+++ /dev/null
-/* $RCSfile$
- * $Author: hansonr $
- * $Date: 2007-06-02 12:14:13 -0500 (Sat, 02 Jun 2007) $
- * $Revision: 7831 $
- *
- * Some portions of this file have been modified by Robert Hanson hansonr.at.stolaf.edu 2012-2017
- * for use in SwingJS via transpilation into JavaScript using Java2Script.
- *
- * Copyright (C) 2000-2005 The Jmol Development Team
- *
- * Contact: jmol-developers@lists.sf.net
- *
- * This library is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * This library is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- */
-
-// Final encoding code from http://acme.com/resources/classes/Acme/JPM/Encoders/GifEncoder.java
-//
-// GifEncoder - write out an image as a GIF
-//
-//
-// Transparency handling and variable bit size courtesy of Jack Palevich.
-//
-// Copyright (C)1996,1998 by Jef Poskanzer <jef@mail.acme.com>. All rights reserved.
-//
-// Redistribution and use in source and binary forms, with or without
-// modification, are permitted provided that the following conditions
-// are met:
-// 1. Redistributions of source code must retain the above copyright
-// notice, this list of conditions and the following disclaimer.
-// 2. Redistributions in binary form must reproduce the above copyright
-// notice, this list of conditions and the following disclaimer in the
-// documentation and/or other materials provided with the distribution.
-//
-// 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.
-//
-// Visit the ACME Labs Java page for up-to-date versions of this and other
-// fine Java utilities: http://www.acme.com/java/
-//
-/// Write out an image as a GIF.
-// <P>
-// <A HREF="/resources/classes/Acme/JPM/Encoders/GifEncoder.java">Fetch the software.</A><BR>
-// <A HREF="/resources/classes/Acme.tar.gz">Fetch the entire Acme package.</A>
-// <P>
-// @see ToGif
-
-package javajs.img;
-
-import javajs.util.CU;
-import javajs.util.Lst;
-import javajs.util.M3;
-import javajs.util.P3;
-
-import java.util.Hashtable;
-import java.util.Map;
-import java.io.IOException;
-
-/**
- *
- * GifEncoder extensively adapted for Jmol by Bob Hanson
- *
- * Color quantization roughly follows the GIMP method
- * "dither Floyd-Steinberg (normal)" but with some twists. (For example, we
- * exclude the background color.)
- *
- * Note that although GIMP code annotation refers to "median-cut", it is really
- * using MEAN-cut. That is what I use here as well.
- *
- * -- commented code allows visualization of the color space using Jmol. Very
- * enlightening!
- *
- * -- much simplified interface with ImageEncoder
- *
- * -- uses simple Hashtable with Integer() to catalog colors
- *
- * -- allows progressive production of animated GIF via Jmol CAPTURE command
- *
- * -- uses general purpose javajs.util.OutputChannel for byte-handling options
- * such as posting to a server, writing to disk, and retrieving bytes.
- *
- * -- allows JavaScript port
- *
- * -- Bob Hanson, first try: 24 Sep 2013; final coding: 9 Nov 2014
- *
- *
- * @author Bob Hanson hansonr@stolaf.edu
- */
-
-public class GifEncoder extends ImageEncoder {
-
- private Map<String, Object> params;
- private P3[] palette;
- private int backgroundColor;
-
- private boolean interlaced;
- private boolean addHeader = true;
- private boolean addImage = true;
- private boolean addTrailer = true;
- private boolean isTransparent;
- private boolean floydSteinberg = true;
- private boolean capturing;
- private boolean looping;
-
- private int delayTime100ths = -1;
- private int bitsPerPixel = 1;
-
- private int byteCount;
-
- /**
- * we allow for animated GIF by being able to re-enter the code with different
- * parameters held in params
- *
- *
- */
- @Override
- protected void setParams(Map<String, Object> params) {
- this.params = params;
- Integer ic = (Integer) params.get("transparentColor");
- if (ic == null) {
- ic = (Integer) params.get("backgroundColor");
- if (ic != null)
- backgroundColor = ic.intValue();
- } else {
- backgroundColor = ic.intValue();
- isTransparent = true;
- }
-
- interlaced = (Boolean.TRUE == params.get("interlaced"));
- if (params.containsKey("captureRootExt") // file0000.gif
- || !params.containsKey("captureMode")) // animated gif
- return;
- interlaced = false;
- capturing = true;
- try {
- byteCount = ((Integer) params.get("captureByteCount")).intValue();
- } catch (Exception e) {
- // ignore
- }
- switch ("maec"
- .indexOf(((String) params.get("captureMode")).substring(0, 1))) {
- case 0: //"movie"
- params.put("captureMode", "add");
- addImage = false;
- addTrailer = false;
- break;
- case 1: // add
- addHeader = false;
- addTrailer = false;
- int fps = Math.abs(((Integer) params.get("captureFps")).intValue());
- delayTime100ths = (fps == 0 ? 0 : 100 / fps);
- looping = (Boolean.FALSE != params.get("captureLooping"));
- break;
- case 2: // end
- addHeader = false;
- addImage = false;
- break;
- case 3: // cancel
- addHeader = false;
- addImage = false;
- out.cancel();
- break;
- }
- }
-
- @Override
- protected void generate() throws IOException {
- if (addHeader)
- writeHeader();
- addHeader = false; // only one header
- if (addImage) {
- createPalette();
- writeGraphicControlExtension();
- if (delayTime100ths >= 0 && looping)
- writeNetscapeLoopExtension();
- writeImage();
- }
- }
-
- @Override
- protected void close() {
- if (addTrailer) {
- writeTrailer();
- } else {
- doClose = false;
- }
- if (capturing)
- params.put("captureByteCount", Integer.valueOf(byteCount));
- }
-
- ////////////// 256-color quantization //////////////
-
- /**
- * a color point in normalized L*a*b space with a flag indicating whether it
- * is the background color
- */
- private class ColorItem extends P3 {
- /**
- *
- */
- protected boolean isBackground;
-
- ColorItem(int rgb, boolean isBackground) {
- this.isBackground = isBackground;
- setT(toLABnorm(rgb));
- }
- }
-
- /**
- * A list of normalized L*a*b points with an index and a center and volume
- *
- */
- private class ColorCell extends Lst<P3> {
-
- /**
- *
- */
- private static final long serialVersionUID = 1L;
- protected int index;
- protected P3 center;
-
- private float volume;
-
- ColorCell(int index) {
- this.index = index;
- }
-
- /**
- * @param doVisualize
- * debugging only
- * @return volume in normalized L*a*b space
- */
- public float getVolume(boolean doVisualize) {
- if (volume != 0)
- return volume;
- if (size() < 2)
- return -1;
- //if (true)
- //return lst.size();
- //float d;
- float maxx = -Integer.MAX_VALUE;
- float minx = Integer.MAX_VALUE;
- float maxy = -Integer.MAX_VALUE;
- float miny = Integer.MAX_VALUE;
- float maxz = -Integer.MAX_VALUE;
- float minz = Integer.MAX_VALUE;
- int n = size();
- for (int i = n; --i >= 0;) {
- P3 xyz = get(i);
- if (xyz.x < minx)
- minx = xyz.x;
- if (xyz.y < miny)
- miny = xyz.y;
- if (xyz.z < minz)
- minz = xyz.z;
- if (xyz.x > maxx)
- maxx = xyz.x;
- if (xyz.y > maxy)
- maxy = xyz.y;
- if (xyz.z > maxz)
- maxz = xyz.z;
- }
- float dx = (maxx - minx);
- float dy = (maxy - miny);
- float dz = (maxz - minz);
- // Jmol visualization only
- // if (doVisualize) {
- // P3 ptRGB = toRGB(center);
- // drawPt(index, -size(), ptRGB);
- // //for (int i = n; --i >= 0;)
- // //drawPt(index, i, toRGB(get(i)));
- // P3 pt0 = toRGB(P3.new3(Math.max(minx, 0), Math.max(miny, 0),
- // Math.max(minz, 0)));
- // P3 pt1 = toRGB(P3.new3(Math.min(maxx, 100), Math.min(maxy, 100),
- // Math.min(maxz, 100)));
- // rgbToXyz(pt0, pt0);
- // xyzToLab(pt0, pt0);
- // rgbToXyz(pt1, pt1);
- // xyzToLab(pt1, pt1);
- // System.out.println("boundbox corners " + pt0 + " " + pt1);
- // System.out.println("draw d" + index + " boundbox color " + ptRGB
- // + " mesh nofill");
- // }
- return volume = dx * dx + dy * dy + dz * dz;
- }
-
- // // Jmol visualization only
- // private void drawPt(int index, int i, P3 rgb) {
- // boolean isMain = (i < 0);
- // P3 lab = rgbToXyz(rgb, null);
- // xyzToLab(lab, lab);
- // System.out.println("draw d" + index + (isMain ? "_" : "_" + i) + " width "
- // + (isMain ? 1.0 : 0.2) + " " + lab
- // + " color " + rgb + (isMain ? " '" + -i + "'" : ""));
- // }
-
- /**
- * Set the average normalized L*a*b value for this cell and return its RGB point
- *
- * @return RGB point
- *
- */
- protected P3 setColor() {
- int count = size();
- center = new P3();
- for (int i = count; --i >= 0;)
- center.add(get(i));
- center.scale(1f / count);
- // Jmol visualization only
- //volume = 0;
- //getVolume(true);
- return toRGB(center);
- }
-
- /**
- * use median_cut algorithm to split the cell, creating a doubly linked
- * list.
- *
- * Paul Heckbert, MIT thesis COLOR IMAGE QUANTIZATION FOR FRAME BUFFER
- * DISPLAY https://www.cs.cmu.edu/~ph/ciq_thesis
- *
- * except, as in GIMP, we use center (not median) here.
- *
- * @param cells
- * @return true if split
- */
- protected boolean splitCell(Lst<ColorCell> cells) {
- int n = size();
- if (n < 2)
- return false;
- int newIndex = cells.size();
- ColorCell newCell = new ColorCell(newIndex);
- cells.addLast(newCell);
- float[][] ranges = new float[3][3];
- for (int ic = 0; ic < 3; ic++) {
- float low = Float.MAX_VALUE;
- float high = -Float.MAX_VALUE;
- for (int i = n; --i >= 0;) {
- P3 lab = get(i);
- float v = (ic == 0 ? lab.x : ic == 1 ? lab.y : lab.z);
- if (low > v)
- low = v;
- if (high < v)
- high = v;
- }
- ranges[0][ic] = low;
- ranges[1][ic] = high;
- ranges[2][ic] = high - low;
- }
- float[] r = ranges[2];
- int mode = (r[0] >= r[1] ? (r[0] >= r[2] ? 0 : 2) : r[1] >= r[2] ? 1 : 2);
- float val = ranges[0][mode] + ranges[2][mode] / 2;
- volume = 0; // recalculate volume if needed
- switch (mode) {
- case 0:
- for (int i = n; --i >= 0;)
- if (get(i).x >= val)
- newCell.addLast(removeItemAt(i));
- break;
- case 1:
- for (int i = n; --i >= 0;)
- if (get(i).y >= val)
- newCell.addLast(removeItemAt(i));
- break;
- case 2:
- for (int i = size(); --i >= 0;)
- if (get(i).z >= val)
- newCell.addLast(removeItemAt(i));
- break;
- }
- return true;
- }
- }
-
- /**
- * Quantize all colors and create the final palette;
- * replace pixels[] with an array of color indices.
- *
- */
- private void createPalette() {
-
- // catalog all pixel colors
-
- Lst<ColorItem> tempColors = new Lst<ColorItem>();
- Map<Integer, ColorItem> ciHash = new Hashtable<Integer, ColorItem>();
- for (int i = 0, n = pixels.length; i < n; i++) {
- int rgb = pixels[i];
- Integer key = Integer.valueOf(rgb);
- ColorItem item = ciHash.get(key);
- if (item == null) {
- item = new ColorItem(rgb, rgb == backgroundColor);
- ciHash.put(key, item);
- tempColors.addLast(item);
- }
- }
- int nColors = tempColors.size();
- System.out.println("GIF total image colors: " + nColors);
- ciHash = null;
-
- // create a set of <= 256 color cells
-
- Lst<ColorCell> cells = quantizeColors(tempColors);
- nColors = cells.size();
- System.out.println("GIF final color count: " + nColors);
-
- // generate the palette and map each cell's rgb color to itself
-
- Map<Integer, ColorCell> colorMap = new Hashtable<Integer, ColorCell>();
- bitsPerPixel = (nColors <= 2 ? 1 : nColors <= 4 ? 2 : nColors <= 16 ? 4 : 8);
- palette = new P3[1 << bitsPerPixel];
- for (int i = 0; i < nColors; i++) {
- ColorCell c = cells.get(i);
- colorMap.put(
- Integer.valueOf(CU.colorPtToFFRGB(palette[i] = c.setColor())), c);
- }
-
- // index all pixels to a pallete color
-
- pixels = indexPixels(cells, colorMap);
- }
-
- /**
- * Quantize colors by generating a set of cells in normalized L*a*b space
- * containing all colors. Start with just two cells -- fixed background color
- * and all others. Keep splitting cells while there are fewer than 256 and
- * some with multiple colors in them.
- *
- * It is possible that we will end up with fewer than 256 colors.
- *
- * @param tempColors
- * @return final list of colors
- */
- private Lst<ColorCell> quantizeColors(Lst<ColorItem> tempColors) {
- int n = tempColors.size();
- Lst<ColorCell> cells = new Lst<ColorCell>();
- ColorCell cc = new ColorCell(0);
- cc.addLast(new ColorItem(backgroundColor, true));
- cells.addLast(cc);
- cc = new ColorCell(1);
- if (n > 256)
- cells.addLast(cc);
- for (int i = 0; i < n; i++) {
- ColorItem c = tempColors.get(i);
- if (c.isBackground)
- continue;
- cc.addLast(c);
- if (n <= 256) {
- cells.addLast(cc);
- cc = new ColorCell(cells.size());
- }
- }
- tempColors.clear();
- if (n > 256)
- while ((n = cells.size()) < 256) {
- float maxVol = 0;
- ColorCell maxCell = null;
- for (int i = n; --i >= 1;) {
- ColorCell c = cells.get(i);
- float v = c.getVolume(false);
- if (v > maxVol) {
- maxVol = v;
- maxCell = c;
- }
- }
- if (maxCell == null || !maxCell.splitCell(cells))
- break;
- }
- return cells;
- }
-
- /**
- *
- * Assign all colors to their closest approximation and return an array of
- * color indexes.
- *
- * Uses Floyd-Steinberg dithering, finding the closest known color and then
- * spreading out the error over four leading pixels. Limits error to +/- 75
- * percent in normalized L*a*b space.
- *
- * @param cells
- * quantized color cells
- * @param colorMap
- * map of quantized rgb to its cell
- * @return array of color indexes, one for each pixel
- *
- */
- private int[] indexPixels(Lst<ColorCell> cells,
- Map<Integer, ColorCell> colorMap) {
- // We need a strip only width+2 wide to process all the errors.
- // Errors are added to the next pixel and the next row's pixels
- // only through p + width + 1:
- // p +1
- // +w-1 +w +w+1
- // so including p as well, we need a total of width + 2 errors.
- //
- // as p moves through the pixels, we just use mod to cycle through
- // this strip.
- //
- int w2 = width + 2;
- P3[] errors = new P3[w2];
- // We should replace, not overwrite, pixels
- // as this may be the raw canvas.buf32.
- int[] newPixels = new int[pixels.length];
- P3 err = new P3();
- P3 lab;
- int rgb;
- Map<Integer, ColorCell> nearestCell = new Hashtable<Integer, ColorCell>();
- for (int i = 0, p = 0; i < height; ++i) {
- boolean notLastRow = (i != height - 1);
- for (int j = 0; j < width; ++j, p++) {
- if (pixels[p] == backgroundColor) {
- // leave as 0
- continue;
- }
- P3 pe = errors[p % w2];
- if (pe == null || pe.x == Float.MAX_VALUE) {
- lab = null;
- rgb = pixels[p];
- } else {
- lab = toLABnorm(pixels[p]);
- err = pe;
- // important not to round the clamp here -- full floating precision
- err.x = clamp(err.x, -75, 75);
- err.y = clamp(err.y, -75, 75);
- err.z = clamp(err.z, -75, 75);
- lab.add(err);
- rgb = CU.colorPtToFFRGB(toRGB(lab));
- }
- Integer key = Integer.valueOf(rgb);
- ColorCell cell = colorMap.get(key);
- if (cell == null) {
- // critical to generate normalized L*a*b from RGB here for nearestCell mapping.
- // otherwise future RGB keys may match the wrong cell
- lab = toLABnorm(rgb);
- cell = nearestCell.get(key);
- if (cell == null) {
- // find nearest cell
- float maxerr = Float.MAX_VALUE;
- // skip 0 0 0
- for (int ib = cells.size(); --ib >= 1;) {
- ColorCell c = cells.get(ib);
- err.sub2(lab, c.center);
- float d = err.lengthSquared();
- if (d < maxerr) {
- maxerr = d;
- cell = c;
- }
- }
- nearestCell.put(key, cell);
- }
- if (floydSteinberg) {
- // dither
- err.sub2(lab, cell.center);
- boolean notLastCol = (j < width - 1);
- if (notLastCol)
- addError(err, 7, errors, p + 1, w2);
- if (notLastRow) {
- if (j > 0)
- addError(err, 3, errors, p + width - 1, w2);
- addError(err, 5, errors, p + width, w2);
- if (notLastCol)
- addError(err, 1, errors, p + width + 1, w2);
- }
- }
- err.x = Float.MAX_VALUE; // used; flag for resetting to 0
- }
- newPixels[p] = cell.index;
- }
- }
- return newPixels;
- }
-
- private void addError(P3 err, int f, P3[] errors, int p, int w2) {
- // GIMP will allow changing the background color.
- if (pixels[p] == backgroundColor)
- return;
- p %= w2;
- P3 errp = errors[p];
- if (errp == null)
- errp = errors[p] = new P3();
- else if (errp.x == Float.MAX_VALUE) // reuse
- errp.set(0, 0, 0);
- errp.scaleAdd2(f / 16f, err, errp);
- }
-
- ///////////////////////// CIE L*a*b / XYZ / sRGB conversion methods /////////
-
- // these could be static, but that just makes for more JavaScript code
-
- protected P3 toLABnorm(int rgb) {
- P3 lab = CU.colorPtFromInt(rgb, null);
- rgbToXyz(lab, lab);
- xyzToLab(lab, lab);
- // normalize to 0-100
- lab.y = (lab.y + 86.185f) / (98.254f + 86.185f) * 100f;
- lab.z = (lab.z + 107.863f) / (94.482f + 107.863f) * 100f;
- return lab;
- }
-
- protected P3 toRGB(P3 lab) {
- P3 xyz = P3.newP(lab);
- // normalized to 0-100
- xyz.y = xyz.y / 100f * (98.254f + 86.185f) - 86.185f;
- xyz.z = xyz.z / 100f * (94.482f + 107.863f) - 107.863f;
- labToXyz(xyz, xyz);
- return xyzToRgb(xyz, xyz);
- }
-
- private static M3 xyz2rgb;
- private static M3 rgb2xyz;
-
- static {
- rgb2xyz = M3.newA9(new float[] { 0.4124f, 0.3576f, 0.1805f, 0.2126f,
- 0.7152f, 0.0722f, 0.0193f, 0.1192f, 0.9505f });
-
- xyz2rgb = M3.newA9(new float[] { 3.2406f, -1.5372f, -0.4986f, -0.9689f,
- 1.8758f, 0.0415f, 0.0557f, -0.2040f, 1.0570f });
- }
-
- public P3 rgbToXyz(P3 rgb, P3 xyz) {
- // http://en.wikipedia.org/wiki/CIE_1931_color_space
- // http://rsb.info.nih.gov/ij/plugins/download/Color_Space_Converter.java
- if (xyz == null)
- xyz = new P3();
- xyz.x = sxyz(rgb.x);
- xyz.y = sxyz(rgb.y);
- xyz.z = sxyz(rgb.z);
- rgb2xyz.rotate(xyz);
- return xyz;
- }
-
- private float sxyz(float x) {
- x /= 255;
- return (float) (x <= 0.04045 ? x / 12.92 : Math.pow(((x + 0.055) / 1.055),
- 2.4)) * 100;
- }
-
- public P3 xyzToRgb(P3 xyz, P3 rgb) {
- // http://en.wikipedia.org/wiki/CIE_1931_color_space
- // http://rsb.info.nih.gov/ij/plugins/download/Color_Space_Converter.java
- if (rgb == null)
- rgb = new P3();
- rgb.setT(xyz);
- rgb.scale(0.01f);
- xyz2rgb.rotate(rgb);
- rgb.x = clamp(srgb(rgb.x), 0, 255);
- rgb.y = clamp(srgb(rgb.y), 0, 255);
- rgb.z = clamp(srgb(rgb.z), 0, 255);
- return rgb;
- }
-
- private float srgb(float x) {
- return (float) (x > 0.0031308f ? (1.055 * Math.pow(x, 1.0 / 2.4)) - 0.055
- : x * 12.92) * 255;
- }
-
- public P3 xyzToLab(P3 xyz, P3 lab) {
- // http://en.wikipedia.org/wiki/Lab_color_space
- // http://rsb.info.nih.gov/ij/plugins/download/Color_Space_Converter.java
- // Lab([0..100], [-86.185..98.254], [-107.863..94.482])
- // XYZn = D65 = {95.0429, 100.0, 108.8900};
- if (lab == null)
- lab = new P3();
- float x = flab(xyz.x / 95.0429f);
- float y = flab(xyz.y / 100);
- float z = flab(xyz.z / 108.89f);
- lab.x = (116 * y) - 16;
- lab.y = 500 * (x - y);
- lab.z = 200 * (y - z);
- return lab;
- }
-
- private float flab(float t) {
- return (float) (t > 8.85645168E-3 /* (24/116)^3 */? Math.pow(t,
- 0.333333333) : 7.78703704 /* 1/3*116/24*116/24 */* t + 0.137931034 /* 16/116 */
- );
- }
-
- public P3 labToXyz(P3 lab, P3 xyz) {
- // http://en.wikipedia.org/wiki/Lab_color_space
- // http://rsb.info.nih.gov/ij/plugins/download/Color_Space_Converter.java
- // XYZn = D65 = {95.0429, 100.0, 108.8900};
- if (xyz == null)
- xyz = new P3();
-
- xyz.setT(lab);
- float y = (xyz.x + 16) / 116;
- float x = xyz.y / 500 + y;
- float z = y - xyz.z / 200;
- xyz.x = fxyz(x) * 95.0429f;
- xyz.y = fxyz(y) * 100;
- xyz.z = fxyz(z) * 108.89f;
-
- return xyz;
- }
-
- private float fxyz(float t) {
- return (float) (t > 0.206896552 /* (24/116) */? t * t * t
- : 0.128418549 /* 3*24/116*24/116 */* (t - 0.137931034 /* 16/116 */));
- }
-
- private float clamp(float c, float min, float max) {
- c = (c < min ? min : c > max ? max : c);
- return (min == 0 ? Math.round(c) : c);
- }
-
- ///////////////////////// GifEncoder writing methods ////////////////////////
-
- /**
- * includes logical screen descriptor
- *
- * @throws IOException
- */
- private void writeHeader() throws IOException {
- putString("GIF89a");
- putWord(width);
- putWord(height);
- putByte(0); // no global color table -- using local instead
- putByte(0); // no background
- putByte(0); // no pixel aspect ratio given
- }
-
- private void writeGraphicControlExtension() {
- if (isTransparent || delayTime100ths >= 0) {
- putByte(0x21); // graphic control extension
- putByte(0xf9); // graphic control label
- putByte(4); // block size
- putByte((isTransparent ? 9 : 0) | (delayTime100ths > 0 ? 2 : 0)); // packed bytes
- putWord(delayTime100ths > 0 ? delayTime100ths : 0);
- putByte(0); // transparent index
- putByte(0); // end-of-block
- }
- }
-
- // see http://www.vurdalakov.net/misc/gif/netscape-looping-application-extension
- // +---------------+
- // 0 | 0x21 | Extension Label
- // +---------------+
- // 1 | 0xFF | Application Extension Label
- // +---------------+
- // 2 | 0x0B | Block Size
- // +---------------+
- // 3 | |
- // +- -+
- // 4 | |
- // +- -+
- // 5 | |
- // +- -+
- // 6 | |
- // +- NETSCAPE -+ Application Identifier (8 bytes)
- // 7 | |
- // +- -+
- // 8 | |
- // +- -+
- // 9 | |
- // +- -+
- // 10 | |
- // +---------------+
- // 11 | |
- // +- -+
- // 12 | 2.0 | Application Authentication Code (3 bytes)
- // +- -+
- // 13 | |
- // +===============+ --+
- // 14 | 0x03 | Sub-block Data Size |
- // +---------------+ |
- // 15 | 0x01 | Sub-block ID |
- // +---------------+ | Application Data Sub-block
- // 16 | | |
- // +- -+ Loop Count (2 bytes) |
- // 17 | | |
- // +===============+ --+
- // 18 | 0x00 | Block Terminator
- // +---------------+
-
- private void writeNetscapeLoopExtension() {
- putByte(0x21); // graphic control extension
- putByte(0xff); // netscape loop extension
- putByte(0x0B); // block size
- putString("NETSCAPE2.0");
- putByte(3);
- putByte(1);
- putWord(0); // loop indefinitely
- putByte(0); // end-of-block
-
- }
-
- private int initCodeSize;
- private int curpt;
-
- private void writeImage() {
- putByte(0x2C);
- putWord(0); //left
- putWord(0); //top
- putWord(width);
- putWord(height);
-
- // <Packed Fields> = LISx xZZZ
-
- // L Local Color Table Flag
- // I Interlace Flag
- // S Sort Flag
- // x Reserved
- // ZZZ Size of Local Color Table
-
- int packedFields = 0x80 | (interlaced ? 0x40 : 0) | (bitsPerPixel - 1);
- putByte(packedFields);
- int colorMapSize = 1 << bitsPerPixel;
- P3 p = new P3();
- for (int i = 0; i < colorMapSize; i++) {
- if (palette[i] != null)
- p = palette[i];
- putByte((int) p.x);
- putByte((int) p.y);
- putByte((int) p.z);
- }
- putByte(initCodeSize = (bitsPerPixel <= 1 ? 2 : bitsPerPixel));
- compress();
- putByte(0);
- }
-
- private void writeTrailer() {
- // Write the GIF file terminator
- putByte(0x3B);
- }
-
- ///// compression routines /////
-
- private static final int EOF = -1;
-
- // Return the next pixel from the image
- private int nextPixel() {
- if (countDown-- == 0)
- return EOF;
- int colorIndex = pixels[curpt];
- // Bump the current X position
- ++curx;
- if (curx == width) {
- // If we are at the end of a scan line, set curx back to the beginning
- // If we are interlaced, bump the cury to the appropriate spot,
- // otherwise, just increment it.
- curx = 0;
- if (interlaced)
- updateY(INTERLACE_PARAMS[pass], INTERLACE_PARAMS[pass + 4]);
- else
- ++cury;
- }
- curpt = cury * width + curx;
- return colorIndex & 0xff;
- }
-
- private static final int[] INTERLACE_PARAMS = { 8, 8, 4, 2, 4, 2, 1, 0 };
-
- /**
- *
- * Group 1 : Every 8th. row, starting with row 0. (Pass 1)
- *
- * Group 2 : Every 8th. row, starting with row 4. (Pass 2)
- *
- * Group 3 : Every 4th. row, starting with row 2. (Pass 3)
- *
- * Group 4 : Every 2nd. row, starting with row 1. (Pass 4)
- *
- * @param yNext
- * @param yNew
- */
- private void updateY(int yNext, int yNew) {
- cury += yNext;
- if (yNew >= 0 && cury >= height) {
- cury = yNew;
- ++pass;
- }
- }
-
- // Write out a word to the GIF file
- private void putWord(int w) {
- putByte(w);
- putByte(w >> 8);
- }
-
- // GIFCOMPR.C - GIF Image compression routines
- //
- // Lempel-Ziv compression based on 'compress'. GIF modifications by
- // David Rowley (mgardi@watdcsu.waterloo.edu)
-
- // General DEFINEs
-
- private static final int BITS = 12;
-
- private 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)
-
- private int nBits; // number of bits/code
- private int maxbits = BITS; // user settable max # bits/code
- private int maxcode; // maximum code, given n_bits
- private int maxmaxcode = 1 << BITS; // should NEVER generate this code
-
- private final static int MAXCODE(int nBits) {
- return (1 << nBits) - 1;
- }
-
- private int[] htab = new int[HSIZE];
- private int[] codetab = new int[HSIZE];
-
- private int hsize = HSIZE; // for dynamic table sizing
-
- private int freeEnt = 0; // first unused entry
-
- // block compression parameters -- after all codes are used up,
- // and compression rate changes, start over.
- private boolean clearFlag = 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.
-
- private int clearCode;
- private int EOFCode;
-
- private int countDown;
- private int pass = 0;
- private int curx, cury;
-
- private void compress() {
-
- // Calculate number of bits we are expecting
- countDown = width * height;
-
- // Indicate which pass we are on (if interlace)
- pass = 0;
- // Set up the current x and y position
- curx = 0;
- cury = 0;
-
- // Set up the necessary values
- clearFlag = false;
- nBits = initCodeSize + 1;
- maxcode = MAXCODE(nBits);
-
- clearCode = 1 << initCodeSize;
- EOFCode = clearCode + 1;
- freeEnt = clearCode + 2;
-
- // Set up the 'byte output' routine
- bufPt = 0;
-
- int ent = nextPixel();
-
- int hshift = 0;
- int fcode;
- for (fcode = hsize; fcode < 65536; fcode *= 2)
- ++hshift;
- hshift = 8 - hshift; // set hash code range bound
-
- int hsizeReg = hsize;
- clearHash(hsizeReg); // clear hash table
-
- output(clearCode);
-
- int c;
- outer_loop: while ((c = nextPixel()) != EOF) {
- fcode = (c << maxbits) + ent;
- int i = (c << hshift) ^ ent; // xor hashing
-
- if (htab[i] == fcode) {
- ent = codetab[i];
- continue;
- } else if (htab[i] >= 0) // non-empty slot
- {
- int disp = hsizeReg - i; // secondary hash (after G. Knott)
- if (i == 0)
- disp = 1;
- do {
- if ((i -= disp) < 0)
- i += hsizeReg;
-
- if (htab[i] == fcode) {
- ent = codetab[i];
- continue outer_loop;
- }
- } while (htab[i] >= 0);
- }
- output(ent);
- ent = c;
- if (freeEnt < maxmaxcode) {
- codetab[i] = freeEnt++; // code -> hashtable
- htab[i] = fcode;
- } else {
- clearBlock();
- }
- }
- // Put out the final code.
- output(ent);
- output(EOFCode);
- }
-
- // output
- //
- // 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.
-
- private int curAccum = 0;
- private int curBits = 0;
-
- private int masks[] = { 0x0000, 0x0001, 0x0003, 0x0007, 0x000F, 0x001F,
- 0x003F, 0x007F, 0x00FF, 0x01FF, 0x03FF, 0x07FF, 0x0FFF, 0x1FFF, 0x3FFF,
- 0x7FFF, 0xFFFF };
-
- private void output(int code) {
- curAccum &= masks[curBits];
-
- if (curBits > 0)
- curAccum |= (code << curBits);
- else
- curAccum = code;
-
- curBits += nBits;
-
- while (curBits >= 8) {
- byteOut((byte) (curAccum & 0xff));
- curAccum >>= 8;
- curBits -= 8;
- }
-
- // If the next entry is going to be too big for the code size,
- // then increase it, if possible.
- if (freeEnt > maxcode || clearFlag) {
- if (clearFlag) {
- maxcode = MAXCODE(nBits = initCodeSize + 1);
- clearFlag = false;
- } else {
- ++nBits;
- if (nBits == maxbits)
- maxcode = maxmaxcode;
- else
- maxcode = MAXCODE(nBits);
- }
- }
-
- if (code == EOFCode) {
- // At EOF, write the rest of the buffer.
- while (curBits > 0) {
- byteOut((byte) (curAccum & 0xff));
- curAccum >>= 8;
- curBits -= 8;
- }
- flushBytes();
- }
- }
-
- // Clear out the hash table
-
- // table clear for block compress
- private void clearBlock() {
- clearHash(hsize);
- freeEnt = clearCode + 2;
- clearFlag = true;
-
- output(clearCode);
- }
-
- // reset code table
- private void clearHash(int hsize) {
- for (int i = 0; i < hsize; ++i)
- htab[i] = -1;
- }
-
- // GIF-specific routines (byte array buffer)
-
- // Number of bytes so far in this 'packet'
- private int bufPt;
-
- // Define the storage for the packet accumulator
- final private byte[] buf = new byte[256];
-
- // Add a byte to the end of the current packet, and if it is 254
- // byte, flush the packet to disk.
- private void byteOut(byte c) {
- buf[bufPt++] = c;
- if (bufPt >= 254)
- flushBytes();
- }
-
- // Flush the packet to disk, and reset the accumulator
- protected void flushBytes() {
- if (bufPt > 0) {
- putByte(bufPt);
- out.write(buf, 0, bufPt);
- byteCount += bufPt;
- bufPt = 0;
- }
- }
-
-}
git://source.jalview.org / jalview.git / blobdiff