That's the problem I think. He's changed from a shared pixel memory in the reference design to a non shared one in his HW accelerated design. That's the impression I get from the diagrams.
It's somewhat moving the goal posts IMO. Guess it's ok since it's a student project.
Pixels are mapped to memory locations, but they don't have to be, if you can access the map directly. I don't exactly know what I'm talking about here, just a thought.
What would be the difference between writing to shared hardware pixels over a shared memory performance wise?
I mean, pixels are just like a memory except that they glow. They hold their value and can be writen a new value in sync with a clock (which is normally 60 Hz for most monitors which is MUCH slower then on chip memory). There could be no performance benefit.
The pixels exist in a shared memory, do they not?