/*******************************************************************************
* 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.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));
}
}
}
}