nesdev.org

psycopathicteen wrote:The bubbles also collide with other bubbles.

Yes, that's just more collision tests that can really take advantage of a collision acceleration structure.

rainwarrior wrote:You test for collision with an 8x8 grid by dividing the coordinate by 8 (i.e. right shift by 3), and looking up a value stored by that index.

Okay, that makes more sense. I thought it seemed unnecessarily crazy, but I didn't really try to imagine what advantage it could possibly have. I assumed everyone was making fun of it because it simply used multiple bounding boxes for each bubble, in which case it would indeed have been horrendously inefficient.

It's usually a good rule of thumb that if a programmer has done something definite and relatively complicated that required thought and planning (as opposed to, say, a jump instruction targeting the address immediately following itself, which reportedly does also occur in Gradius III and is probably a methodological artifact of some sort), they probably had some reason to think it was a good idea, and ridiculing them without thinking it through is unwise.

Chesterton's Fence, basically.

...

Now, if it turns out it does use bounding box tests on all of those "occupied" grid cells... well, then we can probably make fun of the devs.

I need to reread the code again. There must be some reason the bubble stage lags more than the Squidward's house Easter Island head level.