PS: For those interested, programming in OpenCL-OpenGL is way harder, painful and slower(in developer time) than in the CPU.

In particular, you extract all the performance in OpenCL from knowing how to manage memory. We talk about orders of magnitude difference(100x-200x times faster).

This memory management is hell for anybody trained with garbage collectors, Object oriented constructors and so on. It is way harder than pure c and the feedback loop is way longer(unless you invest a lot in hardware).