Modding game code isnt that hard. Give it a try!

Before 2 weeks ago I had never attempted modding, especially changing the game code and recompiling.

It's a bit of a hurdle that some folks aren't willing to jump but trust me... it's really not that difficult.

If you cock it up at any point you just delete the mod folder and start again.

I've noticed quite a bit of coder snobbery in the HL2 modding community that can also make it difficult to get into coding. There's a general attitude of "I had to learn it so you should go through the same pain". I disagree with this. Once you've worked something out, write up a quick tutorial on it and post it to the web so that others can be saved the pain. If they're not willing to learn then fair enough... give em a little attitude.

I do understand the frustration of coders though. Young bright eyed kids hit the forums with good and bad ideas without any comprehension of how much work would be involved to achieve what they want. They often also have no desire to learn how to do the work for themselves and an expectation that coders have nothing better to do than make their dreams come true.

I'll be writing up a tutorial on beginner modding and altering code for Alien Swarm shortly.

But until then here's some assumption smashed...

Altering game code requires a knowledge of how to write c++ code!

BULLSHIT!

The majority of people who create mods and edit the game code wouldn't know how to write a new application in c++. All they do is tweak the code or cut and paste already written code from another valve game into the existing game code in order to create new functionality. You simply need a basic knowledge of the general coding concepts, structure of c++ and be willing to pull the code apart and break it down into understandable chunks.

Learning how c++ works through looking at Alien Swarm code is incredibly difficult, dont try! (as per valve SDK website)

BULLSHIT!

I would say that you'll learn a lot more from looking at code in a working application than following some tutorial that helps you print out "Hello World!" in the windows command console.

It takes an especially brainy person to understand and write code!

BULLSHIT!

I don't believe in the concept of "brainy". Anyone can do anything given time, curiosity and a clear goal. It takes a coder with experience to write good code but isn't that the way with everything. Someone who's been doing something for a long time will be better at it. That's the way of the world and everyone has to start somewhere.

So go ahead, create a mod, install Visual Studio Express 2008. Compile it, then start messing around with the variables. See what you can create!

Things wot I have learned...

Will be writing a tutorial on all I've discovered over the past two days. I've learned so much I dont know where to begin.


VPK revelations

Finally worked out why many things I changed in my mod had no effect in the game. It's all about the VPK.
The VPK files in the Swarm directory of the official game are like a big zip file. Each file in the VPK has parts spread over all of them. In order to know where each part of each file is the game refers to the GCF file. The GCF file is like a guide as to how to read the VPK files. It tells the game where to find all the bits of the file have been stored in the various VPK files.

So when you extract a file from the VPK file and place it in your mod the engine gets confused and makes some assumptions. If it finds a file in your mod directory that normally resides in the VPK then it assumes that it doesnt have to look in the VPK at all. As a result your mod will go all funny because its not finding a shed load of the files it needs.

The way around this is to change the name of the reference file the engine has to look for and then save your modded file under that name.

So for example, if I want to mod mainmenu.res I search the code for that name appearing in a particular .cpp file, change the code to look for mainmenu_mymod.res, then compile. Then I extract mainmenu.res from the swarm VPK file, make my changes and save it to my mod directory as mainmenu_mymod.res.
Now the game has no where else to look but my mod directory.

Build vs Rebuild

This is funny. I really didnt understand the difference between the Build option and the Rebuild option in Visual Studio. As a result I was hitting rebuild each time then waiting nearly an hour for my mod to recompile everything. Hit build and it will only compile the files youve changed and takes 2 mins. LOL I am a twat...