Entries for September 2010

One of the things that I've been wanting for WheelMUD is the ability to have automated source drops. I thought about this a bit, and here is the plan on how to tackle this. This is a 4 phase task.

Phase 1 - Weekly source drops

This will be done manually by me. I have the basic script for this task done already.

Phase 2 - Custom DotNetNuke (DNN) module

I want this module to search an Amazon S3 bucket for the last X files. This will help to keep the size of the website backups relatively small.

I will be moving the weekly drops to this module, and will have the ability to automate the drop. I will use the same script from phase 1, and modify it to post to the Amazon S3 bucket.

Phase 3 - Nightly source drops

Will need to create a new bucket. Will use a copy of the script in phase 2 and change the drop path to the new bucket.

Add functionality to the custom DNN module to integrate with Subversion; ie last revision number and check-in descriptions.

Phase 4  - Continous source drops

New Amazon S3 bucket for build script. Update the functionality of the DNN module.

I'm finally getting around to doing code spikes with NCalc and RuleSets. I created a quick throwaway app to test a simple formula.

Notice the brackets around DieRoll and ST. Those denotes an NCalc parameters. The parameters work a lot like ADO.NET. Here's the snippet that actually does the hard work:

var exp = new Expression(txtFormula.Text);
exp.Parameters["ST"] = int.Parse(txtST.Text);
exp.Parameters["DieRoll"] = dieTotals;string result = exp.Evaluate().ToString();

This formula is a GURPS Lite success roll. Since this is a boolean formula, you will get True or False. You can change the formula or the values and re-evaluate the formula without having to restart the program. That is pretty cool!

Now that I have an idea of how this works, I will next move on how to do this dynamically. In the context of NCalc, RuleSets look like will need some very clear definitions. I'm guessing that there will have to be a table that will have one row for the formula, and another row that contans a list of parameters with some sort of separator (undetermined at this point). I sat down with my brainstorm notebook, and I came up with ToHitFormula, DamageFormula, InitiativeFormula, and several others. These, and some more, will be the required rules. I haven't figured out to do custom rules yet. So far, I see that this setup will allow for a LOT of flexibility. You should be able to edit these formulas in game, without having to reload the game.

I've included this solution in a zip file. This is a Visual Studioi 2010 solution. I'm pretty sure some of you will want to play with this.

I've been exploring options for people to host their own WheelMUD muds on 3rd party servers. I believe I found a viable alternative... Amazon Elastic Compute Cloud, better known as Amazon EC2. Amazon just introduced a low cost, low traffic option to run Windows Server 2008 images. MUDs are low traffic applications, so their new Micro On Demand Instances are perfect for this. Their pricing is about 3 cents an hour. There's 4 regions where you can run your intances; North Virginia (East Coast), North California (West Coast), Ireland (Europe Region), and Singapore (Asia and Oceania Regions). The pricing page is here.

There's a caveat for Micro instances. Amazon does not save the data once the instance is terminated. You will need to create a volume (image of a hard drive)  in their Elastic Block Storage (EBS). The cool thing is that there is an API for all their services, which can be done from various languages, including .NET.

If anybody is interested, I'll be willing to create a tutorial on how to create one of these instances. I know that some people still think that this is way too much work. I'm exploring the posibility of creating a hosting platform specific for WheelMUD.