I ran a number of tests, comparing the performance of both engines.
The results were pretty interesting.
First of all, to compare the two rendering pipelines we can't just look at the FPS-es directly.
In Love, every rect has only 4 vertices whereas in AGen filled shapes are ran through a triangulator which produces 2 triangles per rectangle (6 vertices).
So, I think it's more accurate to compare the number of rendered vertices per second (VPS).
In Love VPS = 4 x rects x FPS and in AGen VPS = 6 x rects x FPS
Using the benchmark demo with moving rects I found that:
-Love levels off at about 3500 rects or 800,000 VPS. At that point, throwing more geometry in, simply lowered the overall FPS
-AGen leveled off at around 2000 rects or 600,000 VPS. This seems like a big difference but keep in mind that 2500 rects would equal Love's renderer at 800,000 VPS
So yeah, Love is faster in this case. Primitives are buffered in AGen, but this is negligible in this case since each rect has only 4 vertices so that generating them per frame doesn't cost very much. The other drawback for Agen are the background chores like world transformations for each sprite, scene graph and partitioning updates, etc.
I'll try to post the results and the new build later.
Edit: Here's a link to the new demo
, if somebody wants to check it out.
Although it's better than the last demo I posted, Love is still faster by about 200,000 vertices per second (on my machine)