Learn C Games Programming Blog
A blog about C, programming games and my ebook(s).
It was kind of silly. I installed Debian 13 in hyper-V, just to see how different it is from Ubuntu. Like Ubuntu, it starts in a default size. I looked in the settings and there was a Displays there so I tried it and got the screen resized to full screen size.
So I then went back to Ubuntu and tried that, and it worked. I believe that what helped was having guest services ticked in the Hyper-v settings.
Is that the use needs to specify file::module_name::…
So to get it to compile, it needed these two lines. Note I changed the filename and the mod filename to poker_lib.
pub mod poker_lib;
use poker_lib::poker_lib::{Card, Game, Player};
SDL releases are few and far between so this is significant news. What’s new you ask? Well lots of things- best to read this page.
It’s highly cross-platform, SDL officially supports Windows, macOS, Linux, iOS, and Android, and several other platforms. It’s written in C, works natively with C++, and has bindings available for several other languages, including C#, Python, and Rust.
One of the projects I’m working on is rewriting the Asteroids game into Rust with SDL3. I’ll publish more here as it proceeds.
I’ve decided that I’m going to learn Rust and as the SDL2 bindings are available for Rust, I’ll be doing a bit of rewriting C into Rust. I’ve always found that working on some code is a good way to learn a programming language.
Every month a new Tiobe Index is published purporting to show the most popular programming languages. Except, if you look at other programming language popularity surveys, lists etc, the Tiobe Index increasingly seems to be at odds with everybody else.
Take the programming language C. As you can imagine I have a particular interest in it. I was at first delighted when I saw it at #3 in the Tiobe Index. In fact, in their most recent index it is listed as the 2nd most popular programming language. Well that is just crazy. No matter how much I might want it, there is no way on Earth that it is the 2nd most popular programming language.
It’s not just me saying it. Let’s look at who else says it.
| Site | C's Ranking | Comments |
|---|---|---|
| Tiobe Index | 2 | Updated monthly |
| GitHub Octoverse Programming languages | 9 | Annually- this is October 2022 |
| Reddit Programming languages | 10 | Subreddits for programming languages |
| Red Monk Programming Language Rankings | 10 | June 2022. Updated every 6 months |
| StackOverflow developer survey | 11 | Annually |
| Statista most used programming languages 2022 | 11 | |
| Hackerrank Developer skills report 2023 | 12 |
There are other programming language lists or surveys but those show what I mean. No one else has C anywhere that high. Here it’s in positions 9-12 with an average roughly around 10.5 if you exclude Tiobe or 9.3 if you don’t. I think their methodology is flawed and biased by age. Older languages appear to carry more weight.
Never mind C, what about JavaScript? Everyone else has it in first place (except HackerRank who has it in 4th). Tiobe index has it in 7th. Misinformation is defined as “false information that is spread, regardless of intent to mislead.”. Maybe that’s a bit harsh but that’s how I regard the Tiobe Index.
Moving to a new PC can be a time consuming process. This is my 10th PC since 1989 and I’ve been accumulating files, old programs, websites, manuals etc. as I moved from PC to PC. My first PC had a 20 MB disk, the 2nd PC had a hard disk with 240 MB capacity. On my new PC it’s 10 TB and 1 TB SSD.
It’s another i7 but 11th Gen Intel(R) Core(TM) i7-11700K. Only 32 GB RAM for now as they didn’t have 64 GB in stock but the motherboard can go up to 128 GB.
I estimated that I had accumulated just over 2 TB of my stuff and once I got my new PC setup started the process of moving files across. 2 TB seems a lot but VMs under Hyper-V can easily eat up a few hundred GBs.
Both PCs had a gigabit network card and were plugged into a gigabit switch so what speed did it give me? 11 MB/S. That’s not gigabit speed which would be about 1000 MB/s but closer to 100 Mbs. Trouble was the switch was plugged into a router and I think that pulled things down. I borrowed a crossover cable. Setup both Pcs with static IP and connected them directly. That was much better and it was soon maxing out at 112 MBs.
Windows of course put its spoke in. If you are copying large files- anything over about 1 MB then it uses the full bandwidth but smaller files pull it down and I’d see as slow as KB/s speeds. So I’d have three or four files copying at the same time.
As well as just copying files to the new PC, I was cleaning up my old PC to sell it so I was either deleting stuff or moving it. Overall my total elapsed time was something like 28 hours over four days and evenings. Plus of course installing software (Visual Studio, VS Code, Android Studio, MS Office). It all takes time. Luckily I’ve been quite disciplined and kept all licences and serial numbers in an encrypted text file.
Then I discovered that my new PC’s video cards had different connectors. My old one had DVIs but this one I could only find an HDMI and 2 DisplayPorts. There was a DVI connector on the video card but the firm that did it put the card in the top slot and the DVI (2nd row) was covered up by a blanking plate! It’s a RTX 2060 card. I removed it and all was well.
One of the things I as told when I learnt C++ and then later C was that a post-inc (i.e. variable++) was faster than a pre-inc i.e. ++variable. Frankly I’m not sure if it is really true but its not a difficult thing to test.
Here’s a short program
#include <stdio.h>
#include "hr_time.h"
#define NUMLOOPS 100000000
int main() {
stopWatch s;
startTimer(&s);
int j=0;
for (int i=0;i<NUMLOOPS;i++){
++j;
}
stopTimer(&s);
printf("PreInc = %10.5f\n",diff(&s));
startTimer(&s);
j=0;
for (int i=0;i<NUMLOOPS;i++){
j--;
}
stopTimer(&s);
printf("PostInc = %10.5f\n",diff(&s));
}You can get the siurce code including hr_time.h and .c from the timings.zip file on GitHub. I used VS Code with clang to build this on Ubuntu. Here is the tasks.json file to build it. It assumes that the file is in your workspace folder and creates a file called ex1. The timings.zip file contains the json files as well.
{
"version": "2.0.0",
"tasks": [
{
"type": "shell",
"label": "clang build active file",
"command": "/usr/bin/clang",
"args": [
"-g",
"${file}","${workspaceFolder}/hr_time.c",
"-o",
"${fileDirname}/ex1",
"-lm"
],
"options": {
"cwd": "/usr/bin"
},
"group": {
"kind": "build",
"isDefault": true
}
}
]
}Ignore the first three runs which were for 10 million not 100 million. All do indeed show that post-inc is indeed faster. Not by a great margin but each of the last 100 million loops takes between 94% and 96% of the preinc time.
When I first learned to program back in 1976, I had a teletype and a BASIC interpreter. Apart from a couple of years writing BASIC programs in my first job, all my work after that was with compilers.
So I’m a bit rusty with interpreters. The idea is that the interpreter reads a line of code and then executes it; parsing it and calling various routines to execute statements and parse then evaluate expressions. It’s kind if unusual to do this with C++. Cling is built on the top of LLVM and Clang libraries.
This is different to sites like repl.it, codepad.org or ideone.com; they compile the whole program and run it. With an interpreter, it runs line by line and you can print out variables at any time. Interpreters are probably more like debuggers.
As well as C++, cling can execute C, Objective-C and that even less used language Objective-C++. Developed at Cern it has a very extensive set of tutorials.
I always wanted to do this and have most of it done. It just needs a bit of polishing plus making it cross-platform. It wasn’t the hardest thing I’ve done although I did start by trying to make the common part for asteroids, player ship, bullets and aliens, the bit that managed position and velocity into a base class.
I then spent a day wrestling with the compiler trying to access this in those methods that used this and in the end found it easier to make it into its own class and had an instance of it in each of the classes. I.e. using composition rather than inheritance.
Rewriting in C++ made things like saving high scores to disk and reloading a bit simpler using C++ strings. Now I just have to get my main PC up and running and then polish the code and publish it on GitHub.
Yes it’s that book again, one I have mentioned a few times. Now there’s a project to convert all of the games from the book into C#, Java, JavaScript, Python, Ruby and VB.NET. As with all Git sites, you can download all code from the site in a zip file or individual files. So far though its very early in the project and there’s only a .BAS file in each of the subfolders for each of the games in the book. If you fancy getting involved, pick a game, a language and start coding. Sadly there’s no desire for C or C++ but that still leaves C# .
I still have this book and its sequel (More BASIC Computer games!) but to be honest I wouldn’t have bothered with most of the games in either book. They are all very much of the era (1978) which was just on the cusp of the home computer revolution and so were mostly obsolete within seven or eight years, due mainly to the terminal I/O. They’re ok for learning programming and of course you could run them in a Linux terminal.