don't dereference a NULL pointer...

include/ACGL/OpenGL/Objects/Buffer.hh

@@ -106,7 +106,7 @@ public:
         : mBuffer( _pBuffer ),
 		  mTarget(_target)
     {
-        mSize = mBuffer->getSize( _target );
+        mSize = (mBuffer == NULL)?0:mBuffer->getSize( mTarget );
     }
 
     virtual ~Buffer(){}
@@ -124,7 +124,7 @@ public:
     // ==================================================================================================== \/
 
     //! the GL buffer can get changed at any time
-    void setBufferObject( SharedBufferObject _pBuffer ) { mBuffer = _pBuffer; mSize = mBuffer->getSize( mTarget ); }
+    void setBufferObject( SharedBufferObject _pBuffer ) { mBuffer = _pBuffer; mSize = (mBuffer == NULL)?0:mBuffer->getSize( mTarget ); }
 
     // ===================================================================================================== \/
     // ============================================================================================ WRAPPERS \/

include/ACGL/OpenGL/Objects/TextureBuffer.hh

@@ -92,11 +92,15 @@ private:
     void bind() {}
 
     void attachBufferToTexture() {
-        assert( Buffer::getSize() > 0 && "glTexBuffer will fail if the buffer is empty" );
-        bindTexture();
-        openGLCriticalErrorOccured();
-
-        glTexBuffer( GL_TEXTURE_BUFFER, mDataType, Buffer::getObjectName() );
+        if (mBuffer == NULL) {
+            // the buffer was in fact detached
+            bindTexture();
+            glTexBuffer( GL_TEXTURE_BUFFER, mDataType, 0 );
+        } else {
+            assert( Buffer::getSize() > 0 && "glTexBuffer will fail if the buffer is empty" );
+            bindTexture();
+            glTexBuffer( GL_TEXTURE_BUFFER, mDataType, Buffer::getObjectName() );
+        }
         openGLCriticalErrorOccured();
     }