Contact

Send e-mail to vnms11@gmail.com

IZEng - engine for game development

IZEng is an open-source game engine with 2D graphics onboard. It encapsulates DirectX work. It includes simple movement models: linear, angular. Supports acceleration, friction, gravity if needed. RockCarrier is one of my games, which is developed on the base of this engine. Documentation included, but not full.

If you have questions, contact: vnms11@gmail.com. Title the letter "IgriZdes Engine".

I developed this small engine when I was studying in the University, so don't be surprised.
Source code with documentation on github  Download

Building and running Android Studio gradle project on android device

Recently I was just checking out if AIDE team added support to build gradle-based projects. So, indeed they added:

AIDE also supports basic Android Studio projects, which follow the default project structure. The full gradle build system is not yet supported though
(source: http://www.android-ide.com/tutorial_androidstudio.html)

So, if your gradle setup is simple, you can just open your android project in AIDE and run.

But what to do if not? As before we have a workarond: create eclipse project files (.classpath + .project) for our project. AIDE works with eclipse project structure quite well. But what to do with the dependencies? It's insane to write all of them by hand. Likely, LibGdx enthusiasts gives us script which generates those strings for us (see for example eclipse task here)

I'll give details on example of how to build & run LibGdx gradle project in AIDE.

MSI X99A SLI PLUS Windows 10 hang issue resolved

I've become a happy owner of MSI X99A Sli Plus mobo. I already read about many issues with asus burninng, msi burning, random Windows hangs due to problems with USB. And I want to say that I encountered nothing of that with my MSI mobo (bios 1.9, recently updated it to 1.B).

But I encountered an annoying hang for which I found a solution, so I want to share it because I don't see it anywhere on the web.

Problem: after unplugging PC from the outlet and plugging back Windows 10 hangs for the first time.
Solution: insert USB stick in one of the USB3.1 slots. You just need to keep 1 USB3.1 slot occupied to not run into that problem

C#: Why Dictionary with hashcode as key is dangerous

Recently, I encountered following code:

        private readonly Dictionary<int, View> _listCellsForDisposal;

            if (!_listCellsForDisposal.Contains(view.GetHashCode()))

             {

                _listCellsForDisposal.Add(view.GetHashCode(), view);

             }

The intent of that code is just add item to the list if it doesn't present. But is it doing work well? It doesn't. Let's see why.

At first, let's look at the signature of GetHashCode:

public override int GetHashCode()

So, it returns int. int in c# is platform-dependent. For example int32 takes 4 bytes, it's range is:

-2,147,483,648 to 2,147,483,647

(source: https://msdn.microsoft.com/ru-ru/library/5kzh1b5w.aspx)

But how many objects can we add to the dictionary?

Why static is pain

Bugs, related to static variables may be difficult to understand. I don't think it's worth investigating. As a general practice, just avoid keeping references to objects in static. When using a static reference you allways must ask youself when to free this static and when to use.

Example: keep reference to view in static variable. User closes our app, OS frees memory, so all statics are freed too. When user opens our app again, static gets newly created view. All is well.
Then, time passes and we add background running service in our app. So, when user quits our app OS can't just free memory - static may be accessed from our background service. And reference to view remains. Afterwards user open app again and static has view that was created FOR ALREADY DESTROYED VIEW HIERARCHY. And it is luck if it will work with new one. It is only one example of what can happen when using statics. Using statics is not bad. But statics need more attention from developer. They often must be freed explicitly (for example, recreated at app start). Better keep only primitive data in statics - ints, strings...

Connect to genymotion emulator from another machine via wifi

1. Change NAT to bridge in VirtualBox settings for emulator (network adapter is same used to access network using which you'll connect)
2. download adb wireless by henry (root)
3. enable debugging
4. disable all adb processes started by genymotion for emulator (I choose "use custom sdk" and then renamed adb.exe -> _adb.exe) and restart emulator
5. adb connect ip:5555
done
adb devices should say:
device (not offline)

Method override in C#

Hi, everyone! Recently, I decided to put all basic info about method overriding in one place. Keeping in mind that method, which is overriden may be virtual or not. Or you may just want to make name hiding (don't know why anybody may want to do that). So, here we go.

Non-virtual methods

class A
{
    void Foo() {}
}

class B: A
{
    void Foo() {} // compiler warning B.Foo() hides A.Foo()
}

To resolve warning:

class B: A
{
    new void Foo() {} // explicitly say to compiler, that hiding is intended using "new" keyword
}