ShaderState Usage/Test: Add setShaderState(GL) for pre-use attachment to the GL context ; GLArrayDataClient-GLSL: Check if ShaderState is attached.

ShaderState Usage/Test: Add setShaderState(GL) for pre-use attachment to the GL context
  - test cases utilize ShaderState before useProgram() was invoked,
    hence we need an API entry to attach the ShaderState explictly

GLArrayDataClient-GLSL: Check if ShaderState is attached.
  - catch error case of non bound ShaderState to GL context

2 files changed, 29 insertions, 6 deletions

diff --git a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
index ee9a21095..99500adfb 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/GLArrayDataClient.java
@@ -158,7 +158,15 @@ 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 ;
+        final Object ext;
+        if(usesGLSL) {
+            ext = ShaderState.getShaderState(gl);
+            if(null == ext) {
+                throw new GLException("A ShaderState must be bound to the GL context, use 'ShaderState.setShaderState(gl)'");
+            }
+        } else {
+            ext = null;
+        }
         if(enable) {
             glArrayHandler.syncData(gl, true, ext);
             glArrayHandler.enableState(gl, true, ext);
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 36abd9d4d..aa9a73bdd 100644
--- a/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java
+++ b/src/jogl/classes/com/jogamp/opengl/util/glsl/ShaderState.java
@@ -63,26 +63,42 @@ public class ShaderState {
      *
      * @see com.jogamp.opengl.util.glsl.ShaderState#useProgram(GL2ES2, boolean)
      * @see com.jogamp.opengl.util.glsl.ShaderState#getShaderState(GL)
+     * @see com.jogamp.opengl.util.glsl.ShaderState#setShaderState(GL)
      * @see com.jogamp.opengl.util.glsl.ShaderState#getCurrentShaderState()
      */
-    public static synchronized ShaderState getCurrentShaderState() { 
+    public static ShaderState getCurrentShaderState() { 
         return getShaderState(GLContext.getCurrentGL());
     }
 
     /**
-     * Fetches the shader state from the GL object's GLContext
+     * Gets the shader state attached to the GL object's GLContext
      *
      * @param gl the GL object referencing the GLContext
      * 
      * @see com.jogamp.opengl.util.glsl.ShaderState#useProgram(GL2ES2, boolean)
      * @see com.jogamp.opengl.util.glsl.ShaderState#getShaderState(GL)
+     * @see com.jogamp.opengl.util.glsl.ShaderState#setShaderState(GL)
      * @see com.jogamp.opengl.util.glsl.ShaderState#getCurrentShaderState()
      */
-    public static synchronized ShaderState getShaderState(GL gl) { 
+    public static ShaderState getShaderState(GL gl) { 
         return (ShaderState) gl.getContext().getAttachedObject(currentStateKey);
     }
 
     /**
+     * Attaches the shader state to the GL object's GLContext
+     *
+     * @param gl the GL object referencing the GLContext
+     * 
+     * @see com.jogamp.opengl.util.glsl.ShaderState#useProgram(GL2ES2, boolean)
+     * @see com.jogamp.opengl.util.glsl.ShaderState#getShaderState(GL)
+     * @see com.jogamp.opengl.util.glsl.ShaderState#setShaderState(GL)
+     * @see com.jogamp.opengl.util.glsl.ShaderState#getCurrentShaderState()
+     */
+    public final ShaderState setShaderState(GL gl) { 
+        return (ShaderState) gl.getContext().attachObject(currentStateKey, this);
+    }
+
+    /**
      * Returns the attached user object for the given name to this ShaderState.
      */
     public final Object getAttachedObject(String name) {
@@ -141,8 +157,7 @@ public class ShaderState {
     public synchronized void useProgram(GL2ES2 gl, boolean on) throws GLException {
         if(null==shaderProgram) { throw new GLException("No program is attached"); }        
         if(on) {
-            // update the current ShaderState to the TLS ..
-            gl.getContext().attachObject(currentStateKey, this);
+            setShaderState(gl);
             if(shaderProgram.linked()) {
                 shaderProgram.useProgram(gl, true);
                 if(resetAllShaderData) {