/*
* (C)2000 by F. Jalvingh, Mumble Internet Services
* For questions and the like: fjalvingh@bigfoot.com
*
* Compression part (C)1996,1998 by Jef Poskanzer <jef@acme.com>. All rights reserved.
*
* This software is placed in the public domain. You are free to use this
* software for any means while respecting the above copyright.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* Optimizations by Jal:
* ---------------------
* Initial: Coded RLE code for building the 8-bit color table.
* 6dec00: Changed code to remove extraneous if's and unrolled some calls.
* Replaced color hashtable with local specialized variant.
* 7dec00: Made specialized direct buffer access versions for BufferedImage
* images..
*
*/
// very slightly adopted by Michael Christen, 12.12.2007
// - removed unused variables
// - replaced old java classes by new one
package de.anomic.ymage;
import java.awt.Canvas;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.image.BufferedImage;
import java.awt.image.ColorModel;
import java.awt.image.DataBuffer;
import java.awt.image.DataBufferByte;
import java.awt.image.DataBufferInt;
import java.awt.image.DataBufferShort;
import java.awt.image.IndexColorModel;
import java.awt.image.PixelGrabber;
import java.awt.image.PixelInterleavedSampleModel;
import java.awt.image.Raster;
import java.awt.image.SampleModel;
import java.awt.image.SinglePixelPackedSampleModel;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
/**
* <p>This class can be used to write an animated GIF file by combining several
* images. It is loosely based on the Acme GIF encoder.</p>
*
* <p>The characteristics of the generated Gif 89a image are:
* <ul>
* <li>Only a single color table is used (no local tables). This table is
* created by combining the colors from all other images.</li>
* </ul>
* </p>
*
* @author F. Jalvingh
*/
public class AnimGifEncoder {
/** The default interlacing indicator */
private boolean m_default_interlace = false;
/** The default delay time, */
private final static int m_default_delay = 100;
/** Set when looping the set is requested. */
private boolean m_loop = true;
/** The outputstream to write the image to. */
private final OutputStream m_os;
/** The (current) list of images to embed in the GIF */
private ArrayList<AnIma> m_ima_ar;
/** The total width and height of all combined images */
private int m_w, m_h;
/** The canvas is used to proprly track images. */
private Canvas m_cv;
/** The index for the "transparant" color. -1 if no transparant found. */
private short m_transparant_ix = -1;
/** The index (palette table entry #) to use for the NEXT color encountered */
private short m_color_ix;
/** The #of bits to use (2log m_color_ix). */
private int m_color_bits;
/// Temp optimization inhibition.
public boolean m_no_opt;
/**
* This constructor creates an empty default codec.
*/
public AnimGifEncoder(final OutputStream os) {
m_os = os;
}
/**
* Creates a codec and specify interlace (not implemented yet).
*/
public AnimGifEncoder(final OutputStream os, final boolean interlace) {
m_os = os;
m_default_interlace = interlace;
}
/**
* <p>For animated GIF's the default is to LOOP all images in the GIF file.
* This means that after displaying all images in the file the first image
* is redisplayed ad infinitum.</p>
* <p>To prevent the images from looping call setLoop(false) before calling
* the encode() method.
* </p>
* <p>The current version does not allow the number of repetitions to be
* specified.
* </p>
*/
public void setLoop(final boolean loop) {
m_loop = loop;
}
/**
* Releases ALL cached resources.
*/
public void flush() {
//-- 1. The basic stuff
m_ccolor_ar = null;
m_cindex_ar = null;
m_cv = null;
m_ima_ar = null;
//-- 2. The compressor.
m_curr_pixels = null;
htab = null;
codetab = null;
accum = null;
}
/*------------------------------------------------------------------*/
/* CODING: Adding images to combine into the animated GIF... */
/*------------------------------------------------------------------*/
/**
* Adds the specified image to the list of images. While adding, the
* image is converted to pixels; each color is added to the color table
* and the resulting 8-bit pixelset is saved. After this call the image
* is released, and only the pixelset remains until the encode call is
* made. Calling encode will release the pixelset.
*/
public void add(final Image ima, final int delaytime, final boolean interlace, final int px, final int py) throws IOException {
final AnIma ai = new AnIma();
ai.m_delay = delaytime;
ai.m_interlace = interlace;
ai.m_x = px;
ai.m_y = py;
//-- Add to the list of images to embed,
if(m_ima_ar == null) // First call?
{
m_ccolor_ar = new int[CHSIZE]; // New colors code table
m_cindex_ar = new short[CHSIZE];
m_ima_ar = new ArrayList<AnIma>(10); // Contains all component images,
m_cv = new Canvas();
}
m_ima_ar.add(ai);
//-- Pre-scan the image!!
if(! m_no_opt)
preCode(ai, ima); // Convert to 8bit and make palette
else
precodeImage(ai, ima);
}
/**
* Adds the specified image to the list of images.
*/
public void add(final Image ima) throws IOException {
add(ima, m_ima_ar == null ? 0 : m_default_delay, m_default_interlace, 0, 0);
}
/**
* Adds the specified image to the list of images.
*/
public void add(final Image ima, final int delay) throws IOException {
add(ima, delay, m_default_interlace, 0, 0);
}
/*------------------------------------------------------------------*/
/* CODING: I/O to the file - helpers... */
/*------------------------------------------------------------------*/
/**
* Writes a string as a #of bytes to the output stream.
*/
private void utStr(final String str) throws IOException {
final byte[] buf = str.getBytes();
m_os.write( buf );
}
private void utWord(final int val) throws IOException {
utByte( (byte) ( val & 0xff));
utByte( (byte) (( val >> 8 ) & 0xff ));
}
private void utByte(final byte b) throws IOException {
m_os.write( b );
}
/*------------------------------------------------------------------*/
/* CODING: Starting the encode process... */
/*------------------------------------------------------------------*/
/**
* Creates the GIF file from all images added to the encoder.
*/
public void encode() throws IOException {
//-- Check validity,
if(m_ima_ar == null || m_ima_ar.size() == 0)
throw new IOException("No images added.");
//-- Init the compressor's tables
htab = new int[HSIZE];
codetab = new int[HSIZE];
accum = new byte[256];
//-- Write the GIF header now,
genHeader();
/*
* Traverse the data for each image. This determines the actual color
* table and the complete output size.
*/
for (int i = 0; i < m_ima_ar.size(); i++) {
final AnIma ai = m_ima_ar.get(i);
genImage(ai);
ai.m_rgb = null;
}
genTrailer();
flush();
}
/*--------------------------------------------------------------*/
/* CODING: Color table code & specialized color hashtable. */
/*--------------------------------------------------------------*/
/*
* This is a hashtable mapping (int, byte). The first int is the actual
* color as gotten from the image. The byte is the index color in the
* colormap for the entry.
* We need to find (byte) by indexing with (int) VERY quicky.
* Furthermore we already know that the table will at max hold 256 entries.
*
* Since all colors >= 0 are transparant, we use (int) = 0 as the empty
* case.
*
* This hashtable uses the same hash mechanism as the LZH compressor: a
* double hash without chaining.
*/
private final static int CHSIZE = 1023;
/// The color hashtable's COLOR table (int rcolors)
private int[] m_ccolor_ar;
/// The color hashtable's INDEX table (byte index)
private short[] m_cindex_ar;
/**
* This retrieves the index for a color code from the color hash. If the
* color doesn't exist it is added to the hash table. This uses the double
* hash mechanism described above. If this call causes >255 colors to be
* stored it throws a too many colors exception.
* The function returns the index code for the color.
*/
private short findColorIndex(final int color) throws IOException {
//-- 1. Primary hash..
int i = (color & 0x7fffffff) % CHSIZE;
if(m_ccolor_ar[i] == color) // Bucket found?
return m_cindex_ar[i];
//-- 2. No match. If the bucket is not empty do the 2nd hash,
if(m_ccolor_ar[i] != 0) // Bucket is full?
{
//-- This was a clash. Locate a new bucket & look for another match!
final int disp = CHSIZE - i;
do
{
i -= disp;
if(i < 0) i += CHSIZE;
if(m_ccolor_ar[i] == color) // Found in 2nd hash?
return m_cindex_ar[i]; // Then return it.
} while(m_ccolor_ar[i] != 0); // Loop till empty bucket.
}
//-- 3. Empty bucket found: add this there as a new index.
if(m_color_ix >= 256)
throw new IOException("More than 255 colors in this GIF are not allowed.");
m_ccolor_ar[i] = color;
m_cindex_ar[i] = m_color_ix;
return m_color_ix++;
}
/*--------------------------------------------------------------*/
/* CODING: Optimized pixel grabbers... */
/*--------------------------------------------------------------*/
/**
* Checks if the image lies in the current complete image, else it extends
* the source image.
*/
private void checkTotalSize(final AnIma ai) {
int t;
t = ai.m_w + ai.m_x; // Get end-X of image,
if(t > m_w) m_w = t; // Adjust complete GIF's size
t = ai.m_h + ai.m_y; // Get total height
if(t > m_h) m_h = t; // Adjust if higher,
}
/*--------------------------------------------------------------*/
/* CODING: The precoder translates all to 8bit indexed... */
/*--------------------------------------------------------------*/
/**
* Traverse this image, and determine it's characteristics. It adds all
* used colors to the color table and determines the completed size of
* the thing. The image is converted to an 8-bit pixelmap where each pixel
* indexes the generated color table.
* This function tries to get the fastest access to the pixel data for
* several types of BufferedImage. This should enhance the encoding speed
* by preventing the loop thru the entire generalized Raster and ColorModel
* method....
* All precode methods build a color table containing all colors used in
* the image, and an 8-bit "image" containing, for each pixel, the index
* into that color table. They also set the transparant color to use.
*/
private void preCode(final AnIma ai, final Image ima) throws IOException {
//-- Call the appropriate encoder depending on the image type.
if(ima instanceof BufferedImage)
precodeBuffered(ai, (BufferedImage) ima);
else
precodeImage(ai, ima);
}
/**
* Tries to decode a buffered image in an optimal way. It checks to see
* if it knows the BufferedImage type and calls the appropriate quick
* decoder. If the image is not implemented we fall back to the generic
* method.
*/
private void precodeBuffered(final AnIma ai, final BufferedImage bi) throws IOException {
//-- 1. Handle all shared tasks...
ai.m_w = bi.getWidth();
ai.m_h = bi.getHeight();
if(ai.m_h == 0 || ai.m_w == 0) return;
checkTotalSize(ai);
//-- 2. Optimize for known types...
boolean done= false;
final int bt = bi.getType();
switch(bt)
{
case BufferedImage.TYPE_BYTE_INDEXED: done = precodeByteIndexed(ai, bi); break;
case BufferedImage.TYPE_INT_BGR: done = precodeIntPacked(ai, bi); break;
case BufferedImage.TYPE_INT_ARGB: done = precodeIntPacked(ai, bi); break;
case BufferedImage.TYPE_USHORT_555_RGB: done = precodeShortPacked(ai, bi); break;
case BufferedImage.TYPE_USHORT_565_RGB: done = precodeShortPacked(ai, bi); break;
case BufferedImage.TYPE_INT_RGB: done = precodeIntPacked(ai, bi); break;
}
if(done) return;
precodeImage(ai, bi);
}
private int getBiOffset(final Raster ras, final PixelInterleavedSampleModel sm, final int x, final int y) {
return (y-ras.getSampleModelTranslateY()) * sm.getScanlineStride() + x-ras.getSampleModelTranslateX();
}
private int getBiOffset(final Raster ras, final SinglePixelPackedSampleModel sm, final int x, final int y) {
return (y-ras.getSampleModelTranslateY()) * sm.getScanlineStride() + x-ras.getSampleModelTranslateX();
}
/*--------------------------------------------------------------*/
/* CODING: BufferedImage.TYPE_BYTE_INDEXED.. */
/*--------------------------------------------------------------*/
/**
* Encodes TYPE_BYTE_INDEXED images.
*/
private boolean precodeByteIndexed(final AnIma ai, final BufferedImage bi) throws IOException {
//-- Get the colormodel, the raster, the databuffer and the samplemodel
final ColorModel tcm = bi.getColorModel();
if(! (tcm instanceof IndexColorModel)) return false;
final IndexColorModel cm = (IndexColorModel) tcm;
final Raster ras = bi.getRaster();
final SampleModel tsm = ras.getSampleModel();
if(! (tsm instanceof PixelInterleavedSampleModel)) return false;
final PixelInterleavedSampleModel sm = (PixelInterleavedSampleModel) tsm;
final DataBuffer dbt = ras.getDataBuffer();
if(dbt.getDataType() != DataBuffer.TYPE_BYTE) return false;
if(dbt.getNumBanks() != 1) return false;
final DataBufferByte db = (DataBufferByte) dbt;
//-- Prepare the color mapping
final short[] map = new short[256]; // Alternate lookup table
for(int i = 0; i < 256; i++) // Set all entries to unused,
map[i] = -1;
/*
* Prepare the run: get all constants e.a. The mechanism runs thru
* all pixels by traversing each X scanline, then moving to the next
* one. One fun thing: we only have to COPY all pixels, since we're
* already byte-packed.
*/
final int endoff = ai.m_w * ai.m_h; // Output image size,
final byte[] par = new byte[endoff]; // Byte-indexed output array,
int doff = 0; // Destination offset,
//-- source
int soff = getBiOffset(ras, sm, 0, 0);
final byte[] px = db.getData(0); // Get the pixelset,
final int esoff = getBiOffset(ras, sm, ai.m_w-1, ai.m_h-1); // calc end offset,
final int iw = sm.getScanlineStride(); // Increment width = databuf's width
while(soff < esoff) { // For all scan lines,
final int xe = soff + ai.m_w; // End for this line
while(soff < xe) { // While within this line
//-- (continue) collect a run,
final int rs = soff; // Save run start
final byte rcolor = px[soff++]; // First color
while(soff < xe && px[soff] == rcolor) // Run till eoln or badclor
soff++;
//-- Run ended. Map the input index to the GIF's index,
short ii = map[rcolor + 0x80];
if (ii == -1){ // Unknown map?
//-- New color. Get it's translated RGB value,
final int rix = rcolor & 0xff; // Translate to unsigned
int rgb = cm.getRGB(rix); // Get RGB value for this input index,
if(rgb >= 0) { // Transparant color?
//-- If there is a transparant color index use it...
if (m_transparant_ix < 0) {
//-- First transparant color found- save it,
if(rgb == 0) rgb = 1; // Zero color protection - req'd for hashtable implementation
m_transparant_ix = findColorIndex(rgb);
}
ii = m_transparant_ix; // Use trans color to fill
} else {
//-- Not transparant,
ii = findColorIndex(rgb); // Add RGB value to the index,
}
map[rcolor + 0x80] = ii;
}
//-- Always write this run.
final int dep = doff + (soff - rs); // End output pos
final byte idx = (byte) ii;
while(doff < dep)
par[doff++] = idx; // Fill output.
}
//-- Prepare for a new line.
soff += iw - ai.m_w; // Increment what's left to next line,
}
ai.m_rgb = par; // Save created thing
return true;
}
/*--------------------------------------------------------------*/
/* CODING: BufferedImage.All int packed stuff.. */
/*--------------------------------------------------------------*/
/**
* Encodes INT pixel-packed images.
*/
private boolean precodeIntPacked(final AnIma ai, final BufferedImage bi) throws IOException {
//-- Get the colormodel, the raster, the databuffer and the samplemodel
final ColorModel cm = bi.getColorModel();
final Raster ras = bi.getRaster();
final SampleModel tsm = ras.getSampleModel();
if(! (tsm instanceof SinglePixelPackedSampleModel)) return false;
final SinglePixelPackedSampleModel sm = (SinglePixelPackedSampleModel) tsm;
final DataBuffer dbt = ras.getDataBuffer();
if(dbt.getDataType() != DataBuffer.TYPE_INT) return false;
if(dbt.getNumBanks() != 1) return false;
final DataBufferInt db = (DataBufferInt) dbt;
/*
* Prepare the run: get all constants e.a. The mechanism runs thru
* all pixels by traversing each X scanline, then moving to the next
* one. One fun thing: we only have to COPY all pixels, since we're
* already byte-packed.
*/
final int endoff = ai.m_w * ai.m_h; // Output image size,
final byte[] par = new byte[endoff]; // Byte-indexed output array,
int doff = 0; // Destination offset,
byte ii;
//-- source
int soff = getBiOffset(ras, sm, 0, 0);
final int[] px = db.getData(0); // Get the pixelset,
final int esoff = getBiOffset(ras, sm, ai.m_w-1, ai.m_h-1); // calc end offset,
final int iw = sm.getScanlineStride(); // Increment width = databuf's width
while(soff < esoff) { // For all scan lines,
final int xe = soff + ai.m_w; // End for this line
while (soff < xe) { // While within this line
//-- (continue) collect a run,
final int rs = soff; // Save run start
final int rcolor = px[soff++]; // First color
while(soff < xe && px[soff] == rcolor) // Run till eoln or badclor
soff++;
//-- Run ended. Map the input index to the GIF's index,
int rgb = cm.getRGB(rcolor); // Get RGB value for this input index,
if(rgb >= 0) { // Transparant color?
//-- If there is a transparant color index use it...
if(m_transparant_ix < 0) {
//-- First transparant color found- save it,
if(rgb == 0) rgb = 1; // Zero color protection - req'd for hashtable implementation
m_transparant_ix = findColorIndex(rgb);
}
ii = (byte)m_transparant_ix; // Use trans color to fill
} else {
//-- Not transparant,
ii = (byte)findColorIndex(rgb); // Add RGB value to the index,
}
//-- Always write this run.
final int dep = doff + (soff - rs); // End output pos
while(doff < dep)
par[doff++] = ii; // Fill output.
}
//-- Prepare for a new line.
soff += iw - ai.m_w; // Increment what's left to next line,
}
ai.m_rgb = par; // Save created thing
return true;
}
/*--------------------------------------------------------------*/
/* CODING: BufferedImage- SHORT type stuff.. */
/*--------------------------------------------------------------*/
/**
* Encodes SHORT pixel-packed images.
*/
private boolean precodeShortPacked(final AnIma ai, final BufferedImage bi) throws IOException {
//-- Get the colormodel, the raster, the databuffer and the samplemodel
final ColorModel cm = bi.getColorModel();
final Raster ras = bi.getRaster();
final SampleModel tsm = ras.getSampleModel();
if(! (tsm instanceof SinglePixelPackedSampleModel)) return false;
final SinglePixelPackedSampleModel sm = (SinglePixelPackedSampleModel) tsm;
final DataBuffer dbt = ras.getDataBuffer();
if(dbt.getDataType() != DataBuffer.TYPE_SHORT) return false;
if(dbt.getNumBanks() != 1) return false;
final DataBufferShort db = (DataBufferShort) dbt;
/*
* Prepare the run: get all constants e.a. The mechanism runs thru
* all pixels by traversing each X scanline, then moving to the next
* one. One fun thing: we only have to COPY all pixels, since we're
* already byte-packed.
*/
final int endoff = ai.m_w * ai.m_h; // Output image size,
final byte[] par = new byte[endoff]; // Byte-indexed output array,
int doff = 0; // Destination offset,
byte ii;
//-- source
int soff = getBiOffset(ras, sm, 0, 0);
final short[] px = db.getData(0); // Get the pixelset,
final int esoff = getBiOffset(ras, sm, ai.m_w-1, ai.m_h-1); // calc end offset,
final int iw = sm.getScanlineStride(); // Increment width = databuf's width
while(soff < esoff) // For all scan lines,
{
final int xe = soff + ai.m_w; // End for this line
while(soff < xe) // While within this line
{
//-- (continue) collect a run,
final int rs = soff; // Save run start
final short rcolor = px[soff++]; // First color
while(soff < xe && px[soff] == rcolor) // Run till eoln or badclor
soff++;
//-- Run ended. Map the input index to the GIF's index,
int rgb = cm.getRGB(rcolor); // Get RGB value for this input index,
if(rgb >= 0) // Transparant color?
{
//-- If there is a transparant color index use it...
if(m_transparant_ix < 0)
{
//-- First transparant color found- save it,
if(rgb == 0) rgb = 1; // Zero color protection - req'd for hashtable implementation
m_transparant_ix = findColorIndex(rgb);
}
ii = (byte)m_transparant_ix; // Use trans color to fill
}
else
{
//-- Not transparant,
ii = (byte)findColorIndex(rgb); // Add RGB value to the index,
}
//-- Always write this run.
final int dep = doff + (soff - rs); // End output pos
while(doff < dep)
par[doff++] = ii; // Fill output.
}
//-- Prepare for a new line.
soff += iw - ai.m_w; // Increment what's left to next line,
}
ai.m_rgb = par; // Save created thing
return true;
}
/*--------------------------------------------------------------*/
/* CODING: The generic Image stuff to translate the GIF */
/*--------------------------------------------------------------*/
/**
* Using a generic Image, this uses a PixelGrabber to get an integer
* pixel array.
*/
private void precodeImage(final AnIma ai, final Image ima) throws IOException {
int[] px;
//-- Wait for the image to arrive,
MediaTracker mt = new MediaTracker(m_cv);
mt.addImage(ima, 0);
try
{
mt.waitForAll(); // Be use all are loaded,
}
catch(final InterruptedException x)
{
throw new IOException("Interrupted load of image");
}
mt.removeImage(ima, 0);
mt = null;
//-- Get the images' size & adjust the complete GIF's size,
ai.m_w = ima.getWidth(m_cv);
ai.m_h = ima.getHeight(m_cv);
if(ai.m_h == 0 || ai.m_w == 0) return;
checkTotalSize(ai);
//-- Grab pixels & convert to 8-bit pixelset.
final PixelGrabber pg = new PixelGrabber(ima, 0, 0, ai.m_w, ai.m_h, true);
try {
pg.grabPixels();
} catch(final InterruptedException x) {
throw new IOException("Interrupted load of image");
}
px = (int[]) pg.getPixels(); // Get the pixels,
translateColorsByArray(ai, px); // Run the translator
}
/**
* For each pixel in the source image, the color is put into the palette
* for the combined GIF. The index of the color is then used in the 8-bit
* pixelset for this image.
*/
private void translateColorsByArray(final AnIma a, final int[] px) throws IOException {
int off;
byte[] par;
final int endoff = a.m_w * a.m_h; // Total #pixels in image
int rstart, rcolor; // Run data.
byte newc;
//-- Collect runs of pixels of the same color; then handle them;
par = new byte[endoff]; // Allocate output matrix
off = 0; // Output offset,
while(off < endoff) {
//-- Collect the current run of pixels.
rstart = off;
rcolor = px[off++]; // Get 1st pixel of run,
while(off < endoff && px[off] == rcolor) // Fast loop!
off++;
//-- Translate the color to an index, and handle transparency,
if(rcolor >= 0) // Is this a TRANSPARANT color?
{
//-- If there is a transparant color index use it...
if(m_transparant_ix < 0)
{
//-- First transparant color found- save it,
if(rcolor == 0) rcolor = 1; // Zero color protection - req'd for hashtable implementation
m_transparant_ix = findColorIndex(rcolor);
}
newc = (byte)m_transparant_ix; // Set color to fill run with
}
else
{
//-- Not transparant- is an index known for this color?
final int i = (rcolor & 0x7fffffff) % CHSIZE;
if(m_ccolor_ar[i] == rcolor) // Bucket found?
newc = (byte)m_cindex_ar[i];
else
newc = (byte)findColorIndex(rcolor); // Get color index,
}
//-- Always fill the run with the replaced color,
while(rstart < off)
par[rstart++] = newc;
//-- This run has been done!!
}
a.m_rgb = par; // Save completed map;
}
/**
* Generates the color map by using the color table and creating all
* rgb tables. These are then written to the output. This gets called when
* all images have been added and pre-traversed.
*/
private void genColorTable() throws IOException {
// Turn colors into colormap entries.
final int nelem = 1 << m_color_bits;
final byte[] reds = new byte[nelem];
final byte[] grns = new byte[nelem];
final byte[] blus = new byte[nelem];
//-- Now enumerate the color table.
for (int i = CHSIZE; --i >= 0;) { // Count backwards (faster)
if(m_ccolor_ar[i] != 0) { // A color was found?
reds[ m_cindex_ar[i] ] = (byte) ( (m_ccolor_ar[i] >> 16) & 0xff);
grns[ m_cindex_ar[i] ] = (byte) ( (m_ccolor_ar[i] >> 8) & 0xff);
blus[ m_cindex_ar[i] ] = (byte) ( m_ccolor_ar[i] & 0xff );
}
}
//-- Write the map to the stream,
for (int i = 0; i < nelem; i++) { // Save all elements,
utByte(reds[i]);
utByte(grns[i]);
utByte(blus[i]);
}
}
/**
* Writes the GIF file header, containing all up to the first image data
* structure: color table, option fields etc.
*/
private void genHeader() throws IOException {
// Figure out how many bits to use.
if(m_color_ix <= 2)
m_color_bits = 1;
else if(m_color_ix <= 4)
m_color_bits = 2;
else if(m_color_ix <= 8)
m_color_bits = 3;
else if(m_color_ix <= 16)
m_color_bits = 4;
else
m_color_bits = 8;
//-- Start with the headerm
utStr("GIF89a" ); // Gif89a Header: signature & version
//-- Logical Screen Descriptor Block
utWord(m_w); // Collated width & height of all images
utWord(m_h);
final byte b = (byte)(0xF0 | (m_color_bits-1));// There IS a color map, 8 bits per color source resolution. not sorted,
utByte(b); // Packet fields,
utByte((byte)0); // Background Color Index assumed 0.
utByte((byte)0); // Pixel aspect ratio 1:1: zero always works...
//-- Now write the Global Color Map.
genColorTable();
if (m_loop && m_ima_ar.size() > 1) {
//-- Generate a Netscape loop thing,
utByte((byte) 0x21);
utByte((byte) 0xff);
utByte((byte) 0x0b);
utStr("NETSCAPE2.0");
utByte((byte) 0x03);
utByte((byte) 1);
utWord(0); // Repeat indefinitely
utByte((byte)0);
}
}
/**
* Writes the GIF file trailer, terminating the GIF file.
*/
private void genTrailer() throws IOException {
// Write the GIF file terminator
utByte((byte) ';');
}
/**
* Writes a single image instance.
*/
private void genImage(final AnIma ai) throws IOException {
//-- Write out a Graphic Control Extension for transparent colour & repeat, if necessary,
if(m_transparant_ix != -1 || m_ima_ar.size() > 1) {
byte transpar;
utByte( (byte) '!'); // 0x21 Extension Introducer
utByte( (byte) 0xf9); // Graphic Control Label
utByte( (byte) 4); // Block Size,
if(m_transparant_ix >= 0) { // There IS transparancy?
utByte((byte) 1); // TRANS flag SET
transpar = (byte) m_transparant_ix;
} else {
utByte((byte) 0); // TRANS flag CLEAR
transpar = 0;
}
utWord( ai.m_delay ); // Delay time,
utByte(transpar); // And save the index,
utByte( (byte) 0);
}
//-- Write the Image Descriptor
utByte((byte)',');
utWord(ai.m_x); // Image left position,
utWord(ai.m_y); // Image right position
utWord(ai.m_w);
utWord(ai.m_h); // And it's size,
utByte((byte) (ai.m_interlace ? 0x40 : 0)); // Packed fields: interlaced Y/N, no local table no sort,
//-- The table-based image data...
final int initcodesz = m_color_bits <= 1 ? 2 : m_color_bits;
utByte((byte) initcodesz); // Output initial LZH code size, min. 2 bits,
genCompressed(ai, initcodesz+1); // Generate the compressed data,
utByte((byte) 0); // Zero-length packet (end series)
}
/*------------------------------------------------------------------*/
/* CODING: Stuff to compress!!! */
/*------------------------------------------------------------------*/
/*
* Most of this compressor code has been reaped from the ACME GifEncoder
* package. See there for more details.
* This code will be revised for speed in the next release though.
*/
/** Pixmap from ima currently compressed */
private byte[] m_curr_pixels;
/** Current pixel source index in above map */
private int m_px_ix;
/** End index within above index. */
private int m_px_endix;
private void genCompressed(final AnIma a, final int initcodesz) throws IOException {
//-- Set all globals to retrieve pixel data quickly. $$TODO: Interlaced
m_curr_pixels = a.m_rgb;
m_px_ix = 0;
m_px_endix = a.m_w * a.m_h; // Last index,
//-- Coder variables.
int i, c, ent, disp, hsize_reg, hshift, fcode;
//-- Init: the bit-code writer's variables,
cur_accum = 0;
cur_bits = 0;
free_ent = 0;
clear_flg = false;
maxbits = BITS; // user settable max # bits/code
maxmaxcode = 1 << BITS; // should NEVER generate this code
a_count = 0;
g_init_bits = initcodesz; // Initial #of bits
// Set up the necessary values
clear_flg = false;
n_bits = g_init_bits;
maxcode = MAXCODE( n_bits );
ClearCode = 1 << ( initcodesz - 1 );
EOFCode = ClearCode + 1;
free_ent = ClearCode + 2;
char_init();
hshift = 0;
for ( fcode = hsize; fcode < 65536; fcode *= 2 )
++hshift;
hshift = 8 - hshift; // set hash code range bound
hsize_reg = hsize;
cl_hash( hsize_reg ); // clear hash table
output(ClearCode);
ent = m_curr_pixels[m_px_ix++]; // Get 1st pixel value,
outer_loop: while(m_px_ix < m_px_endix) // While not at end
{
c = m_curr_pixels[m_px_ix++]; // Get next pixel value,
fcode = ( c << maxbits ) + ent;
i = ( c << hshift ) ^ ent; // xor hashing
if(htab[i] == fcode)
{
ent = codetab[i];
continue;
}
else if ( htab[i] >= 0 ) // non-empty slot
{
disp = hsize_reg - i; // secondary hash (after G. Knott)
if ( i == 0 ) // ?? Should be inpossible?? JAL
disp = 1;
do
{
if( (i -= disp) < 0 )
i += hsize_reg;
if ( htab[i] == fcode )
{
ent = codetab[i];
continue outer_loop;
}
}
while ( htab[i] >= 0 );
}
output(ent);
ent = c;
if ( free_ent < maxmaxcode )
{
codetab[i] = free_ent++; // code -> hashtable
htab[i] = fcode;
}
else
cl_block();
}
// Put out the final code.
output(ent);
outputEOF();
}
static final int EOF = -1;
// GIFCOMPR.C - GIF Image compression routines
//
// Lempel-Ziv compression based on 'compress'. GIF modifications by
// David Rowley (mgardi@watdcsu.waterloo.edu)
// General DEFINEs
static final int BITS = 12;
static final int HSIZE = 5003; // 80% occupancy
// GIF Image compression - modified 'compress'
//
// Based on: compress.c - File compression ala IEEE Computer, June 1984.
//
// By Authors: Spencer W. Thomas (decvax!harpo!utah-cs!utah-gr!thomas)
// Jim McKie (decvax!mcvax!jim)
// Steve Davies (decvax!vax135!petsd!peora!srd)
// Ken Turkowski (decvax!decwrl!turtlevax!ken)
// James A. Woods (decvax!ihnp4!ames!jaw)
// Joe Orost (decvax!vax135!petsd!joe)
int n_bits; // number of bits/code
int maxbits = BITS; // user settable max # bits/code
int maxcode; // maximum code, given n_bits
int maxmaxcode = 1 << BITS; // should NEVER generate this code
final int MAXCODE( final int n_bits ) {
return ( 1 << n_bits ) - 1;
}
int[] htab;
int[] codetab;
int hsize = HSIZE; // for dynamic table sizing
int free_ent = 0; // first unused entry
// block compression parameters -- after all codes are used up,
// and compression rate changes, start over.
boolean clear_flg = false;
// Algorithm: use open addressing double hashing (no chaining) on the
// prefix code / next character combination. We do a variant of Knuth's
// algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
// secondary probe. Here, the modular division first probe is gives way
// to a faster exclusive-or manipulation. Also do block compression with
// an adaptive reset, whereby the code table is cleared when the compression
// ratio decreases, but after the table fills. The variable-length output
// codes are re-sized at this point, and a special CLEAR code is generated
// for the decompressor. Late addition: construct the table according to
// file size for noticeable speed improvement on small files. Please direct
// questions about this implementation to ames!jaw.
int g_init_bits;
int ClearCode;
int EOFCode;
// Output the given code.
// Inputs:
// code: A n_bits-bit integer. If == -1, then EOF. This assumes
// that n_bits =< wordsize - 1.
// Outputs:
// Outputs code to the file.
// Assumptions:
// Chars are 8 bits long.
// Algorithm:
// Maintain a BITS character long buffer (so that 8 codes will
// fit in it exactly). Use the VAX insv instruction to insert each
// code in turn. When the buffer fills up empty it and start over.
int cur_accum = 0;
int cur_bits = 0;
static int masks[] = {
0x0000, 0x0001, 0x0003, 0x0007, 0x000F,
0x001F, 0x003F, 0x007F, 0x00FF,
0x01FF, 0x03FF, 0x07FF, 0x0FFF,
0x1FFF, 0x3FFF, 0x7FFF, 0xFFFF };
void output(final int code) throws IOException {
cur_accum |= ( code << cur_bits );
cur_bits += n_bits;
while( cur_bits >= 8 ) {
//-- Expanded char_out code
accum[a_count++] = (byte) cur_accum;
if ( a_count >= 254 )
flush_char();
//-- End of char_out expansion
cur_accum >>= 8;
cur_bits -= 8;
}
// If the next entry is going to be too big for the code size,
// then increase it, if possible.
// $$Rewrote if (JAL)
if(clear_flg) {
maxcode = MAXCODE(n_bits = g_init_bits);
clear_flg = false;
} else if(free_ent > maxcode) {
++n_bits;
if (n_bits == maxbits)
maxcode = maxmaxcode;
else
maxcode = MAXCODE(n_bits);
}
}
/**
* Removed from output() above to skip an extra IF in the main loop. Must
* be called instead of calling output(EOFCode).
*/
private void outputEOF() throws IOException {
output(EOFCode); // Actually output the code
//-- At EOF, write the rest of the buffer.
while( cur_bits > 0)
{
//-- Expanded char_out.
accum[a_count++] = (byte) cur_accum;
if ( a_count >= 254 )
flush_char();
//-- End of char_out expansion
cur_accum >>= 8;
cur_bits -= 8;
}
flush_char();
}
// Clear out the hash table
// table clear for block compress
void cl_block() throws IOException {
cl_hash( hsize );
free_ent = ClearCode + 2;
clear_flg = true;
output(ClearCode);
}
// reset code table
void cl_hash( final int hsize ) {
for(int i = hsize; --i >= 0;)
htab[i] = -1;
}
// GIF Specific routines
// Number of characters so far in this 'packet'
int a_count;
// Set up the 'byte output' routine
void char_init() {
a_count = 0;
}
// Define the storage for the packet accumulator
byte[] accum;
// Add a character to the end of the current packet, and if it is 254
// characters, flush the packet to disk.
void char_out(final byte c) throws IOException {
accum[a_count++] = c;
if ( a_count >= 254 )
flush_char();
}
// Flush the packet to disk, and reset the accumulator
void flush_char() throws IOException {
if( a_count > 0) {
m_os.write( a_count );
m_os.write( accum, 0, a_count );
a_count = 0;
}
}
// test method for ymage classes
public static void main(final String[] args) {
System.setProperty("java.awt.headless", "true");
final ymageMatrix m = new ymageMatrix(200, 300, ymageMatrix.MODE_SUB, "FFFFFF");
ymageMatrix.demoPaint(m);
final File file = new File("/Users/admin/Desktop/testimage.gif");
OutputStream os;
try {
os = new FileOutputStream(file);
final AnimGifEncoder age = new AnimGifEncoder(os);
age.add(m.getImage());
age.add(m.getImage());
age.encode();
os.close();
} catch (final FileNotFoundException e) {
e.printStackTrace();
} catch (final IOException e) {
e.printStackTrace();
}
}
}
class GifColorEntry {
/** The actual RGB color for this entry */
public int m_color;
/** The colortable [palette] entry number for this color */
public int m_index;
public GifColorEntry(final int col, final int ix) {
m_color = col;
m_index = ix;
}
};
class AnIma {
/** This-image's interlace flag */
public boolean m_interlace;
/** This-image's delay factor */
public int m_delay;
/** This-image's source and destination within the completed image */
public int m_x, m_y;
/** This image's width and height */
public int m_w, m_h;
/** This-image's 8-bit pixelset. It indexes the m_color_ar table. */
public byte[] m_rgb;
};