• Advertisement

C# Managing Item Decay In Turn Based Survival

Recommended Posts

So I am building a survival / roguelike? (not sure of the "real" definition of that but the game has perma-death, randomly / procedurally generated worlds, etc.) and I am starting to prototype item decay. Let me example how the turn based system is currently simulated as that is probably important for this discussion.

The way the turn based simulation works is there is a singleton GameActionManager object that keeps track of the action units that have pasted since the being of the game. 1 action unit = 1 second in the game and generally this is progressed from the the player performing an action. When the player does anything that has an action unit cost associated with it, it calls a method on the GameActionManager to increase the current action units. The other things the GameActionManager exposes are methods to register / unregister "event listeners" (currently using delegates). When the GameActionManager increases the action units, it notifies all of these listeners so the can perform the right action (like a burning tile decreasing the health of the structure that is burning, an enemy can move toward or attack something, etc.).

I am also only simulating a small portion of the world at a given time since well, the world eventually will be huge and well computers can only do so much. My current goal for the simulated area is 120 x 80 tiles (with is a total of 9600 tiles). So as the player moves, game entities (enemies, structures, items, etc.) come in and out of the simulation area (and register / unregister with the GameActionManager). With this size in mind, none of the things that currently attach listeners to the GameActionManager has the chance of getting big enough to have me think that I really need to think about an alternative solution for when it becomes an issue because I don't see it becoming an issue any time soon (at least at the current stage of development). Items however is a different story.

The game is going to have a ton of different items and 1 or more items can be on any tile. If each tile averaged 2.5 items (which I will grant you seem ridiculous but I always think crazy extremes when it comes to this kind of thing), that would be close for 25000 items that would possible have to manage decay. So instead of having each item attach a "listener", since the action for managing decay is going to be exactly the same thing for each item (just a method call), I figured having 1 listener that knows about all the items would be better.

The general approach that I am taking for this first prototype is to have a singleton manager class (lets call it ItemDecayManager). Any time a item that has decay come into the simulated area, it would register itself with the manager and when it leaves the simulated area, it would unregister itself (which would just add and remove itself from a private List the manager is maintaining). Any time the action units are increased, the ItemDecayManager's listener on the would fire and just loop through the List of registered item and just perform the required function call.

I have done some crude benchmarking and it currently can handle 100000 items at which point it starts to have a little effect on the FPS (but still around 80) even when moving about 15 times per second (and each move causes an action unit increase). Also bear in mind these numbers of from running the game in the Unity editor which has a bit of extra overhead that running the real game build not not have.

While I am going to run with this solution for now I want to throw out this idea and get any kind of feedback i can because I imagine when more is happen as the action units increase (and even imagining the process for managing decay become more even just slight more complex than the current simple calculation), this solution might not hold up and I would like to have so ideas ready for the situations. I also think of anything that is going to be simulation, this is going to be the first things to have issues  from the shear number of items that could be in the simulation area.

Thanks in advance for any and all comments.


Share this post

Link to post
Share on other sites

Try to determine the absolute maximum number of items that might realistically occur in the typical game session (be generous), then increase it by 10%. Benchmark for that number of items, and if it performs acceptably then move on. Don't worry about optimizing for the "crazy extremes" cases. (I have a hard time believing that 100000 items is anywhere in the neighborhood of realistic; no player has time to sort through that amount of stuff.)

Share this post

Link to post
Share on other sites

Is it actually necessary to simulate all the intermediate ticks of decay, or do you only care about the end result?

For example, let's say the player lights a barrel on fire, walks away for 20 minutes, and walks back. Is it important that you simulated 1,200 discrete action units, or is it only important that the barrel has taking 1,200 points of decay (and presumably has long since been destroyed)?

If the latter, then there is no need to actually simulate anything beyond the viewing radius of the player. Just record the timestamp/turn on which a status effect (like burning) was applied to a given object, and stop updating it once the player can't see it anymore. If the player wanders back, you can just update the state based on the timestamp.

This can work fine even for broader effects, such as fire that spreads over time. As long as you know where the fire was lit, and how long it has been, you can put an upper bound on the extent of the fire, and only need to update individual items when that extent intersects the player's viewing radius.

TL;DR: processor cycles are valuable. If the player can't see a thing, might as well not perform detailed simulation of it.

Share this post

Link to post
Share on other sites

My advice is to think of how far a person could be and see the item. That amount of steps *2.5 will allow the person to pick it up if they want it. If they don't want it, it should decay.

Share this post

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Advertisement
  • Advertisement
  • Popular Tags

  • Advertisement
  • Popular Now

  • Similar Content

    • By Florencia Sylvester Anelli
      Hi everyone! I've developed a game called The Last Dog (ZOMBIES + DOGS) and was wondering if you could give it a try in order for me to analyse your behaviour in analytics. Give it a shot! Please download it here: https://florsyl.wixsite.com/thelastdog2 and let me know if you detect any bugs. VIDEO.3gp

    • By Manuel Berger
      Hello fellow devs!
      Once again I started working on an 2D adventure game and right now I'm doing the character-movement/animation. I'm not a big math guy and I was happy about my solution, but soon I realized that it's flawed.
      My player has 5 walking-animations, mirrored for the left side: up, upright, right, downright, down. With the atan2 function I get the angle between player and destination. To get an index from 0 to 4, I divide PI by 5 and see how many times it goes into the player-destination angle.

      In Pseudo-Code:
      angle = atan2(destination.x - player.x, destination.y - player.y) //swapped y and x to get mirrored angle around the y axis
      index = (int) (angle / (PI / 5));
      PlayAnimation(index); //0 = up, 1 = up_right, 2 = right, 3 = down_right, 4 = down

      Besides the fact that when angle is equal to PI it produces an index of 5, this works like a charm. Or at least I thought so at first. When I tested it, I realized that the up and down animation is playing more often than the others, which is pretty logical, since they have double the angle.

      What I'm trying to achieve is something like this, but with equal angles, so that up and down has the same range as all other directions.

      I can't get my head around it. Any suggestions? Is the whole approach doomed?

      Thank you in advance for any input!
    • By devbyskc
      Hi Everyone,
      Like most here, I'm a newbie but have been dabbling with game development for a few years. I am currently working full-time overseas and learning the craft in my spare time. It's been a long but highly rewarding adventure. Much of my time has been spent working through tutorials. In all of them, as well as my own attempts at development, I used the audio files supplied by the tutorial author, or obtained from one of the numerous sites online. I am working solo, and will be for a while, so I don't want to get too wrapped up with any one skill set. Regarding audio, the files I've found and used are good for what I was doing at the time. However I would now like to try my hand at customizing the audio more. My game engine of choice is Unity and it has an audio mixer built in that I have experimented with following their tutorials. I have obtained a great book called Game Audio Development with Unity 5.x that I am working through. Half way through the book it introduces using FMOD to supplement the Unity Audio Mixer. Later in the book, the author introduces Reaper (a very popular DAW) as an external program to compose and mix music to be integrated with Unity. I did some research on DAWs and quickly became overwhelmed. Much of what I found was geared toward professional sound engineers and sound designers. I am in no way trying or even thinking about getting to that level. All I want to be able to do is take a music file, and tweak it some to get the sound I want for my game. I've played with Audacity as well, but it didn't seem to fit the bill. So that is why I am looking at a better quality DAW. Since being solo, I am also under a budget contraint. So of all the DAW software out there, I am considering Reaper or Presonus Studio One due to their pricing. My question is, is investing the time to learn about using a DAW to tweak a sound file worth it? Are there any solo developers currently using a DAW as part of their overall workflow? If so, which one? I've also come across Fabric which is a Unity plug-in that enhances the built-in audio mixer. Would that be a better alternative?
      I know this is long, and maybe I haven't communicated well in trying to be brief. But any advice from the gurus/vets would be greatly appreciated. I've leaned so much and had a lot of fun in the process. BTW, I am also a senior citizen (I cut my programming teeth back using punch cards and Structured Basic when it first came out). If anyone needs more clarification of what I am trying to accomplish please let me know.  Thanks in advance for any assistance/advice.
    • By Yosef BenSadon
      Hi , I was considering this start up http://adshir.com/, for investment and i would like a little bit of feedback on what the developers community think about the technology.
      So far what they have is a demo that runs in real time on a Tablet at over 60FPS, it runs locally on the  integrated GPU of the i7 . They have a 20 000 triangles  dinosaur that looks impressive,  better than anything i saw on a mobile device, with reflections and shadows looking very close to what they would look in the real world. They achieved this thanks to a  new algorithm of a rendering technique called Path tracing/Ray tracing, that  is very demanding and so far it is done mostly for static images.
      From what i checked around there is no real option for real time ray tracing (60 FPS on consumer devices). There was imagination technologies that were supposed to release a chip that supports real time ray tracing, but i did not found they had a product in the market or even if the technology is finished as their last demo  i found was with a PC.  The other one is OTOY with their brigade engine that is still not released and if i understand well is more a cloud solution than in hardware solution .
      Would there  be a sizable  interest in the developers community in having such a product as a plug-in for existing game engines?  How important  is Ray tracing to the  future of high end real time graphics?
  • Advertisement