openGL – WLGfx

Java vs C++ for 3D mesh building

A few days ago, playing around with LibGDX again I was getting back into 3D programming and created a very simple demo of a load of spheres and the camera rotating around the scene as below:

Which on my laptop ran just fine. It took about a second to generate all the meshes for each of the spheres.

Took bloody ages on my phone though, even though it’s a quad core 64 bit android phone. Approximately 5 to 8 seconds. Ouch.

None of this nonsense in C++ for starters. I know this from a very old project I was working back in the day. Procedural map generator. More about that here: PROCMAP DBP LINK

So for the last couple of days (actually on the evenings because of work), I’ve looked into creating a single sphere mesh and then duplicating it. In LibGdx

A minor problem to start off with is that a lot of LibGdx’s mesh generators have been deprecated and I don’t know how long for now, and I can’t find examples on how to use the new stuff. This would have made things easier, but that minor problem got bigger.

It seems that ModelBuilder only runs on the GL thread, so I tried the MeshBuilder. No luck there after trying to hunt info down on google, (Maybe google is hiding it from me :P) how to use the thing.

So I gave up, closed the project, might go back to it if the next step fails.

I’m waiting on a huge update from Qt. Oh! At this time it has finished downloading and updated.

The previous versions of Qt didn’t work with the latest Android SDK/NDK. Fingers crossed with this one…

Next…

WebGL 3D

After faffing about with CopperCube and CopperLicht, which is fun to play around with, I’ve found it quite restricting for the type of demonstrations that I want to do. So I’ve decided to head on back to Parallax3D, bypassing the urge to play with LibGDX again.

The reason for dumping CopperLicht is simple. I don’t like Javascript at all. With GWT, it is rare I need to use JSNI with it.

LibGDX is good but each LibGDX project has to be a complete GWT module in itself, which means copying over all the GWT stuff again. It probably is likely that I could integrate it into a GWT project and I might try it at some point.

However, Parallax3D just appears to have everything and is a simple Jar file which is added to a GWT project.

So… It’s finding out what mesh files (hopefully wavefront OBJ’s as well) and I’ll be up and running if the weather is bad this weekend.

I also need to FTP this site as my homes Sky router isn’t working with the DNS service.

Enough of this. Time to setup a project on my lappy.

Variable names are important

For the last two days I’ve been working on decoding video frames and displaying them. The idea is to run against the system clock which I’ve had working everytime so far. This time though, I decided to make a general decoder so that I didn’t have to worry about FFMpeg’s video decoded format which up until now has always been YUV420 which I just had a GL using SL shader convert on the fly. Everything gets converted to an RGBA bitmap so I don’t have to worry about it.

Anyway, variable names…

I buffer up the frames and then test them against the current system clock for a frame that’s ready to be presented. I had two variable names, frame and frame_temp which are pretty innocent. Unfortunately though, and which I kept missing whilst going through the code, I was grabbing a pointer in frame_temp and testing it. If it fell below the current system time then it would then be assigned to frame. If there was a previous frame then it would be cleared from the buffer queue and added to the unused buffer queue.

Now this is what I missed.

Frame_temp is first used, frame is unitialised (actually null), the tests are done on frame_temp and if failed then just exits with a null pointer. Fair enough.

It was a “typo”.

Hidden between four lines of code using frame_temp I had used the variable frame instead (which is null to start with). When I accessed a method on that class it would crash.

The error message was very obscure and nothing on google search or anywhere else was any help.

My mistake…

Most of the time I rely on debug log outputs. And whilst running this code, everything was running just as it should. It’s hard to follow multiple threads in debug output.

Finally, I ran it through gdb which took me straight to the line of code where it crashed. The line right after the “typo”.

Lesson learnt…

It’s been a while

Yes, most definitely it has been some time since I last posted anything on my blog. That’s because this last month I have hardly had any real chill time to myself. Well, I have had some, but it never lasts for long enough.

Anyway, I’ve still been faffing about. I recently purchased CopperCube so that I could delve deeper into WebGL. Plus I’m familiar with Irrlicht, and CopperLicht makes working with 3D graphics a doddle.

I’ve also found that I can actually call myself a full-stack developer considering recent projects I’ve been working on. One project involves a C/C++ TCP/UDP server for communications, A Java TCP server to use Java AWT graphics, GWT for a web interface instead of installing software. The server does many things, too many to mention, but I’m well chuffed with it.

Setting up the server involves freshly installing Linux. Then installing Apache Tomcat. Making a few modifications to the system and then installing the software.

Device connect on the network via ethernet or wifi and will automatically detect the location of the server because of the UDP heart beat. Clever stuff really. Probably not, but all the same, it works great.

I’ve also played around with having a home TCP server which can be made use of from my mobile phone while I am out, my tablet or a PC, as well as a GWT web interface.

After playing around with all of this, there’s lot’s more I want to play with. Maybe Vaadin or similar. Move on to desktop 3D graphics again instead of openGLES 2.

I’ve also finally got myself an i7 laptop with nVidia graphics. Cheap off eBay! So I can develop on the go. That’s if the battery is good in it.

There’s other things over this last month that have tickled my fancy, but I won’t mentioned that here. Tempting though.

Hopefully this weekend I will have a long one as I’m booking Friday and Monday off because I seriously need to relax a little.

Until next time…

WLGfx@home updated

Click here: WLGfx@home to view my PCs hosted site.

If it doesn’t load up then my home PC is not switched on.

There’s still quite a bit to do to this site, especially to do with the 3D stuff. I’ve got to setup a decent scene to show off with. Some cool shaders and some decent meshes.

Online GL shader editor

Just so I don’t lose or forget about it, I’ve found a very handy online openGL shader editor…

ShaderFrog

From basic shaders including texturing and lighting right up to procedural shaders and more.

All I need now is to run a sample project in Qt to test out some of these and then transfer them to GWT and Parallax. Good stuff can now be done.

Godot 4 Terrain Generator – progress

July 27, 2024
by csnorwood

I’ve just uploading another video to youtube about the current progress of my work on 3d terrain generation.

Here I am mixing two noise values, a main noise for the actual terrain and the other which is only added at 10% strength adds extra terrain detail patches.

There’s still a lot of ideas yet I want to add to this and I am getting through them bit by bit.

Audio issues are still ongoing and hopefully will be resolved in future videos.

Until next time… Carl out…

Godot 3D terrain testing

Just using GDScripts SurfaceTool, here’s a quick glimpse of what I’ve been fiddling around with.

For some strange reason Godot keeps calling me back, and each time I play with something else. This is the latest.

Think of now using a threaded solution to generate meshes using 3D noise and maybe even stretch it a little and animate it with 4D noise as a constant time dimension added.

I dunno…

I was thinking just then, “hey, you do know that adding 6Tb storage to your PC is a big deal?” Well, that’s when it struck me, actually, yes it is!

They’ve been sat in the NAS case for almost a year now since I cut Windows on all my PC’s at home. And I never got round to setting it up for Linux. It kinda got that way, I had a 2Tb SSD to shove all my stuff on.

So a week later and Aliexpress delivers my HD caddies. Straight away, unboxed, 2 x 3Tb drives straight into them, and all setup. And voila! They all work and now I’m sat here with a tiny Mini PC, with about 10.5Tb of storage in total connected to it.

So, yeah… It’s a big deal.

… Now on to organising it all. (That’s the bummer…)

Z80 Spectrum 48K assembler

June 15, 2024
by csnorwood

So I finally got around to making my very first recording with my voice over to quickly demonstrate how easy it is to edit and run assembler code on a ZX Spectrum emulator.

Click here to view the video on Youtube.

ZX Spectrum 48k (adventure)

I’m hoping to record a video showing where I’m up to with my trip down memory lane.

Portable monitors are awesome! … ?

Straight up, yes they are. I have two, an 11 inch standard HD and a 15 inch 4K. Both power over USB, both have extra USB C ports on them and both have USB C video input and HDMI.

They are also thin, very light and come with a magnetic cover which acts as a stand. The brightness and colours are perfect to me.

But, …

When it comes to the resolution and the size of the monitor itself, especially the 4K monitor, ‘size matters’.

I do a lot of programming and screen real estate is essential for displaying code. The more code you can see on the screen, the better. And here’s were the 4K monitor falters.

At that resolution, you know 4 times the space of a HD screen. Well, in resolution anyway. You’d think, or at least I did, silly me. You’d think that opening 4 browser windows in each corner or the monitor. Oh yeah, that is cool.

Nope. It’s a 15 inch screen. Splitting it up into 4, 7 inch screens doesn’t work. Simple as. You strain your eyes reading tiny, tiny text.

For programming they are superb. But to split the screen up smaller, nope.

Oh, I’ve also got a 28 inch 4k monitor and I can confirm it doesn’t look too bad splitting 4 browser windows.

Microsoft and Chrome

I’ve not long got a new PC and my first Windows 11. As usual, I set it up the way I like it.

Then, I boot up to find Edge has opened all my Chrome tabs.

The weeks go by and I see reports of the same thing on YouTube.

And now today, I’m getting emails from Microsoft asking me to recover my Google account through them.

Hmm

2024 Updates

So it is time for me to setup a new development folder. This time around, unlike the many years in the past, all the test projects will be dumped into a testing folder before they are allowed to join any main stream projects that I am working on.

Now with a PC upgrade I am capable of working a lot faster (8 cores/16 threads helps here), especially with running local AI’s and also working in Linux and MacOS. Most of this will be all on the same machine.

Current projects:

Media server and device management software/server.
- Video playback
- Image viewer
- Devices manual updates by client
- plus many other features…
Godot Game
- Terrain generator and texture painting
- Fauna splatting
- Various generators to add objects in a scene
- Miscellaneous player controls (ie. sliding down slopes and climbing walls)
Home AI chat on the go.
- Home AI that runs on a server that allows me to chat over the internet using my phone
- Text or speech input.
- Optional text to speech output
- Selection of local LLM’s (ie Llama chat, or Mistral Instruct)

With WSL in windows it does make it easier to develop and test Linux software, however it is not that good because it doesn’t give raw access to hardware. This is not a problem for development and testing.

There will be a lot more to come over the months as things start to get organised and time is given to these projects.

Catch you all soon…

Carl

Testing before an interview

It’s extremely important if you are taking a laptop to an interview to showcase a project that you’ve been working on to thoroughly test it before going. I found this out recently.

It was a Node JS project I had been working on for about six months, it loaded up, built and ran fine the night before and even on the morning of the interview. Doubts that anything could go wrong just didn’t exist. This project was working.

But that wasn’t the case in the end.

During the interview I booted up, loaded the project in as I had been doing, no changes to the system or project. Then I ran the project and opened up the page in a web browser.

Garbage! That’s what I got on the screen. Just garbage!

According to the output log from the project it was all going fine, but that’s not what was on the screen in the browser. I could see some of the text and icons but they were all squashed up on the screen. Argh! I thought. How could this happen?

I had to resort to just explaining the project and apologising for the failure for it to work properly.

Interview over and headed back home on the train. Furious at myself for this to happen.

Whilst on the train, I opened up my laptop to write a thank you email for the interview which I had to connect to my phones hot spot. Email sent, I decided to open up the project to quickly see why it all went wrong. The project ran, I opened it up in the browser… And it just worked!

After a very short investigation I found what the problem was. A CSS file was being requested from a CDN (content delivery network) which when connected to the internet could get access to and use in the project. During the interview, I did not connect to the internet and the CSS file was not loaded into the page. No layout information, colours, nothing…

So that was it. No internet. Project cannot access that single CSS file.

Of course now I’ve added the CSS file directly to the project and it does work completely offline.

Lesson learned.

ChatGPT vs Google Bard: AI programming in C++

Bard fails miserably at recursive programming where ChatGPT gave an almost finished result.

I asked both to write a C++ program given a folder to monitor its contents and recurs down through all sub folders and monitor those files too.

At the moment, Bard hasn’t got a grip on recursive programming. ChatGPT came out the clear winner. Although I did have to coax it to get it to include the right header files.

The final result definitely wouldn’t be production worthy but a good start to show how to work on this particular task type.

#include <iostream>
#include <sys/inotify.h>
#include <unistd.h>
#include <cstring>
#include <vector>
#include <dirent.h>

#define EVENT_SIZE (sizeof(struct inotify_event))
#define EVENT_BUF_LEN (1024 * (EVENT_SIZE + 16))

void monitorDirectory(const char* directory, int fd, std::vector<int>& watchDescriptors) {
    // Add a watch for the specified directory
    int wd = inotify_add_watch(fd, directory, IN_MODIFY | IN_CREATE | IN_DELETE | IN_MOVED_FROM | IN_MOVED_TO);
    if (wd < 0) {
        std::cerr << "Failed to add watch for directory: " << directory << std::endl;
        return;
    }

    watchDescriptors.push_back(wd);

    // Scan subdirectories
    DIR* dir = opendir(directory);
    if (!dir) {
        std::cerr << "Failed to open directory: " << directory << std::endl;
        return;
    }

    struct dirent* entry;
    while ((entry = readdir(dir)) != nullptr) {
        if (entry->d_type == DT_DIR) {
            if (std::strcmp(entry->d_name, ".") != 0 && std::strcmp(entry->d_name, "..") != 0) {
                std::string subdirectory = std::string(directory) + "/" + entry->d_name;
                monitorDirectory(subdirectory.c_str(), fd, watchDescriptors);
            }
        }
    }

    closedir(dir);
}

int main() {
    int fd = inotify_init();
    if (fd < 0) {
        std::cerr << "Failed to initialize inotify" << std::endl;
        return 1;
    }

    const char* directory = "/home/wlgfx/Downloads";
    std::vector<int> watchDescriptors;
    monitorDirectory(directory, fd, watchDescriptors);

    std::cout << "Monitoring changes in directory: " << directory << std::endl;

    char buffer[EVENT_BUF_LEN];
    while (true) {
        int length = read(fd, buffer, EVENT_BUF_LEN);
        if (length < 0) {
            std::cerr << "Failed to read events" << std::endl;
            break;
        }

        int i = 0;
        while (i < length) {
            struct inotify_event* event = (struct inotify_event*)&buffer[i];
            if (event->len) {
                if (event->mask & IN_CREATE)
                    std::cout << "File created: " << event->name << std::endl;
                else if (event->mask & IN_DELETE)
                    std::cout << "File deleted: " << event->name << std::endl;
                else if (event->mask & IN_MODIFY)
                    std::cout << "File modified: " << event->name << std::endl;
                else if (event->mask & IN_MOVED_FROM)
                    std::cout << "File/Folder moved from: " << event->name << std::endl;
                else if (event->mask & IN_MOVED_TO)
                    std::cout << "File/Folder moved to: " << event->name << std::endl;
            }
            i += EVENT_SIZE + event->len;
        }
    }

    // Cleanup
    for (int wd : watchDescriptors)
        inotify_rm_watch(fd, wd);

    close(fd);

    return 0;
}

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