Transport Tycoon Forums

Brumi wrote:Hi all,
Recently I've been trying to make an AI on my own. My (far-to-achieve) ambition is to make some sort of remake of the old AI, I think that should be quite easy compared to building a really intelligent AI.
I'm a real amateur in programming, I use the library pathfinder according to the guidelines at http://wiki.openttd.org/AI:RoadPathfinder. In fact, I just copied the code.
So, my questions:
1) Is there some way to add a penalty for road-rail level crossings without modifying the code of the pathfinder?

3) How do you know that the pathinder failed to find a path? Is it OK to add a time limit?

I hope I will be able develop the AI for some alpha-release. Currently it chooses a service completely randomly, builds the two truck stations and then connects them todether. The next step for me is to build and start the vehicles. Of course my biggest problem will be exception handling, currently there is almost none.

Brumi wrote:1) Is there some way to add a penalty for road-rail level crossings without modifying the code of the pathfinder?

Brumi wrote:2) I noticed that my pathfinder is slow compared to other AIs that use the library pathfinder (for example, Convoy and TransAI). So, is there some way to make the pathfinder faster? (again, without modifying the library code) I don't mind if the pathfinder doesn't find the optimal route.

Brumi wrote:3) How do you know that the pathinder failed to find a path? Is it OK to add a time limit?

Wiki wrote:FindPath returns false if it isn't finished with pathfinding. When it's done, it returns either the path it found or null to indicate no route exists.

local counter = 0;
local path = false;
//MAXIMUM_PATH_TRIES is a constant declared in main.nut
while (path == false && counter < MAXIMUM_PATH_TRIES) {
  path = pathfinder.FindPath(100);
  counter++;
  AIController.Sleep(1);
}

if(path == false){
    //Did not find path in time
}
if(path == null){
    //Could not find a path
}

Xander wrote:It's perfectly fine to add a timer. I do the following:

Yexo wrote:

Xander wrote:It's perfectly fine to add a timer. I do the following:

I hope that's not a copy/paste of your code, since you never update counter.

Brumi wrote:Thank you both.
Currently I can't promise anything, but I will try my best I'll be studying IT from September and I hope that won't take away all my time, instead it should help a lot (I hope we will learn about A*, I'm really interested in that, but the page on Wikipedia is still very high-level for me).

Xander wrote:ICT or Computer Science? What level (university or high school)?

Brumi wrote:1) Is there some way to add a penalty for road-rail level crossings without modifying the code of the pathfinder?

import("pathfinder.road", "RoadPathFinder", 3);

class MyRoadPF extends RoadPathFinder {}
function MyRoadPF ::_Cost(path, new_tile, new_direction, self)
{
   local cost = ::RoadPathFinder._Cost(path, new_tile, new_direction, self);
   if (AITile.HasTransportType(new_tile, AITile.TRANSPORT_RAIL)) cost += your_cost;
   return cost;
}

local pathfinder = RoadPathFinder();

local pathfinder = MyRoadPF();

Roujin wrote:hurray for inheritance