4 files changed, 37 insertions, 4 deletions
diff --git a/src/com/mbien/opencl/CLBuffer.java b/src/com/mbien/opencl/CLBuffer.java
index 618cfa96..e42b9064 100644
--- a/src/com/mbien/opencl/CLBuffer.java
+++ b/src/com/mbien/opencl/CLBuffer.java
@@ -21,7 +21,7 @@ public final class CLBuffer<B extends Buffer> extends CLMemory<B> {
     
     static <B extends Buffer> CLBuffer<B> create(CLContext context, B directBuffer, int flags, int glBuffer) {
 
-        if(!directBuffer.isDirect())
+        if(directBuffer != null && !directBuffer.isDirect())
             throw new IllegalArgumentException("buffer is not a direct buffer");
 
         CL cl = context.cl;
diff --git a/src/com/mbien/opencl/CLDevice.java b/src/com/mbien/opencl/CLDevice.java
index f1a402be..e8d55eb1 100644
--- a/src/com/mbien/opencl/CLDevice.java
+++ b/src/com/mbien/opencl/CLDevice.java
@@ -2,6 +2,7 @@ package com.mbien.opencl;
 
 import com.sun.gluegen.runtime.PointerBuffer;
 import java.nio.Buffer;
+import java.nio.ByteBuffer;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumSet;
@@ -164,6 +165,16 @@ public final class CLDevice {
     }
 
     /**
+     * Returns the maximum number of work-items that can be specified in each
+     * dimension of the work-group.
+     * The minimum value is (1, 1, 1).
+     */
+    public int[] getMaxWorkItemSizes() {
+        int n = (int) deviceInfo.getLong(CL_DEVICE_MAX_WORK_ITEM_DIMENSIONS);
+        return deviceInfo.getInts(n, CL_DEVICE_MAX_WORK_ITEM_SIZES);
+    }
+
+    /**
      * Returns the max size in bytes of the arguments that can be passed to a kernel.
      * The minimum value is 256.
      */
@@ -417,13 +428,28 @@ public final class CLDevice {
     }
 
 
-    private class CLDeviceInfoAccessor extends CLInfoAccessor {
+    private final class CLDeviceInfoAccessor extends CLInfoAccessor {
 
         @Override
         protected int getInfo(int name, long valueSize, Buffer value, PointerBuffer valueSizeRet) {
             return cl.clGetDeviceInfo(ID, name, valueSize, value, valueSizeRet);
         }
 
+        private int[] getInts(int n, int key) {
+
+            ByteBuffer buffer = localBB.get();
+            int ret = getInfo(key, buffer.capacity(), buffer, null);
+            CLException.checkForError(ret, "error while asking device for infos");
+
+            int[] array = new int[n];
+            for(int i = 0; i < array.length; i++) {
+                array[i] = (int)buffer.getLong();
+            }
+            buffer.rewind();
+            
+            return array;
+        }
+
     }
 
 
diff --git a/src/com/mbien/opencl/CLGLContext.java b/src/com/mbien/opencl/CLGLContext.java
index 6336dfc8..48efb6c0 100644
--- a/src/com/mbien/opencl/CLGLContext.java
+++ b/src/com/mbien/opencl/CLGLContext.java
@@ -94,6 +94,13 @@ public final class CLGLContext extends CLContext {
         return GLObjectType.valueOf(array[0]);
     }
 
+    public int getGLObjectID(CLBuffer<?> buffer) {
+        int[] array = new int[1];
+        int ret = ((CLGLI)cl).clGetGLObjectInfo(buffer.ID, null, 0, array, 0);
+        CLException.checkForError(ret, "error while asking for gl object info");
+        return array[0];
+    }
+
     public enum GLObjectType {
 
         GL_OBJECT_BUFFER(CL_GL_OBJECT_BUFFER),
diff --git a/src/com/mbien/opencl/CLInfoAccessor.java b/src/com/mbien/opencl/CLInfoAccessor.java
index 7a303dc3..d2e58f3d 100644
--- a/src/com/mbien/opencl/CLInfoAccessor.java
+++ b/src/com/mbien/opencl/CLInfoAccessor.java
@@ -14,7 +14,7 @@ import static com.mbien.opencl.CLException.*;
  */
 abstract class CLInfoAccessor {
 
-    private final static ThreadLocal<ByteBuffer> localBB = new ThreadLocal<ByteBuffer>() {
+    protected final static ThreadLocal<ByteBuffer> localBB = new ThreadLocal<ByteBuffer>() {
 
         @Override
         protected ByteBuffer initialValue() {
@@ -22,7 +22,7 @@ abstract class CLInfoAccessor {
         }
 
     };
-    private final static ThreadLocal<PointerBuffer> localPB = new ThreadLocal<PointerBuffer>() {
+    protected final static ThreadLocal<PointerBuffer> localPB = new ThreadLocal<PointerBuffer>() {
 
         @Override
         protected PointerBuffer initialValue() {