Well, if you wanted that, you could position the ego and set ego_dir to 3 or 7. That would cause him/her to move in the direction of the conveyor.
You could also use the green signal line to be right and blue water line to be left.
if(ego_touching_signal_line) {
ego_dir=3;
}
etc.
Then, if you wanted to have him jump, you could detect the player pressing up, and switch to a view of him jumping (pad the bottom of the cels with space, so he's still in the same Y-axis to make your book-keeping easier.). This could also set a jumping flag. That way, if he comes across something nasty on the conveyor, if the jumping flag is set, it will ignore the nasty thing.
if (ego_dir==1) {
set(jumping);
set.view(ego,jumping);
end.of.loop(ego,done_flag);
ego_dir==3;
}
if (done_flag) {
reset(jumping);
set.view(ego,normal);
}
Something like that, and a similar structure for ducking. If you want gravity, then you could try making no signal or water lines set the ego_dir to 5 with the appropriate falling animation, and suspension of jumping and crouching.
