package org.loon.framework.android.game.core;
import java.io.BufferedInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import org.loon.framework.android.game.core.graphics.LColor;
import org.loon.framework.android.game.core.graphics.LImage;
import org.loon.framework.android.game.core.graphics.device.LGraphics;
import org.loon.framework.android.game.core.graphics.geom.Dimension;
import org.loon.framework.android.game.core.graphics.geom.Rectangle;
import org.loon.framework.android.game.core.resource.Resources;
/**
* Copyright 2008 - 2009
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*
* @project loonframework
* @author chenpeng
* @emailceponline@yahoo.com.cn
* @version 0.1
*/
public class GIFDecoder {
public static final int STATUS_OK = 0;
public static final int STATUS_FORMAT_ERROR = 1;
public static final int STATUS_OPEN_ERROR = 2;
protected BufferedInputStream in;
protected int status;
protected int width, height;
protected boolean gctFlag;
protected int gctSize;
protected int loopCount = 1;
protected int[] gct, lct, act;
protected int bgIndex, bgColor, lastBgColor, pixelAspect;
protected boolean lctFlag;
protected boolean interlace;
protected int lctSize;
protected int ix, iy, iw, ih;
protected Rectangle lastRect;
protected LImage image;
protected LImage lastImage;
protected byte[] block = new byte[256];
protected int blockSize = 0;
protected int dispose = 0;
protected int lastDispose = 0;
protected boolean transparency = false;
protected int delay = 0;
protected int transIndex;
protected static final int MaxStackSize = 4096;
protected short[] prefix;
protected byte[] suffix;
protected byte[] pixelStack;
protected byte[] pixels;
protected ArrayList<GifFrame> frames;
protected int frameCount;
static class GifFrame {
public GifFrame(LImage im, int del) {
image = im;
delay = del;
}
public LImage image;
public int delay;
}
public int getDelay(int n) {
delay = -1;
if ((n >= 0) && (n < frameCount)) {
delay = ((GifFrame) frames.get(n)).delay;
}
return delay;
}
public int getFrameCount() {
return frameCount;
}
public LImage getImage() {
return getFrame(0);
}
public int getLoopCount() {
return loopCount;
}
protected void setPixels() {
int[] dest = image.getPixels();
if (lastDispose > 0) {
if (lastDispose == 3) {
int n = frameCount - 2;
if (n > 0) {
lastImage = getFrame(n - 1);
} else {
lastImage = null;
}
}
if (lastImage != null) {
int[] prev = lastImage.getPixels();
image.setPixels(prev, width, height);
if (lastDispose == 2) {
LGraphics g = image.getLGraphics();
LColor c = null;
if (transparency) {
c = new LColor(0, 0, 0, 0);
} else {
c = new LColor(lastBgColor);
}
g.setColor(c);
g.fill(lastRect);
g.dispose();
}
}
}
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;
int dlim = dx + iw;
if ((k + width) < dlim) {
dlim = k + width;
}
int sx = i * iw;
while (dx < dlim) {
int index = ((int) pixels[sx++]) & 0xff;
int c = act[index];
if (c != 0) {
dest[dx] = c;
}
dx++;
}
}
}
image.setPixels(dest, width, height);
}
public LImage getFrame(int n) {
LImage im = null;
if ((n >= 0) && (n < frameCount)) {
im = ((GifFrame) frames.get(n)).image;
}
return im;
}
public Dimension getFrameSize() {
return new Dimension(width, height);
}
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;
}
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;
}
public int read(String fileName) {
status = STATUS_OK;
InputStream in = Resources.getResourceAsStream(fileName);
if (in != null) {
status = read(in);
} else {
status = STATUS_OPEN_ERROR;
}
return status;
}
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];
}
if (prefix == null)
prefix = new short[MaxStackSize];
if (suffix == null)
suffix = new byte[MaxStackSize];
if (pixelStack == null)
pixelStack = new byte[MaxStackSize + 1];
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;
}
datum = bits = count = first = top = pi = bi = 0;
for (i = 0; i < npix;) {
if (top == 0) {
if (bits < code_size) {
if (count == 0) {
count = readBlock();
if (count <= 0)
break;
bi = 0;
}
datum += (((int) block[bi]) & 0xff) << bits;
bits += 8;
bi++;
count--;
continue;
}
code = datum & code_mask;
datum >>= code_size;
bits -= code_size;
if ((code > available) || (code == end_of_information))
break;
if (code == clear) {
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;
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;
}
top--;
pixels[pi++] = pixelStack[top];
i++;
}
for (i = pi; i < npix; i++) {
pixels[i] = 0;
}
}
protected boolean err() {
return status != STATUS_OK;
}
protected void init() {
status = STATUS_OK;
frameCount = 0;
frames = new ArrayList<GifFrame>();
gct = null;
lct = null;
}
protected int read() {
int curByte = 0;
try {
curByte = in.read();
} catch (IOException e) {
status = STATUS_FORMAT_ERROR;
}
return curByte;
}
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;
}
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];
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;
}
protected void readContents() {
boolean done = false;
while (!(done || err())) {
int code = read();
switch (code) {
case 0x2C:
readImage();
break;
case 0x21:
code = read();
switch (code) {
case 0xf9:
readGraphicControlExt();
break;
case 0xff:
readBlock();
String app = "";
for (int i = 0; i < 11; i++) {
app += (char) block[i];
}
if (app.equals("NETSCAPE2.0")) {
readNetscapeExt();
} else
skip();
break;
default:
skip();
}
break;
case 0x3b:
done = true;
break;
case 0x00:
break;
default:
status = STATUS_FORMAT_ERROR;
}
}
}
protected void readGraphicControlExt() {
read();
int packed = read();
dispose = (packed & 0x1c) >> 2;
if (dispose == 0) {
dispose = 1;
}
transparency = (packed & 1) != 0;
delay = readShort() * 10;
transIndex = read();
read();
}
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];
}
}
protected void readImage() {
ix = readShort();
iy = readShort();
iw = readShort();
ih = readShort();
int packed = read();
lctFlag = (packed & 0x80) != 0;
interlace = (packed & 0x40) != 0;
lctSize = 2 << (packed & 7);
if (lctFlag) {
lct = readColorTable(lctSize);
act = lct;
} else {
act = gct;
if (bgIndex == transIndex)
bgColor = 0;
}
int save = 0;
if (transparency) {
save = act[transIndex];
act[transIndex] = 0;
}
if (act == null) {
status = STATUS_FORMAT_ERROR;
}
if (err())
return;
decodeImageData();
skip();
if (err())
return;
frameCount++;
image = new LImage(width, height,true);
setPixels();
frames.add(new GifFrame(image, delay));
if (transparency) {
act[transIndex] = save;
}
resetFrame();
}
protected void readLSD() {
width = readShort();
height = readShort();
int packed = read();
gctFlag = (packed & 0x80) != 0;
gctSize = 2 << (packed & 7);
bgIndex = read();
pixelAspect = read();
}
protected void readNetscapeExt() {
do {
readBlock();
if (block[0] == 1) {
int b1 = ((int) block[1]) & 0xff;
int b2 = ((int) block[2]) & 0xff;
loopCount = (b2 << 8) | b1;
}
} while ((blockSize > 0) && !err());
}
protected int readShort() {
return read() | (read() << 8);
}
protected void resetFrame() {
lastDispose = dispose;
lastRect = new Rectangle(ix, iy, iw, ih);
lastImage = image;
lastBgColor = bgColor;
dispose = 0;
transparency = false;
delay = 0;
lct = null;
}
protected void skip() {
do {
readBlock();
} while ((blockSize > 0) && !err());
}
}
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