adding support for zeroing buffers - patch'ish by MatthiasM

build.xml

@@ -266,6 +266,7 @@
 			<class name="org.lwjgl.opengl.CallbackUtil" />
             <class name="org.lwjgl.opencl.CL" />
             <class name="org.lwjgl.opencl.CallbackUtil" />
+      <class name="org.lwjgl.BufferUtils" />
 		</javah>
 	</target>
 

src/java/org/lwjgl/BufferUtils.java

@@ -155,4 +155,41 @@ public final class BufferUtils {
 		return buffer.position() << getElementSizeExponent(buffer);
 	}
 
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(ByteBuffer b) {
+	    zeroBuffer0(b, b.position(), b.remaining());
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(ShortBuffer b) {
+	    zeroBuffer0(b, b.position()*2L, b.remaining()*2L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(CharBuffer b) {
+	    zeroBuffer0(b, b.position()*2L, b.remaining()*2L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(IntBuffer b) {
+	    zeroBuffer0(b, b.position()*4L, b.remaining()*4L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(FloatBuffer b) {
+	    zeroBuffer0(b, b.position()*4L, b.remaining()*4L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(LongBuffer b) {
+	    zeroBuffer0(b, b.position()*8L, b.remaining()*8L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	public static void zeroBuffer(DoubleBuffer b) {
+	    zeroBuffer0(b, b.position()*8L, b.remaining()*8L);
+	}
+
+	/** Fill buffer with zeros from position to remaining */
+	private static native void zeroBuffer0(Buffer b, long off, long size);
 }

src/native/common/org_lwjgl_BufferUtils.c

@@ -0,0 +1,5 @@
+#include "org_lwjgl_BufferUtils.h"
+
+JNIEXPORT void JNICALL Java_org_lwjgl_BufferUtils_zeroBuffer0(JNIEnv *env, jclass clazz, jobject buffer, jlong offset, jlong size) {
+	memset((char*)(*env)->GetDirectBufferAddress(env, buffer) + (size_t)offset, 0, (size_t)size);
+}