Add include

diff --git a/vv/vvBlendImageActor.cxx b/vv/vvBlendImageActor.cxx
index 24434d14bb0b9623f84ee32f5eb4030eb3f5387b..77ae059723db66360a7cfcdd65d22b096aa68d3d 100644 (file)
--- a/vv/vvBlendImageActor.cxx
+++ b/vv/vvBlendImageActor.cxx
@@ -21,6 +21,7 @@ It is distributed under dual licence
   #include <vtk_glew.h>
 #else
   #include <vtkgl.h>
+  #include <vtkOpenGLExtensionManager.h>
 #endif
 #include <vtkOpenGLRenderWindow.h>
 #include <vtkOpenGLRenderer.h>