/*******************************************************************************
* Copyright 2011 See AUTHORS file.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
******************************************************************************/
package com.badlogic.gdx.utils;
import java.io.ByteArrayOutputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.OutputStream;
/** Extends {@link DataOutputStream} with additional convenience methods.
* @author Nathan Sweet */
public class DataOutput extends DataOutputStream {
public DataOutput (OutputStream out) {
super(out);
}
/** Writes a 1-5 byte int.
* @param optimizePositive If true, small positive numbers will be more efficient (1 byte) and small negative numbers will be
* inefficient (5 bytes). */
public int writeInt (int value, boolean optimizePositive) throws IOException {
if (!optimizePositive) value = (value << 1) ^ (value >> 31);
if (value >>> 7 == 0) {
write((byte)value);
return 1;
}
write((byte)((value & 0x7F) | 0x80));
if (value >>> 14 == 0) {
write((byte)(value >>> 7));
return 2;
}
write((byte)(value >>> 7 | 0x80));
if (value >>> 21 == 0) {
write((byte)(value >>> 14));
return 3;
}
write((byte)(value >>> 14 | 0x80));
if (value >>> 28 == 0) {
write((byte)(value >>> 21));
return 4;
}
write((byte)(value >>> 21 | 0x80));
write((byte)(value >>> 28));
return 5;
}
/** Writes a length and then the string as UTF8.
* @param value May be null. */
public void writeString (String value) throws IOException {
if (value == null) {
write(0);
return;
}
int charCount = value.length();
if (charCount == 0) {
writeByte(1);
return;
}
writeInt(charCount + 1, true);
// Try to write 8 bit chars.
int charIndex = 0;
for (; charIndex < charCount; charIndex++) {
int c = value.charAt(charIndex);
if (c > 127) break;
write((byte)c);
}
if (charIndex < charCount) writeString_slow(value, charCount, charIndex);
}
private void writeString_slow (String value, int charCount, int charIndex) throws IOException {
for (; charIndex < charCount; charIndex++) {
int c = value.charAt(charIndex);
if (c <= 0x007F) {
write((byte)c);
} else if (c > 0x07FF) {
write((byte)(0xE0 | c >> 12 & 0x0F));
write((byte)(0x80 | c >> 6 & 0x3F));
write((byte)(0x80 | c & 0x3F));
} else {
write((byte)(0xC0 | c >> 6 & 0x1F));
write((byte)(0x80 | c & 0x3F));
}
}
}
}