Preserve endianness when duplicating bytebuffers

jme3-android/src/main/java/com/jme3/renderer/android/AndroidGL.java

@@ -34,6 +34,7 @@
 import android.opengl.*;
 import com.jme3.renderer.RendererException;
 import com.jme3.renderer.opengl.*;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 
 import java.nio.Buffer;
@@ -233,7 +234,7 @@ public void glGetBufferSubData(int target, long offset, ByteBuffer data) {
         try {
             ByteBuffer source = (ByteBuffer) mapped;
             source.limit(byteCount);
-            data.duplicate().put(source);
+            ByteBufferUtils.duplicate(data).put(source);
         } finally {
             unmapBufferAfterRead(target);
         }
@@ -414,7 +415,7 @@ public void glGetBoolean(int pname, ByteBuffer params) {
         boolean[] values = new boolean[count];
         GLES20.glGetBooleanv(pname, values, 0);
 
-        ByteBuffer destination = params.duplicate();
+        ByteBuffer destination = ByteBufferUtils.duplicate(params);
         for (boolean value : values) {
             destination.put((byte) (value ? GLES20.GL_TRUE : GLES20.GL_FALSE));
         }

jme3-core/src/main/java/com/jme3/environment/util/EnvMapUtils.java

@@ -40,6 +40,7 @@
 import com.jme3.texture.*;
 import com.jme3.texture.image.ColorSpace;
 import com.jme3.ui.Picture;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.TempVars;
 
@@ -155,7 +156,7 @@ public static TextureCubeMap duplicateCubeMap(TextureCubeMap sourceMap) {
         Image cubeImage = new Image(srcImg.getFormat(), srcImg.getWidth(), srcImg.getHeight(), null, srcImg.getColorSpace());
 
         for (ByteBuffer d : srcImg.getData()) {
-            cubeImage.addData(d.duplicate());
+            cubeImage.addData(ByteBufferUtils.duplicate(d));
         }
 
         cubeImage.setMipMapSizes(srcImg.getMipMapSizes());
@@ -749,5 +750,3 @@ public static TextureCubeMap createPrefilteredEnvMap(int size, Image.Format imag
     }
 }
 
-
-

jme3-core/src/main/java/com/jme3/renderer/opengl/GLRenderer.java

@@ -63,6 +63,7 @@
 import com.jme3.texture.TextureImage;
 import com.jme3.texture.image.ColorSpace;
 import com.jme3.texture.image.LastTextureState;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.ListMap;
 import com.jme3.util.MipMapGenerator;
@@ -3041,7 +3042,7 @@ private Image cloneImageForUpload(Image image, boolean scaleToPot) {
             if (buffer == null) {
                 return null;
             }
-            data.add(buffer.duplicate());
+            data.add(ByteBufferUtils.duplicate(buffer));
         }
         return new Image(image.getFormat(), image.getWidth(), image.getHeight(), image.getDepth(),
                 data, null, image.getColorSpace());

jme3-core/src/main/java/com/jme3/scene/VertexBuffer.java

@@ -34,6 +34,7 @@
 import com.jme3.export.*;
 import com.jme3.math.FastMath;
 import com.jme3.renderer.Renderer;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.NativeObject;
 import java.io.IOException;
@@ -452,9 +453,9 @@ public void setStride(int stride) {
      * Returns the raw internal data buffer used by this VertexBuffer.
      * This buffer is not safe to call from multiple threads since buffers
      * have their own internal position state that cannot be shared.
-     * Call getData().duplicate(), getData().asReadOnlyBuffer(), or
-     * the more convenient getDataReadOnly() if the buffer may be accessed
-     * from multiple threads.
+     * Call getData().duplicate() for typed buffers, {@link ByteBufferUtils#duplicate(java.nio.ByteBuffer)}
+     * for ByteBuffers, getData().asReadOnlyBuffer(), or the more convenient
+     * getDataReadOnly() if the buffer may be accessed from multiple threads.
      *
      * @return A native buffer, in the specified {@link Format format}.
      */

jme3-core/src/main/java/com/jme3/shader/bufferobject/BufferObject.java

@@ -42,6 +42,7 @@
 import com.jme3.export.OutputCapsule;
 import com.jme3.export.Savable;
 import com.jme3.renderer.Renderer;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.NativeObject;
 
@@ -172,10 +173,10 @@ public void setData(ByteBuffer data) {
             }
             return;
         }
-        ByteBuffer source = data == this.data ? data.duplicate() : data;
+        ByteBuffer source = data == this.data ? ByteBufferUtils.duplicate(data) : data;
         ByteBuffer oldData = this.data;
 
-        this.data = BufferUtils.createByteBuffer(source.limit() - source.position());
+        this.data = BufferUtils.createByteBuffer(source.limit() - source.position()).order(source.order());
         this.data.put(source);
 
         if (oldData != null) {
@@ -199,7 +200,7 @@ public ByteBuffer getData() {
                 data = BufferUtils.createByteBuffer(regionsEnd + 1);
             } else if (data.limit() <= regionsEnd) {
                 // new buffer
-                ByteBuffer newData = BufferUtils.createByteBuffer(regionsEnd + 1);
+                ByteBuffer newData = BufferUtils.createByteBuffer(regionsEnd + 1).order(data.order());
 
                 // copy old buffer in new buffer
                 if (newData.limit() < data.limit()) data.limit(newData.limit());

jme3-core/src/main/java/com/jme3/shader/bufferobject/BufferRegion.java

@@ -31,6 +31,8 @@
  */
 package com.jme3.shader.bufferobject;
 
+import com.jme3.util.ByteBufferUtils;
+
 import java.io.IOException;
 import java.nio.ByteBuffer;
 
@@ -73,7 +75,7 @@ public ByteBuffer getData() {
         ByteBuffer source = bo.getData();
         assert end < source.capacity() : "Can't set limit at " + end + " on capacity " + source.capacity();
 
-        ByteBuffer view = source.duplicate();
+        ByteBuffer view = ByteBufferUtils.duplicate(source);
         view.position(start);
         view.limit(end + 1);
 

jme3-core/src/main/java/com/jme3/shader/bufferobject/DirtyRegionsIterator.java

@@ -31,6 +31,8 @@
  */
 package com.jme3.shader.bufferobject;
 
+import com.jme3.util.ByteBufferUtils;
+
 import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Iterator;
@@ -49,7 +51,7 @@ private static class DirtyRegion extends BufferRegion {
         @Override
         public ByteBuffer getData() {
             ByteBuffer source = bo.getData();
-            ByteBuffer view = source.duplicate();
+            ByteBuffer view = ByteBufferUtils.duplicate(source);
             view.position(start);
             view.limit(end + 1);
             return view.slice().order(source.order());

jme3-core/src/main/java/com/jme3/util/ByteBufferUtils.java

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2009-2026 jMonkeyEngine
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * * 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.
+ *
+ * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
+ *   may be used to endorse or promote products derived from this software
+ *   without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "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 THE COPYRIGHT OWNER 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.
+ */
+package com.jme3.util;
+
+import java.nio.ByteBuffer;
+
+/**
+ * Utility methods for ByteBuffer views.
+ */
+public final class ByteBufferUtils {
+
+    private ByteBufferUtils() {
+    }
+
+    /**
+     * Duplicates a ByteBuffer and preserves its byte order.
+     *
+     * @param source the buffer to duplicate
+     * @return a duplicate with independent position, limit, and mark
+     */
+    public static ByteBuffer duplicate(ByteBuffer source) {
+        ByteBuffer duplicate = source.duplicate();
+        duplicate.order(source.order());
+        return duplicate;
+    }
+}

jme3-core/src/main/java/com/jme3/util/MipMapGenerator.java

@@ -220,10 +220,10 @@ private static MipChain generateMipChainForSlice(Image sourceImage,
             totalSize += size;
         }
 
-        ByteBuffer combined = BufferUtils.createByteBuffer(totalSize);
+        ByteBuffer combined = BufferUtils.createByteBuffer(totalSize).order(levels.get(0).order());
 
         for (ByteBuffer level : levels) {
-            ByteBuffer duplicate = level.duplicate();
+            ByteBuffer duplicate = ByteBufferUtils.duplicate(level);
             duplicate.clear();
             combined.put(duplicate);
         }
@@ -246,7 +246,7 @@ private static Image scaleLevel(Image inputImage,
         validateImage(inputImage);
 
         int outputSize = levelSize(inputImage.getFormat(), outputWidth, outputHeight);
-        ByteBuffer outputBuffer = BufferUtils.createByteBuffer(outputSize);
+        ByteBuffer outputBuffer = BufferUtils.createByteBuffer(outputSize).order(inputImage.getData(inputSlice).order());
 
         Image outputImage = new Image(
                 inputImage.getFormat(),
@@ -519,11 +519,11 @@ private static ByteBuffer copyBaseLevel(ByteBuffer source, int baseLevelSize) {
             );
         }
 
-        ByteBuffer duplicate = source.duplicate();
+        ByteBuffer duplicate = ByteBufferUtils.duplicate(source);
         duplicate.clear();
         duplicate.limit(baseLevelSize);
 
-        ByteBuffer copy = BufferUtils.createByteBuffer(baseLevelSize);
+        ByteBuffer copy = BufferUtils.createByteBuffer(baseLevelSize).order(source.order());
         copy.put(duplicate);
         copy.flip();
 

jme3-core/src/test/java/com/jme3/shader/bufferobject/DirtyRegionsIteratorTest.java

@@ -112,6 +112,31 @@ public void testSetDataHandlesSelfAlias() {
         assertEquals((byte) 0x44, result.get());
     }
 
+    @Test
+    public void testSetDataPreservesSourceOrder() {
+        BufferObject bo = new BufferObject();
+        ByteBuffer source = ByteBuffer.allocateDirect(4).order(ByteOrder.LITTLE_ENDIAN);
+        source.putInt(0x01020304);
+        source.flip();
+
+        bo.setData(source);
+
+        ByteBuffer result = bo.getData();
+        assertEquals(ByteOrder.LITTLE_ENDIAN, result.order());
+        assertEquals(0x01020304, result.getInt());
+    }
+
+    @Test
+    public void testGrowingDataPreservesExistingOrder() {
+        BufferObject bo = new BufferObject();
+        bo.setRegions(Arrays.asList(new BufferRegion(0, 3)));
+        bo.getData().order(ByteOrder.LITTLE_ENDIAN);
+
+        bo.setRegions(Arrays.asList(new BufferRegion(0, 7)));
+
+        assertEquals(ByteOrder.LITTLE_ENDIAN, bo.getData().order());
+    }
+
     @Test
     public void testSetDataNullClearsBuffer() {
         BufferObject bo = new BufferObject();

jme3-core/src/test/java/com/jme3/util/MipMapGeneratorTest.java

@@ -34,6 +34,7 @@
 import com.jme3.texture.Image;
 import com.jme3.texture.image.ColorSpace;
 import java.nio.ByteBuffer;
+import java.nio.ByteOrder;
 import java.util.ArrayList;
 import org.junit.jupiter.api.Test;
 
@@ -74,4 +75,18 @@ public void testGenerateMipMapsRejectsNullDataBuffer() {
         assertThrows(IllegalArgumentException.class,
                 () -> MipMapGenerator.generateMipMaps(image, true, false));
     }
+
+    @Test
+    public void testGenerateMipMapsPreservesDataOrder() {
+        ByteBuffer data = BufferUtils.createByteBuffer(2 * 2 * 4).order(ByteOrder.BIG_ENDIAN);
+        for (int i = 0; i < data.capacity(); i++) {
+            data.put((byte) i);
+        }
+        data.flip();
+
+        Image image = new Image(Image.Format.RGBA8, 2, 2, data, ColorSpace.Linear);
+        MipMapGenerator.generateMipMaps(image, true, false);
+
+        assertEquals(ByteOrder.BIG_ENDIAN, image.getData(0).order());
+    }
 }

jme3-desktop/src/main/java/com/jme3/system/JmeDesktopSystem.java

@@ -39,6 +39,7 @@
 import com.jme3.system.JmeContext.Type;
 import com.jme3.texture.Image;
 import com.jme3.texture.image.ColorSpace;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.res.Resources;
 
 import jme3tools.converters.ImageToAwt;
@@ -102,7 +103,7 @@ private static BufferedImage ensureOpaque(BufferedImage original) {
 
     @Override
     public void writeImageFile(OutputStream outStream, String format, ByteBuffer imageData, int width, int height) throws IOException {
-        BufferedImage awtImage = ImageToAwt.convert(new Image(Image.Format.RGBA8, width, height, imageData.duplicate(), ColorSpace.Linear), false, true, 0);
+        BufferedImage awtImage = ImageToAwt.convert(new Image(Image.Format.RGBA8, width, height, ByteBufferUtils.duplicate(imageData), ColorSpace.Linear), false, true, 0);
         awtImage = verticalFlip(awtImage);
 
         ImageWriter writer = ImageIO.getImageWritersByFormatName(format).next();

jme3-networking/src/main/java/com/jme3/network/kernel/tcp/SelectorKernel.java

@@ -33,6 +33,7 @@
 
 import com.jme3.network.Filter;
 import com.jme3.network.kernel.*;
+import com.jme3.util.ByteBufferUtils;
 import java.io.IOException;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
@@ -161,7 +162,7 @@ public void broadcast( Filter<? super Endpoint> filter, ByteBuffer data, boolean
             // Give it the data... but let each endpoint track their
             // own completion over the shared array of bytes by
             // duplicating it
-            p.send( data.duplicate(), false, false );
+            p.send( ByteBufferUtils.duplicate(data), false, false );
         }
 
         // Wake up the selector so it can reinitialize its

jme3-plugins/src/gltf/java/com/jme3/scene/plugins/gltf/GltfUtils.java

@@ -69,6 +69,7 @@
 import com.jme3.scene.VertexBuffer;
 import com.jme3.scene.plugins.gltf.GltfLoader.SkinBuffers;
 import com.jme3.texture.Texture;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 import com.jme3.util.IntMap;
 import com.jme3.util.LittleEndien;
@@ -1034,7 +1035,7 @@ public static Buffer getBufferView(ByteBuffer source, int byteOffset,  int count
         boolean tightlyPacked = (stride == elemSize);
 
         if (tightlyPacked) {
-            ByteBuffer view = source.duplicate();
+            ByteBuffer view = ByteBufferUtils.duplicate(source);
             view.position(start).limit(start + bytes);
             view = view.slice().order(ByteOrder.LITTLE_ENDIAN);
 

jme3-plugins/src/main/java/com/jme3/texture/plugins/StbImageLoader.java

@@ -17,6 +17,7 @@
 import com.jme3.math.FastMath;
 import com.jme3.texture.Image;
 import com.jme3.texture.image.ColorSpace;
+import com.jme3.util.ByteBufferUtils;
 import com.jme3.util.BufferUtils;
 
 public class StbImageLoader implements AssetLoader {
@@ -124,8 +125,7 @@ private static Image.Format selectFormat(int channels, boolean is16bit, boolean
     private ByteBuffer convertImageData(StbImageResult imgData, Image.Format jmeFormat) {
         int outputSize = jmeFormat.getBitsPerPixel() / 8 * imgData.getWidth() * imgData.getHeight();
         ByteBuffer jmeImageBuffer = BufferUtils.createByteBuffer(outputSize);
-        ByteBuffer source = imgData.getData().duplicate();
-        source.order(imgData.getData().order());
+        ByteBuffer source = ByteBufferUtils.duplicate(imgData.getData());
         source.position(0).limit(imgData.getDataSize());
 
         if (!imgData.is16Bit() && !imgData.isFloat()) {