-/* $RCSfile$
- * $Author: nicove $
- * $Date: 2007-03-30 12:26:16 -0500 (Fri, 30 Mar 2007) $
- * $Revision: 7275 $
- *
- * 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) 2002-2005 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.
- */
-package javajs.img;
-
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.util.Map;
-import java.util.zip.Deflater;
-import java.util.zip.DeflaterOutputStream;
-
-
-
-/**
- *
- * Modified by Bob Hanson hansonr@stolaf.edu to be a subclass of ImageEncoder
- * and to use javajs.util.OutputChannel instead of just returning bytes. Also includes:
- *
- * -- JavaScript-compatible image processing
- *
- * -- transparent background option
- *
- * -- more efficient calculation of needs for pngBytes
- *
- * -- option to use pre-created PNGJ image data (3/19/14; Jmol 14.1.12)
- *
- * -- PNGJ format:
- *
- * // IHDR chunk
- *
- * // tEXt chunk "Jmol type - <PNG0|PNGJ|PNGT><0000000pt>+<000000len>"
- *
- * // tEXt chunk "Software - Jmol <version>"
- *
- * // tEXt chunk "Creation Time - <date>"
- *
- * // tRNS chunk transparent color, if desired
- *
- * // IDAT chunk (image data)
- *
- * // IEND chunk
- *
- * // [JMOL ZIP FILE APPENDIX]
- *
- * Original Comment:
- *
- * PngEncoder takes a Java Image object and creates a byte string which can be
- * saved as a PNG file. The Image is presumed to use the DirectColorModel.
- *
- * Thanks to Jay Denny at KeyPoint Software http://www.keypoint.com/ who let me
- * develop this code on company time.
- *
- * You may contact me with (probably very-much-needed) improvements, comments,
- * and bug fixes at:
- *
- * david@catcode.com
- *
- * @author J. David Eisenberg
- * @author http://catcode.com/pngencoder/
- * @author Christian Ribeaud (christian.ribeaud@genedata.com)
- * @author Bob Hanson (hansonr@stolaf.edu)
- *
- * @version 1.4, 31 March 2000
- */
-public class PngEncoder extends CRCEncoder {
-
- /** Constants for filters */
- public static final int FILTER_NONE = 0;
- public static final int FILTER_SUB = 1;
- public static final int FILTER_UP = 2;
- public static final int FILTER_LAST = 2;
-
- private static final int PT_FIRST_TAG = 37;
-
- private boolean encodeAlpha;
- private int filter = FILTER_NONE;
- private int bytesPerPixel;
- private int compressionLevel;
- private String type;
- private Integer transparentColor;
-
- private byte[] appData;
- private String appPrefix;
- private String comment;
- private byte[] bytes;
-
-
- public PngEncoder() {
- super();
- }
-
- @Override
- protected void setParams(Map<String, Object> params) {
- if (quality < 0)
- quality = (params.containsKey("qualityPNG") ? ((Integer) params
- .get("qualityPNG")).intValue() : 2);
- if (quality > 9)
- quality = 9;
- encodeAlpha = false;
- filter = FILTER_NONE;
- compressionLevel = quality;
- transparentColor = (Integer) params.get("transparentColor");
- comment = (String) params.get("comment");
- type = (params.get("type") + "0000").substring(0, 4);
- bytes = (byte[]) params.get("pngImgData");
- appData = (byte[]) params.get("pngAppData");
- appPrefix = (String) params.get("pngAppPrefix");
- }
-
-
-
- @Override
- protected void generate() throws IOException {
- if (bytes == null) {
- if (!pngEncode()) {
- out.cancel();
- return;
- }
- bytes = getBytes();
- } else {
- dataLen = bytes.length;
- }
- int len = dataLen;
- if (appData != null) {
- setJmolTypeText(appPrefix, bytes, len, appData.length,
- type);
- out.write(bytes, 0, len);
- len = (bytes = appData).length;
- }
- out.write(bytes, 0, len);
- }
-
-
- /**
- * Creates an array of bytes that is the PNG equivalent of the current image,
- * specifying whether to encode alpha or not.
- *
- * @return true if successful
- *
- */
- private boolean pngEncode() {
-
- byte[] pngIdBytes = { -119, 80, 78, 71, 13, 10, 26, 10 };
-
- writeBytes(pngIdBytes);
- //hdrPos = bytePos;
- writeHeader();
- writeText(getApplicationText(appPrefix, type, 0, 0));
-
- writeText("Software\0" + comment);
- writeText("Creation Time\0" + date);
-
- if (!encodeAlpha && transparentColor != null)
- writeTransparentColor(transparentColor.intValue());
- //dataPos = bytePos;
- return writeImageData();
- }
-
- /**
- * Fill in the Jmol type text area with number of bytes of PNG data and number
- * of bytes of Jmol state data and fix checksum.
- *
- * If we do not do this, then the checksum will be wrong, and Jmol and some
- * other programs may not be able to read the PNG image.
- *
- * This was corrected for Jmol 12.3.30. Between 12.3.7 and 12.3.29, PNG files
- * created by Jmol have incorrect checksums.
- *
- * @param prefix
- *
- * @param b
- * @param nPNG
- * @param nState
- * @param type
- */
- private static void setJmolTypeText(String prefix, byte[] b, int nPNG, int nState, String type) {
- String s = "tEXt" + getApplicationText(prefix, type, nPNG, nState);
- CRCEncoder encoder = new PngEncoder();
- byte[] test = s.substring(0, 4 + prefix.length()).getBytes();
- for (int i = test.length; -- i >= 0;)
- if (b[i + PT_FIRST_TAG] != test[i]) {
- System.out.println("image is not of the right form; appending data, but not adding tEXt tag.");
- return;
- }
- encoder.setData(b, PT_FIRST_TAG);
- encoder.writeString(s);
- encoder.writeCRC();
- }
-
- /**
- * Generate the PNGJ directory identifier:
- *
- * xxxxxxxxx\0ttttiiiiiiiii+ddddddddd
- *
- * where
- *
- * xxxxxxxxx is a unique 9-character software identifier
- * tttt is a four-byte software-specific type indicator (PNG0, PNGJ, PNGT, etc.)
- * iiiiiiiii is the file pointer to the start of app data
- * ddddddddd is the length of the app data
- *
- * @param prefix up to 9 characters to allow software to recognize itself
- * @param type PNGx, where x is J or T for Jmol; original type "PNG" is now "PNG0"
- * @param nPNG
- * @param nData
- * @return
- */
- private static String getApplicationText(String prefix, String type,
- int nPNG, int nData) {
- String sPNG = "000000000" + nPNG;
- sPNG = sPNG.substring(sPNG.length() - 9);
- String sData = "000000000" + nData;
- sData = sData.substring(sData.length() - 9);
- if (prefix == null)
- prefix = "#SwingJS.";
- if (prefix.length() < 9)
- prefix = (prefix + ".........");
- if (prefix.length() > 9)
- prefix = prefix.substring(0, 9);
- return prefix + "\0" + type + sPNG + "+" + sData;
- }
-
- // /**
- // * Set the filter to use
- // *
- // * @param whichFilter from constant list
- // */
- // public void setFilter(int whichFilter) {
- // this.filter = (whichFilter <= FILTER_LAST ? whichFilter : FILTER_NONE);
- // }
-
- // /**
- // * Retrieve filtering scheme
- // *
- // * @return int (see constant list)
- // */
- // public int getFilter() {
- // return filter;
- // }
-
- // /**
- // * Set the compression level to use
- // *
- // * @param level 0 through 9
- // */
- // public void setCompressionLevel(int level) {
- // if ((level >= 0) && (level <= 9)) {
- // this.compressionLevel = level;
- // }
- // }
-
- // /**
- // * Retrieve compression level
- // *
- // * @return int in range 0-9
- // */
- // public int getCompressionLevel() {
- // return compressionLevel;
- // }
-
- /**
- * Write a PNG "IHDR" chunk into the pngBytes array.
- */
- private void writeHeader() {
-
- writeInt4(13);
- startPos = bytePos;
- writeString("IHDR");
- writeInt4(width);
- writeInt4(height);
- writeByte(8); // bit depth
- writeByte(encodeAlpha ? 6 : 2); // color type or direct model
- writeByte(0); // compression method
- writeByte(0); // filter method
- writeByte(0); // no interlace
- writeCRC();
- }
-
- private void writeText(String msg) {
- writeInt4(msg.length());
- startPos = bytePos;
- writeString("tEXt" + msg);
- writeCRC();
- }
-
- /**
- * Write a PNG "tRNS" chunk into the pngBytes array.
- *
- * @param icolor
- */
- private void writeTransparentColor(int icolor) {
-
- writeInt4(6);
- startPos = bytePos;
- writeString("tRNS");
- writeInt2((icolor >> 16) & 0xFF);
- writeInt2((icolor >> 8) & 0xFF);
- writeInt2(icolor & 0xFF);
- writeCRC();
- }
-
- private byte[] scanLines; // the scan lines to be compressed
- private int byteWidth; // width * bytesPerPixel
-
- //private int hdrPos, dataPos, endPos;
- //private byte[] priorRow;
- //private byte[] leftBytes;
-
-
- /**
- * Write the image data into the pngBytes array. This will write one or more
- * PNG "IDAT" chunks. In order to conserve memory, this method grabs as many
- * rows as will fit into 32K bytes, or the whole image; whichever is less.
- *
- *
- * @return true if no errors; false if error grabbing pixels
- */
- private boolean writeImageData() {
-
- bytesPerPixel = (encodeAlpha ? 4 : 3);
- byteWidth = width * bytesPerPixel;
-
- int scanWidth = byteWidth + 1; // the added 1 is for the filter byte
-
- //boolean doFilter = (filter != FILTER_NONE);
-
- int rowsLeft = height; // number of rows remaining to write
- //int startRow = 0; // starting row to process this time through
- int nRows; // how many rows to grab at a time
-
- int scanPos; // where we are in the scan lines
-
- Deflater deflater = new Deflater(compressionLevel);
- ByteArrayOutputStream outBytes = new ByteArrayOutputStream(1024);
-
- DeflaterOutputStream compBytes = new DeflaterOutputStream(outBytes,
- deflater);
-
- int pt = 0; // overall image byte pointer
-
- // Jmol note: The entire image has been stored in pixels[] already
-
- try {
- while (rowsLeft > 0) {
- nRows = Math.max(1, Math.min(32767 / scanWidth, rowsLeft));
- scanLines = new byte[scanWidth * nRows];
- // if (doFilter)
- // switch (filter) {
- // case FILTER_SUB:
- // leftBytes = new byte[16];
- // break;
- // case FILTER_UP:
- // priorRow = new byte[scanWidth - 1];
- // break;
- // }
- int nPixels = width * nRows;
- scanPos = 0;
- //startPos = 1;
- for (int i = 0; i < nPixels; i++, pt++) {
- if (i % width == 0) {
- scanLines[scanPos++] = (byte) filter;
- //startPos = scanPos;
- }
- scanLines[scanPos++] = (byte) ((pixels[pt] >> 16) & 0xff);
- scanLines[scanPos++] = (byte) ((pixels[pt] >> 8) & 0xff);
- scanLines[scanPos++] = (byte) ((pixels[pt]) & 0xff);
- if (encodeAlpha) {
- scanLines[scanPos++] = (byte) ((pixels[pt] >> 24) & 0xff);
- }
- // if (doFilter && i % width == width - 1) {
- // switch (filter) {
- // case FILTER_SUB:
- // filterSub();
- // break;
- // case FILTER_UP:
- // filterUp();
- // break;
- // }
- // }
- }
-
- /*
- * Write these lines to the output area
- */
- compBytes.write(scanLines, 0, scanPos);
-
- //startRow += nRows;
- rowsLeft -= nRows;
- }
- compBytes.close();
-
- /*
- * Write the compressed bytes
- */
- byte[] compressedLines = outBytes.toByteArray();
- writeInt4(compressedLines.length);
- startPos = bytePos;
- writeString("IDAT");
- writeBytes(compressedLines);
- writeCRC();
- writeEnd();
- deflater.finish();
- return true;
- } catch (IOException e) {
- System.err.println(e.toString());
- return false;
- }
- }
-
- /**
- * Write a PNG "IEND" chunk into the pngBytes array.
- */
- private void writeEnd() {
- writeInt4(0);
- startPos = bytePos;
- writeString("IEND");
- writeCRC();
- }
-
- ///**
- //* Perform "sub" filtering on the given row.
- //* Uses temporary array leftBytes to store the original values
- //* of the previous pixels. The array is 16 bytes long, which
- //* will easily hold two-byte samples plus two-byte alpha.
- //*
- //*/
- //private void filterSub() {
- // int offset = bytesPerPixel;
- // int actualStart = startPos + offset;
- // int leftInsert = offset;
- // int leftExtract = 0;
- // //byte current_byte;
- //
- // for (int i = actualStart; i < startPos + byteWidth; i++) {
- // leftBytes[leftInsert] = scanLines[i];
- // scanLines[i] = (byte) ((scanLines[i] - leftBytes[leftExtract]) % 256);
- // leftInsert = (leftInsert + 1) % 0x0f;
- // leftExtract = (leftExtract + 1) % 0x0f;
- // }
- //}
- //
- ///**
- //* Perform "up" filtering on the given row. Side effect: refills the prior row
- //* with current row
- //*
- //*/
- //private void filterUp() {
- // int nBytes = width * bytesPerPixel;
- // for (int i = 0; i < nBytes; i++) {
- // int pt = startPos + i;
- // byte b = scanLines[pt];
- // scanLines[pt] = (byte) ((scanLines[pt] - priorRow[i]) % 256);
- // priorRow[i] = b;
- // }
- //}
-
-}