Making RPG events

From Spheriki

Events in RPGs aren't that hard to make really.

We can have a linear event system like this:

var current_event = 0; // global variable

And whenever you refer to any events in the game, you do:

switch (current_event) {
  case 0: 
    /* code */  
  break; 

  case 1: 
    /* code */ 
  break; 

  default: 
    /* code */ 
}

Say you were talking to someone in a town...

function TalkToJim() 
{ 
  switch (current_event) 
  { 
    case 0: 
      ShowText("Jim:\n\"If you're considering going after Freddy...\nYou'll need a sword.\""); 
    break;

    case 1: 
      ShowText("Jim:\n\"Good luck in finding your friend!\"");
    break; 

    default:
      ShowText("Jim:\n\"I'm glad Freddy is safe now.\""); 
      // Jim refuses to give any more helpful information beyond event one :) 
  }
}

And whenever you complete an event with this system you'd do:

++current_event;

e.g.

function OnRescueFreddy() 
{ 
  ShowText("Freddy:\n\"Thanks for saving me from that bush fire there...\"");
  FollowPerson("Freddy", GetInputPerson(), 16); // Freddy (the sprite within the map) now follows you 
  ++current_event; // on to the next event in our linear game! 
}

The problem with this kind of event system is you end up having to have things like:

function OnRescueFreddy() 
{ 
  if (current_event != 1) { 
    ShowText("Freddy:\n\"You cannot rescue me yet, dang.\""); 
    return; 
  } 

  ShowText("Freddy:\n\"Thanks for saving me from that bush fire there...\""); 
  FollowPerson("Freddy", GetInputPerson(), 16); // Freddy (the sprite within the map) now follows you 
  ++current_event; // on to the next event in our linear game! 
}

So maybe we should try a not so linear system?

var event = new Object(); 
event.buy_a_sword = 0; 
event.rescue_freddy = 0; 
// etc

Jim would change to be something like:

function TalkToJim() 
{ 
  if(event.buy_a_sword == 0 && event.rescue_freddy == 0) {
      ShowText("Jim:\n\"If you're considering going after Freddy...\nYou'll need a sword.\""); 
  } else { 
    if (event.buy_a_sword == 1) 
      ShowText("Jim:\n\"Good luck in finding your friend!\""); 
    else 
      ShowText("Jim:\n\"You rescued Freddy without a sword?!\""); 
  } else {
      ShowText("Jim:\n\"I'm glad Freddy is safe now.\""); 
  }
}

And OnRescueFreddy() would become:

function OnRescueFreddy() 
{ 
  ShowText("Freddy:\n\"Thanks for saving me from that bush fire there...\""); 
  FollowPerson("Freddy", GetInputPerson(), 16); // Freddy (the sprite within the map) now follows you 
  event.rescue_freddy = 1; 
}

Now, I did event.rescue_freddy = 1, but I could have done: