GLSL DataArray/Handler: Remove ShaderState state and pass it through: ShaderState.getShaderState(gl)

This removes the dependency of a GLSL GLDataArray object to a specific ShaderState
and enables sharing of this VBO data, i.e. via a shared context.

Test: TestSharedContextVBOES2NEWT

5 files changed, 82 insertions, 104 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
index 3600081bc..ee9a21095 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
@@ -11,6 +11,7 @@ import javax.media.opengl.GL;
 import javax.media.opengl.GLException;
 import javax.media.opengl.fixedfunc.GLPointerFuncUtil;
 
+import jogamp.opengl.util.GLArrayHandler;
 import jogamp.opengl.util.GLFixedArrayHandler;
 import jogamp.opengl.util.glsl.GLSLArrayHandler;
 
@@ -45,7 +46,7 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
   {
       GLArrayDataClient adc = new GLArrayDataClient();
       GLArrayHandler glArrayHandler = new GLFixedArrayHandler(adc);
-      adc.init(null, index, comps, dataType, normalized, 0, null, initialSize, false, glArrayHandler, 0, 0, 0, 0);
+      adc.init(null, index, comps, dataType, normalized, 0, null, initialSize, false, glArrayHandler, 0, 0, 0, 0, false);
       return adc;
   }
 
@@ -76,36 +77,32 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
   {
       GLArrayDataClient adc = new GLArrayDataClient();
       GLArrayHandler glArrayHandler = new GLFixedArrayHandler(adc);
-      adc.init(null, index, comps, dataType, normalized, stride, buffer, comps*comps, false, glArrayHandler, 0, 0, 0, 0);
+      adc.init(null, index, comps, dataType, normalized, stride, buffer, comps*comps, false, glArrayHandler, 0, 0, 0, 0, false);
       return adc;
   }
 
   /**
    * Create a client side buffer object, using a custom GLSL array attribute name
    * and starting with a new created Buffer object with initialSize size
-   * 
-   * @param st The ShaderState managing the state of the used shader program, vertex attributes and uniforms 
    * @param name  The custom name for the GL attribute. 
    * @param comps The array component number
    * @param dataType The array index GL data type
    * @param normalized Whether the data shall be normalized
    * @param initialSize
    */
-  public static GLArrayDataClient createGLSL(ShaderState st, String name, 
-                                             int comps, int dataType, boolean normalized, int initialSize)
+  public static GLArrayDataClient createGLSL(String name, int comps, 
+                                             int dataType, boolean normalized, int initialSize)
     throws GLException
   {
       GLArrayDataClient adc = new GLArrayDataClient();
-      GLArrayHandler glArrayHandler = new GLSLArrayHandler(st, adc);
-      adc.init(name, -1, comps, dataType, normalized, 0, null, initialSize, true, glArrayHandler, 0, 0, 0, 0);
+      GLArrayHandler glArrayHandler = new GLSLArrayHandler(adc);
+      adc.init(name, -1, comps, dataType, normalized, 0, null, initialSize, true, glArrayHandler, 0, 0, 0, 0, true);
       return adc;
   }
 
   /**
    * Create a client side buffer object, using a custom GLSL array attribute name
    * and starting with a given Buffer object incl it's stride
-   * 
-   * @param st The ShaderState managing the state of the used shader program, vertex attributes and uniforms
    * @param name  The custom name for the GL attribute. 
    * @param comps The array component number
    * @param dataType The array index GL data type
@@ -113,14 +110,13 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
    * @param stride
    * @param buffer the user define data
    */
-  public static GLArrayDataClient createGLSL(ShaderState st, String name,
-                                             int comps, int dataType, boolean normalized, int stride, 
-                                             Buffer buffer)
+  public static GLArrayDataClient createGLSL(String name, int comps,
+                                             int dataType, boolean normalized, int stride, Buffer buffer)
     throws GLException
   {
       GLArrayDataClient adc = new GLArrayDataClient();
-      GLArrayHandler glArrayHandler = new GLSLArrayHandler(st, adc);
-      adc.init(name, -1, comps, dataType, normalized, stride, buffer, comps*comps, true, glArrayHandler, 0, 0, 0, 0);
+      GLArrayHandler glArrayHandler = new GLSLArrayHandler(adc);
+      adc.init(name, -1, comps, dataType, normalized, stride, buffer, comps*comps, true, glArrayHandler, 0, 0, 0, 0, true);
       return adc;
   }
 
@@ -162,12 +158,13 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
             // init/generate VBO name if not done yet
             init_vbo(gl);
         }
+        final Object ext = usesGLSL ? ShaderState.getShaderState(gl) : null ;
         if(enable) {
-            glArrayHandler.syncData(gl, true);
-            glArrayHandler.enableState(gl, true);
+            glArrayHandler.syncData(gl, true, ext);
+            glArrayHandler.enableState(gl, true, ext);
         } else {
-            glArrayHandler.enableState(gl, false);
-            glArrayHandler.syncData(gl, false);
+            glArrayHandler.enableState(gl, false, ext);
+            glArrayHandler.syncData(gl, false, ext);
         }
         bufferEnabled = enable;
     }
@@ -349,7 +346,7 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
 
   protected void init(String name, int index, int comps, int dataType, boolean normalized, int stride, Buffer data, 
                       int initialSize, boolean isVertexAttribute, GLArrayHandler handler,
-                      int vboName, long vboOffset, int vboUsage, int vboTarget)
+                      int vboName, long vboOffset, int vboUsage, int vboTarget, boolean usesGLSL)
     throws GLException
   {
     super.init(name, index, comps, dataType, normalized, stride, data, isVertexAttribute,
@@ -357,6 +354,7 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
 
     this.initialSize = initialSize;
     this.glArrayHandler = handler;
+    this.usesGLSL = usesGLSL;
     this.sealed=false;
     this.bufferEnabled=false;
     this.enableBufferAlways=false;
@@ -385,5 +383,6 @@ public class GLArrayDataClient extends GLArrayDataWrapper implements GLArrayData
   protected int initialSize;
 
   protected GLArrayHandler glArrayHandler;
+  protected boolean usesGLSL;
 }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataServer.java b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataServer.java
index 8b254a9c9..d3bb2e3fd 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataServer.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataServer.java
@@ -9,14 +9,14 @@ import javax.media.opengl.GLArrayData;
 import javax.media.opengl.GLException;
 import javax.media.opengl.fixedfunc.GLPointerFuncUtil;
 
+import jogamp.opengl.util.GLArrayHandler;
+import jogamp.opengl.util.GLArrayHandlerInterleaved;
 import jogamp.opengl.util.GLDataArrayHandler;
 import jogamp.opengl.util.GLFixedArrayHandler;
 import jogamp.opengl.util.GLFixedArrayHandlerFlat;
-import jogamp.opengl.util.GLFixedArrayHandlerInterleaved;
 import jogamp.opengl.util.glsl.GLSLArrayHandler;
 import jogamp.opengl.util.glsl.GLSLArrayHandlerFlat;
 
-import com.jogamp.opengl.util.glsl.ShaderState;
 
 public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataEditable {
 
@@ -53,7 +53,7 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
     GLArrayDataServer ads = new GLArrayDataServer();
     GLArrayHandler glArrayHandler = new GLFixedArrayHandler(ads);
     ads.init(null, index, comps, dataType, normalized, stride, buffer, buffer.limit(), false, glArrayHandler,
-             0, 0, vboUsage, GL.GL_ARRAY_BUFFER);
+             0, 0, vboUsage, GL.GL_ARRAY_BUFFER, false);
     return ads;
   }
 
@@ -85,15 +85,13 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
     GLArrayDataServer ads = new GLArrayDataServer();
     GLArrayHandler glArrayHandler = new GLFixedArrayHandler(ads);
     ads.init(null, index, comps, dataType, normalized, 0, null, initialSize, false, glArrayHandler,
-             0, 0, vboUsage, GL.GL_ARRAY_BUFFER);
+             0, 0, vboUsage, GL.GL_ARRAY_BUFFER, false);
     return ads;
   }
 
   /**
    * Create a VBO, using a custom GLSL array attribute name
    * and starting with a new created Buffer object with initialSize size
-   * 
-   * @param st The ShaderState managing the state of the used shader program, vertex attributes and uniforms
    * @param name  The custom name for the GL attribute    
    * @param comps The array component number
    * @param dataType The array index GL data type
@@ -101,23 +99,20 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
    * @param initialSize
    * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
    */
-  public static GLArrayDataServer createGLSL(ShaderState st, String name,
-                                             int comps, int dataType, boolean normalized, int initialSize, 
-                                             int vboUsage) 
+  public static GLArrayDataServer createGLSL(String name, int comps,
+                                             int dataType, boolean normalized, int initialSize, int vboUsage) 
     throws GLException 
   {
     GLArrayDataServer ads = new GLArrayDataServer();
-    GLArrayHandler glArrayHandler = new GLSLArrayHandler(st, ads);
+    GLArrayHandler glArrayHandler = new GLSLArrayHandler(ads);
     ads.init(name, -1, comps, dataType, normalized, 0, null, initialSize,
-             true, glArrayHandler, 0, 0, vboUsage, GL.GL_ARRAY_BUFFER);
+             true, glArrayHandler, 0, 0, vboUsage, GL.GL_ARRAY_BUFFER, true);
     return ads;
   }  
   
   /**
    * Create a VBO, using a custom GLSL array attribute name
    * and starting with a given Buffer object incl it's stride
-   * 
-   * @param st The ShaderState managing the state of the used shader program, vertex attributes and uniforms
    * @param name  The custom name for the GL attribute     
    * @param comps The array component number
    * @param dataType The array index GL data type
@@ -126,15 +121,15 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
    * @param buffer the user define data
    * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
    */
-  public static GLArrayDataServer createGLSL(ShaderState st, String name,
-                                             int comps, int dataType, boolean normalized, int stride,
-                                             Buffer buffer, int vboUsage) 
+  public static GLArrayDataServer createGLSL(String name, int comps,
+                                             int dataType, boolean normalized, int stride, Buffer buffer,
+                                             int vboUsage) 
     throws GLException
   {
     GLArrayDataServer ads = new GLArrayDataServer();
-    GLArrayHandler glArrayHandler = new GLSLArrayHandler(st, ads);
+    GLArrayHandler glArrayHandler = new GLSLArrayHandler(ads);
     ads.init(name, -1, comps, dataType, normalized, stride, buffer, buffer.limit(), true, glArrayHandler,
-             0, 0, vboUsage, GL.GL_ARRAY_BUFFER);
+             0, 0, vboUsage, GL.GL_ARRAY_BUFFER, true);
     return ads;
   }
 
@@ -158,7 +153,7 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
     GLArrayDataServer ads = new GLArrayDataServer();
     GLArrayHandler glArrayHandler = new GLDataArrayHandler(ads);
     ads.init(null, -1, comps, dataType, false, stride, buffer, buffer.limit(), false, glArrayHandler,
-             0, 0, vboUsage, vboTarget);
+             0, 0, vboUsage, vboTarget, false);
     return ads;
   }
 
@@ -180,17 +175,15 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
     GLArrayDataServer ads = new GLArrayDataServer();
     GLArrayHandler glArrayHandler = new GLDataArrayHandler(ads);
     ads.init(null, -1, comps, dataType, false, 0, null, initialSize, false, glArrayHandler,
-             0, 0, vboUsage, vboTarget);
+             0, 0, vboUsage, vboTarget, false);
     return ads;
   }
 
   
   /**
-   * Create a VBO for interleaved array data
+   * Create a VBO for fixed function interleaved array data
    * starting with a new created Buffer object with initialSize size.
-   * <p>User needs to <i>configure</i> the interleaved segments via {@link #addFixedSubArray(int, int, int)}
-   * for fixed function arrays or via {@link #addGLSLSubArray(ShaderState, String, int, int)} for GLSL 
-   * attributes.</p>  
+   * <p>User needs to <i>configure</i> the interleaved segments via {@link #addFixedSubArray(int, int, int)}.</p>
    * 
    * @param comps The total number of all interleaved components.
    * @param dataType The array index GL data type
@@ -198,22 +191,19 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
    * @param initialSize 
    * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
    */
-  public static GLArrayDataServer createInterleaved(int comps, int dataType, boolean normalized, int initialSize, 
+  public static GLArrayDataServer createFixedInterleaved(int comps, int dataType, boolean normalized, int initialSize, 
                                               int vboUsage)
     throws GLException
   {
     GLArrayDataServer ads = new GLArrayDataServer();
-    GLArrayHandler glArrayHandler = new GLFixedArrayHandlerInterleaved(ads);
+    GLArrayHandler glArrayHandler = new GLArrayHandlerInterleaved(ads);
     ads.init(GLPointerFuncUtil.mgl_InterleaveArray, -1, comps, dataType, false, 0, null, initialSize, false, glArrayHandler,
-             0, 0, vboUsage, GL.GL_ARRAY_BUFFER);
+             0, 0, vboUsage, GL.GL_ARRAY_BUFFER, false);
     return ads;
   }
 
-  int interleavedOffset = 0;
-  
   /**
-   * Configure a segment of this interleaved array (see {@link #createInterleaved(int, int, boolean, int, int)})
-   * for fixed function usage.
+   * Configure a segment of this fixed function interleaved array (see {@link #createFixedInterleaved(int, int, boolean, int, int)}).
    * <p>
    * This method may be called several times as long the sum of interleaved components does not
    * exceed the total number of components of the created interleaved array.</p>
@@ -231,6 +221,9 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
           final int iOffC = interleavedOffset / getComponentSizeInBytes();
           throw new GLException("Interleaved offset > total components ("+iOffC+" > "+getComponentCount()+")");
       }
+      if(usesGLSL) {
+          throw new GLException("buffer uses GLSL");          
+      }
       GLArrayDataWrapper ad = GLArrayDataWrapper.createFixed(
               index, comps, getComponentType(), 
               getNormalized(), getStride(), getBuffer(), 
@@ -245,8 +238,29 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
   }
   
   /**
-   * Configure a segment of this interleaved array (see {@link #createInterleaved(int, int, boolean, int, int)})
-   * for GLSL usage.
+   * Create a VBO for GLSL interleaved array data
+   * starting with a new created Buffer object with initialSize size.
+   * <p>User needs to <i>configure</i> the interleaved segments via {@link #addGLSLSubArray(int, int, int)}.</p>
+   * 
+   * @param comps The total number of all interleaved components.
+   * @param dataType The array index GL data type
+   * @param normalized Whether the data shall be normalized
+   * @param initialSize 
+   * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
+   */
+  public static GLArrayDataServer createGLSLInterleaved(int comps, int dataType, boolean normalized, int initialSize, 
+                                              int vboUsage)
+    throws GLException
+  {
+    GLArrayDataServer ads = new GLArrayDataServer();
+    GLArrayHandler glArrayHandler = new GLArrayHandlerInterleaved(ads);
+    ads.init(GLPointerFuncUtil.mgl_InterleaveArray, -1, comps, dataType, false, 0, null, initialSize, false, glArrayHandler,
+             0, 0, vboUsage, GL.GL_ARRAY_BUFFER, true);
+    return ads;
+  }
+  
+  /**
+   * Configure a segment of this GLSL interleaved array (see {@link #createGLSLInterleaved(int, int, boolean, int, int)}).
    * <p>
    * This method may be called several times as long the sum of interleaved components does not
    * exceed the total number of components of the created interleaved array.</p>
@@ -254,17 +268,18 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
    * The memory of the the interleaved array is being used.</p>
    * <p>
    * Must be called before using the array, eg: {@link #seal(boolean)}, {@link #putf(float)}, .. </p>
-   * 
-   * @param st The ShaderState managing the state of the used shader program, vertex attributes and uniforms
    * @param name  The custom name for the GL attribute, maybe null if vboTarget is {@link GL#GL_ELEMENT_ARRAY_BUFFER}
    * @param comps This interleaved array segment's component number
    * @param vboTarget {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
    */
-  public GLArrayData addGLSLSubArray(ShaderState st, String name, int comps, int vboTarget) {
+  public GLArrayData addGLSLSubArray(String name, int comps, int vboTarget) {
       if(interleavedOffset >= getComponentCount() * getComponentSizeInBytes()) {
           final int iOffC = interleavedOffset / getComponentSizeInBytes();
           throw new GLException("Interleaved offset > total components ("+iOffC+" > "+getComponentCount()+")");
       }
+      if(!usesGLSL) {
+          throw new GLException("buffer uses fixed function");          
+      }
       GLArrayDataWrapper ad = GLArrayDataWrapper.createGLSL(
               name, comps, getComponentType(), 
               getNormalized(), getStride(), getBuffer(), 
@@ -272,7 +287,7 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
       ad.setVBOEnabled(isVBO());
       interleavedOffset += comps * getComponentSizeInBytes();
       if(GL.GL_ARRAY_BUFFER == vboTarget) { 
-          GLArrayHandler handler = new GLSLArrayHandlerFlat(st, ad);
+          GLArrayHandler handler = new GLSLArrayHandlerFlat(ad);
           glArrayHandler.addSubHandler(handler);
       }
       return ad;
@@ -341,11 +356,11 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
   protected void init(String name, int index, int comps, int dataType, boolean normalized, 
                       int stride, Buffer data, int initialSize, boolean isVertexAttribute,
                       GLArrayHandler glArrayHandler,
-                      int vboName, long vboOffset, int vboUsage, int vboTarget)
+                      int vboName, long vboOffset, int vboUsage, int vboTarget, boolean usesGLSL)
     throws GLException
   {
     super.init(name, index, comps, dataType, normalized, stride, data, initialSize, isVertexAttribute, glArrayHandler,
-               vboName, vboOffset, vboUsage, vboTarget);
+               vboName, vboOffset, vboUsage, vboTarget, usesGLSL);
 
     vboEnabled=true;
   }
@@ -358,5 +373,7 @@ public class GLArrayDataServer extends GLArrayDataClient implements GLArrayDataE
         vboName = tmp[0];
     }
   }
+  
+  private int interleavedOffset = 0;  
 }
 
diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLArrayHandler.java b/src/jogl/classes/com/jogamp/opengl/util/GLArrayHandler.java
deleted file mode 100644
index b30e220bd..000000000
--- a/src/jogl/classes/com/jogamp/opengl/util/GLArrayHandler.java
+++ /dev/null
@@ -1,40 +0,0 @@
-
-package com.jogamp.opengl.util;
-
-import javax.media.opengl.*;
-
-/**
- * Handles consistency of buffer data and array state.
- * Implementations shall consider buffer types (VBO, ..), interleaved, etc.
- * They also need to consider array state types, i.e. fixed function or GLSL.
- */
-public interface GLArrayHandler {
-
-  /**
-   * Implementation shall associate the data with the array
-   * and synchronize the data with the GPU.
-   * 
-   * @param gl current GL object
-   * @param enable true if array data shall be valid, otherwise false.
-   */
-  public void syncData(GL gl, boolean enable);
-  
-  /**
-   * Implementation shall enable or disable the array state.
-   * 
-   * @param gl current GL object
-   * @param enable true if array shall be enabled, otherwise false.
-   */
-  public void enableState(GL gl, boolean enable);
-  
-  /**
-   * Supporting interleaved arrays, where sub handlers may handle 
-   * the array state and the <i>master</i> handler the buffer consistency.
-   *   
-   * @param handler the sub handler
-   * @throws UnsupportedOperationException if this array handler does not support interleaved arrays
-   */
-  public void addSubHandler(GLArrayHandler handler) throws UnsupportedOperationException;
-
-}
-
diff --git a/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java b/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java
index a2a012e08..36abd9d4d 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java
@@ -49,7 +49,8 @@ import com.jogamp.opengl.util.GLArrayDataEditable;
 
 public class ShaderState {
     public static final boolean DEBUG = Debug.isPropertyDefined("jogl.debug.GLSLState", true, AccessController.getContext());
-
+    private static final String currentStateKey = "jogamp.opengl.glsl.ShaderState" ;
+    
     public ShaderState() {
     }
 
@@ -78,7 +79,7 @@ public class ShaderState {
      * @see com.jogamp.opengl.util.glsl.ShaderState#getCurrentShaderState()
      */
     public static synchronized ShaderState getShaderState(GL gl) { 
-        return (ShaderState) gl.getContext().getAttachedObject(ShaderState.class.getName());
+        return (ShaderState) gl.getContext().getAttachedObject(currentStateKey);
     }
 
     /**
@@ -141,7 +142,7 @@ public class ShaderState {
         if(null==shaderProgram) { throw new GLException("No program is attached"); }        
         if(on) {
             // update the current ShaderState to the TLS ..
-            gl.getContext().attachObject(ShaderState.class.getName(), this);
+            gl.getContext().attachObject(currentStateKey, this);
             if(shaderProgram.linked()) {
                 shaderProgram.useProgram(gl, true);
                 if(resetAllShaderData) {
diff --git a/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderUtil.java b/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderUtil.java
index c81e1f961..9ccd38bf1 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderUtil.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderUtil.java
@@ -461,11 +461,12 @@ public class ShaderUtil {
     private static Impl getImpl(GL _gl) {
         GL2ES2 gl = _gl.getGL2ES2();
         GLContext context = gl.getContext();
-        Impl impl = (Impl) context.getAttachedObject(ShaderUtil.class.getName());
+        Impl impl = (Impl) context.getAttachedObject(implObjectKey);
         if (impl == null) {
             impl = new GL2ES2Impl();
-            context.attachObject(ShaderUtil.class.getName(), impl);
+            context.attachObject(implObjectKey, impl);
         }
         return impl;
     }
+    private static final String implObjectKey = "jogamp.opengl.glsl.ShaderUtilImpl" ;
 }