Hello.
I would like to use multiple gifs in my game, but currently i only know how to import one gif with the inbuild GifImage class.
Can anyone help me?
Thanks in advance.
Srax.
Srax wrote ...
2015/3/24
Is it possible to use the "GifImage" inbuild class multiple times?
A class is a blueprint for objects of specific types. Usually, a class will allow you to create as many instances as you want from it. In other words, you do not need multiple GifImage classes to create multiple GifImage objects. Each time 'new GifImage' is executed, a new object (or instance) will be created from the class.
danpost wrote...
A class is a blueprint for objects of specific types. Usually, a class will allow you to create as many instances as you want from it. In other words, you do not need multiple GifImage classes to create multiple GifImage objects. Each time 'new GifImage' is executed, a new object (or instance) will be created from the class.1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 | import greenfoot.*; // (World, Actor, GreenfootImage, Greenfoot and MouseInfo)import java.awt.AlphaComposite;import java.awt.Color;import java.awt.Dimension;import java.awt.Graphics2D;import java.awt.Rectangle;import java.awt.image.BufferedImage;import java.awt.image.DataBufferInt;import java.io.BufferedInputStream;import java.io.FileInputStream;import java.io.IOException;import java.io.InputStream;import java.net.URL;import java.util.List;import java.util.ArrayList;/** * This class can be used to read animated gif image files and extract the individual * images of the animation sequence. * <p> * To use GifImage in an actor, declare it as an instance variable: * * <pre> * {@code * GifImage gifImage = new GifImage("idleGif.gif"); * } * </pre> * * Then, in the act() method of your actor, set the actor's image to the current image * from your GifImage instance: * * <pre> * {@code * setImage(gifImage.getCurrentImage()); * } * </pre> * * @author Michael Berry * @author Neil Brown */public class GifImage{ /** The images used in the animation. */ private GreenfootImage[] images; /** The delay between each frame. */ private int[] delay; /** The index of the current frame in the GIF file. */ private int currentIndex; /** The time passed since the last frame in ms. */ private long time; /** The GIF file that contains the animation. */ private String file; /** Whether the animation is paused or not. */ private boolean pause; /** * Construct a new GifImage instance using the specified image file. * The animation will initially be running. Use getImage() at any time * to get the current image in the animation sequence. */ public GifImage(String file) { this.file = file; pause = false; if(file.toLowerCase().endsWith(".gif")) { loadImages(); } else { images = new GreenfootImage[] {new GreenfootImage(file)}; delay = new int[] {1000}; // Doesn't matter, as long as it's not zero currentIndex = 0; time = System.currentTimeMillis(); } } /** * Get all the images used in the animation * @return a list of GreenfootImages, corresponding to each frame. */ public List<GreenfootImage> getImages() { ArrayList<GreenfootImage> images = new ArrayList<GreenfootImage>(this.images.length); for(GreenfootImage image : this.images) { images.add(image); } return images; } /** * Pause the animation. */ public void pause() { pause = true; } /** * Resume the animation. */ public void resume() { pause = false; time = System.currentTimeMillis(); } /** * Determines whether the animation is running * @return true if the animation is running, false otherwise */ public boolean isRunning() { return !pause; } /** * Get the current image in the animation sequence. This will * change over time. * @return The current image */ public GreenfootImage getCurrentImage() { long delta = System.currentTimeMillis() - time; while (delta >= delay[currentIndex] && !pause) { delta -= delay[currentIndex]; time += delay[currentIndex]; currentIndex = (currentIndex+1) % images.length; } return images[currentIndex]; } /** * Load the images */ private void loadImages() { GifDecoder decode = new GifDecoder(); decode.read(file); int numFrames = decode.getFrameCount(); if(numFrames>0) { images = new GreenfootImage[numFrames]; delay = new int[numFrames]; } else { images = new GreenfootImage[1]; images[0] = new GreenfootImage(1, 1); } for (int i=0 ; i<numFrames ; i++) { GreenfootImage image = new GreenfootImage(decode.getFrame(i).getWidth(), decode.getFrame(i).getHeight()); BufferedImage frame = image.getAwtImage(); Graphics2D g = (Graphics2D)frame.getGraphics(); g.drawImage(decode.getFrame(i), null, 0, 0); delay[i] = decode.getDelay(i); images[i] = image; } time = System.currentTimeMillis(); } /** * Class GifDecoder - Decodes a GIF file into one or more frames. <br><br> * * <i>I (Michael) edited this slightly on 10/09/08 to bring class up to date with generics and therefore remove warnings. * Also edited so that resources are grabbed from the jar file and not externally, so no security exceptions.</i> * <br><br> * <pre> * Example: * GifDecoder d = new GifDecoder(); * d.read("sample.gif"); * int n = d.getFrameCount(); * for (int i = 0; i < n; i++) { * BufferedImage frame = d.getFrame(i); // frame i * int t = d.getDelay(i); // display duration of frame in milliseconds * // do something with frame * } * </pre> * * No copyright asserted on the source code of this class. May be used for any * purpose, however, refer to the Unisys LZW patent for any additional * restrictions. Please forward any corrections to kweiner@fmsware.com. * * @author Kevin Weiner, FM Software; LZW decoder adapted from John Cristy's * ImageMagick. * @version 1.03 November 2003 * */ private class GifDecoder { /** * File read status: No errors. */ public static final int STATUS_OK = 0; /** * File read status: Error decoding file (may be partially decoded) */ public static final int STATUS_FORMAT_ERROR = 1; /** * File read status: Unable to open source. */ public static final int STATUS_OPEN_ERROR = 2; private BufferedInputStream in; private int status; private int width; // full image width private int height; // full image height private boolean gctFlag; // global color table used private int gctSize; // size of global color table private int loopCount = 1; // iterations; 0 = repeat forever private int[] gct; // global color table private int[] lct; // local color table private int[] act; // active color table private int bgIndex; // background color index private int bgColor; // background color private int lastBgColor; // previous bg color private int pixelAspect; // pixel aspect ratio private boolean lctFlag; // local color table flag private boolean interlace; // interlace flag private int lctSize; // local color table size private int ix, iy, iw, ih; // current image rectangle private Rectangle lastRect; // last image rect private BufferedImage image; // current frame private BufferedImage lastImage; // previous frame private byte[] block = new byte[256]; // current data block private int blockSize = 0; // block size // last graphic control extension info private int dispose = 0; // 0=no action; 1=leave in place; 2=restore to bg; 3=restore to prev private int lastDispose = 0; private boolean transparency = false; // use transparent color private int delay = 0; // delay in milliseconds private int transIndex; // transparent color index private static final int MaxStackSize = 4096; // max decoder pixel stack size // LZW decoder working arrays private short[] prefix; private byte[] suffix; private byte[] pixelStack; private byte[] pixels; private ArrayList<GifFrame> frames; // frames read from current file private int frameCount; /** * A single frame */ private class GifFrame { public GifFrame(BufferedImage im, int del) { image = im; delay = del; } private BufferedImage image; private int delay; } /** * Gets display duration for specified frame. * * @param n * int index of frame * @return delay in milliseconds */ public int getDelay(int n) { // delay = -1; if ((n >= 0) && (n < frameCount)) { delay = (frames.get(n)).delay; } return delay; } /** * Gets the number of frames read from file. * * @return frame count */ public int getFrameCount() { return frameCount; } /** * Gets the first (or only) image read. * * @return BufferedImage containing first frame, or null if none. */ public BufferedImage getImage() { return getFrame(0); } /** * Gets the "Netscape" iteration count, if any. A count of 0 means repeat * indefinitiely. * * @return iteration count if one was specified, else 1. */ public int getLoopCount() { return loopCount; } /** * Creates new frame image from current data (and previous frames as specified * by their disposition codes). */ protected void setPixels() { // expose destination image's pixels as int array int[] dest = ((DataBufferInt) image.getRaster().getDataBuffer()).getData(); // fill in starting image contents based on last image's dispose code if (lastDispose > 0) { if (lastDispose == 3) { // use image before last int n = frameCount - 2; if (n > 0) { lastImage = getFrame(n - 1); } else { lastImage = null; } } if (lastImage != null) { int[] prev = ((DataBufferInt) lastImage.getRaster().getDataBuffer()).getData(); System.arraycopy(prev, 0, dest, 0, width * height); // copy pixels if (lastDispose == 2) { // fill last image rect area with background color Graphics2D g = image.createGraphics(); Color c = null; if (transparency) { c = new Color(0, 0, 0, 0); // assume background is transparent } else { c = new Color(lastBgColor); // use given background color } g.setColor(c); g.setComposite(AlphaComposite.Src); // replace area g.fill(lastRect); g.dispose(); } } } // copy each source line to the appropriate place in the destination int pass = 1; int inc = 8; int iline = 0; for (int i = 0; i < ih; i++) { int line = i; if (interlace) { if (iline >= ih) { pass++; switch (pass) { case 2: iline = 4; break; case 3: iline = 2; inc = 4; break; case 4: iline = 1; inc = 2; } } line = iline; iline += inc; } line += iy; if (line < height) { int k = line * width; int dx = k + ix; // start of line in dest int dlim = dx + iw; // end of dest line if ((k + width) < dlim) { dlim = k + width; // past dest edge } int sx = i * iw; // start of line in source while (dx < dlim) { // map color and insert in destination int index = ((int) pixels[sx++]) & 0xff; int c = act[index]; if (c != 0) { dest[dx] = c; } dx++; } } } } /** * Gets the image contents of frame n. * * @return BufferedImage representation of frame, or null if n is invalid. */ public BufferedImage getFrame(int n) { BufferedImage im = null; if ((n >= 0) && (n < frameCount)) { im = ((GifFrame) frames.get(n)).image; } return im; } /** * Gets image size. * * @return GIF image dimensions */ public Dimension getFrameSize() { return new Dimension(width, height); } /** * Reads GIF image from stream * * @param BufferedInputStream * containing GIF file. * @return read status code (0 = no errors) */ public int read(BufferedInputStream is) { init(); if (is != null) { in = is; readHeader(); if (!err()) { readContents(); if (frameCount < 0) { status = STATUS_FORMAT_ERROR; } } } else { status = STATUS_OPEN_ERROR; } try { is.close(); } catch (IOException e) { } return status; } /** * Reads GIF image from stream * * @param InputStream * containing GIF file. * @return read status code (0 = no errors) */ public int read(InputStream is) { init(); if (is != null) { if (!(is instanceof BufferedInputStream)) is = new BufferedInputStream(is); in = (BufferedInputStream) is; readHeader(); if (!err()) { readContents(); if (frameCount < 0) { status = STATUS_FORMAT_ERROR; } } } else { status = STATUS_OPEN_ERROR; } try { is.close(); } catch (IOException e) { } return status; } /** * Reads GIF file from specified file/URL source (URL assumed if name contains * ":/" or "file:") * * @param name * String containing source * @return read status code (0 = no errors) */ public int read(String name) { status = STATUS_OK; try { URL url = this.getClass().getClassLoader().getResource(name); if(url==null) { name = "images/" + name; url = this.getClass().getClassLoader().getResource(name); if(url==null) { throw new RuntimeException("The gif file \"" + name + "\" doesn't exist."); } } in = new BufferedInputStream(url.openStream()); status = read(in); } catch (IOException e) { status = STATUS_OPEN_ERROR; } return status; } /** * Decodes LZW image data into pixel array. Adapted from John Cristy's * ImageMagick. */ protected void decodeImageData() { int NullCode = -1; int npix = iw * ih; int available, clear, code_mask, code_size, end_of_information, in_code, old_code, bits, code, count, i, datum, data_size, first, top, bi, pi; if ((pixels == null) || (pixels.length < npix)) { pixels = new byte[npix]; // allocate new pixel array } if (prefix == null) prefix = new short[MaxStackSize]; if (suffix == null) suffix = new byte[MaxStackSize]; if (pixelStack == null) pixelStack = new byte[MaxStackSize + 1]; // Initialize GIF data stream decoder. data_size = read(); clear = 1 << data_size; end_of_information = clear + 1; available = clear + 2; old_code = NullCode; code_size = data_size + 1; code_mask = (1 << code_size) - 1; for (code = 0; code < clear; code++) { prefix[code] = 0; suffix[code] = (byte) code; } // Decode GIF pixel stream. datum = bits = count = first = top = pi = bi = 0; for (i = 0; i < npix;) { if (top == 0) { if (bits < code_size) { // Load bytes until there are enough bits for a code. if (count == 0) { // Read a new data block. count = readBlock(); if (count <= 0) break; bi = 0; } datum += (((int) block[bi]) & 0xff) << bits; bits += 8; bi++; count--; continue; } // Get the next code. code = datum & code_mask; datum >>= code_size; bits -= code_size; // Interpret the code if ((code > available) || (code == end_of_information)) break; if (code == clear) { // Reset decoder. code_size = data_size + 1; code_mask = (1 << code_size) - 1; available = clear + 2; old_code = NullCode; continue; } if (old_code == NullCode) { pixelStack[top++] = suffix[code]; old_code = code; first = code; continue; } in_code = code; if (code == available) { pixelStack[top++] = (byte) first; code = old_code; } while (code > clear) { pixelStack[top++] = suffix[code]; code = prefix[code]; } first = ((int) suffix[code]) & 0xff; // Add a new string to the string table, if (available >= MaxStackSize) break; pixelStack[top++] = (byte) first; prefix[available] = (short) old_code; suffix[available] = (byte) first; available++; if (((available & code_mask) == 0) && (available < MaxStackSize)) { code_size++; code_mask += available; } old_code = in_code; } // Pop a pixel off the pixel stack. top--; pixels[pi++] = pixelStack[top]; i++; } for (i = pi; i < npix; i++) { pixels[i] = 0; // clear missing pixels } } /** * Returns true if an error was encountered during reading/decoding */ protected boolean err() { return status != STATUS_OK; } /** * Initializes or re-initializes reader */ protected void init() { status = STATUS_OK; frameCount = 0; frames = new ArrayList<GifFrame>(); gct = null; lct = null; } /** * Reads a single byte from the input stream. */ protected int read() { int curByte = 0; try { curByte = in.read(); } catch (IOException e) { status = STATUS_FORMAT_ERROR; } return curByte; } /** * Reads next variable length block from input. * * @return number of bytes stored in "buffer" */ protected int readBlock() { blockSize = read(); int n = 0; if (blockSize > 0) { try { int count = 0; while (n < blockSize) { count = in.read(block, n, blockSize - n); if (count == -1) break; n += count; } } catch (IOException e) { } if (n < blockSize) { status = STATUS_FORMAT_ERROR; } } return n; } /** * Reads color table as 256 RGB integer values * * @param ncolors * int number of colors to read * @return int array containing 256 colors (packed ARGB with full alpha) */ protected int[] readColorTable(int ncolors) { int nbytes = 3 * ncolors; int[] tab = null; byte[] c = new byte[nbytes]; int n = 0; try { n = in.read(c); } catch (IOException e) { } if (n < nbytes) { status = STATUS_FORMAT_ERROR; } else { tab = new int[256]; // max size to avoid bounds checks int i = 0; int j = 0; while (i < ncolors) { int r = ((int) c[j++]) & 0xff; int g = ((int) c[j++]) & 0xff; int b = ((int) c[j++]) & 0xff; tab[i++] = 0xff000000 | (r << 16) | (g << 8) | b; } } return tab; } /** * Main file parser. Reads GIF content blocks. */ protected void readContents() { // read GIF file content blocks boolean done = false; while (!(done || err())) { int code = read(); switch (code) { case 0x2C: // image separator readImage(); break; case 0x21: // extension code = read(); switch (code) { case 0xf9: // graphics control extension readGraphicControlExt(); break; case 0xff: // application extension readBlock(); String app = ""; for (int i = 0; i < 11; i++) { app += (char) block[i]; } if (app.equals("NETSCAPE2.0")) { readNetscapeExt(); } else skip(); // don't care break; default: // uninteresting extension skip(); } break; case 0x3b: // terminator done = true; break; case 0x00: // bad byte, but keep going and see what happens break; default: status = STATUS_FORMAT_ERROR; } } } /** * Reads Graphics Control Extension values */ protected void readGraphicControlExt() { read(); // block size int packed = read(); // packed fields dispose = (packed & 0x1c) >> 2; // disposal method if (dispose == 0) { dispose = 1; // elect to keep old image if discretionary } transparency = (packed & 1) != 0; delay = readShort() * 10; // delay in milliseconds transIndex = read(); // transparent color index read(); // block terminator } /** * Reads GIF file header information. */ protected void readHeader() { String id = ""; for (int i = 0; i < 6; i++) { id += (char) read(); } if (!id.startsWith("GIF")) { status = STATUS_FORMAT_ERROR; return; } readLSD(); if (gctFlag && !err()) { gct = readColorTable(gctSize); bgColor = gct[bgIndex]; } } /** * Reads next frame image */ protected void readImage() { ix = readShort(); // (sub)image position & size iy = readShort(); iw = readShort(); ih = readShort(); int packed = read(); lctFlag = (packed & 0x80) != 0; // 1 - local color table flag interlace = (packed & 0x40) != 0; // 2 - interlace flag // 3 - sort flag // 4-5 - reserved lctSize = 2 << (packed & 7); // 6-8 - local color table size if (lctFlag) { lct = readColorTable(lctSize); // read table act = lct; // make local table active } else { act = gct; // make global table active if (bgIndex == transIndex) bgColor = 0; } int save = 0; if (transparency) { save = act[transIndex]; act[transIndex] = 0; // set transparent color if specified } if (act == null) { status = STATUS_FORMAT_ERROR; // no color table defined } if (err()) return; decodeImageData(); // decode pixel data skip(); if (err()) return; frameCount++; // create new image to receive frame data image = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB_PRE); setPixels(); // transfer pixel data to image frames.add(new GifFrame(image, delay)); // add image to frame list if (transparency) { act[transIndex] = save; } resetFrame(); } /** * Reads Logical Screen Descriptor */ protected void readLSD() { // logical screen size width = readShort(); height = readShort(); // packed fields int packed = read(); gctFlag = (packed & 0x80) != 0; // 1 : global color table flag // 2-4 : color resolution // 5 : gct sort flag gctSize = 2 << (packed & 7); // 6-8 : gct size bgIndex = read(); // background color index pixelAspect = read(); // pixel aspect ratio } /** * Reads Netscape extenstion to obtain iteration count */ protected void readNetscapeExt() { do { readBlock(); if (block[0] == 1) { // loop count sub-block int b1 = ((int) block[1]) & 0xff; int b2 = ((int) block[2]) & 0xff; loopCount = (b2 << 8) | b1; } } while ((blockSize > 0) && !err()); } /** * Reads next 16-bit value, LSB first */ protected int readShort() { // read 16-bit value, LSB first return read() | (read() << 8); } /** * Resets frame state for reading next image. */ protected void resetFrame() { lastDispose = dispose; lastRect = new Rectangle(ix, iy, iw, ih); lastImage = image; lastBgColor = bgColor; int dispose = 0; boolean transparency = false; int delay = 0; lct = null; } /** * Skips variable length blocks up to and including next zero length block. */ protected void skip() { do { readBlock(); } while ((blockSize > 0) && !err()); } }} |
1 2 3 4 | GifImage gifImage = new GifImage("idleGif.gif"); public void act() { setImage(gifImage.getCurrentImage()); |
Then, for example:
'gifImage', 'gifImage2' are just variable names - you can use whatever names you want.
1 | GifImage gifImage2 = new GifImage("idleGif2.gif"); |
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