I had to switch from ARBImaging.glBlendEquation() to GL14.glBlendEquation,
because ATI openGL drivers do not support ARBImaging.
I can not find the basic GL_FUNC_ADD in GL14.
I can switch to GL_FUNC_REVERSE_SUBTRACT via EXTBlendSubtract, but not back to ADD...
I think GL_FUNC_ADD plus the other basic modes should be available from GL14. (Or EXTBlendSubtract)
Currently I have to use ARBImaging.GL_FUNC_ADD, which works, but does not seem correct.
-Frostregen