Since JDK 5 the OGL-based Java2D pipeline has provided acceleration for GradientPaint
and TexturePaint, but only when antialiasing is disabled. We should be able to marry
that code with our existing OGLMaskFill code (which currently only handles single
Color antialiased fills) in order to provide acceleration for antialiased
Gradient/TexturePaint fills, as long as the GL_ARB_multitexture extension is
available.