how to extend states for character

Questions & Answers
1

I am working on a 2d game in unity3d (c#) with the character controlled by the arrow keys and with 2 action buttons.

My problem is simple, I can solve it, but the solution seems bit dirty to me. I am using a very simple state machine, the hero is moving in horizontal or vertical way (floor and ladder)

my current state extending is:

HeroState -> HeroStateStatic -> HeroStateMovement

Then I extend static or movement to final states:

HeroStateMovement -> HeroStateRunning or HeroStateStatic -> HeroStateLookUp

however I am always calling a huge external function (in Hero class) which decides what to do next and then switch the state

I believe I should have this reasoning within the state itself but states at ladder has different set of checks and possible choices then states at floor and I don’t know how to rework those classes to have all necessary code written just one (that’s why now is in hero and not in the states) … is there anything like cross-extending technique?

(I know how to use abstract classes and interfaces but it probably does not solve my trouble)

thanks for your help

2

You’re extending too much. Don’t extend unless you want to share code. Even then, it’s probably better to push code that all hero states can use into HeroState and just call it from the other states and not extend.

Also, to handle all your transitions within your state machine, the states need to change the state when needed:

if (jumpButtonPressed) hero.changeState(new JumpState());
OR
if (jumpButtonPressed) hero.changeState(HeroState.JumpState);

see this article for more details: State · Design Patterns Revisited · Game Programming Patterns

Also read the other patterns on the side for example the Component pattern, which unity also uses to dodge the hell of multiple object hierarchies:
http://gameprogrammingpatterns.com/component.html