Player (244)
Joined: 8/10/2008
Posts: 113
$57C together with $57B indicate Bart's position in the level. 0 is the very left of the level. As you move to the right, $57B will increase. When it changes value (cycles/loops or whatever you like to call it) from 0xFF to 0, $57C increases by 1. In the jonk level, the very right of the level is $57C=5. The other way of looking at position is to use where the screen is located in the level and then add the player's position on top of that. That's what $54 and $56/$57 are used for. $57B is calculated as the value of $54 added to the value of $56. I can see that the game can become messy when poking these values. My guess is that the actual graphics are controlled by another mechanism. So if you want to teleport Bart around a level, you would need to make sure the graphics, the window position and Bart's own coordinates match. Or else it will look like he's outside the game's geometry. I'm not sure I can help you with this. I'm not sure where the confusion for $575 comes from. It's essentially the x sub-pixel. It's calculated by adding the x-speed ($573) to whatever is already stored in $575. When it cycles, Bart gains an additional pixel in the x-direction. If you're on the ground and release the d-pad, it's reset to 0 though. Most games I've seen keep the sub-pixels when you stop moving, but that's of course a choice entirely up to the game designers.
Editor, Active player (400)
Joined: 2/11/2018
Posts: 193
Thanks. I tried unsystematically throwing myself into walls in the ice cave but didn't get anywhere. I did give the genetic algorithm bot a go though and it helped me get through the very first section of the level. I'm on the small climbing platforms now, and need to figure out the fastest way to turn around on them. Would be good if I could bot that too, but it doesn't seem to be getting any results. If I can get that then the rest of cave should be quite simple.