Just finished this thing today, happy with the result
How'd you get that effect? I'm really curious.
I would assume you linked the player's X coordinate to the alpha value of a layer, but that would mean that if they went backwards the effect would reverse? It's really neat though.
Pretty much. Each portal object has a destination portal and a direction. The portal will render whatever is inside the destination portal (minus the portal itself) to a framebuffer (which I guess is analogous to a surface in game maker), then render that to the area it takes up. The alpha for a right-side portal depends on how close the player is to the right side, and same thing for a left-side one. It teleports you to the destination portal when you're in the center, so you have to mess with the alpha values to keep it from "jumping" when you have a transition between a dark and light scene like that.
The portals take up the entire screen and fade out to the left or right, so they kind of conveniently match up with a bit of tweaking.
