Omar Emara
5ee116d448
This patch implements the Simple Star Glare node. This is only an approximation of the existing implementation in the CPU compositor, an approximation that removes the row-column dependency in the original algorithm, yielding an order of magnitude faster computations. The difference due to the approximation is readily visible in artificial test cases, but is less visible in actual use cases, so it was agreed that this approximation is worthwhile. For the future, we can look into approximating this further using a closed form IIR recursive filter with parallel interconnection and block-based parallelism. Which is expected to yield another order of magnitude faster computations. The different passes can potentially be combined into a single shader with some preprocessor tricks, but doing that complicated that code in a way that makes it difficult to experiment with future optimizations, so I decided to leave it as is for now. Differential Revision: https://developer.blender.org/D16724 Reviewed By: Clement Foucault