Monkey Game Development: Beginner's Guide

Since you are reading this book, we can safely assume that you have got the bug that makes a lot of people want to become a great and successful game developer. We have all played these awesome games and read stories about individuals who became wealthy overnight by selling their games on markets such as the Apple AppStore. And you want that too, right? We all do, and there is nothing wrong with that. Go for it! The way to get there was very difficult and long, in the past. For example, not long ago, learning Objective-C and using Xcode was the only way to create a game for the iPhone. Objective-C is not easy to learn if you are a complete beginner when it comes to programming. And a lot of people will tell you to study C and C++ in general before you head into Objective-C. Some people will tell you to study the BASIC language at first. You can imagine that it will take some time to study all this, never mind studying the techniques that are relevant to game development!

Now, with Monkey and various other game creation tools, this process has become much easier and quicker than before. A programming language that is based on a BASIC dialect is easy to learn and the features of Monkey will help you bring your dream of becoming a game developer to life.

Ahh, the magic term... cross-platform development! It is the current hype thing. Because before the era of smart phones and tablets, the Windows platform, OSX and Linux were basically the only markets, where an individual game developer could publish games to. Game consoles were accessible only to huge game development companies with a lot of financial background.

Even these days, it is almost impossible to publish a game for an individual on some platforms. But new markets have arisen and new development tools such as Monkey are available now. Today it is more and more important to target several platforms with your game.

Why miss out on the money that can be made and the extra exposure for your game? There are so many markets to cater to, such as Apple AppStore, Android Market, and others, that it would be silly to throw away the opportunity to publish on them and rake in the extra cash. So, a cross-platform development tool such as Monkey is worth its weight in gold, and you will realize this very soon.

Under the hood, Monkey is a translator. That means it will translate your program, which is written in the Monkey programming language, into source code for the supported target languages. And because of this, your program will be able to run on various platforms, such as iOS, Android, XNA, OSX, and Windows.

After Monkey has translated your program into source code for a certain target platform, it will then utilize native tools and SDKs (Software Development Kits) on these platforms to finish the compilation and linking process. For this, you will need to install various tools and SDKs. For example, you need to install Xcode and the iOS SDK to create iPhone apps. Or, to create a Flash app, you need to install the Flex Actionscript compiler.

The following illustration shows the process of creating an application with Monkey:

Don't worry about installing any of these SDKs and other tools for now. We will go through this together. Your default installation of Monkey can always export to HTML5 . To play HTML5 games, the only tool you need to have installed is a current version of an HTML5-compatible browser, such as FireFox, Safari, Chrome, or Internet Explorer.

Every good toolman has a good toolbox. Monkey's toolbox is small but well-equipped. It is basically a combination of two tools and some accessories. The first tool is TRANS, the source code translator. It is responsible for transforming/translating your Monkey source code into code, which can be compiled for each target platform. Basically, you feed it with one programming language and it spills out your code in a different programming language.

The second tool is Monk, the in-built source code editor for Monkey. You can also use other code editors as well, but we will work with Monk in this book, and it wouldn't hurt for you to do the same. A great benefit is that your Monkey installation includes all the source code for the tools, modules, and other stuff. So, if you happen to own a license for BlitzMAX (another programming language) and know what you are doing with it, then you could add features to Monk yourself or change it according to your needs.

The same thing goes for TRANS; you could change it as per your needs. The good thing is that you don't need another programming language. TRANS is self-compiling.

The accessories are Monkey's source code modules. They provide you with all the needed functionality for your games. We will learn more about this module, later on.

I guess it is time for the first action. If you haven't already installed Monkey, then you should do so now.

Head over to the Monkey website at http://www.monkeycoder.co.nz and grab your copy of Monkey. This book is based on the full version, so you should get that. Of course, you have to buy it first, but you won't regret this investment. And keep in mind that it is only a one-time investment. Other game creation tools are only available through subscription price models which can become very costly later on. It is not so with Monkey; you buy it once, and then you never have to pay for it again.

Ok, let's go and get it:

Please welcome… Monk

Yes, here it is. Monk. Monkey's very own code editor.

This is the place where most of the magic will happen. The magic you will create—your own games. Your own awesome games. You still want to do it, right? Ok, then let's carry on.

When it comes to writing your Monkey code, you won't need anything else. There are other source code editors you could use to code your games with, but this book will utilize Monk for all the coding action.

How Monk works and which tools it provides you with, for your development, will be explained in Chapter 2,Getting to Know your Monkey — a Trip to the Zoo.

MSERVER—Monkey's own web server

Since Version 39, Monkey has been shipped with its own HTML server. This was necessary as certain operations required some security rights for actions such as writing the app state within an HTML app. When MServer starts, you will see a window such as the following:

Later on, when you let an HTML5 game run via Monk, MSERVER will provide you with useful information for certain actions of the game.

Now that you have this task out of the way, close Monk again. Why? Because we should first see what kinds of games you could create, and then get familiar with Monkey and its feature set.

Game developers should always play other computer games, not only to have fun but also to study them. When you play a game, try to analyze how it could be done; how a certain feature affects gameplay. Or look at the technical aspects of a game, such as what kind of graphic effects a game uses, how the game rewards the player, and so on. You can get so much information out of a game, that it really can help you become a better game developer and designer.

And to get a better picture of Monkey's abilities, you should take the time now to play some games that have already been created with Monkey. As two of Monkey's target platforms are HTML5 and Flash, we can do this inside your browser.

Just make sure you have installed Internet Explorer 9, Firefox 4, Safari, or Google's Chrome browser. Chrome seems to feature the best performance when it comes to HTML5, but it is up to your personal preference.

Ok, head again to Monkey's website, and from there into the apps section. Have a look and play the first game we want to try.

Pirate TriPeaks is a solitaire kind of card game. You can find it at http://www.monkeycoder.co.nz/Community/topics.php?forum=1059&app_id=59.

The gameplay is easy, features nice animations of its graphics, and has some good sound effects. You have to click on matching cards to have them removed onto the open stack on the right. Also, you can click on a hidden card on the left stack to have it flip over and be visible on the right stack. The round ends once all cards from the left side are gone or in the event of removing all cards lying out in the open.

Play a few rounds and try to see what kind of gameplay or visual features make Pirate TriPeaks special.

Next stop, Surviball. You can find this awesome game at http://www.monkeycoder.co.nz/Community/topics.php?forum=1048&app_id=48.

This game kind of looks a bit like the old Marble Madness. Your goal there is to move a marble through a parcour filled with obstacles, ramps, and enemies. In Surviball, you have to direct a marble over a difficult course filled with tiles that give your marble a good speed boost, when sometimes that is not what you need at that very moment.

When you play Surviball, try to pay attention to the controls and the graphical effects.

Ok, so you want to create the next Diablo game, or another Star Craft. Do yourself a favor and take a step back; better, take 10 steps. Each of these games was created by an army of people. We are not talking about five to 10 people. Multiply these figures by 10 or 20 and the result will give you a good estimate of how many people are working on titles like the ones I have mentioned.

The games we have just played were created by individuals. They did the graphics, the sound effects, and the coding, all on their own. So when you start game development, set a small goal. The most important aspect for a game developer is to finish projects. Go for something that you can finish easily and in a short period of time. There are thousands of wannabe game developers out there who have never had something released in their whole career. You will definitely agree that someone who has never finished a game project can't call themselves a game developer.

There will be a time when you will be participating in some online communities, mostly regarding game development. And of course, you will ask questions. Sometimes they will be good ones, but also sometimes questions about things that you could have figured out on your own. If other people see this, it could happen that you will get told to read the manual/instructions first before asking. Do yourself a huge favor and do just that, as it is rule number one. For every tool you use, read the instructions first. It can be dry and boring sometimes, but don't skip that task. It might come back to you, if you don't. When it comes to Monkey, it ships with a good-sized documentation. Monkey's creator and some helpers took quite some time to create the documentation. You will find information about Monkey's language, the specific modules of Monkey, and also two nice little tutorials to get you started. You will find all this when you open Monk and click on the Docs tab of the coding area.

When you are done with this, come back to this book and we will go over what you have seen. So go... now

The Monkey standard modules

Modules are a huge part of the concept of Monkey. Besides the general language features, other commands are added to Monkey, via modules. They are written in Monkey code and maybe native code (C++, JavaScript, and so on). These modules either provide new commands and/or interface with commands from external native code, so you can use them in your game. In the following text, we will see what they are good for. It won't be a detailed explanation of how they work; only what you can do with them.

For more information on modules, please look into the Monkey documentation within the Module Reference section.

Lang

The lang module adds basic features to Monkey, such as Print, different data type-related handling functions, and one of the most important features, objects—the base for Monkey's class implementation. Here is a short code example:

Function Main()
Print ("Hello World")
End

Lists

If you know the concept of linked lists, this module provides something that will be familiar to you. If not, Wikipedia has a good explanation at http://en.wikipedia.org/wiki/Linked_list.

A list is a data container that lets you store something, from the same type of object as a node, inside memory. The list supports easy addition and removing from objects. You can iterate through the list of nodes in each direction. Another nice feature of a list is that you can convert it to an array of strings. To find a specific node inside the list, you need to iterate through the list, node-by-node, till you find the one you need.

Here is a small code example for a list in Monkey, without further explanation:

Function Main()
'create a new list
Local myList:=New StringList
'add some data
myList.AddLast "first entry"
myList.AddLast "second entry"
myList.AddLast "third entry"
'iterate through a list with an EachIn loop
For Local item:=Eachin myList
Print item
Next
End

Map

A map data container is similar to a list, as it is built from nodes too, and you can iterate through them. And node of a map is a pair of a value object and a key object. This key can only exist once. With it, you can retrieve the corresponding value very fast. If you need to find elements of a data container very fast, choose a map over a list.

The following image shows how map nodes have a relationship with each other. In a list, there is always a pre and post node from a current one. In a map, nodes have a loose relationship with each other. That means that you CAN iterate through a map, like you can with a list, but the real strength comes from searching nodes with the corresponding keys. So when you add a node to a map, this node will be placed inside a pool of nodes.

That is shown in the following screenshot with with Node 6. Knowing their keys, you can retrieve the corresponding data very very fast.

Here is a small code example with no further explanation:

Function Main()
'Define a string map with a string key
Local myMap:= New StringMap<String>
'insert entries
myMap.Insert("First","First entry")
myMap.Insert("Second","Second entry")
myMap.Insert("Third","Third entry")
'Print all entries
Print (myMap.Get("Third"))
Print (myMap.Get("First"))
Print (myMap.Get("Second"))
End

Math

Almost each game needs something to be calculated. The Math module provides a good set of mathematical functions for your game developing needs. Here is a nice example where the Sin function is used:

Function Main()
Local pi:Float
pi = 3.14159265
Print (Sin(pi))
End

Random

Since our game should not always run in the same way as the last time we played it, we need some randomness in it. The random module provides functions just for that—to retrieve random numbers. The following code is a little example of how to retrieve a random number:

Function Main()
'Retrieve a random number and print it inside the console
Local r:Float = Rnd(10,100)
Print (r)
End

Set

A set stores objects. It is like a shoebox that you can store your toy cars in. Like lists and maps, you can iterate through them. The difference from a list is that the objects in a set can only exist once in it. No matter how many times you add an object to it, the set will contain it only once. So it is good to keep track of a number of objects.

In the next example, you will see that the same entries won't be stored inside the set:

Function Main()
'create a new set
Local mySet:=New StringSet
'Add entries
mySet.Insert("First")
mySet.Insert("Second")
mySet.Insert("Second")
mySet.Insert("Second")
mySet.Insert("Third")
'Print all entries in the set
For Local s:= Eachin mySet
Print (s)
Next
End

Stack

Monkey provides a few ways to store data. The last module in this category is Stack. Imagine a stack of books. Basically, you can store them by placing one book on top of another (Push). If you want to take away one, you take it back from the top (Pop). Of course, you can squish a book in between the stack (Insert) or remove one from in between (Remove). And like all data storing features, you can iterate through a Stack in all directions.

Here is a small example for the usage of Stacks:

Function Main()
'create a new stack
Local myStack:=New Stack<String>
'Add entries
myStack.Push("First")
myStack.Push("Second")
myStack.Push("Third")
'Print all entries in the set
For Local s:= Eachin myStack
Print (s)
Next
End

Wow! A lot to read and not much to do. Ok, you got some playtime here but also some good information. Let us revise what we have learned so far and looked at in this chapter:

So what's next? Do you agree that we can now dive into the inner caves of Monkey, bring out some fine functionality, and create your first game? Yes? You should answer more loudly! YES! Ok, so let's get rolling with the next chapter!