/*
* Copyright (c) 2009-2012 jMonkeyEngine
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* * 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.
*
* * Neither the name of 'jMonkeyEngine' nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 COPYRIGHT OWNER 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.
*/
package com.jme3.scene.plugins.blender.file;
import java.io.BufferedInputStream;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.logging.Logger;
import java.util.zip.GZIPInputStream;
/**
* An input stream with random access to data.
* @author Marcin Roguski
*/
public class BlenderInputStream extends InputStream {
private static final Logger LOGGER = Logger.getLogger(BlenderInputStream.class.getName());
/** The default size of the blender buffer. */
private static final int DEFAULT_BUFFER_SIZE = 1048576; // 1MB
/**
* Size of a pointer; all pointers in the file are stored in this format. '_' means 4 bytes and '-' means 8 bytes.
*/
private int pointerSize;
/**
* Type of byte ordering used; 'v' means little endian and 'V' means big endian.
*/
private char endianess;
/** Version of Blender the file was created in; '248' means version 2.48. */
private String versionNumber;
/** The buffer we store the read data to. */
protected byte[] cachedBuffer;
/** The total size of the stored data. */
protected int size;
/** The current position of the read cursor. */
protected int position;
/**
* Constructor. The input stream is stored and used to read data.
* @param inputStream
* the stream we read data from
* @throws BlenderFileException
* this exception is thrown if the file header has some invalid data
*/
public BlenderInputStream(InputStream inputStream) throws BlenderFileException {
// the size value will canche while reading the file; the available() method cannot be counted on
try {
size = inputStream.available();
} catch (IOException e) {
size = 0;
}
if (size <= 0) {
size = BlenderInputStream.DEFAULT_BUFFER_SIZE;
}
// buffered input stream is used here for much faster file reading
BufferedInputStream bufferedInputStream;
if (inputStream instanceof BufferedInputStream) {
bufferedInputStream = (BufferedInputStream) inputStream;
} else {
bufferedInputStream = new BufferedInputStream(inputStream);
}
try {
this.readStreamToCache(bufferedInputStream);
} catch (IOException e) {
throw new BlenderFileException("Problems occured while caching the file!", e);
} finally {
try {
inputStream.close();
} catch (IOException e) {
LOGGER.warning("Unable to close stream with blender file.");
}
}
try {
this.readFileHeader();
} catch (BlenderFileException e) {// the file might be packed, don't panic, try one more time ;)
this.decompressFile();
position = 0;
this.readFileHeader();
}
}
/**
* This method reads the whole stream into a buffer.
* @param inputStream
* the stream to read the file data from
* @throws IOException
* an exception is thrown when data read from the stream is invalid or there are problems with i/o
* operations
*/
private void readStreamToCache(InputStream inputStream) throws IOException {
int data = inputStream.read();
cachedBuffer = new byte[size];
size = 0;// this will count the actual size
while (data != -1) {
if (size >= cachedBuffer.length) {// widen the cached array
byte[] newBuffer = new byte[cachedBuffer.length + (cachedBuffer.length >> 1)];
System.arraycopy(cachedBuffer, 0, newBuffer, 0, cachedBuffer.length);
cachedBuffer = newBuffer;
}
cachedBuffer[size++] = (byte) data;
data = inputStream.read();
}
}
/**
* This method is used when the blender file is gzipped. It decompresses the data and stores it back into the
* cachedBuffer field.
*/
private void decompressFile() {
GZIPInputStream gis = null;
try {
gis = new GZIPInputStream(new ByteArrayInputStream(cachedBuffer));
this.readStreamToCache(gis);
} catch (IOException e) {
throw new IllegalStateException("IO errors occured where they should NOT! " + "The data is already buffered at this point!", e);
} finally {
try {
if (gis != null) {
gis.close();
}
} catch (IOException e) {
LOGGER.warning(e.getMessage());
}
}
}
/**
* This method loads the header from the given stream during instance creation.
* @param inputStream
* the stream we read the header from
* @throws BlenderFileException
* this exception is thrown if the file header has some invalid data
*/
private void readFileHeader() throws BlenderFileException {
byte[] identifier = new byte[7];
int bytesRead = this.readBytes(identifier);
if (bytesRead != 7) {
throw new BlenderFileException("Error reading header identifier. Only " + bytesRead + " bytes read and there should be 7!");
}
String strIdentifier = new String(identifier);
if (!"BLENDER".equals(strIdentifier)) {
throw new BlenderFileException("Wrong file identifier: " + strIdentifier + "! Should be 'BLENDER'!");
}
char pointerSizeSign = (char) this.readByte();
if (pointerSizeSign == '-') {
pointerSize = 8;
} else if (pointerSizeSign == '_') {
pointerSize = 4;
} else {
throw new BlenderFileException("Invalid pointer size character! Should be '_' or '-' and there is: " + pointerSizeSign);
}
endianess = (char) this.readByte();
if (endianess != 'v' && endianess != 'V') {
throw new BlenderFileException("Unknown endianess value! 'v' or 'V' expected and found: " + endianess);
}
byte[] versionNumber = new byte[3];
bytesRead = this.readBytes(versionNumber);
if (bytesRead != 3) {
throw new BlenderFileException("Error reading version numberr. Only " + bytesRead + " bytes read and there should be 3!");
}
this.versionNumber = new String(versionNumber);
}
@Override
public int read() throws IOException {
return this.readByte();
}
/**
* This method reads 1 byte from the stream.
* It works just in the way the read method does.
* It just not throw an exception because at this moment the whole file
* is loaded into buffer, so no need for IOException to be thrown.
* @return a byte from the stream (1 bytes read)
*/
public int readByte() {
return cachedBuffer[position++] & 0xFF;
}
/**
* This method reads a bytes number big enough to fill the table.
* It does not throw exceptions so it is for internal use only.
* @param bytes
* an array to be filled with data
* @return number of read bytes (a length of array actually)
*/
private int readBytes(byte[] bytes) {
for (int i = 0; i < bytes.length; ++i) {
bytes[i] = (byte) this.readByte();
}
return bytes.length;
}
/**
* This method reads 2-byte number from the stream.
* @return a number from the stream (2 bytes read)
*/
public int readShort() {
int part1 = this.readByte();
int part2 = this.readByte();
if (endianess == 'v') {
return (part2 << 8) + part1;
} else {
return (part1 << 8) + part2;
}
}
/**
* This method reads 4-byte number from the stream.
* @return a number from the stream (4 bytes read)
*/
public int readInt() {
int part1 = this.readByte();
int part2 = this.readByte();
int part3 = this.readByte();
int part4 = this.readByte();
if (endianess == 'v') {
return (part4 << 24) + (part3 << 16) + (part2 << 8) + part1;
} else {
return (part1 << 24) + (part2 << 16) + (part3 << 8) + part4;
}
}
/**
* This method reads 4-byte floating point number (float) from the stream.
* @return a number from the stream (4 bytes read)
*/
public float readFloat() {
int intValue = this.readInt();
return Float.intBitsToFloat(intValue);
}
/**
* This method reads 8-byte number from the stream.
* @return a number from the stream (8 bytes read)
*/
public long readLong() {
long part1 = this.readInt();
long part2 = this.readInt();
long result = -1;
if (endianess == 'v') {
result = part2 << 32 | part1;
} else {
result = part1 << 32 | part2;
}
return result;
}
/**
* This method reads 8-byte floating point number (double) from the stream.
* @return a number from the stream (8 bytes read)
*/
public double readDouble() {
long longValue = this.readLong();
return Double.longBitsToDouble(longValue);
}
/**
* This method reads the pointer value. Depending on the pointer size defined in the header, the stream reads either
* 4 or 8 bytes of data.
* @return the pointer value
*/
public long readPointer() {
if (pointerSize == 4) {
return this.readInt();
}
return this.readLong();
}
/**
* This method reads the string. It assumes the string is terminated with zero in the stream.
* @return the string read from the stream
*/
public String readString() {
StringBuilder stringBuilder = new StringBuilder();
int data = this.readByte();
while (data != 0) {
stringBuilder.append((char) data);
data = this.readByte();
}
return stringBuilder.toString();
}
/**
* This method sets the current position of the read cursor.
* @param position
* the position of the read cursor
*/
public void setPosition(int position) {
this.position = position;
}
/**
* This method returns the position of the read cursor.
* @return the position of the read cursor
*/
public int getPosition() {
return position;
}
/**
* This method returns the blender version number where the file was created.
* @return blender version number
*/
public String getVersionNumber() {
return versionNumber;
}
/**
* This method returns the size of the pointer.
* @return the size of the pointer
*/
public int getPointerSize() {
return pointerSize;
}
/**
* This method aligns cursor position forward to a given amount of bytes.
* @param bytesAmount
* the byte amount to which we aligh the cursor
*/
public void alignPosition(int bytesAmount) {
if (bytesAmount <= 0) {
throw new IllegalArgumentException("Alignment byte number shoulf be positivbe!");
}
long move = position % bytesAmount;
if (move > 0) {
position += bytesAmount - move;
}
}
@Override
public void close() throws IOException {
// this method is unimplemented because some loaders (ie. TGALoader) tend close the stream given from the outside
// because the images can be stored directly in the blender file then this stream is properly positioned and given to the loader
// to read the image file, that is why we do not want it to be closed before the reading is done
// and anyway this stream is only a cached buffer, so it does not hold any open connection to anything
}
}