GlueGen Struct [1]: Enhance com.jogamp.common.nio.* to serve a most native-free-code Struct-Code generation

Recfactored all NIO buffer utils to Buffers, i.e. buffer <-> address, memcpy, strnlen, etc

Buffers:
- Added copyNativeToDirectByteBuffer(..), allowing to copy a native memory slice into a direct buffer.
- Added typeNameToBufferClass(String) and sizeOfBufferElem(Class<? extends Buffer>)
- Completed slize2<Type>(..) buffer-mapping methods
- Exposure of safe getDirectByteBuffer(..) w/ null-check (package private)

Added NativeBuffer.storeDirectAddress(..), allowing to write the array address into a native buffer (struct, etc),
allowing to referencing the ElementBuffer (linear array of elements) and PointerBuffer (array of pointer).
Hint: This can be read via PointerBuffer.wrap(..).get(0)

Added ElementBuffer (a NativeBuffer) mapping an array of elements,
completing native abstraction next to PointerBuffer (array of pointer).

ElementBuffer can dereference an existing element-array by native address via ElementBuffer.derefPointer(..).
Views of its content can be directly accessed via ElementBuffer.slice(..).

+++

These utilities and buffer abstractions will allow to reuse code and simplify the GlueGen struct get/set implementations
and help to reduce native code injection.

9 files changed, 901 insertions, 202 deletions

diff --git a/src/java/com/jogamp/common/nio/AbstractBuffer.java b/src/java/com/jogamp/common/nio/AbstractBuffer.java
index a774c39..b31929b 100644
--- a/src/java/com/jogamp/common/nio/AbstractBuffer.java
+++ b/src/java/com/jogamp/common/nio/AbstractBuffer.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2010 JogAmp Community. All rights reserved.
+ * Copyright 2010-2023 JogAmp Community. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification, are
  * permitted provided that the following conditions are met:
@@ -34,6 +34,9 @@ package com.jogamp.common.nio;
 import com.jogamp.common.os.*;
 
 import java.nio.Buffer;
+import java.nio.ByteBuffer;
+import java.nio.IntBuffer;
+import java.nio.LongBuffer;
 
 /**
  * @author Sven Gothel
@@ -41,6 +44,8 @@ import java.nio.Buffer;
  */
 @SuppressWarnings("rawtypes")
 public abstract class AbstractBuffer<B extends AbstractBuffer> implements NativeBuffer<B> {
+    /** Platform dependent pointer size in bytes, i.e. 32bit or 64bit wide, depending of the CPU pointer width. */
+    public static final int POINTER_SIZE;
 
     protected final Buffer buffer;
     protected final int elementSize;
@@ -49,6 +54,7 @@ public abstract class AbstractBuffer<B extends AbstractBuffer> implements Native
 
     static {
         Platform.initSingleton(); // loads native gluegen_rt library
+        POINTER_SIZE = Platform.is32Bit() ? Buffers.SIZEOF_INT : Buffers.SIZEOF_LONG ;
     }
 
     /**
@@ -118,11 +124,44 @@ public abstract class AbstractBuffer<B extends AbstractBuffer> implements Native
     public final Buffer getBuffer() {
         return buffer;
     }
-
     @Override
     public final boolean isDirect() {
         return buffer.isDirect();
     }
+    @Override
+    public long getDirectBufferAddress() {
+        if( isDirect() ) {
+            return Buffers.getDirectBufferAddressImpl(buffer);
+        } else {
+            return 0;
+        }
+    }
+    @Override
+    public void storeDirectAddress(final ByteBuffer directDest) {
+        final long addr = getDirectBufferAddress();
+        switch(POINTER_SIZE) {
+            case 4:
+                directDest.putInt(0, (int) ( addr & 0x00000000FFFFFFFFL ) );
+                break;
+            case 8:
+                directDest.putLong(0, addr);
+                break;
+        }
+        directDest.position(directDest.position()+POINTER_SIZE);
+    }
+
+    @Override
+    public void storeDirectAddress(final ByteBuffer directDest, final int destBytePos) {
+        final long addr = getDirectBufferAddress();
+        switch(POINTER_SIZE) {
+            case 4:
+                directDest.putInt(destBytePos, (int) ( addr & 0x00000000FFFFFFFFL ) );
+                break;
+            case 8:
+                directDest.putLong(destBytePos, addr);
+                break;
+        }
+    }
 
     @Override
     public final boolean hasArray() {
@@ -143,9 +182,11 @@ public abstract class AbstractBuffer<B extends AbstractBuffer> implements Native
         return buffer.array();
     }
 
+    protected String toSubString() {
+        return "[direct["+isDirect()+", addr 0x"+Long.toHexString(getDirectBufferAddress())+"], hasArray "+hasArray()+", capacity "+capacity+", position "+position+", elementSize "+elementSize+", buffer[capacity "+buffer.capacity()+", lim "+buffer.limit()+", pos "+buffer.position()+"]]";
+    }
     @Override
     public String toString() {
-        return "AbstractBuffer[direct "+isDirect()+", hasArray "+hasArray()+", capacity "+capacity+", position "+position+", elementSize "+elementSize+", buffer[capacity "+buffer.capacity()+", lim "+buffer.limit()+", pos "+buffer.position()+"]]";
+        return "AbstractBuffer"+toSubString();
     }
-
 }
diff --git a/src/java/com/jogamp/common/nio/Buffers.java b/src/java/com/jogamp/common/nio/Buffers.java
index f37eaa9..b22e41e 100644
--- a/src/java/com/jogamp/common/nio/Buffers.java
+++ b/src/java/com/jogamp/common/nio/Buffers.java
@@ -1,6 +1,6 @@
 /*
+ * Copyright (c) 2010-2023 JogAmp Community. All rights reserved.
  * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
- * Copyright (c) 2010 JogAmp Community. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -39,7 +39,6 @@
  */
 package com.jogamp.common.nio;
 
-import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.nio.Buffer;
 import java.nio.ByteBuffer;
@@ -233,146 +232,74 @@ public class Buffers {
     }
 
     /**
-     * Calls slice on the specified buffer while maintaining the byteorder.
-     * @see #slice(java.nio.Buffer, int, int)
+     * Helper routine to set a ByteBuffer to the native byte order, if
+     * that operation is supported by the underlying NIO
+     * implementation.
      */
-    @SuppressWarnings("unchecked")
-    public static <B extends Buffer> B slice(final B buffer) {
-        if (buffer instanceof ByteBuffer) {
-            final ByteBuffer bb = (ByteBuffer) buffer;
-            return (B) bb.slice().order(bb.order()); // slice and duplicate may change byte order
-        } else if (buffer instanceof IntBuffer) {
-            return (B) ((IntBuffer) buffer).slice();
-        } else if (buffer instanceof ShortBuffer) {
-            return (B) ((ShortBuffer) buffer).slice();
-        } else if (buffer instanceof FloatBuffer) {
-            return (B) ((FloatBuffer) buffer).slice();
-        } else if (buffer instanceof DoubleBuffer) {
-            return (B) ((DoubleBuffer) buffer).slice();
-        } else if (buffer instanceof LongBuffer) {
-            return (B) ((LongBuffer) buffer).slice();
-        } else if (buffer instanceof CharBuffer) {
-            return (B) ((CharBuffer) buffer).slice();
-        }
-        throw new IllegalArgumentException("unexpected buffer type: " + buffer.getClass());
+    public static ByteBuffer nativeOrder(final ByteBuffer buf) {
+        return buf.order(ByteOrder.nativeOrder());
     }
 
     /**
-     * Slices the specified buffer with offset as position and offset+size as limit
-     * while maintaining the byteorder.
-     * Concurrency warning: this method changes the buffers position and limit but
-     * will restore it before return.
+     * Returns {@link Buffer} class matching the given lower case `typeName`
+     * @param typeName lower-case type name
+     * @return matching {@link Buffer} class or `null`
+     * @see #sizeOfBufferElem(Class)
      */
-    public static <B extends Buffer> B slice(final B buffer, final int offset, final int size) {
-        final int pos = buffer.position();
-        final int limit = buffer.limit();
-
-        B slice = null;
-        try {
-            buffer.position(offset).limit(offset+size);
-            slice = slice(buffer);
-        } finally {
-            buffer.position(pos).limit(limit);
+    public static Class<? extends Buffer> typeNameToBufferClass(final String typeName) {
+        if (typeName == null) {
+            return null;
         }
-
-        return slice;
+        if( "byte".equals(typeName) ) {
+            return ByteBuffer.class;
+        } else if( "short".equals(typeName) ) {
+            return ShortBuffer.class;
+        } else if( "char".equals(typeName) ) {
+            return CharBuffer.class;
+        } else if( "int".equals(typeName) ) {
+            return IntBuffer.class;
+        } else if( "float".equals(typeName) ) {
+            return FloatBuffer.class;
+        } else if( "long".equals(typeName) ) {
+            return LongBuffer.class;
+        } else if( "double".equals(typeName) ) {
+            return DoubleBuffer.class;
+        }
+        return null;
     }
 
     /**
-     * Slices a ByteBuffer <i>or</i> a FloatBuffer to a FloatBuffer
-     * at the given position with the given size in float-space.
-     * <p>
-     * The returned sliced buffer's start position is always zero.
-     * </p>
-     * <p>
-     * The returned sliced buffer is {@link FloatBuffer#mark() marked} at it's {@link FloatBuffer#position() start position}. Hence
-     * {@link FloatBuffer#reset()} will rewind it to start after applying relative operations like {@link FloatBuffer#get()}.
-     * </p>
-     * <p>
-     * Using a ByteBuffer as the source guarantees
-     * keeping the source native order programmatically.
-     * This works around <a href="http://code.google.com/p/android/issues/detail?id=16434">Honeycomb / Android 3.0 Issue 16434</a>.
-     * This bug is resolved at least in Android 3.2.
-     * </p>
-     *
-     * @param buf source Buffer, maybe ByteBuffer (recommended) or FloatBuffer.
-     *            Buffer's position is ignored and floatPos is being used.
-     * @param floatStartPos {@link Buffers#SIZEOF_FLOAT} position
-     * @param floatSize {@link Buffers#SIZEOF_FLOAT} size
-     * @return FloatBuffer w/ native byte order as given ByteBuffer
+     * Returns the size of a single element of the given buffer class in bytes
+     * or <code>0</code> if the given buffer is <code>null</code>.
+     * @see #typeNameToBufferClass(String)
+     * @see #sizeOfBufferElem(Object)
      */
-    public static final FloatBuffer slice2Float(final Buffer buf, final int floatStartPos, final int floatSize) {
-        final int pos;
-        final int limit;
-        if(null != buf) {
-            pos = buf.position();
-            limit = buf.limit();
-        } else {
-            pos = 0;
-            limit = 0;
+    public static int sizeOfBufferElem(final Class<? extends Buffer> bufferClz) {
+        if (bufferClz == null) {
+            return 0;
         }
-        final FloatBuffer res;
-        try {
-            if(buf instanceof ByteBuffer) {
-                final ByteBuffer bb = (ByteBuffer) buf;
-                bb.position( floatStartPos * Buffers.SIZEOF_FLOAT );
-                bb.limit( (floatStartPos + floatSize) * Buffers.SIZEOF_FLOAT );
-                res = bb.slice().order(bb.order()).asFloatBuffer(); // slice and duplicate may change byte order
-            } else if(buf instanceof FloatBuffer) {
-                final FloatBuffer fb = (FloatBuffer) buf;
-                fb.position( floatStartPos );
-                fb.limit( floatStartPos + floatSize );
-                res = fb.slice(); // slice and duplicate may change byte order
-            } else {
-                throw new InternalError("Buffer not ByteBuffer, nor FloarBuffer, nor backing array given");
-            }
-        } finally {
-            if(null != buf) {
-                buf.position(pos).limit(limit);
-            }
+        if (ByteBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_BYTE;
+        } else if (ShortBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_SHORT;
+        } else if (CharBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_CHAR;
+        } else if (IntBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_INT;
+        } else if (FloatBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_FLOAT;
+        } else if (LongBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_LONG;
+        } else if (DoubleBuffer.class.isAssignableFrom(bufferClz)) {
+            return SIZEOF_DOUBLE;
         }
-        res.mark();
-        return res;
-    }
-
-    /**
-     * Slices a primitive float backing array to a FloatBuffer at the given position with the given size
-     * in float-space by {@link FloatBuffer#wrap(float[], int, int) wrapping} the backing array.
-     * <p>
-     * Due to {@link FloatBuffer#wrap(float[], int, int) wrapping} the backing array,
-     * the returned sliced buffer's {@link FloatBuffer#position() start position} equals
-     * the given <code>floatStartPos</code> within the given backing array
-     * while it's {@link FloatBuffer#arrayOffset() array-offset} is zero.
-     * This has the advantage of being able to dismiss the {@link FloatBuffer#arrayOffset() array-offset}
-     * in user code, while only being required to consider it's {@link FloatBuffer#position() position}.
-     * </p>
-     * <p>
-     * The returned sliced buffer is {@link FloatBuffer#mark() marked} at it's {@link FloatBuffer#position() start position}. Hence
-     * {@link FloatBuffer#reset()} will rewind it to start after applying relative operations like {@link FloatBuffer#get()}.
-     * </p>
-     *
-     * @param backing source float array
-     * @param floatStartPos {@link Buffers#SIZEOF_FLOAT} position
-     * @param floatSize {@link Buffers#SIZEOF_FLOAT} size
-     * @return FloatBuffer w/ native byte order as given ByteBuffer
-     */
-    public static final FloatBuffer slice2Float(final float[] backing, final int floatStartPos, final int floatSize) {
-        return (FloatBuffer) FloatBuffer.wrap(backing, floatStartPos, floatSize).mark();
-    }
-
-
-    /**
-     * Helper routine to set a ByteBuffer to the native byte order, if
-     * that operation is supported by the underlying NIO
-     * implementation.
-     */
-    public static ByteBuffer nativeOrder(final ByteBuffer buf) {
-        return buf.order(ByteOrder.nativeOrder());
+        throw new RuntimeException("Unexpected buffer type " + bufferClz.getName());
     }
 
     /**
      * Returns the size of a single element of the given buffer in bytes
      * or <code>0</code> if the given buffer is <code>null</code>.
+     * @see #sizeOfBufferElem(Class)
      */
     public static int sizeOfBufferElem(final Object buffer) {
         if (buffer == null) {
@@ -564,6 +491,429 @@ public class Buffers {
 
 
     //----------------------------------------------------------------------
+    // Slice routines (mapping buffer to typed-buffer w/o copy)
+    //
+    /**
+     * Calls slice on the specified buffer while maintaining the byteorder.
+     * @see #slice(java.nio.Buffer, int, int)
+     */
+    @SuppressWarnings("unchecked")
+    public static <B extends Buffer> B slice(final B buffer) {
+        if (buffer instanceof ByteBuffer) {
+            final ByteBuffer bb = (ByteBuffer) buffer;
+            return (B) bb.slice().order(bb.order()); // slice and duplicate may change byte order
+        } else if (buffer instanceof IntBuffer) {
+            return (B) ((IntBuffer) buffer).slice();
+        } else if (buffer instanceof ShortBuffer) {
+            return (B) ((ShortBuffer) buffer).slice();
+        } else if (buffer instanceof FloatBuffer) {
+            return (B) ((FloatBuffer) buffer).slice();
+        } else if (buffer instanceof DoubleBuffer) {
+            return (B) ((DoubleBuffer) buffer).slice();
+        } else if (buffer instanceof LongBuffer) {
+            return (B) ((LongBuffer) buffer).slice();
+        } else if (buffer instanceof CharBuffer) {
+            return (B) ((CharBuffer) buffer).slice();
+        }
+        throw new IllegalArgumentException("unexpected buffer type: " + buffer.getClass());
+    }
+
+    /**
+     * Slices the specified buffer with offset as position and offset+size as limit
+     * while maintaining the byteorder.
+     * Concurrency warning: this method changes the buffers position and limit but
+     * will restore it before return.
+     */
+    public static <B extends Buffer> B slice(final B buffer, final int offset, final int size) {
+        final int pos = buffer.position();
+        final int limit = buffer.limit();
+
+        B slice = null;
+        try {
+            buffer.position(offset).limit(offset+size);
+            slice = slice(buffer);
+        } finally {
+            buffer.position(pos).limit(limit);
+        }
+
+        return slice;
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a FloatBuffer to a FloatBuffer
+     * at the given `elementStartPos` with the given `elementCount` in float-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * The returned sliced buffer is {@link FloatBuffer#mark() marked} at it's {@link FloatBuffer#position() start position}. Hence
+     * {@link FloatBuffer#reset()} will rewind it to start after applying relative operations like {@link FloatBuffer#get()}.
+     * </p>
+     * <p>
+     * Using a ByteBuffer as the source guarantees
+     * keeping the source native order programmatically.
+     * This works around <a href="http://code.google.com/p/android/issues/detail?id=16434">Honeycomb / Android 3.0 Issue 16434</a>.
+     * This bug is resolved at least in Android 3.2.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or FloatBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_FLOAT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_FLOAT}
+     * @return FloatBuffer w/ native byte order as given ByteBuffer
+     */
+    public static final FloatBuffer slice2Float(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final FloatBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_FLOAT );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_FLOAT );
+                res = bb.slice().order(bb.order()).asFloatBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof FloatBuffer) {
+                final FloatBuffer fb = (FloatBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor FloarBuffer, nor backing array given");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a FloatBuffer at the given `elementStartPos` with the given `elementCount`
+     * in float-space by {@link FloatBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * Due to {@link FloatBuffer#wrap(float[], int, int) wrapping} the backing array,
+     * the returned sliced buffer's {@link FloatBuffer#position() start position} equals
+     * the given <code>floatStartPos</code> within the given backing array
+     * while it's {@link FloatBuffer#arrayOffset() array-offset} is zero.
+     * This has the advantage of being able to dismiss the {@link FloatBuffer#arrayOffset() array-offset}
+     * in user code, while only being required to consider it's {@link FloatBuffer#position() position}.
+     * </p>
+     * <p>
+     * The returned sliced buffer is {@link FloatBuffer#mark() marked} at it's {@link FloatBuffer#position() start position}. Hence
+     * {@link FloatBuffer#reset()} will rewind it to start after applying relative operations like {@link FloatBuffer#get()}.
+     * </p>
+     *
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_FLOAT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_FLOAT}
+     * @return FloatBuffer w/ native byte order as given ByteBuffer
+     */
+    public static final FloatBuffer slice2Float(final float[] backing, final int elementStartPos, final int elementCount) {
+        return (FloatBuffer) FloatBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a ShortBuffer to a ShortBuffer
+     * at the given `elementStartPos` with the given `elementCount` in short-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * See {@link #slice2Float(Buffer, int, int)} for details.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or ShortBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_SHORT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_SHORT}
+     * @return ShortBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(Buffer, int, int)
+     */
+    public static final ShortBuffer slice2Short(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final ShortBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_SHORT );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_SHORT );
+                res = bb.slice().order(bb.order()).asShortBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof ShortBuffer) {
+                final ShortBuffer fb = (ShortBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor ShortBuffer");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a ShortBuffer at the given `elementStartPos` with the given `elementCount`
+     * in short-space by {@link ShortBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * See {@link #slice2Float(float[], int, int)} for details.
+     * </p>
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_SHORT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_SHORT}
+     * @return ShortBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(float[], int, int)
+     */
+    public static final ShortBuffer slice2Short(final short[] backing, final int elementStartPos, final int elementCount) {
+        return (ShortBuffer) ShortBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a CharBuffer to a CharBuffer
+     * at the given `elementStartPos` with the given `elementCount` in short-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * See {@link #slice2Float(Buffer, int, int)} for details.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or CharBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_CHAR}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_CHAR}
+     * @return CharBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(Buffer, int, int)
+     */
+    public static final CharBuffer slice2Char(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final CharBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_CHAR );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_CHAR );
+                res = bb.slice().order(bb.order()).asCharBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof CharBuffer) {
+                final CharBuffer fb = (CharBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor CharBuffer");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a CharBuffer at the given `elementStartPos` with the given `elementCount`
+     * in short-space by {@link CharBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * See {@link #slice2Float(float[], int, int)} for details.
+     * </p>
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_CHAR}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_CHAR}
+     * @return CharBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(float[], int, int)
+     */
+    public static final CharBuffer slice2Char(final char[] backing, final int elementStartPos, final int elementCount) {
+        return (CharBuffer) CharBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a IntBuffer to a IntBuffer
+     * at the given `elementStartPos` with the given `elementCount` in int-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * See {@link #slice2Float(Buffer, int, int)} for details.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or IntBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_INT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_INT}
+     * @return IntBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(Buffer, int, int)
+     */
+    public static final IntBuffer slice2Int(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final IntBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_INT );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_INT );
+                res = bb.slice().order(bb.order()).asIntBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof IntBuffer) {
+                final IntBuffer fb = (IntBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor IntBuffer");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a IntBuffer at the given `elementStartPos` with the given `elementCount`
+     * in int-space by {@link IntBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * See {@link #slice2Float(float[], int, int)} for details.
+     * </p>
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_INT}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_INT}
+     * @return IntBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(float[], int, int)
+     */
+    public static final IntBuffer slice2Int(final int[] backing, final int elementStartPos, final int elementCount) {
+        return (IntBuffer) IntBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a LongBuffer to a LongBuffer
+     * at the given `elementStartPos` with the given `elementCount` in long-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * See {@link #slice2Float(Buffer, int, int)} for details.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or LongBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_LONG}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_LONG}
+     * @return LongBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(Buffer, int, int)
+     */
+    public static final LongBuffer slice2Long(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final LongBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_LONG );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_LONG );
+                res = bb.slice().order(bb.order()).asLongBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof LongBuffer) {
+                final LongBuffer fb = (LongBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor LongBuffer");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a LongBuffer at the given `elementStartPos` with the given `elementCount`
+     * in long-space by {@link LongBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * See {@link #slice2Float(float[], int, int)} for details.
+     * </p>
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_LONG}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_LONG}
+     * @return LongBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(float[], int, int)
+     */
+    public static final LongBuffer slice2Long(final long[] backing, final int elementStartPos, final int elementCount) {
+        return (LongBuffer) LongBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+
+    /**
+     * Slices a ByteBuffer <i>or</i> a DoubleBuffer to a DoubleBuffer
+     * at the given `elementStartPos` with the given `elementCount` in double-space.
+     * <p>
+     * The returned sliced buffer's start position is zero.
+     * </p>
+     * <p>
+     * See {@link #slice2Float(Buffer, int, int)} for details.
+     * </p>
+     *
+     * @param buf source Buffer, maybe ByteBuffer (recommended) or DoubleBuffer.
+     *            Buffer's position is ignored and `elementStartPos` is being used.
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_DOUBLE}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_DOUBLE}
+     * @return DoubleBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(Buffer, int, int)
+     */
+    public static final DoubleBuffer slice2Double(final Buffer buf, final int elementStartPos, final int elementCount) {
+        if( null == buf ) {
+            throw new IllegalArgumentException("Buffer is null");
+        }
+        final int pos = buf.position();
+        final int limit = buf.limit();
+        final DoubleBuffer res;
+        try {
+            if(buf instanceof ByteBuffer) {
+                final ByteBuffer bb = (ByteBuffer) buf;
+                bb.position( elementStartPos * Buffers.SIZEOF_DOUBLE );
+                bb.limit( (elementStartPos + elementCount) * Buffers.SIZEOF_DOUBLE );
+                res = bb.slice().order(bb.order()).asDoubleBuffer(); // slice and duplicate may change byte order
+            } else if(buf instanceof DoubleBuffer) {
+                final DoubleBuffer fb = (DoubleBuffer) buf;
+                fb.position( elementStartPos );
+                fb.limit( elementStartPos + elementCount );
+                res = fb.slice(); // slice and duplicate may change byte order
+            } else {
+                throw new IllegalArgumentException("Buffer not ByteBuffer, nor DoubleBuffer");
+            }
+        } finally {
+            buf.position(pos).limit(limit);
+        }
+        res.mark();
+        return res;
+    }
+    /**
+     * Slices a primitive float backing array to a DoubleBuffer at the given `elementStartPos` with the given `elementCount`
+     * in double-space by {@link DoubleBuffer#wrap(float[], int, int) wrapping} the backing array.
+     * <p>
+     * See {@link #slice2Float(float[], int, int)} for details.
+     * </p>
+     * @param backing source float array
+     * @param elementStartPos element start position w/ element of size {@link Buffers#SIZEOF_DOUBLE}
+     * @param elementCount element count for element of size {@link Buffers#SIZEOF_DOUBLE}
+     * @return DoubleBuffer w/ native byte order as given ByteBuffer
+     * @see #slice2Float(float[], int, int)
+     */
+    public static final DoubleBuffer slice2Double(final double[] backing, final int elementStartPos, final int elementCount) {
+        return (DoubleBuffer) DoubleBuffer.wrap(backing, elementStartPos, elementCount).mark();
+    }
+    //----------------------------------------------------------------------
     // Copy routines (type-to-type)
     //
     /**
@@ -1710,4 +2060,72 @@ public class Buffers {
             }
         }
     }
+
+    /**
+     * Copy `len` native bytes @ `source_address` into a newly created direct {@link ByteBuffer}.
+     * @param source_address memory address of bytes to copy from
+     * @param len number of bytes to copy
+     * @return newly created direct {@link ByteBuffer} holding the copied bytes
+     */
+    public static ByteBuffer copyNativeToDirectByteBuffer(final long source_address, final long len) {
+        final Method id;
+        if( Integer.MAX_VALUE < len ) {
+            throw new IllegalArgumentException("length "+len+" > MAX_INT");
+        }
+        final int lenI = (int)len;
+        final ByteBuffer bb = Buffers.newDirectByteBuffer(lenI);
+        if( null == bb ) {
+            throw new RuntimeException("New direct ByteBuffer is NULL");
+        }
+        if( 0 < lenI ) {
+            final long byteBufferPtr = getDirectBufferAddressImpl(bb);
+            memcpyImpl(byteBufferPtr, source_address, lenI);
+        }
+        return bb;
+    }
+
+    /* pp */ static ByteBuffer getDirectByteBuffer(final long aptr, final int byteCount) {
+        final ByteBuffer r = getDirectByteBufferImpl(aptr, byteCount);
+        return null != r ? nativeOrder( r ) : null;
+    }
+
+    /* pp */ static void storeDirectAddress(final long addr, final ByteBuffer dest, final int destBytePos, final int nativeSizeInBytes) {
+        switch(nativeSizeInBytes) {
+            case 4:
+                dest.putInt(destBytePos, (int) ( addr & 0x00000000FFFFFFFFL ) );
+                break;
+            case 8:
+                dest.putLong(destBytePos, addr);
+                break;
+            default:
+                throw new InternalError("invalid nativeSizeInBytes "+nativeSizeInBytes);
+        }
+    }
+
+    /**
+     * Returns <code>strnlen(cstrptr, maxlen)</code> according to POSIX.1-2008.
+     * <p>
+     * The `strnlen()` function returns the number of bytes in the string pointed to by `cstrptr`, excluding the terminating null byte ('\0'), but at most `maxlen`.
+     * In doing this, `strnlen()` looks only at the first `maxlen` characters in the string pointed to by `cstrptr` and never beyond `cstrptr[maxlen-1]`.
+     * </p>
+     */
+    public static int strnlen(final long cstrptr, final int maxlen) {
+        return strnlenImpl(cstrptr, maxlen);
+    }
+
+    /**
+     * Returns <code>memcpy(dest, src, len)</code> according to POSIX.1-2001, POSIX.1-2008.
+     * <p>
+     * The `memcpy()` function copies `len` bytes from memory area `src` to memory area `dest`.  The memory areas must not overlap.<br/>
+     * The `memcpy()` function returns a pointer to `dest`.
+     * </p>
+    public static long memcpy(final long dest, final long src, final long len) {
+        return memcpyImpl(dest, src, len);
+    }
+     */
+
+    /* pp */ static native long getDirectBufferAddressImpl(Object directBuffer);
+    private static native ByteBuffer getDirectByteBufferImpl(long aptr, int byteCount);
+    private static native int strnlenImpl(long cstrptr, int maxlen);
+    private static native long memcpyImpl(long dest, long src, long len);
 }
diff --git a/src/java/com/jogamp/common/nio/ElementBuffer.java b/src/java/com/jogamp/common/nio/ElementBuffer.java
new file mode 100644
index 0000000..f9909b8
--- /dev/null
+++ b/src/java/com/jogamp/common/nio/ElementBuffer.java
@@ -0,0 +1,197 @@
+/**
+ * Copyright 2010-2023 JogAmp Community. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without modification, are
+ * permitted provided that the following conditions are met:
+ *
+ *    1. Redistributions of source code must retain the above copyright notice, this list of
+ *       conditions and the following disclaimer.
+ *
+ *    2. 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.
+ *
+ * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``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 JogAmp Community 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.
+ *
+ * The views and conclusions contained in the software and documentation are those of the
+ * authors and should not be interpreted as representing official policies, either expressed
+ * or implied, of JogAmp Community.
+ */
+
+package com.jogamp.common.nio;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Hardware independent container holding an array of linearly aligned elements,
+ * while its {@link #getDirectBufferAddress()} is-a pointer-type value, i.e. the element-array address.
+ * <p>
+ * An instance maps an array of linearly aligned elements, represented as bytes.
+ * </p>
+ */
+public class ElementBuffer extends AbstractBuffer<ElementBuffer> {
+    /** supports backup array */
+    ElementBuffer(final int elementSize, final ByteBuffer b) {
+        super(b, elementSize, b.capacity()/elementSize);
+    }
+
+    /** Returns a non direct PointerBuffer in native order, having a backup array */
+    public static ElementBuffer allocate(final int elementSize, final int elementCount) {
+        return new ElementBuffer(elementSize, ByteBuffer.allocate(elementCount * elementSize));
+    }
+
+    /** Returns a direct PointerBuffer in native order, w/o backup array */
+    public static ElementBuffer allocateDirect(final int elementSize, final int elementCount) {
+        return new ElementBuffer(elementSize, Buffers.newDirectByteBuffer(elementCount * elementSize));
+    }
+
+    public static ElementBuffer wrap(final int elementSize, final ByteBuffer src) {
+        return new ElementBuffer(elementSize, src);
+    }
+    public static ElementBuffer wrap(final int elementSize, final int elementCount, final ByteBuffer src, final int srcByteOffset) {
+        final int oldPos = src.position();
+        final int oldLimit = src.limit();
+        src.position(srcByteOffset);
+        src.limit(srcByteOffset + ( elementSize * elementCount ));
+        final ElementBuffer r = new ElementBuffer(elementSize, src.slice().order(src.order())); // slice and duplicate may change byte order
+        src.position(oldPos);
+        src.limit(oldLimit);
+        return r;
+    }
+    public static ElementBuffer derefPointer(final int elementSize, final int elementCount, final long aptr) {
+        if( 0 == aptr ) {
+            throw new NullPointerException("aptr is null");
+        }
+        final ByteBuffer bb = Buffers.getDirectByteBuffer(aptr, elementCount * elementSize);
+        if( null == bb ) {
+            throw new InternalError("Couldn't dereference aptr 0x"+Long.toHexString(aptr)+", size "+elementCount+" * "+elementSize);
+        }
+        return new ElementBuffer(elementSize, bb);
+    }
+    public static ElementBuffer derefPointer(final int elementSize, final int elementCount, final ByteBuffer ptrSrc, final int ptrSrcByteOffset) {
+        return derefPointer(elementSize, elementCount, PointerBuffer.wrap(ptrSrc, ptrSrcByteOffset, 1).get(0));
+    }
+
+    @Override
+    public final ElementBuffer put(final ElementBuffer src) {
+        if (remaining() < src.remaining()) {
+            throw new IndexOutOfBoundsException("remaining[this "+remaining()+" < src "+src.remaining()+"], this "+this+", src "+src);
+        }
+        if( this.elementSize() != src.elementSize() ) {
+            throw new IllegalArgumentException("Element-Size mismatch source "+src+", dest "+this);
+        }
+        final ByteBuffer tmp = ByteBuffer.allocate(elementSize);
+        while (src.hasRemaining()) {
+            put( src.get(tmp) );
+        }
+        return this;
+    }
+
+    /** Returns the ByteBuffer, i.e. {@link #getBuffer()} w/o casting. */
+    public final ByteBuffer getByteBuffer() {
+        return (ByteBuffer) buffer;
+    }
+
+    /**
+     * Returns a slice of this instance's ByteBuffer `[offset..offset+length)`, i.e. referencing the underlying bytes.
+     * @param offset starting element-index within this buffer
+     * @param length element count
+     * @return slice of this instance's ByteBuffer
+     */
+    public final ByteBuffer slice(final int offset, final int length) {
+        if (0 > offset || offset + length > capacity) {
+            throw new IndexOutOfBoundsException("idx "+offset+" + elementCount "+length+" not within [0.."+capacity+"), "+this);
+        }
+        final ByteBuffer src = (ByteBuffer)buffer;
+        final int oldPos = src.position();
+        final int oldLimit = src.limit();
+        src.position(elementSize*offset);
+        src.limit(elementSize * (offset + length));
+        final ByteBuffer ref = src.slice().order(src.order()); // slice and duplicate may change byte order
+        src.position(oldPos);
+        src.limit(oldLimit);
+        return ref;
+    }
+
+    /** Absolute get method. Copy the element-bytes at the given index, storing them into `destElemBytes`. */
+    public final ByteBuffer get(final int idx, final ByteBuffer destElemBytes) {
+        if (0 > idx || idx >= capacity) {
+            throw new IndexOutOfBoundsException("idx "+idx+" not within [0.."+capacity+"), "+this);
+        }
+        final ByteBuffer bBuffer = (ByteBuffer)buffer;
+        for(int i=0; i<elementSize; ++i) {
+            destElemBytes.put(i, bBuffer.get(elementSize*idx+i));
+        }
+        return destElemBytes;
+    }
+    /** Relative get method. Copy the element-bytes at the current position and increment the position by one, storing the element-bytes into `destElemBytes`. */
+    public final ByteBuffer get(final ByteBuffer destElemBytes) {
+        final ByteBuffer r = get(position, destElemBytes);
+        position++;
+        return r;
+    }
+    /**
+     * Relative bulk get method. Copy the element-bytes <code> [ position .. position+length [</code>
+     * to the destination array <code> [ destElements[offset] .. destElements[offset+length] [ </code>
+     * and increment the position by <code>length</code>. */
+    public final ElementBuffer get(final ByteBuffer[] destElements, int offset, int length) {
+        if (destElements.length<offset+length) {
+            throw new IndexOutOfBoundsException("dest.length "+destElements.length+" < (offset "+offset+" + length "+length+")");
+        }
+        if (remaining() < length) {
+            throw new IndexOutOfBoundsException("remaining "+remaining()+" < length "+length+", this "+this);
+        }
+        while(length>0) {
+            get(position++, destElements[offset++]);
+            length--;
+        }
+        return this;
+    }
+
+    /** Absolute put method. Put the element-bytes at the given element-index */
+    public final ElementBuffer put(final int idx, final ByteBuffer srcElemBytes) {
+        if (0 > idx || idx >= capacity) {
+            throw new IndexOutOfBoundsException("idx "+idx+" not within [0.."+capacity+"), "+this);
+        }
+        final ByteBuffer bBuffer = (ByteBuffer)buffer;
+        for(int i=0; i<elementSize; ++i) {
+            bBuffer.put(elementSize*idx+i, srcElemBytes.get(i));
+        }
+        return this;
+    }
+    /** Relative put method. Put the element-bytes at the current position and increment the position by one. */
+    public final ElementBuffer put(final ByteBuffer srcElemBytes) {
+        put(position, srcElemBytes);
+        position++;
+        return this;
+    }
+    /**
+     * Relative bulk put method. Put the element-bytes <code> [ srcElements[offset] .. srcElements[offset+length] [</code>
+     * at the current position and increment the position by <code>length</code>. */
+    public final ElementBuffer put(final ByteBuffer[] srcElements, int offset, int length) {
+        if (srcElements.length<offset+length) {
+            throw new IndexOutOfBoundsException("src.length "+srcElements.length+" < (offset "+offset+" + length "+length+")");
+        }
+        if (remaining() < length) {
+            throw new IndexOutOfBoundsException("remaining "+remaining()+" < length "+length+", this "+this);
+        }
+        while(length>0) {
+            put(position++, srcElements[offset++]);
+            length--;
+        }
+        return this;
+    }
+
+    @Override
+    public String toString() {
+        return "ElementBuffer"+toSubString();
+    }
+}
diff --git a/src/java/com/jogamp/common/nio/NativeBuffer.java b/src/java/com/jogamp/common/nio/NativeBuffer.java
index d81da9d..5ee6af8 100644
--- a/src/java/com/jogamp/common/nio/NativeBuffer.java
+++ b/src/java/com/jogamp/common/nio/NativeBuffer.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2010 JogAmp Community. All rights reserved.
+ * Copyright 2010-2023 JogAmp Community. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification, are
  * permitted provided that the following conditions are met:
@@ -32,6 +32,7 @@
 package com.jogamp.common.nio;
 
 import java.nio.Buffer;
+import java.nio.ByteBuffer;
 
 /**
  * Hardware independent container for various kinds of buffers.
@@ -76,19 +77,34 @@ public interface NativeBuffer<B extends NativeBuffer> {
      */
     public Object array() throws UnsupportedOperationException ;
 
+    /** Returns the underlying buffer object. */
     public Buffer getBuffer();
-
+    /** Return true if the underlying buffer is NIO direct, otherwise false. */
     public boolean isDirect();
+    /** Returns the native address of the underlying buffer if {@link #isDirect()}, otherwise {@code 0}. */
+    public long getDirectBufferAddress();
+    /**
+     * Store the {@link #getDirectBufferAddress()} into the given {@link ByteBuffer} using relative put.
+     * <p>
+     * The native pointer value is stored either as a 32bit (int) or 64bit (long) wide value,
+     * depending of the CPU pointer width.
+     * </p>
+     */
+    public void storeDirectAddress(final ByteBuffer directDest);
+    /**
+     * Store the {@link #getDirectBufferAddress()} into the given {@link ByteBuffer} using absolute put.
+     * <p>
+     * The native pointer value is stored either as a 32bit (int) or 64bit (long) wide value,
+     * depending of the CPU pointer width.
+     * </p>
+     **/
+    public void storeDirectAddress(final ByteBuffer directDest, final int destOffset);
 
     public B rewind();
 
-    public B put(int index, long value);
-
-    public B put(long value);
-
+    /**
+     * Relative bulk get method. Copy the source values <code> src[position .. capacity] [</code>
+     * to this buffer and increment the position by <code>capacity-position</code>.
+     */
     public B put(B src);
-
-    public long get();
-
-    public long get(int idx);
 }
diff --git a/src/java/com/jogamp/common/nio/PointerBuffer.java b/src/java/com/jogamp/common/nio/PointerBuffer.java
index 7498756..2a2cdd9 100644
--- a/src/java/com/jogamp/common/nio/PointerBuffer.java
+++ b/src/java/com/jogamp/common/nio/PointerBuffer.java
@@ -1,5 +1,5 @@
 /**
- * Copyright 2010 JogAmp Community. All rights reserved.
+ * Copyright 2010-2023 JogAmp Community. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without modification, are
  * permitted provided that the following conditions are met:
@@ -40,22 +40,21 @@ import com.jogamp.common.os.Platform;
 import com.jogamp.common.util.LongObjectHashMap;
 
 /**
- * Hardware independent container for native pointer arrays.
- *
+ * Hardware independent container holding an array of native pointer,
+ * while its {@link #getDirectBufferAddress()} is-a pointer-pointer type value.
+ * <p>
+ * An instance maps an array of pointers of referenced Buffer objects, represented as longs.
+ * </p>
+ * <p>
  * The native values (NIO direct ByteBuffer) might be 32bit or 64bit wide,
- * depending of the CPU pointer width.
- *
+ * depending of the CPU pointer width, see {@link #POINTER_SIZE}.
+ * </p>
  * @author Sven Gothel
  * @author Michael Bien
  */
 public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
-    public static final int ELEMENT_SIZE = Platform.is32Bit() ? Buffers.SIZEOF_INT : Buffers.SIZEOF_LONG ;
     protected LongObjectHashMap dataMap = null;
 
-    static {
-        Platform.initSingleton(); // loads native gluegen_rt library
-    }
-
     /** no backup array, use for direct usage only */
     static PointerBuffer create(final ByteBuffer bb) {
         return Platform.is32Bit() ? new PointerBuffer( bb.asIntBuffer() ) : new PointerBuffer( bb.asLongBuffer() );
@@ -63,12 +62,12 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
 
     /** supports backup array */
     PointerBuffer(final IntBuffer b) {
-        super(b, ELEMENT_SIZE, b.capacity());
+        super(b, POINTER_SIZE, b.capacity());
     }
 
     /** supports backup array */
     PointerBuffer(final LongBuffer b) {
-        super(b, ELEMENT_SIZE, b.capacity());
+        super(b, POINTER_SIZE, b.capacity());
     }
 
     private final void validateDataMap() {
@@ -78,7 +77,7 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
         }
     }
 
-    /** Returns a non direct PointerBuffer in native order, having a backup array */
+    /** Returns a non direct PointerBuffer, having a backup array */
     public static PointerBuffer allocate(final int size) {
         if (Platform.is32Bit()) {
             return new PointerBuffer(IntBuffer.wrap(new int[size]));
@@ -89,12 +88,30 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
 
     /** Returns a direct PointerBuffer in native order, w/o backup array */
     public static PointerBuffer allocateDirect(final int size) {
-        return create(Buffers.newDirectByteBuffer(ELEMENT_SIZE * size));
+        return create(Buffers.newDirectByteBuffer(POINTER_SIZE * size));
     }
 
+    /** Wraps given {@link ByteBuffer} {@code src} up to it {@link ByteBuffer#capacity()}/{@link #POINTER_SIZE} pointers. */
     public static PointerBuffer wrap(final ByteBuffer src) {
         return create(src);
     }
+    /**
+     * Wraps given {@link ByteBuffer} {@code src} @ {@code srcByteOffset} to contain {@code elementCount} pointers.
+     * @param src
+     * @param srcByteOffset
+     * @param elementCount
+     * @return
+     */
+    public static PointerBuffer wrap(final ByteBuffer src, final int srcByteOffset, final int elementCount) {
+        final int oldPos = src.position();
+        final int oldLimit = src.limit();
+        src.position(srcByteOffset);
+        src.limit(srcByteOffset + POINTER_SIZE*elementCount);
+        final ByteBuffer ref = src.slice().order(src.order()); // slice and duplicate may change byte order
+        src.position(oldPos);
+        src.limit(oldLimit);
+        return create(ref);
+    }
 
     /**
      * @return new PointerBuffer sharing the same buffer data of this instance (identity),
@@ -114,13 +131,10 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
         return npb;
     }
 
-    /**
-     * Relative bulk get method. Copy the source values <code> src[position .. capacity] [</code>
-     * to this buffer and increment the position by <code>capacity-position</code>. */
     @Override
     public final PointerBuffer put(final PointerBuffer src) {
         if (remaining() < src.remaining()) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("remaining[this "+remaining()+" < src "+src.remaining()+"], this "+this+", src "+src);
         }
         if( null == src.dataMap && null == dataMap ) {
             // fast path no dataMap usage on both
@@ -147,19 +161,10 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
         return this;
     }
 
-    /** Relative get method. Get the pointer value at the current position and increment the position by one. */
-    @Override
-    public final long get() {
-        final long r = get(position);
-        position++;
-        return r;
-    }
-
     /** Absolute get method. Get the pointer value at the given index */
-    @Override
     public final long get(final int idx) {
         if (0 > idx || idx >= capacity) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("idx "+idx+" not within [0.."+capacity+"), "+this);
         }
         if (Platform.is32Bit()) {
             return ((IntBuffer) buffer).get(idx)  & 0x00000000FFFFFFFFL;
@@ -167,17 +172,22 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
             return ((LongBuffer) buffer).get(idx);
         }
     }
-
+    /** Relative get method. Get the pointer value at the current position and increment the position by one. */
+    public final long get() {
+        final long r = get(position);
+        position++;
+        return r;
+    }
     /**
      * Relative bulk get method. Copy the pointer values <code> [ position .. position+length [</code>
      * to the destination array <code> [ dest[offset] .. dest[offset+length] [ </code>
      * and increment the position by <code>length</code>. */
     public final PointerBuffer get(final long[] dest, int offset, int length) {
         if (dest.length<offset+length) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("dest.length "+dest.length+" < (offset "+offset+" + length "+length+")");
         }
         if (remaining() < length) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("remaining "+remaining()+" < length "+length+", this "+this);
         }
         while(length>0) {
             dest[offset++] = get(position++);
@@ -187,10 +197,9 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
     }
 
     /** Absolute put method. Put the pointer value at the given index */
-    @Override
     public final PointerBuffer put(final int idx, final long v) {
         if (0 > idx || idx >= capacity) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("idx "+idx+" not within [0.."+capacity+"), "+this);
         }
         if (Platform.is32Bit()) {
             ((IntBuffer) buffer).put(idx, (int) v);
@@ -199,24 +208,21 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
         }
         return this;
     }
-
     /** Relative put method. Put the pointer value at the current position and increment the position by one. */
-    @Override
     public final PointerBuffer put(final long value) {
         put(position, value);
         position++;
         return this;
     }
-
     /**
      * Relative bulk put method. Put the pointer values <code> [ src[offset] .. src[offset+length] [</code>
      * at the current position and increment the position by <code>length</code>. */
     public final PointerBuffer put(final long[] src, int offset, int length) {
         if (src.length<offset+length) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("src.length "+src.length+" < (offset "+offset+" + length "+length+")");
         }
         if (remaining() < length) {
-            throw new IndexOutOfBoundsException();
+            throw new IndexOutOfBoundsException("remaining "+remaining()+" < length "+length+", this "+this);
         }
         while(length>0) {
             put(position++, src[offset++]);
@@ -239,7 +245,7 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
             throw new IllegalArgumentException("Buffer is not direct");
         }
         final long mask = Platform.is32Bit() ?  0x00000000FFFFFFFFL : 0xFFFFFFFFFFFFFFFFL ;
-        final long bbAddr = getDirectBufferAddressImpl(bb) & mask;
+        final long bbAddr = Buffers.getDirectBufferAddressImpl(bb) & mask;
         if(0==bbAddr) {
             throw new RuntimeException("Couldn't determine native address of given Buffer: "+bb);
         }
@@ -272,10 +278,8 @@ public class PointerBuffer extends AbstractBuffer<PointerBuffer> {
         return bb;
     }
 
-    private native long getDirectBufferAddressImpl(Object directBuffer);
-
     @Override
     public String toString() {
-        return "PointerBuffer:"+super.toString();
+        return "PointerBuffer"+toSubString();
     }
 }
diff --git a/src/java/com/jogamp/common/nio/StructAccessor.java b/src/java/com/jogamp/common/nio/StructAccessor.java
index 8ae0c29..79e8a36 100644
--- a/src/java/com/jogamp/common/nio/StructAccessor.java
+++ b/src/java/com/jogamp/common/nio/StructAccessor.java
@@ -1,6 +1,6 @@
 /*
+ * Copyright (c) 2010-2023 JogAmp Community. All rights reserved.
  * Copyright (c) 2003 Sun Microsystems, Inc. All Rights Reserved.
- * Copyright (c) 2010 JogAmp Community. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
@@ -42,22 +42,28 @@ package com.jogamp.common.nio;
 import java.nio.*;
 
 /**
- * @author Kenneth Russel, et al.
+ * @author Kenneth Russel, Sven Gothel, Michael Bien, et al.
  */
 public class StructAccessor {
 
     private final ByteBuffer bb;
 
+    /** Create a new instance. The {@link ByteBuffer} will be {@link ByteBuffer#rewind()} and native-order to be used with native code set. */
     public StructAccessor(final ByteBuffer bb) {
-        // Setting of byte order is concession to native code which needs
-        // to instantiate these
         this.bb = bb.order(ByteOrder.nativeOrder());
+        this.bb.rewind();
     }
 
+    /** Return the underlying native direct ByteBuffer */
     public final ByteBuffer getBuffer() {
         return bb;
     }
 
+    /** Returns the native address of the underlying native ByteBuffer. */
+    public final long getDirectBufferAddress() {
+        return Buffers.getDirectBufferAddressImpl(bb);
+    }
+
     /**
      * Returns a slice of the current ByteBuffer starting at the
      * specified byte offset and extending the specified number of
diff --git a/src/junit/com/jogamp/gluegen/test/junit/generation/BaseClass.java b/src/junit/com/jogamp/gluegen/test/junit/generation/BaseClass.java
index db8c157..34cd925 100644
--- a/src/junit/com/jogamp/gluegen/test/junit/generation/BaseClass.java
+++ b/src/junit/com/jogamp/gluegen/test/junit/generation/BaseClass.java
@@ -28,6 +28,7 @@
 
 package com.jogamp.gluegen.test.junit.generation;
 
+import com.jogamp.common.nio.AbstractBuffer;
 import com.jogamp.common.nio.Buffers;
 import com.jogamp.common.nio.PointerBuffer;
 import com.jogamp.common.os.MachineDataInfo;
@@ -465,8 +466,8 @@ public class BaseClass extends SingletonJunitCase {
         return pb;
     }
     PointerBuffer safeByteBuffer2PointerBuffer(final ByteBuffer bb, final int elements) {
-        Assert.assertEquals("ByteBuffer capacity not PointerBuffer ELEMENT_SIZE * "+elements, elements * PointerBuffer.ELEMENT_SIZE, bb.capacity());
-        Assert.assertEquals("ByteBuffer remaining not PointerBuffer ELEMENT_SIZE * "+elements, elements * PointerBuffer.ELEMENT_SIZE, bb.remaining());
+        Assert.assertEquals("ByteBuffer capacity not PointerBuffer POINTER_SIZE * "+elements, elements * AbstractBuffer.POINTER_SIZE, bb.capacity());
+        Assert.assertEquals("ByteBuffer remaining not PointerBuffer POINTER_SIZE * "+elements, elements * AbstractBuffer.POINTER_SIZE, bb.remaining());
         return validatePointerBuffer(PointerBuffer.wrap(bb), elements);
     }
 
@@ -849,7 +850,7 @@ public class BaseClass extends SingletonJunitCase {
               Assert.assertEquals(l0, l1);
               Assert.assertEquals(l0, l2);
 
-              final ByteBuffer bb = Buffers.newDirectByteBuffer(PointerBuffer.ELEMENT_SIZE);
+              final ByteBuffer bb = Buffers.newDirectByteBuffer(AbstractBuffer.POINTER_SIZE);
               for(int j=0; j<bb.limit(); j++) {
                   bb.put(j, (byte)(0xAA+j));
               }
diff --git a/src/native/common/Buffers.c b/src/native/common/Buffers.c
new file mode 100644
index 0000000..0898e6b
--- /dev/null
+++ b/src/native/common/Buffers.c
@@ -0,0 +1,30 @@
+
+#include <jni.h>
+
+#include <assert.h>
+#include <string.h>
+
+#include <gluegen_stdint.h>
+
+#include "com_jogamp_common_nio_Buffers.h"
+
+JNIEXPORT jlong JNICALL 
+Java_com_jogamp_common_nio_Buffers_getDirectBufferAddressImpl(JNIEnv *env, jclass _unused, jobject directBuffer) {
+    return ( NULL != directBuffer ) ? (jlong) (intptr_t)  (*env)->GetDirectBufferAddress(env, directBuffer) : 0L ; 
+}
+
+JNIEXPORT jobject JNICALL 
+Java_com_jogamp_common_nio_Buffers_getDirectByteBufferImpl(JNIEnv *env, jclass _unused, jlong japtr, jint jbyteCount) {
+    return ( 0 != japtr && 0 < jbyteCount ) ? (*env)->NewDirectByteBuffer(env, (void *)(intptr_t)japtr, jbyteCount) : NULL;
+}
+
+JNIEXPORT jint JNICALL 
+Java_com_jogamp_common_nio_Buffers_strnlenImpl(JNIEnv *env, jclass _unused, jlong jcstrptr, jint jmaxlen) {
+    return ( 0 != jcstrptr && 0 < jmaxlen ) ? strnlen((const char *)(void *)(intptr_t)jcstrptr, jmaxlen) : 0;
+}
+
+JNIEXPORT jlong JNICALL 
+Java_com_jogamp_common_nio_Buffers_memcpyImpl(JNIEnv *env, jclass _unused, jlong jdest, jlong jsrc, jlong jlen) {
+    return ( 0 != jdest && 0 != jsrc && 0 < jlen ) ? memcpy((void *)(intptr_t)jdest, (void *)(intptr_t)jsrc, (size_t)jlen) : jdest;
+}
+
diff --git a/src/native/common/PointerBuffer.c b/src/native/common/PointerBuffer.c
deleted file mode 100644
index f3e25d3..0000000
--- a/src/native/common/PointerBuffer.c
+++ /dev/null
@@ -1,14 +0,0 @@
-
-#include <jni.h>
-
-#include <assert.h>
-
-#include <gluegen_stdint.h>
-
-#include "com_jogamp_common_nio_PointerBuffer.h"
-
-JNIEXPORT jlong JNICALL 
-Java_com_jogamp_common_nio_PointerBuffer_getDirectBufferAddressImpl(JNIEnv *env, jclass _unused, jobject directBuffer) {
-    return ( NULL != directBuffer ) ? (jlong) (intptr_t)  (*env)->GetDirectBufferAddress(env, directBuffer) : 0L ; 
-}
-