Mega Code Archive
Fast Float Buffer
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//package com.ryanm.droid.rugl.util;
import java.lang.ref.SoftReference;
import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
/**
* Convenient work-around for poor {@link FloatBuffer#put(float[])} performance.
* This should become unnecessary in gingerbread, @see <a href
* ="http://code.google.com/p/android/issues/detail?id=11078">Issue 11078</a>
*
* @author ryanm
*/
public class FastFloatBuffer {
/**
* Underlying data - give this to OpenGL
*/
public ByteBuffer bytes;
private FloatBuffer floats;
private IntBuffer ints;
/**
* Use a {@link SoftReference} so that the array can be collected if
* necessary
*/
private static SoftReference<int[]> intArray = new SoftReference<int[]>(
new int[0]);
/**
* Constructs a new direct native-ordered buffer
*
* @param capacity
* the number of floats
*/
public FastFloatBuffer(int capacity) {
bytes = ByteBuffer.allocateDirect((capacity * 4)).order(
ByteOrder.nativeOrder());
floats = bytes.asFloatBuffer();
ints = bytes.asIntBuffer();
}
/**
* See {@link FloatBuffer#flip()}
*/
public void flip() {
bytes.flip();
floats.flip();
ints.flip();
}
/**
* See {@link FloatBuffer#put(float)}
*
* @param f
*/
public void put(float f) {
bytes.position(bytes.position() + 4);
floats.put(f);
ints.position(ints.position() + 1);
}
/**
* It's like {@link FloatBuffer#put(float[])}, but about 10 times faster
*
* @param data
*/
public void put(float[] data) {
int[] ia = intArray.get();
if (ia == null || ia.length < data.length) {
ia = new int[data.length];
intArray = new SoftReference<int[]>(ia);
}
for (int i = 0; i < data.length; i++) {
ia[i] = Float.floatToRawIntBits(data[i]);
}
bytes.position(bytes.position() + 4 * data.length);
floats.position(floats.position() + data.length);
ints.put(ia, 0, data.length);
}
/**
* For use with pre-converted data. This is 50x faster than
* {@link #put(float[])}, and 500x faster than
* {@link FloatBuffer#put(float[])}, so if you've got float[] data that
* won't change, {@link #convert(float...)} it to an int[] once and use this
* method to put it in the buffer
*
* @param data
* floats that have been converted with
* {@link Float#floatToIntBits(float)}
*/
public void put(int[] data) {
bytes.position(bytes.position() + 4 * data.length);
floats.position(floats.position() + data.length);
ints.put(data, 0, data.length);
}
/**
* Converts float data to a format that can be quickly added to the buffer
* with {@link #put(int[])}
*
* @param data
* @return the int-formatted data
*/
public static int[] convert(float... data) {
int[] id = new int[data.length];
for (int i = 0; i < data.length; i++) {
id[i] = Float.floatToRawIntBits(data[i]);
}
return id;
}
/**
* See {@link FloatBuffer#put(FloatBuffer)}
*
* @param b
*/
public void put(FastFloatBuffer b) {
bytes.put(b.bytes);
floats.position(bytes.position() >> 2);
ints.position(bytes.position() >> 2);
}
/**
* @return See {@link FloatBuffer#capacity()}
*/
public int capacity() {
return floats.capacity();
}
/**
* @return See {@link FloatBuffer#position()}
*/
public int position() {
return floats.position();
}
/**
* See {@link FloatBuffer#position(int)}
*
* @param p
*/
public void position(int p) {
bytes.position(4 * p);
floats.position(p);
ints.position(p);
}
/**
* @return See {@link FloatBuffer#slice()}
*/
public FloatBuffer slice() {
return floats.slice();
}
/**
* @return See {@link FloatBuffer#remaining()}
*/
public int remaining() {
return floats.remaining();
}
/**
* @return See {@link FloatBuffer#limit()}
*/
public int limit() {
return floats.limit();
}
/**
* See {@link FloatBuffer#clear()}
*/
public void clear() {
bytes.clear();
floats.clear();
ints.clear();
}
}
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