add the linear search implementation from matlab library
add timing info
realize the access to global memory block is slower. Use a new local memory implementation for root search. Speed is drastically improved.
before eliminate the function InterpolateTexture. Realize it is too slow to call the function
Commented the function InterpolateTexture and move the root searching algorithm into the parent function.
implemented the vectorization of the loop for the sources. want to try vectorization of the loop for the time now..
give up vectorization of the loop for the time for now, as it is almost real-time and the recursive function call is not easily vectorizable.
before adding a compare branch for changing the main_v3 for openfoam