X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=src%2Forg%2Fxwt%2Ftranslators%2FGIF.java;h=e69de29bb2d1d6434b8b29ae775ad8c2e48c5391;hb=db4ab6de30e095d6448fb826c2e6f0d4ac53cc7b;hp=572c124c5bb92b81b7bfe381217647cb5facb173;hpb=3591b88b94a6bb378af3d4abe6eb5233ce583104;p=org.ibex.core.git diff --git a/src/org/xwt/translators/GIF.java b/src/org/xwt/translators/GIF.java index 572c124..e69de29 100644 --- a/src/org/xwt/translators/GIF.java +++ b/src/org/xwt/translators/GIF.java @@ -1,445 +0,0 @@ -/* - * This file was adapted from D J Hagberg's GifDecoder.java - * - * This software is copyrighted by D. J. Hagberg, Jr., and other parties. - * The following terms apply to all files associated with the software - * unless explicitly disclaimed in individual files. - * - * The authors hereby grant permission to use, copy, modify, distribute, - * and license this software and its documentation for any purpose, provided - * that existing copyright notices are retained in all copies and that this - * notice is included verbatim in any distributions. No written agreement, - * license, or royalty fee is required for any of the authorized uses. - * Modifications to this software may be copyrighted by their authors - * and need not follow the licensing terms described here, provided that - * the new terms are clearly indicated on the first page of each file where - * they apply. - * - * IN NO EVENT SHALL THE AUTHORS OR DISTRIBUTORS BE LIABLE TO ANY PARTY - * FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES - * ARISING OUT OF THE USE OF THIS SOFTWARE, ITS DOCUMENTATION, OR ANY - * DERIVATIVES THEREOF, EVEN IF THE AUTHORS HAVE BEEN ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - * - * THE AUTHORS AND DISTRIBUTORS SPECIFICALLY DISCLAIM ANY WARRANTIES, - * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE, AND NON-INFRINGEMENT. THIS SOFTWARE - * IS PROVIDED ON AN "AS IS" BASIS, AND THE AUTHORS AND DISTRIBUTORS HAVE - * NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR - * MODIFICATIONS. - * - * GOVERNMENT USE: If you are acquiring this software on behalf of the - * U.S. government, the Government shall have only "Restricted Rights" - * in the software and related documentation as defined in the Federal - * Acquisition Regulations (FARs) in Clause 52.227.19 (c) (2). If you - * are acquiring the software on behalf of the Department of Defense, the - * software shall be classified as "Commercial Computer Software" and the - * Government shall have only "Restricted Rights" as defined in Clause - * 252.227-7013 (c) (1) of DFARs. Notwithstanding the foregoing, the - * authors grant the U.S. Government and others acting in its behalf - * permission to use and distribute the software in accordance with the - * terms specified in this license. - * - */ -package org.xwt.translators; - -import org.ibex.*; -import org.ibex.util.*; -import java.io.BufferedInputStream; -import java.io.InputStream; -import java.io.IOException; - -/** Converts an InputStream carrying a GIF image into an ARGB int[] */ -public class GIF { - - // Public Methods ///////////////////////////////////////////////////////// - - private GIF() { } - - private static Queue instances = new Queue(10); - - public static void load(InputStream is, Picture p) { - GIF g = (GIF)instances.remove(false); - if (g == null) g = new GIF(); - try { - g._load(is, p); - } catch (Exception e) { - if (Log.on) Log.info(GIF.class, e); - return; - } - // FIXME: must reset fields - // if (instances.size() < 10) instances.append(g); - } - - private void _load(InputStream is, Picture p) throws IOException { - this.p = p; - if (is instanceof BufferedInputStream) _in = (BufferedInputStream)is; - else _in = new BufferedInputStream(is); - decodeAsBufferedImage(0); - p.isLoaded = true; - p = null; - _in = null; - } - - - /** Decode a particular frame from the GIF file. Frames must be decoded in order, starting with 0. */ - private void decodeAsBufferedImage(int page) throws IOException, IOException { - - // If the user requested a page already decoded, we cannot go back. - if (page <= index ) return; - - // If we just started reading this stream, initialize the global info. - if (index < 0 ) { - if (!readIntoBuf(6) || _buf[0] != 'G' || _buf[1] != 'I' || _buf[2] != 'F' || - _buf[3] != '8' || !(_buf[4] == '7' || _buf[4] == '9') || _buf[5] != 'a') - throw new IOException("Not a GIF8Xa file."); - if (!readGlobalImageDescriptor()) throw new IOException("Unable to read GIF header."); - } - - // Loop through the blocks in the image. - int block_identifier; - while (true) { - if(!readIntoBuf(1)) throw new IOException("Unexpected EOF(1)"); - block_identifier = _buf[0]; - if (block_identifier == ';') throw new IOException("No image data"); - if (block_identifier == '!') { - if (!readExtensionBlock()) throw new IOException("Unexpected EOF(2)"); - continue; - } - - // not a valid start character -- ignore it. - if (block_identifier != ',') continue; - - if (!readLocalImageDescriptor()) throw new IOException("Unexpected EOF(3)"); - p.data = new int[p.width * p.height]; - readImage(); - - // If we did not decode the requested index, need to go on - // to the next one (future implementations should consider - // caching already-decoded images here to allow for random - // access to animated GIF pages). - index++; - if (index < page) continue; - - // If we did decode the requested index, we can return. - break; - } - - // Return the image thus-far decoded - return; - } - - /** Actually read the image data */ - private void readImage() - throws IOException, IOException { - int len = p.width; - int rows = p.height; - int initialCodeSize; - int v; - int xpos = 0, ypos = 0, pass = 0, i; - int prefix[] = new int[(1 << MAX_LWZ_BITS)]; - int append[] = new int[(1 << MAX_LWZ_BITS)]; - int stack[] = new int[(1 << MAX_LWZ_BITS)*2]; - int top_idx; - int codeSize, clearCode, inCode, endCode, oldCode, maxCode, code, firstCode; - - // Initialize the decoder - if (!readIntoBuf(1)) throw new IOException("Unexpected EOF decoding image"); - initialCodeSize = _buf[0]; - - // Look at the right color map, setting up transparency if called for. - int[] cmap = global_color_map; - if (hascmap) cmap = color_map; - if (trans_idx >= 0) cmap[trans_idx] = 0x00000000; - - /* Initialize the decoder */ - /* Set values for "special" numbers: - * clear code reset the decoder - * end code stop decoding - * code size size of the next code to retrieve - * max code next available table position - */ - clearCode = 1 << initialCodeSize; - endCode = clearCode + 1; - codeSize = initialCodeSize + 1; - maxCode = clearCode + 2; - oldCode = -1; - firstCode = -1; - - for (i = 0; i < clearCode; i++) append[i] = i; - top_idx = 0; // top of stack. - - bitsInWindow = 0; - bytes = 0; - window = 0L; - done = false; - c = -1; - - /* Read until we finish the image */ - ypos = 0; - for (i = 0; i < rows; i++) { - for (xpos = 0; xpos < len;) { - - if (top_idx == 0) { - /* Bummer -- our stack is empty. Now we have to work! */ - code = getCode(codeSize); - if (code < 0) return; - - if (code > maxCode || code == endCode) return; - if (code == clearCode) { - codeSize = initialCodeSize + 1; - maxCode = clearCode + 2; - oldCode = -1; - continue; - } - - // Last pass reset the decoder, so the first code we - // see must be a singleton. Seed the stack with it, - // and set up the old/first code pointers for - // insertion into the string table. We can't just - // roll this into the clearCode test above, because - // at that point we have not yet read the next code. - if (oldCode == -1) { - stack[top_idx++] = append[code]; - oldCode = code; - firstCode = code; - continue; - } - - inCode = code; - - // maxCode is always one bigger than our - // highest assigned code. If the code we see - // is equal to maxCode, then we are about to - // add a new string to the table. ??? - if (code == maxCode) { - stack[top_idx++] = firstCode; - code = oldCode; - } - - // Populate the stack by tracing the string in the - // string table from its tail to its head - while (code > clearCode) { - stack[top_idx++] = append[code]; - code = prefix[code]; - } - firstCode = append[code]; - - // If there's no more room in our string table, quit. - // Otherwise, add a new string to the table - if (maxCode >= (1 << MAX_LWZ_BITS)) return; - - // Push the head of the string onto the stack - stack[top_idx++] = firstCode; - - // Add a new string to the string table - prefix[maxCode] = oldCode; - append[maxCode] = firstCode; - maxCode++; - - // maxCode tells us the maximum code value we can accept. - // If we see that we need more bits to represent it than - // we are requesting from the unpacker, we need to increase - // the number we ask for. - if ((maxCode >= (1 << codeSize)) && (maxCode < (1<= rows) { - pass++; - if (pass > 3) return; - ypos = _interlaceStart[pass]; - } - } else ypos++; - } - return; - } - - /** Extract the next compression code from the file. */ - private int getCode(int code_size) throws IOException { - int ret; - - while (bitsInWindow < code_size) { - // Not enough bits in our window to cover the request - if (done) return -1; - - if (bytes == 0) { - // Not enough bytes in our buffer to add to the window - bytes = getDataBlock(); - c = 0; - if (bytes <= 0) { - done = true; - break; - } - } - // Tack another byte onto the window, see if that's enough - window += (_buf[c]) << bitsInWindow; - ++c; - bitsInWindow += 8; - bytes--; - } - - - // The next code will always be the last code_size bits of the window - ret = ((int)window) & ((1 << code_size) - 1); - - // Shift data in the window to put the next code at the end - window >>= code_size; - bitsInWindow -= code_size; - return ret; - } - - /** Read the global image descriptor and optional global color map. Sets global_* variables. */ - private boolean readGlobalImageDescriptor() throws IOException { - int packed; - int aspect; // we ignore this. - int ofs; - - if (!readIntoBuf(7) ) return false; - global_width = _buf[0] | (_buf[1] << 8); - global_height = _buf[2] | (_buf[3] << 8); - packed = _buf[4]; - global_bgcolor = _buf[5]; - aspect = _buf[6]; - global_cmapsize = 2 << (packed & 0x07); - global_hascmap = (packed & GLOBALCOLORMAP) == GLOBALCOLORMAP; - global_color_map = null; - - // Read the color map, if we have one. - if (global_hascmap) { - if (!readColorMap(global_cmapsize,true)) { - return false; - } - } - - return true; - } - - /** Read a local image descriptor and optional local color map. */ - private boolean readLocalImageDescriptor() throws IOException { - int packed; - - if (!readIntoBuf(9) ) return false; - - left = _buf[0] | (_buf[1] << 8); - top = _buf[2] | (_buf[3] << 8); - p.width = _buf[4] | (_buf[5] << 8); - p.height = _buf[6] | (_buf[7] << 8); - packed = _buf[8]; - hascmap = (packed & LOCALCOLORMAP) == LOCALCOLORMAP; - cmapsize = 2 << (packed & 0x07); - interlaced = (packed & INTERLACE) == INTERLACE; - color_map = null; - - // Read the local color table, if there is one. - return !(hascmap && !readColorMap(cmapsize,false)); - } - - /** Read a color map (global or local). */ - private boolean readColorMap(int nColors, boolean isGlobal) - throws IOException { - int[] map = new int[nColors]; - for( int i=0; i < nColors; ++i) { - if (!readIntoBuf(3) ) return false; - map[i] = (_buf[0] << 16) | (_buf[1] << 8) | _buf[2] | 0xFF000000; - } - if (isGlobal) global_color_map = map; - else color_map = map; - return true; - } - - /** Read the contents of a GIF89a Graphical Extension Block. */ - private boolean readExtensionBlock() throws IOException { - if (!readIntoBuf(1) ) return false; - int label = _buf[0]; - int count = -1; - switch (label) { - case 0x01: // Plain Text Extension - case 0xff: // Application Extension - case 0xfe: // Comment Extension - break; - case 0xf9: // Graphic Control Extension - count = getDataBlock(); - if (count < 0) return true; - // Check for transparency setting. - if ((_buf[0] & HASTRANSPARENCY) != 0) trans_idx = _buf[3]; - else trans_idx = -1; - } - do { count = getDataBlock(); } while (count > 0); - return true; - } - - /** Read a block of data from the GIF file. */ - private int getDataBlock() throws IOException { - if (!readIntoBuf(1) ) return -1; - int count = _buf[0]; - if (count != 0) if (!readIntoBuf(count) ) return -1; - return count; - } - - /** Read the indicated number of bytes into _buf, our instance-wide buffer. */ - private boolean readIntoBuf(int count) throws IOException { - for(int i = 0; i < count; i++) if ((_buf[i] = _in.read()) == -1) return false; - return true; - } - - // Private Data ////////////////////////////////////////////////////////// - - private Picture p; - - // State management stuff - private int index = -1; - private BufferedInputStream _in = null; - private int[] _buf = new int[BUFSIZE]; - - // Transparency settings - private int trans_idx = -1; - - // Global image descriptor contents - private int global_width = 0; - private int global_height = 0; - private int global_bgcolor = 0; - private int global_cmapsize = 0; - private boolean global_hascmap = false; - private int[] global_color_map = null; - - // Local image descriptor contents - private int left = 0; - private int top = 0; - private int cmapsize = 0; - private boolean hascmap = false; - private boolean interlaced = false; - private int[] color_map = null; - - // Variables used in getCode(...) to track sliding bit-window. - private int bytes = 0; - private boolean done; - private int c; - private long window; - private int bitsInWindow = 0; - - // Class-wide constants. - private static final int INTERLACE = 0x40; - private static final int GLOBALCOLORMAP = 0x80; - private static final int LOCALCOLORMAP = 0x80; - private static final int HASTRANSPARENCY = 0x01; - private static final int MAX_LWZ_BITS = 12; - private static final int BUFSIZE = 280; - private static final int[] _interlaceStep = { 8, 8, 4, 2 }; - private static final int[] _interlaceStart = { 0, 4, 2, 1 }; -} - - -