David | Learn C Games Programming Blog

Author: David

A rather powerful C Graphics library

Posted on June 23, 2020June 19, 2020 by David

I’m not going to be departing from SDL2 any day soon, but if I were starting from scratch, I would seriously consider raylib. It ticks many boxes!

Written in C(C99). Tick.
Cross platform including Raspberry Pi desktop. Tick.
Open source and liberal licensing tick.
Full 3D support with animated models. Tick.
Extensive Sound support. Tick.
Very open license that even allows static linking with closed software. Tick.
Lots of examples. Tick.

There’s even a set of open source games on GitHub. including several that you can play in your browser (HTML5). Documntation is in the form of a 36-page Wiki. I took a quick glance through there and was impressed with some of the features. For example, OpenGl can be used directly and not through X11 though that is also available.

Plus full marks for including struct sizes on the data structures page. That’s not something you often see, nor is instructions for configuring Visual Studio, Visual Studio Cocde, Codeblocks, Eclipse and Sublime Text. The cheat sheet (which you can also download as a pdf) gives an idea of the number of functions in Raylib. They cover five pages!

A Game engine in C – permafrost

Posted on June 22, 2020June 15, 2020 by David

It just shows what you can do in 38,000 lines of code. Permafrost Engine is an OpenGL 3.3 Real Time Strategy game engine written in C. The image is from the game Everglory.

You need SDL 2 plus a few other dependencies listed on the site to build the engine. It’s also cross-platform.

I’ve added it as a permanent link to the C Code links.

Playing with VSCodium

Posted on June 21, 2020June 14, 2020 by David

There are some subtle differences between it and Visual Studio Code. The main one is the not having access to the VisualStudio market place. The C/C++ template isn’t there but instead is installed by default.

However I have found that the tasks and launch json files created from the F1 menu don’t have the C++ choices. What this means is that you have to get them from an official Visual Studio source, like Visual Studio Code installed on 64-bit Windows/Ubuntu/Mac.

I’d already done this so I used WinSCP to send them via ssh from my Windows box to the Pi. It’s a slight irritation but once you’ve got them setup it works ok. I can build applications haven’t got debugging working yet though.

There is an alternate Extensions Marketplace which has 266 items in it. That’s a screenshot of the programming language extensions.

Benchmarking my Raspberry Pi

Posted on June 20, 2020June 14, 2020 by David

I played with a couple of free packages today. I can recommend hardinfo. (sudo apt install hardinfo to install then hardinfo to run ) though less about the benchmarks than the information it gives on your system.

I’ve got both 32-bit Raspbian and 64-bit Raspberry Pi OS on two sd cards and intend to run both and compare benchmarks just to see the difference.

Another benchmark utility that looks interesting is sysbench (sudo apt install sysbench to install). It runs from the terminal and lets you run benchmarks against file io, cpu, memory threads, mutex and oltp. Just type sysbench and you’ll get a list of commands.

How to install VSCodium on a Raspberry Pi.

Posted on June 19, 2020June 19, 2020 by David

It was very easy. This was onto my Pi 4 running 64-bit Raspberry Pi OS.

Go to the releases page on the vsCodium website, it’s on GitHub. If you are running 32-bit Pi OS then you need the codium_1.46.0-1591900344_armhf.deb file (the number will most likely have changed). For the 64-bit one, you need the codium_1.46.0-1591900344_arm64.deb.

When you click on the link it will download and ask if you want to keep it. It will then give you the option of opening it and select the archiver. That will install it for you.

After that, to run it from the command line just type codium.

Or as I just discovered. Look on the pull down menu, go onto accessories and you should see (probably near the bottom) VSCodium. Move the mouse over and right-click.You’ll see a popup menu with Add to Desktop and Properties. If you click the former, you get an icon on your desktop.

Screenshots were captured with the Flameshot utility. It’s installed with sudo apt install flameshot. That’s the VSCodium and Flameshot icons.

Creative computing games

Posted on June 18, 2020June 12, 2020 by David

Yesterday’s post reminded me of one of the joys of my youth. The Creative Computing magazines’ “BASIC Computer games” book and it’s sequel “More BASIC Computer games.” . I bought these in 1982, and they weren’t cheap then- about £20 each.

Of course over the years they got lost but I bought them again a few years back. Some of the games in here are classics- A simple Star Trek game, Hammurabi, mugwump, golf, various landers. Of course they are all in BASIC but relatively easy to convert to C.

You don’t have to buy the books (they are pretty expensive on Amazon and no I’m not selling mine!) as many of the games are available online. One source is this classic BASIC games web page. Here’s another link with more games but they are scans of the pages.

I promise I won’t be putting any more BASIC listings up. These are just an inspiration to create small games in C or adapt these.

While at Uni in my first year, I adapted a copy of the Star Trek game adding in a whole lot of new features. It doesn’t say much about the interactive mainframe there that with just four people playing the game, the mainframe was brought to its knees!

Browsing the source code of old and commercial games

Posted on June 17, 2020June 12, 2020 by David

Archive photos — Image by Pexels from Pixabay

This page on a website called WikiZero has a long and very extensive list of games whose source code is available. That doesn’t always mean you can build the game. Many games are very old and in BASIC or assembly (.g. Elite is available in various forms).

It might have been created for a different platform or more likely the source code is available but the graphics and sound assets aren’t, unless you have bought the game, perhaps from sites like gog.com and so have them.

One thing to be aware of, many of the links on WikiZero go to the excellent wayback machine which is part of archive.org. This is under threat by some commercial publishers because they have lent ebooks during the Covid lockdown period without any limitation. So if you are interested in anything I suggest you check it out sooner rather than later, just in case.

For instance here is the C source code for a TRS-80 game from 1979 called Paravia. It looks like a much expanded version of the Classic Computer game Hammurabi. Note the wayback machine can take a few seconds to retrieve a webpage. They have a very large chunk of the web’s websites in there…

Goto is considered bad programming in C but

Posted on June 16, 2020June 11, 2020 by David

There is one case for using goto when you have nested loops and you’d like to jump all the way out. The goto statement was very popular in BASIC but often resulted in programs being like spaghetti with gotos all over the place.

Here’s a contrived example where I have used a goto.

#include <stdio.h> 

int array[10][10][10];
int main() {
    // Populate array
    for (int y=0;y<10;y++)
      for (int x=0;x<10;x++) 
        for (int z=0;z<10;z++) {
          if (array[x][y][z]==0)
            goto exit;
    }
exit:;
}

In my C programs, for-loops are the most popular followed by while-loops, do-while loops and gotos are hardly ever used at all.

My trial by Windows Defender is over

Posted on June 15, 2020June 10, 2020 by David

EXpression opf irritation! — Image by prettysleepy1 from Pixabay

There’s nothing wrong with this short C program, which is in my ebook and which I was compiling to test it.

#include <stdio.h>

int main() {

	int a = 10;
	for (int i = 0; i < 5; i++) {
		a--;
		printf("i = %d\n", i);
		if (a == 8) break;
	}
}

Nothing wrong, except Windows Defender went ape-shit every time I compiled it! Talk about annoying. This was in Visual Studio. I’m fairly scrupulous about keeping nasties off my PC but if you believed Defender I had some weird Trojan.

I did a search and found an unanswered question on StackOverflow from someone with the same reported trojan. So I answered it!

Thankfully there was an update from Windows Defender last night and they have quashed this false positive. If the worst came to the worst, I’d hop on to Hyper-V and compile it in Ubuntu or Raspberry Pi OS with clang. But still a bit irritating!

Another Visual Studio Code source – VSCodium

Posted on June 14, 2020June 8, 2020 by David

VSCodium As they say “This is not a fork. This is a repository of scripts to automatically build Microsoft’s vscode repository into freely-licensed binaries with a community-driven default configuration.”

Microsoft’s code includes telemetry and tracking code. The code built here is the same as Microsoft’s but with that telemetry and tracking code removed. Also it includes builds for both ARM (32 and 64-bit) which you don’t get from Microsoft.

The Docs page provides info on how to copy JSON bindings from Visual Studio Code to VSCodium. I shall be giving this a try. Much as I like the code.headmelted.com Visual Studio Code, it doesn’t appear to be updated very often whereas VSCodium seems to be built every night.