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.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());
}
}
}
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.
GifImage gifImage2 = new GifImage("idleGif2.gif");You need to login to post a reply.