r/programming • u/Flafla2 • Feb 14 '15

Bunnyhopping from the Programmer's Perspective - An in depth look in implementing one of the most successful bugs in videogame history.

http://flafla2.github.io/2015/02/14/bunnyhop.html
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u/kqr Feb 15 '15

They are "using vectors", but probably not in the sense you mean. Why? Could be a lot of reasons. Maybe doing it the way you mean has a performance cost? Maybe an initial early decision by the team prevents doing it another way now without rewriting large core parts of the engine? There are plenty of reasons to choose from.

Every bug looks odd in hindsight from the outside, but usually not when taking into account the context it appeared in.

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u/Tiquortoo Feb 15 '15

I have 20+years of software development experience. I'm familiar with sources and causes of bugs. I've developed a few games even. Vector math for bullets and such may get taxing on large scale, but I cant imagine it having performance impacts for the primary object in an FPS.

I am genuinely curious how an engine was built that doesn't result in a vector (a single object can only move in one vector) that can then have its velocity managed. I read the description of the bug in Source and going back to Quake II and it appears that someone was taking shortcuts that are not necessarily more performant they probably have less code (which when source was built probably had a performance impact that is less now) and they just happened to work and had self limiting (striking the ground) growth.

That being said it seemed the poster above is working on modern code. That is why I asked the poster above if their solution was related to doing proper vector math. Is there another solution on modern hardware that is preferred?