Empowerment: Sliding Ninjas - The Game Maker's Companion: Game Development - page 82

Figure 4-9. The actions for the obj_solid Collision event of the Zool wall state object

22. Finally, add a Step, End Step event and include a Check Object action that checks if
there is NOT an obj_wall Object at the Relative position X = facing , Y = 0 .
23. Immediately follow this with a Change Instance action ( main1 tab) that will change
into obj_zool_air and Perform Events ( Destroy and Create ) as it does so. This makes
sure that Zool falls off the wall if it should disappear for any reason later on.
There are now a few changes we need to make to the other Zool objects to incorporate
obj_zool_wall . First, we'll add appropriate transitions to the wall state from both the air and land
state objects. Then we need to include the sprite drawing for ZSTATE_CLING and ZSTATE_CLIMB in
the parent Zool object.

Adding State Transitions and Sprite Drawing to the Wall State Object
1.

Reopen obj_zool_land and select the End Step event. Include a new Check Object
action ( control tab) that checks for the Object obj_wall at the Relative position
X = facing , Y = 0 .

2. Immediately follow this with a Change Instance action ( main1 tab) that will change

into obj_zool_wall and Perform Events ( Destroy and Create ) as it does so. This will
now make Zool automatically grab onto walls if there is a wall directly in front of him at
the end of a step.

Reopen obj_zool_air and select the End Step event. Directly below the Set Gravity
action (as part of the events grouped in the block), include a new Check Object action
( control tab). This should check for the Object obj_wall at the Relative position
X = facing , Y = 0 .

3.