Guides – I Wanna Be The Dev

Uh mazing: 01 An introduction to 3d game development

For this post, we’ll cover a what goes into building a 3d game. Fun, right? Maybe not super exciting but there are some important concepts we need to cover. Without further ado, getting started designing a video game for newbs.

If you’re interested in building video games, you’ve probably played a video game or two in your time. I know I’ve wasted way to many hours… When you’re playing any 3d game, you’re perspective of the world is usually either 1st person (most shooters) or 3rd person (most RPG’s) Or, you might observing from above (most an RTS). It turns out, these don’t make much difference once you get further into building the world. What you probably don’t think about, is the fact that you, or your avatar, are not moving. That’s right – in a 3d game: You don’t move – the rest of the world does.

In a 3d game: You don’t move, the rest of the world does

Graphics Rendering, a summarized explanation

Now, let me explain how graphics work, in a nutshell.

You have a flat 2d screen.
The screen has pixels!
Just like a painter, you are tricking the human eye into seeing 3d
Graphics rendering starts with a single pixel, moves to a line, then a triangle.
The entire world is made of triangles
Every detail added on top of that, is just enhancing groups of triangles.

Pretty simple right? Drawing triangles? I tend to think so. The real magic with the triangles – comes with positioning, and movement rules. Positioning is when things start to get a bit more complicated.

I took a video game design course in college. Some of the best take-aways from that course were which libraries to use, and, how to use the positioning. The easiest way I can explain positioning, or coordinates, is to start with a square. Now, draw two lines, one from top to bottom, the other from left to right. You now have two axis. Usually, the top to bottom one is the Y axis, and the left to right one is the X axis. So – if you move the Y axis along the X axis (draw the top to bottom bar a little to the right from where it started) You’ll have moved to a new coordinate along the X axis. The way we represent these positions in software are with Vectors. vector(1.0f, 2.0f) would mean a position of 1 on the x and 2 on the y axis.

Rendering

Now, lets go 3d! Remember the square, and drawing the lines across it? Do that with a cube. Yes, you’ve suddenly got a third line going from front to back. This is the z-axis. A vector can represent this as well. vector(1.0f, 2.0f, 1.0f) where the 3rd item is the position on the z-axis.

Now, it’s great to travel on axis – but if we can only look one direction, how do we turn, or look up? This is where rotation comes into play. And here’s where the programming gets tricky – because now, instead of just moving the world around your perspective – you need to rotate the world around your perspective, yet not rotate everything in the world at the same time! Fortunately, this is where other’s work can be helpful. Rendering engines take care of a lot of the complicated math using well known, powerful algorithms. If you’re still curious about using a camera approach, here is an example of a camera, and render method using C# and OpenGL

Textures, Sounds, and Networking

It isn’t enough to simply draw lines, squares, or donuts. For a game to be immersive it will need the donut to look like it got home from the bakery, the line will need to go ‘zap’ as it flashes by, and the kid across town is going to need to know where the square is. These auxiliary pieces to a game are crucial to some of the best games out there. To some extent, these can be overlooked in 3d world development. At the same time, the can’t be missed.

These will be covered a bit later on – there are tutorials out there already. And it is possible to develop the piece in some isolation. Well, textures might belong to the engine. that said, there are lots of opportunities to cover them.

Summary

This introduction covers some of the different high level aspects of the 3d world. Because 3d development is such a large item. Having a plan on what to attack next is useful to avoid scope creep and other difficulties getting anything working. As this guide is built out – it will somewhat follow my own approach to a development plan.

Introduction to Programming 000

Quite some time ago, I went to college for Computer Science degree. I knew that I wanted to provide for a family, that I didn’t want to perform a job with a lot of manual labor, and that doctors and lawyers would fit the bill. But I also knew that I was good with computers, I’d hacked a few games after all. I’d even written a few programs. In fact, the first one I ever “wrote” I can still provide from memory.

10 print Hello World
20 goto 10

But let me get into what this post is really about. An introduction to the world of programming. Currently, I’m teaching my son 6th grade math. It’s introducing him to Algebra. Algebra is cool. It makes math useful, repeatable even. It’s kind of what programming does. The first things you learn in school are definitions, terminology, the words, and what they mean. That way you can communicate with everyone else that learns about the same subject. Without further ado, let me introduce you to some common concepts of programming.

Operators

Just like 6th grade math, you need operators to do anything. Consider 2+2. It equals 4. That’s what your 1st grade teacher taught you. The ‘+‘ sign is the most important piece here. It is the operator. It tells you what to do with the things around it. There are lots of operators out there. Most of the ones you learned in Math apply. And there are few other special operators – but we need to cover other items before we introduce them.

Variables

Leaning back on algebra, variables are representational. They can vary in what they represent. For example, if we say x is a variable, and we have an equation x+1=2, we know that the x variable is 1. Or, if we say, the total is x+1, we can set x to a certain number, say 2, and know that the total is 3. Variables are a huge part of programming. Without them, we wouldn’t be able to record the result of operations. Now, speaking of operations, one of the special operators, is the assignment operator.

In many languages, the assignment operator is notated by the = sign. In other languages, it is a combined => symbol. An example of an assignment operation, would be as follow.

x = 10+2
if we were to print the value of x, it would say 12.

Types

Unlike Algebra, programming variables can be different types. This is because, different things need to be tracked in a computer. In algebra, you’re just tracking numbers. Examples of different types are:

integer
boolean
string
object
float

An analogy would be something like measurements. If you try to measure flour for a cookie recipe, and you use 2 tablespoons instead of cups – or – you used 2 grams instead of 2 cups – you end up with goop (I know from experience, goop doesn’t taste good). And for this reason, programming languages use types. Keeping track of a of number is an integer. Keeping track of someone’s name, well, that’s a string, and keeping track of your next door neighbor and their email address (is creepy) but that group of types, that’s an object.

Differences between Programming languages

I’m not going to cover a lot on different programming languages at this time. Just know they are out there. A lot of the core principles are the same, or similar, even if the terminology is different. This is because the C programming language became an effective way for programmers to convey ideas. If you’re into language history, think of it as the ‘Latin’ of the programming world in that a lot of other languages stem from it.

Next step

At this point, I’m going to recommend downloading Golang and finding a text editor or IDE. Because eventually, we’ll get started on using some of these concepts in an actual application. Once you’ve gotten an IDE – head on over to Program 1: Build a simple text bot!

Guide: Implementing a PhpUnit Development Environment in PhpStorm

Preperation

For this example, I will be starting with the following:

PhpTraits repository https://github.com/Waryway/PhpTraits
PhpStorm Project
- Make certain you have a php interpreter referenced in your storm project
- Also make certain you have Composer referenced by PHPStorm
- A desire to test.allTheThings()

Installing Libraries

First, use composer do some work. We need a copy of phpunit. Get it with this:

"require-dev":{
    "phpunit/phpunit":"6.4.3"
}

As this is a ‘library’ style app – use an exact version. The lock file gets ignored in favor of precise dependencies in the composer.json.

Now run composer update to pull in the requested phpunit package.

Setup phpunit in the general settings, under phpunit

Adding a new test

Or rather, a test skeleton

Open the file to test in the Project View
Place you cursor on a method to test within the file
Go To Navigate -> Test
Create New test
I tend to set mine up with a test prefix to keep tests more obviously separate from code.
Click Ok then Open up the new file
Add a line to pull in the composer autoloader
Clean up the Namespace reference to the TestCase if you are using PSR-4
Disclaimer: Strongly avoid namespacing unit tests. They should not be built out like a code base. They are testing units.
Add an empty testHydrate method.
Add a super obvious assertion.
Add a phpunit.xml fileI put it in the test directory.
Run the test (At this point, I needed to restart phpstorm to detect that I actually had a ‘test’ to run.
Build the tests out further.

Conclusion

Ending of the beginning

I’ve gone ahead and built out the ‘hydrate’ test against a trait. Note the use of the trait object that phpunit provides. Pretty slick, right? I’ll continue to build out this repository – core libraries need the most directed test coverage.

Even adding the ‘test’ cases around the hydrate method – I have found use cases I didn’t consider while writing the code – and have adjusted the code to reflect the behavior I expect.