |
| 575 | setHints(hints); |
| 576 | |
| 577 | curframe = new GifFrame(this, disposal_method, delay, |
| 578 | (curframe == null), model, |
| 579 | x, y, width, height); |
| 580 | |
| 581 | // allocate the raster data |
| 582 | byte rasline[] = new byte[width]; |
| 583 | |
| 584 | if (verbose) { |
| 585 | System.out.print("Reading a " + width + " by " + height + " " + |
| 586 | (interlace ? "" : "non-") + "interlaced image..."); |
| 587 | } |
| 588 | |
| 589 | boolean ret = parseImage(x, y, width, height, |
| 590 | interlace, ExtractByte(block, 9), |
| 591 | block, rasline, model); |
| 592 | |
| 593 | if (!ret) { |
| 594 | abort(); |
| 595 | } |
| 596 | |
| 597 | if (verbose) { |
| 598 | System.out.println("done in " |
| 599 | + (System.currentTimeMillis() - tm) |
| 600 | + "ms"); |
| 601 | } |
| 602 | |
| 603 | return ret; |
| 604 | } |
| 605 | |
| 606 | public static byte[] grow_colormap(byte[] colormap, int newlen) { |
| 607 | byte[] newcm = new byte[newlen * 3]; |
| 608 | System.arraycopy(colormap, 0, newcm, 0, colormap.length); |
| 609 | return newcm; |
| 610 | } |
| 611 | } |
| 612 | |
| 613 | class GifFrame { |
| 614 | private static final boolean verbose = false; |
| 615 | private static IndexColorModel trans_model; |
| 616 | |
| 617 | static final int DISPOSAL_NONE = 0x00; |
| 618 | static final int DISPOSAL_SAVE = 0x01; |
| 619 | static final int DISPOSAL_BGCOLOR = 0x02; |
| 620 | static final int DISPOSAL_PREVIOUS = 0x03; |
| 621 | |
| 622 | GifImageDecoder decoder; |
| 623 | |
| 624 | int disposal_method; |
| 625 | int delay; |
| 626 | |
| 627 | IndexColorModel model; |
| 628 | |
| 629 | int x; |
| 630 | int y; |
| 631 | int width; |
| 632 | int height; |
| 633 | |
| 634 | boolean initialframe; |
| 635 | |
| 636 | public GifFrame(GifImageDecoder id, int dm, int dl, boolean init, |
| 637 | IndexColorModel cm, int x, int y, int w, int h) { |
| 638 | this.decoder = id; |
| 639 | this.disposal_method = dm; |
| 640 | this.delay = dl; |
| 641 | this.model = cm; |
| 642 | this.initialframe = init; |
| 643 | this.x = x; |
| 644 | this.y = y; |
| 645 | this.width = w; |
| 646 | this.height = h; |
| 647 | } |
| 648 | |
| 649 | private void setPixels(int x, int y, int w, int h, |
| 650 | ColorModel cm, byte[] pix, int off, int scan) { |
| 651 | decoder.setPixels(x, y, w, h, cm, pix, off, scan); |
| 652 | } |
| 653 | |
| 654 | public boolean dispose() { |
| 655 | if (decoder.imageComplete(ImageConsumer.SINGLEFRAMEDONE, false) == 0) { |
| 656 | return false; |
| 657 | } else { |
| 658 | if (delay > 0) { |
| 659 | try { |
| 660 | if (verbose) { |
| 661 | System.out.println("sleeping: "+delay); |
| 662 | } |
| 663 | Thread.sleep(delay); |
| 664 | } catch (InterruptedException e) { |
| 665 | return false; |
| 666 | } |
| 667 | } else { |
| 668 | Thread.yield(); |
| 669 | } |
| 670 | |
| 671 | if (verbose && disposal_method != 0) { |
| 672 | System.out.println("disposal method: "+disposal_method); |
| 673 | } |
| 674 | |
| 675 | int global_width = decoder.global_width; |
| 676 | int global_height = decoder.global_height; |
| 677 | |
| 678 | if (x < 0) { |
| 679 | width += x; |
| 680 | x = 0; |
| 681 | } |
| 682 | if (x + width > global_width) { |
| 683 | width = global_width - x; |
| 684 | } |
| 685 | if (width <= 0) { |
| 686 | disposal_method = DISPOSAL_NONE; |
| 687 | } else { |
| 688 | if (y < 0) { |
| 689 | height += y; |
| 690 | y = 0; |
| 691 | } |
| 692 | if (y + height > global_height) { |
| 693 | height = global_height - y; |
| 694 | } |
| 695 | if (height <= 0) { |
| 696 | disposal_method = DISPOSAL_NONE; |
| 697 | } |
| 698 | } |
| 699 | |
| 700 | switch (disposal_method) { |
| 701 | case DISPOSAL_PREVIOUS: |
| 702 | byte[] saved_image = decoder.saved_image; |
| 703 | IndexColorModel saved_model = decoder.saved_model; |
| 704 | if (saved_image != null) { |
| 705 | setPixels(x, y, width, height, |
| 706 | saved_model, saved_image, |
| 707 | y * global_width + x, global_width); |
| 708 | } |
| 709 | break; |
| 710 | case DISPOSAL_BGCOLOR: |
| 711 | byte tpix; |
| 712 | if (model.getTransparentPixel() < 0) { |
| 713 | model = trans_model; |
| 714 | if (model == null) { |
| 715 | model = new IndexColorModel(8, 1, |
| 716 | new byte[4], 0, true); |
| 717 | trans_model = model; |
| 718 | } |
| 719 | tpix = 0; |
| 720 | } else { |
| 721 | tpix = (byte) model.getTransparentPixel(); |
| 722 | } |
| 723 | byte[] rasline = new byte[width]; |
| 724 | if (tpix != 0) { |
| 725 | for (int i = 0; i < width; i++) { |
| 726 | rasline[i] = tpix; |
| 727 | } |
| 728 | } |
| 729 | |
| 730 | // clear saved_image using transparent pixels |
| 731 | // this will be used as the background in the next display |
| 732 | if( decoder.saved_image != null ) { |
| 733 | for( int i = 0; i < global_width * global_height; i ++ ) |
| 734 | decoder.saved_image[i] = tpix; |
| 735 | } |
| 736 | |
| 737 | setPixels(x, y, width, height, model, rasline, 0, 0); |
| 738 | break; |
| 739 | case DISPOSAL_SAVE: |
| 740 | decoder.saved_model = model; |
| 741 | break; |
| 742 | } |
| 743 | } |
| 744 | return true; |
| 745 | } |
| 746 | } |