Great read! I'm a web developer but I play the hell out of video games. I really liked how the author explained what effects you're trying to mitigate in the collision detection algorithms. It instantly put it into a very clear and familiar context for me - I haven't programmed under these conditions, but I've definitely played games and seen silly things like this happen:

>This will prevent characters from “popping” through the slope from the opposite side.

>If you don’t ensure this, the player will move horizontally right off the ramp for a while, until gravity catches up and drags him down, making him bounce on the ramp, instead of smoothly descending it.