Rogues’ Rendezvous: Vertically Sliced - The Game Maker's Companion: Game Development - page 280

8. Open obj_flynn_wall and edit the End Step event. Change the line at the start of the

action that reads:

if( place_meeting( x+facing, y, obj_wall ) != true )

to:

if( is_climbable( facing, 0 ) != true )
9. Still in the End Step event of obj_flynn_wall , remove the middle two lines (plus the
comment) that cope with Flynn extending too high above the top of the wall (by
making him slip down). Happily, this situation can't happen anymore as there has to
be a wall at Flynn's hand position in order for is_climbable to return true .
10. Next, change the last line that sets image_index to 0 so that it sets image_speed to 0
instead. This will stop Flynn from snapping back to the first frame of the animation
each time he stops climbing. Stopping the speed will bring the animation to a halt on
its current frame instead, which looks more natural.
11. Edit the Begin Step event for obj_flynn_wall and add the following line directly above
the line that defaults the state to FSTATE_CLING .

if( state != FSTATE_CLIMB_TOP )

This prevents the state from being changed back to clinging when the climbing up
animation has started. It's also worth indenting the line after it to keep things tidy.