Develop a (chess) program in Visual Studio 2022 (C# NET 6.0) [Huo Chess example]

Advertisements
Huo Chess DV (GUI Edition)

Goal

Some years have passed since the latest major update of Huo Chess. The goal of this article is to catch up with the developments of the latest years and show how an application built in previous versions of the Visual Studio can be ported into Visual Studio 2022. We will also show what is new with the newest .NET 6.0 Platform and what are the implications of the latest developments in the tools provided by Microsoft for building applications with C#. We will use the Huo Chess micro-chess engine published in this site as an example to show all the above in a short and concise way.

Important Notes: The new versions of the Huo Chess application in Visual Studio 2022 C# NET 6.0 are called ‘Huo Chess DV’ (from Huo Chess Delta Version).

Overview

Things in computers evolve over time. In the ‘old days’ we had BASIC. Then we had .NET Framework. Now we have .NET Platform (see also here), the latest weapon in the arsenal of Microsoft that allows developers to develop cross-platform applications with a single framework.

.NET frameworks and libraries (source)

And yes, .NET Platform is not the same with .NET Framework. In fact the latter is almost dead, as its support will soon end, whereas .NET is the latest framework (without the word… Framework in its tile, computer world always finds ways to confuse the uninitiated as alchemy used to do in the old days) you should choose. It has been around for some years now and its latest version is .NET 6.0. The .NET platform contains all the necessary tools, drivers and libraries to allow the modern programmer develop their programs.

And just to add more complexity to the already complex landscape, one needs to know that .NET Framework was initially succeeded by .NET Core. It was only after .NET Core 3.1 that it was decided to name the new framework .NET (without the ‘Core’) and that is what we now have .NET. Net (pun intended). [1] [2] [3].

The new .NET Platform allows for easier development of applications for various platforms, from Android to Mac. Details on how this is done is beyond the limited scope of this article.

The purpose of this article is to show how the open source micro-chess engine of Huo Chess was ported into Visual Studio 2022 and .NET 6.0. The next sections will present the problems and obstacles one might face when using the new platform and how they can be used to minimize the size of the application as much as possible.

Tutorials for building a chess program

There are many available tutorials on how to build a chess program. These are all based on Huo Chess open source code and will come in handy when trying to create your own first program. The logic of the program is explained, the functions used and the way the program thinks.

Tutorials on how to develop a chess program include:

This article only covers the porting of Huo Chess into Visual Studio 2022 and .NET 6.0, so in case you are lacking the basic understanding on how to program a chess application please visit these articles first. In any case, you are more than welcomed to continue reading and use the source code provided below as it is. Many times learning to program entails starting directly to… program. That is how I used to learn programming in Commodore and that is always the best way to start. Learning should always go hand in hand with practice.

After all remember: There is no way to learn without experimenting and making mistakes (but keeping a backups is always useful).

Huo Chess source code

The Huo Chess chess program is an open source micro-chess engine specifically designed for simplicity for educational purposes. One can view the code and easily understand the basic structure of a chess engine using Mini-Max algorithm for its thinking process. Reusing the code is allowed by all means (and even encouraged), as long as the source of the code is cited properly.

You can download the latest files for previous Visual Studio versions via the relative sites:

Download the code from the sites above, open them in your local Visual Studio 2022 and… let the fun begin.

In this article, I will describe how the Visual Studio 2019 Huo Chess based on .NET Framework was ported into Visual Studio 2022 and .NET 6.0. In the process I will describe some changes that were necessary and you will be asked to apply those changes to the program you downloaded yourself.

If you are impatient or find that difficult, you can always download the ported (‘fixed’) program from the last chapter at the end of this article.

First things First: Fixing dpi issues

Modern world is different than the world during the Commodore era in many ways. One of them is higher dpis. A modern program should handle that higher dpi of the screens effectively, otherwise it will look blurry. If you try to compile and run the program you already downloaded, you can see that for yourself.

Huo Chess previous version had an issue with how high-dpi screens were handled, making the UI of the chessboard look blurry without the fix. The changes described below are the changes needed to fix the Huo Chess issues for laptops with high dpi [28].

Please do try to apply those changes yourself in the project you already downloaded and see how they can improve the UI look and feel of the program.

Change 1: The application needs to add a compatibility declaration for Windows 10 in the manifest file:

<compatibility xmlns="urn:schemas-microsoft.com:compatibility.v1">
  <application>
    <!-- Windows 10 compatibility -->
    <supportedOS Id="{8e0f7a12-bfb3-4fe8-b9a5-48fd50a15a9a}" />
  </application>
</compatibility>

Note: If you cannot find the manifest, add it to the solution.

Change 2: We also need to enable per-monitor DPI awareness in the solution’s app.config:

<System.Windows.Forms.ApplicationConfigurationSection>
  <add key="DpiAwareness" value="PerMonitorV2" />
</System.Windows.Forms.ApplicationConfigurationSection>  

Note: If you cannot find the app.config of your application read here for more.

With these changes, the application will handle high dpi of a modern screen fine. However you will still have a problem: the pieces in the chessboard will look small. Try to figure out how to fix that yourself (if you are impatient, just download the source files at the end of this article).

Tip: Try to change the zoom option in the pictureBoxes in the chessboard.

Porting in Visual Studio 2022…

The first thing to do when developing a new application is of course to download and open the IDE. So go and get the latest Visual Studio, open it and then load the program of Huo Chess. In that way you will load the application and you will also be able to build it and run it.

However, that will not make your application a .NET application. Instead, the existing (old) .NET Framework will still be used.

In order to make your application an application that utlizes the latest .NET Platform, you must create a new project and select to create…

  • Console C# application .NET for the Huo Chess console application (DO NOT select the .NET Framework console application, this is the old framework) [4] [5]
  • WinForms C# NET application for the Huo Chess GUI application (DO NOT select the .NET Framework console application, this is the old framework) [6]

After you create the applications, ‘all’ you need to do is copy the code of the old Huo Chess applications into the new projects. Do it your self and learn something through that process. You will learn that copying is not as simple as it seems. Some times you will forget times, some other times you will see that the new .NET application needs something additional in order to compile.

Follow the Visual Studio Intellisense suggestions to walk your way through the hurdles.

For example, you might be missing a ‘using’ statement in the beginning of the program for elements of the application. If that happens (and it WILL happen since the structure of the application in the new project is somewhat different that the old one), first take some time to understand the problem.

Consider for example the following example…

The problem seems to be with the StreamWriter that is highlighted accordingly. If you hover over the Intellisense lightbulb on the left, you will see some suggestions on how to fix the problem.

We will follow the first suggestion and simply add the missing ‘using’ directive in the beginning of the program. Essentially we were using the StreamWriter function without adding the relevant reference to the library containing that functionality. By simply adding the reference as below, the program compiled successfully.

Hopefully with some effort (depending on your level) you will be able to transfer Huo Chess from previous Visual Studio versions to the latest Visual Studio 2022.

So let’s move to the next and crucial step: Publishing!

Publishing the application

Once we created the application and successfully compiled it, we need to create the executable of our application that we will share with others when distributing our chess program. That is where the new .NET Platform has many options for publishing to various systems.

We will explore the best possible parameters to use so as to achieve the major goal for Huo Chess when it comes to size. And that is only one thing: Minimum size!

In summary, the following parameters are used:

  • Target framework: Net 6.0 – Windows 7.0
  • Deployment mode: Framework dependent
  • Target runtime: win-x86 for the console application / win-x64 for the winForms application
  • Other details: Set to produce a single file with no manifest

So essentially we are publishing for not the latest version of Windows, but we are using the latest framework .NET 6.0.

The publishing is conducted in Framework Dependent mode, meaning that the publishing will generate the minimum needed size of the application that will expect the host system to contain the .NET framework in order to run. Of course that is logical to expect, since the .NET framework is developed to be shared in as many computers as possible so that developers can use it – the was we used to us Java that was again supposed to be installed everywhere.

If we choose the other option to produce a Self-contained application, Visual Studio will publish a huge-sized application (counting in MBs) that will contain all needed .NET libraries for it to run. Useful to make sure your application will run even in a system without the .NET, but not useful for Huo Chess.

It is also important to select a specific target runtime for the publishing to generate code for that specific runtime. Try choosing other runtimes to see how easy it is and check out what will happen.

Last but not least, we choose to publish one single file. Doing so provides us with the true size of the application. There is no point in choosing to publish in multiple files and ‘fool ourselves’ that our application is small just because we choose to look at the size only of the .exe file in the folder…

Application trimming

Because of the changes brought by .NET, the size of the applications is somewhat (or significantly) increased vis-à-vis previous versions of the .NET Framework. Being modern, flexible and cross-platform has a price after all.

For Huo Chess this means that the console edition is now 159 KB (from 44 KB that it used to be) and the GUI edition is now 239 KB (from 96 KB that it used to be).

In order to fix that problem, Microsoft added functionalities to trim the code and optimize its size. There are many articles for application trimming in the References at the end of this article that you can read [17-20] [22] [23].

One basic thing to do in order to reduce the size of your application is to disable the implicit usings. ‘Implicit usings’ essentially tell the Visual Studio to add additional needed references to your project as it sees fit based on your code. Disabling this and selecting on your own the ‘using’ statements to have (like the one for the IO we added above) is the way to go when you need minimum size.

There is also an option to allow application trimming, however this applies only to specific publishing configurations and not to the ones we have selected above for Huo Chess. The trimming options look something like…

<PublishSingleFile>true</PublishSingleFile>
<PublishTrimmed>true</PublishTrimmed>
<TrimMode>Link</TrimMode>

However as already said, you cannot use the trimming options when publishing in Framework dependent mode. If we had selected to publish a Self-contained application these options would greatly reduce the size of our application.

The following file has a nice comparison of the resulting application sizes for Huo Chess console and GUI applications for various publishing and trimming configurations.

Please refer to the references below for trimming in order to read more on that topic.

Huo Chess for Visual Studio 2022 (C# NET 6.0)

As promised in the beginning, here one can download the latest Huo Chess projects for Visual Studio 2022.

Use these projects to learn how to program, to view them as you are reading the relative tutorials available in Harmonia Philosophica, or simple to experiment with your own ideas on how a chess program should look like! Again, re-using the code is free and encouraged, as long as you properly indicate where you found it!

Keep experimenting! Keep coding! And have fun!

References

  1. What is .NET?
  2. Five Things You Should Know About .NET 5
  3. Introduction to .NET
  4. Difference Between .NET and .NET Core
  5. How To Create EXE For .Net Core Console Application
  6. What is the difference between a Windows Forms App and Windows Forms App (.NET Framework)
  7. What’s the difference between .NET Core, .NET Framework, and Xamarin?
  8. MSBuild reference for .NET SDK projects
  9. Libraries Feature Switches
  10. Implicit global using directives for new C# projects only
  11. using directive
  12. An introduction to NuGet
  13. Install and manage packages in Visual Studio using the NuGet Package Manager
  14. Quickstart: Install and use a package using the dotnet CLI
  15. Package versioning
  16. Dependencies
  17. .NET 5.0 App Trimming and Potential for Future Progress
  18. App Trimming in .NET 5: Reduce Your App Sizes Dramatically
  19. How to reduce .Net Core App Size
  20. Reduce the size of your app in .NET Core 3 and above
  21. Remove Unused References
  22. App Trimming in .NET 5
  23. Trim self-contained deployments and executables
  24. Working with Assemblies and the Global Assembly Cache
  25. How to: Remove an Assembly from the Global Assembly Cache
  26. What’s new in Microsoft .NET 6
  27. c# How do I create a manifest file?
  28. winforms – Font blurry in Windows Forms C#

HUO Writer: A simple AI writer with basic Neural Network capabilities (QB64)

Advertisements

News

  • 2021-02-14: Updated phrases the AI uses. Added more comments to make the code more readable and easier to configure new phrases.

Goal

The goal of Huo Writer is to be a program that thinks philosophically. By getting user input on a specific topic, it can generate phrases with deep philosphical meaning so as to trigger thoughts on the human user.

The goal of the article is to serve as a simple tutorial on how to build a program that can have a conversation with a human, for people with limited or no programming skills.

Go directly at the end to get the code of the program.

Other programming tutorials

Introduction

Programming is easy. And difficult.

It is easy in the sense that all you have to do in order to do it, is… do it! As in all things. There is no magic words to use, no secret key, no hidden doors to unlock. Simply open your computer and start programming. As simple as getting up in the morning and making coffee.

Of course, you must know how to make coffee.

That is the difficult part of programming. But do not worry. As in all other programming tutorials in our portal, we will try to keep it simple.

First of all, we will use the simplest high-level language for our tutorial, i.e. QBasic (and in particular, the 64-bit version which can run in any modern Operating System, QB64). BASIC is, as the name implies, basic. Very easy to learn. There are tons of resources in the Internet on the language; be sure to search for QB64 (QBasic 64 bit) mainly, so as to make sure you search for the right thing.

Secondly, the program itself is ultra-simple. The code is based on a very limited set of commands (mainly PRINT, IF, CASE, INPUT, RANDOMIZE) which you can easily learn. And even if you don’t you are able to understand what they do by reading this article!

Huo Writer on faith, problems, helping…

Yet and despite the above, the actual result is very good! The program actually does sound like a philosopher and writes deep stochastic phrases which will trouble you and invoke thoughts.

Look at the text below…

Never do faith supports us.
Would faith exist without you?
Ignorant men.
Others create reality.
Don’t you remember?
Stop thinking. And you will see…

~ HUO Writer, 2020-09-01

It was written by the program when discussing about the tags faith, helping, problems. Taking into account how simple and ultra-light the program is, it is really good! Don’t you agree? (Note the small gramatical errors, these are still part of the problems still to be solved)

Is it Artificial Intelligence though?

Well, surely it wasn’t created on its own, so yes it is artificial. And it does include some very basic rules to randomly generate what it says. Last but not least, the result seems like it is intelligent, so that is the greatest argument in favor of answering yes to this question. After all, how to I know that you are not robot?

I. How the program works

The program works in the following simple steps:

  1. Ask input from the user: The program needs from the user to enter some tags related to topic of discussion. For each tag, the gender (male, female, neutral, adjective, indifferent) and the number (plural, single, indifferent) must be defined. Note that some of the values are not exactly ‘correct’, for example the ‘adjective’ is not a gender. The values entered are then used by the program to properly formulate the phrases it will generate to speak with the human.
  2. Generate the phrases to say, by not-fully randomly combining the tags provided by the user with specific words and phrases in the database of the program.

Simple huh?

Well, it is!

The most difficult part is to enter meaningful and cleverly selected words and phrases in the database so that the phrases generated by the program can sound as philosophical and meaningful. As in any other thing, the ‘Garbage in-Garbage out’ principle stands strong.

II. Step 1: Get user input

Getting user input is as simple as using the… INPUT command in QBasic and ask from the user the input.

Just see the code below on how the program asks from that input.

PRINT "What is our theme of discussion to-day?"
PRINT ""
INPUT "Number of tags: ", tagsNo
PRINT "Thank you"
SLEEP 2
PRINT "": PRINT "Now…": PRINT ""
SLEEP 2
PRINT "Please enter related tags one by one…"
SLEEP 2
PRINT "One word only per tag please. All in small letters."
PRINT "Enter Bye or just press Enter to exit."
'Read related tags for the subject of discussion
FOR I = 1 TO tagsNo

PRINT ""
INPUT "Enter Tag: ", Tags$(I, 1)
IF Tags$(I, 1) = "Bye" OR Tags$(I, 1) = "" THEN END

TagGender:
INPUT "ENTER THE TAG'S GENDER (m, f, n, a, i) : ", Tags$(I, 2)
IF Tags$(I, 2) <> "m" AND Tags$(I, 2) <> "f" AND Tags$(I, 2) <> "n" AND Tags$(I, 2) <> "a" AND Tags$(I, 2) <> "i" THEN GOTO TagGender

TagNumber:
INPUT "ENTER THE NUMBER OF THE TAG (s, p, i) : ", Tags$(I, 3)
IF Tags$(I, 3) <> "s" AND Tags$(I, 3) <> "p" AND Tags$(I, 3) <> "i" THEN GOTO TagNumber

NEXT I

Initially the program asks for the number of the tags to be entered and then, for each tag (hence the FOR… NEXT loop), the user is asked to enter the parameters (gender, number) of the tag.

As you can see, all the tags entered as placed inside the Tags$ table. This table will be then used to generate the phrases.

The tag itself is stored in dimension 1 of the table, while the parameters of the tag are stored in the dimensions 2 and 3 of the table.

Tags table dimentions

  • Dimension 1: The tag itself
  • Dimension 2: This stores the gender
  • Dimension 3: This stores the number

These parameters will be used later on in validation rules necessary for the correct creation of the phrases.

III. Step 2: Generating the phrases

Based on the input of the user, the program combines the tags with specific phrases or words in the database of the program.

The program generates the following phrases:

  1. Phrase H.1: The first phrase, combining phrases from tables H1$, H2$, one of the tags and a phrase from table H3$.
  2. Phrase H.2: The second phrase, combining a phrase from table H4$, one of the tags and a phrase from table H5$.
  3. Intermediate phrase 1: A connecting phrase, which includes a phrase from table I1$.
  4. Phrase K: The third phrase, combining phrases from tables K1$, K2$ and K3$.
  5. Intermediate phrase 2: A connecting phrase, which includes a phrase from table I2$.
  6. Terminating phrase: The closing phrase, which includes a phrase from table T$.

As mentioned, the elements used for each phrase as documented in the program’s database. By ‘database’ we do not refer to a relational database, but to tables (e.g. tables H1$, H2$, H3$ used for the first phrase) which are populated with data with the code of the program.

These rables are filled in as follows…

'PHRASE 3 (Phrase K)
'Set Variables for third phrase (Phrase K) generation
'----------------------------------------------------
K1$(1, 1) = "Death": K1$(1, 2) = "i": K1$(1, 3) = "i"
K1$(2, 1) = "Life": K1$(2, 2) = "i": K1$(2, 3) = "i"
K1$(3, 1) = "Self": K1$(3, 2) = "i": K1$(3, 3) = "i"
K1$(4, 1) = "God": K1$(4, 2) = "i": K1$(4, 3) = "i"
K1$(5, 1) = "Existence": K1$(5, 2) = "i": K1$(5, 3) = "i"
K1$(6, 1) = "Being": K1$(6, 2) = "i": K1$(6, 3) = "i"
K1$(7, 1) = "Reality": K1$(7, 2) = "i": K1$(7, 3) = "i"
K1$(8, 1) = "Others": K1$(8, 2) = "i": K1$(8, 3) = "p"
K1$(9, 1) = "Thought": K1$(9, 2) = "i": K1$(9, 3) = "i"
K1$(10, 1) = "Knowledge": K1$(10, 2) = "i": K1$(10, 3) = "i"
'-----------------------------------------------------
K2$(1, 1) = " defines ": K2$(1, 2) = "i": K2$(1, 3) = "s"
K2$(2, 1) = " is defined by ": K2$(2, 2) = "i": K2$(2, 3) = "s"
K2$(3, 1) = " creates ": K2$(3, 2) = "i": K2$(3, 3) = "s"
K2$(4, 1) = " is created by ": K2$(4, 2) = "i": K2$(4, 3) = "s"
K2$(5, 1) = " define ": K2$(5, 2) = "i": K2$(5, 3) = "p"
K2$(6, 1) = " are defined by ": K2$(6, 2) = "i": K2$(6, 3) = "p"
K2$(7, 1) = " create ": K2$(7, 2) = "i": K2$(7, 3) = "p"
K2$(8, 1) = " are created by ": K2$(8, 2) = "i": K2$(8, 3) = "p"
'------------------------------------------------
K3$(1, 1) = "death.": K3$(1, 2) = "i": K3$(1, 3) = "i"
K3$(2, 1) = "life.": K3$(2, 2) = "i": K3$(2, 3) = "i"
K3$(3, 1) = "self.": K3$(3, 2) = "i": K3$(3, 3) = "i"
K3$(4, 1) = "being.": K3$(4, 2) = "i": K3$(4, 3) = "i"
K3$(5, 1) = "others.": K3$(5, 2) = "i": K3$(5, 3) = "i"
K3$(6, 1) = "existence.": K3$(6, 2) = "i": K3$(6, 3) = "i"
K3$(7, 1) = "reality.": K3$(7, 2) = "i": K3$(7, 3) = "i"
K3$(8, 1) = "God.": K3$(8, 2) = "i": K3$(8, 3) = "i"
K3$(9, 1) = "thought.": K3$(9, 2) = "i": K3$(9, 3) = "i"
K3$(10, 1) = "knowledge.": K3$(10, 2) = "i": K3$(10, 3) = "i"

As you can see, as with tags, dimensions 2 and 3 are used to store the gender and the number of the elements.

The tables documented above are for the creation of the K Phrase (i.e. the third phrase). The program randomly selects an element from each table and finally creates the phrase to show to the use.

The phrases are generated, by generating random number and then using these numbers to get the relevant entries from the tables defined above.

An example of the code used to get random numbers and create the phrases (the example is from Phrase K) is depicted below.

'----------------------
'Generate third phrase
'----------------------
PhraseK:
RANDOMIZE TIMER
A = INT(RND * 9) + 1: B = INT(RND * 7) + 1: C = INT(RND * 9) + 1
IF C = A THEN GOTO PhraseK
'If number is not equal (plural with plural, single with single) or the number of the next element is not indifferent, then generate phrase again
IF K1$(A, 3) <> K2$(B, 3) AND K2$(B, 3) <> "i" THEN GOTO PhraseK

As said before, the code is simple. In most cases it is. It is the idea that could be complex either in percieving it, implementing it or both. (or selling it I would say, but that is part of another bigger discussion)

Phrases generation rules

There are some basic validation rules applied for the phrases generation. As the program progresses, these rules will be amended and improved.

One rule for example is the following: the number of an element must match with the number of the tag combined with that element. The code below does exactly that thing: If the number (i.e. the 3rd dimension) of the first and the second element do not match, then the program is instructed to go back and generate the phrase again.

IF K1$(A, 3) <> K2$(B, 3) AND K2$(B, 3) <> "i" THEN GOTO PhraseK

If the validation fails, then the program generates a new phrase.

Printing the phrase

After the phrases are generated, they are printied on the screen. With what else than the… PRINT command.

Voila!

A philospher at your own hands!

APPENDIX I – Neural Network

If the user activates the Learning Mode, the program asks for input after each phrase it produces. If the input is negative (i.e. the user says that he did not like the phrase generated) then the program stores the combination in a table storing ‘bad’ combinations with the code below.

PRINT "": PRINT "Was this sentence a good one? (y/n)"
e$ = ""
DO
    DO
        hyn$ = INKEY$
    LOOP WHILE hyn$ = ""
    SELECT CASE hyn$
        CASE "y", "Y"
            e$ = ""
        CASE "n", "N"
            BadCombinationsK(Kcounter, 1) = A
            BadCombinationsK(Kcounter, 2) = B
            BadCombinationsK(Kcounter, 3) = C
        CASE ELSE
            e$ = "A"
    END SELECT
LOOP WHILE e$ <> ""
PRINT "Thank you for your input.": PRINT ""

The next time the program speaks with the user, the bad combinations are not used in the phrase generation.

An example of the code doing that is depicted below.

'Neural network: Check if the combination selected was discarded by human previously. If yes, generate a different one!
FOR I = 1 TO Kcounter
IF BadCombinationsK(I, 1) = A AND BadCombinationsK(I, 2) = B AND BadCombinationsK(I, 3) = C THEN GOTO PhraseK
NEXT I

This is the simplest form of a neural network: The program ‘learns’ from human interaction and adjusts the ‘nodes’ (elements used for the phrases) inside its ‘brain’ (tables holding the elements used for the phrases) accordingly.

Note that this works only inside the same instance of the program. Whenever you restart the program the ‘bad nodes’ are forgotten, since they are not stored permanently anywhere.

APPENDIX II – The source code

You can click at the link below to get the source code.

Simply copy-paste it into a QBasic editor and execute.

APPENDIX III – How to configure the program

The program is easy to configure. And that is why it is so fun! I have added phrases which are related to my personality and the way I am thinking. You can alter them to reflect yours!

You can also add new elements for the phrases! Simple go and add new elements in the relative tables. When doing that, rememeber to also define the gender and number of the element.

After having added the new element, do not forget to increase the relative constant which defines the size of the table! The constants defining the size of the elements’ tables can be found in the beginning of the program.

Programming for kids: Developing a chess program in BASIC – Part 4: Advanced concepts

Advertisements

Hello again!

After having published various tutorials on basic chess programming, it is time to move on to more advanced concepts.

Programming for kids – How to program a chess program in BASIC

Existing chess tutorials

Huo Chess resources

This article will touch-base on some more advanced concepts in chess programming:

  • Thinking for more moves ahead in the game
  • Improving the position evaluation
  • Selecting the best move (miniMax concept introduction)

Up to now the program we have developed (see the previous lessons, where you can download the program) can think in one (1) move depth. This means that it simply (well, not ‘simply’ – we have gone a long way to make this happen) scans all the possible moves and then selects the one with the highest score.

This has just gave us an insight of the way a computer may think for chess, but a very limited one. The basic thing for thinking for chess is thinking in depth. Everybody would agree that thinking in more depth makes someone a better player.

How can we make that happen?

Simple!

We will copy-and-paste (sort of speak) the main computerMove SUB (Move depth 1 – Existing) two times more, so that the computer also thinks two moves more in depth. In essence, there will be two additional ‘thinking SUB-routines’: One which thinks of the potential human moves (Move depth 2) and another that thinks of the reactions of the computer to those moves (Move depth 3).

After that we will have the following structure:

DEPTH 1: computerMove: This routine thinks of the potential moves of the computer at the first level of thinking. If the thinkingDepth is not reached (i.e. if it is not set to 1, but e.g. 3) then the HumanMove1 SUB is called.

IF Move = thinkingDepth THEN
   'If the score is better than the existing best score, then this is the best move now (and the best score)
   IF ((playerColor$ = "b" AND positionScore >= bestPositionScore) OR (playerColor$ = "w" AND positionScore <= bestPositionScore)) THEN
           bestStartingRank = startingRank
           bestStartingColumn = startingColumn
           bestFinishingRank = finishingRank
           bestFinishingColumn = finishingColumn
           bestPositionScore = positionScore
   END IF
END IF

IF Move < thinkingDepth THEN CALL HumanMove1(chessboard$())

DEPTH 2: HumanMove1: This routine is scanning for all the possible answers of the human opponent. For each of those movements, the next thinking depth routine is called.

DEPTH 3: ComputerMove2: The last routine. Searches for possible moves at depth 3 (i.e. 3 half-moves). The move which ends up with the position with the best score at the end, is the one chosen.

IF ((playerColor$ = "b" AND positionScore >= bestPositionScore) OR (playerColor$ = "w" AND positionScore <= bestPositionScore)) THEN
          bestStartingRank = startingRank
          bestStartingColumn = startingColumn
          bestFinishingRank = finishingRank
          bestFinishingColumn = finishingColumn
          bestPositionScore = positionScore
END IF

With these you will have the program think in depth of 3 half-moves (i.e. a move of the computer, a move of the human opponent and a last move by the computer).

You can download the program below.

Download Source Code

Simply copy and paste the code in your QBasic editor and try it out!

One can also download a graphics version, where I have added the graphics engine by Deep Chess (by Thomas McBurney).

Important: For it to work, copy the PIECES.EGA file you will find in the Deep Chess site to the same folder as your program (this file contains the images of the pieces).

Make sure you keep on coming to this page for updates of the code.

Opening Book Editor

The latest versions (v0.6) of the code have an opening book functionality. In order to generate the files of the opening book you can use the Opening Book Editor found below.

Simply run the program, play the moves you want to store in the opening book and they will all be stored in separate txt files. These files must then be places in the same folder as the Huo Chess executable for the latter to utilize them.

As with Huo Chess, make sure you visit this page again to check for any updates or improvements in the code!

Advanced concepts: Improving the computer thinking

The algorithm described above is simple and does make the computer think in depth. When using the code below, you will see an obvious latency in computer’s thinking vis-a-vis the time needed by the previous version which thinks in depth of only 1 move.

However it does not make good moves!

What is needed for that to happen?

First improvement: Improvement of the position evaluation.

Now we are just counting the material in the final position.

SUB countScore

positionScore = 0

FOR I = 1 TO 8
    FOR J = 1 TO 8

IF chessboard$(I, J) = "wpawn" THEN positionScore = positionScore + 1
IF chessboard$(I, J) = "wrook" THEN positionScore = positionScore + 5
IF chessboard$(I, J) = "wknight" THEN positionScore = positionScore + 3
IF chessboard$(I, J) = "wbishop" THEN positionScore = positionScore + 3
IF chessboard$(I, J) = "wqueen" THEN positionScore = positionScore + 9
IF chessboard$(I, J) = "wking" THEN positionScore = positionScore + 100

IF chessboard$(I, J) = "bpawn" THEN positionScore = positionScore - 1
IF chessboard$(I, J) = "brook" THEN positionScore = positionScore - 5
IF chessboard$(I, J) = "bknight" THEN positionScore = positionScore - 3
IF chessboard$(I, J) = "bbishop" THEN positionScore = positionScore - 3
IF chessboard$(I, J) = "bqueen" THEN positionScore = positionScore - 9
IF chessboard$(I, J) = "bking" THEN positionScore = positionScore - 100

    NEXT J
NEXT I

END SUB

But material is not everything.

For example in the initial position all moves seem to result in the same material score, however it is known that in the chess opening the good player always moves hies pieces near the center of the chess board, avoid unnecessary movements of the king and the queen and avoids to move the same piece twice.

Make sure to check the latest version of Huo Chess uploaded, to see how qualitative criteria were added in the countScore SUB!

EXERCISE: Try to improve the countScore SUB to cater for the above. You might need to also introduce a new variable which will count the number of moves we are in the game, so that the computer knows if we are at the opening, the middle of the final stage of the game.

Second improvement: Apply the MiniMax algorithm

The thinking mechanism of the program we have desribed is inefficient. One could say that it is inherently flawed.

The program searches for the best score at the end of 3 half-moves, but does not cater at all for the fact that the human opponent moves (at move depth 2) will not be the ones which maximize the score for the computer, but the ones maximizing the score for the human opponent.

In other words: The variants (set of moves) which include completely stupid human opponent moves end up in high scores in favor of the computer and that is why, those variants will at the end be chosen.

But in real life the human opponent will never play his worst moves, but quite the opposite: He will play his best moves so as to win the computer!

The following example will better illustrate the problem.

Imagine we are at the following position…

Important note: The Huo Chess program was developed with simple text-like ‘graphics’. There is also a graphics-version based on Deep Basic chess program (by Thomas McBurney), which you can also download.

An initial version of Huo Chess which simply thought in terms of the best score at the end of 3-half-moves, would play… Qf7+ in this position.

But this is a bad move! Why does it play that?

Simple.

The computer assumes that at the next move human will play something stupid and then it will be able to capture the king of the opponent. The set of moves “1. Qf7+ [something stupid] 2. Qxe8” results in the best (highest) score for the computer, so this move is selected.

The algorithm did not even think that human after Qf7+ will simply play KxQf7 and take the queen, simply because this move results in low score for the computer.

But how do you take into account the best moves for the human opponent (MAXimize value) and at the same time the worst possible variants for the computer (MINImize value)? In other words, at the end, how can the computer play its best move taking into account the worst scenario, which we will have only if the human opponent plays his best move?

EXERCISE: Try to think of the above on your own, WITHOUT reading online about the MiniMax algorithm. First of all – who knows? – you might think of something better! Secondly, one only masters knowledge when he has tried on his own and failed to acquire it. Having things ready for you simply does not lead to wisdom.

The solution to the above problem is the MinMax algorithm. The current version of Huo Chess utilizes it, so you can read there how it works. However note that you can never learn anything by simply copying the program of someone else. Unless you write the program on your own, make mistakes, spend countless nights and days pondering upon them, you will never truly develop anything.

Make sure you check the relevant Huo Chess C# tutorials which refer in more depth to the algorithm (which stays the same regardless of the programming language you use of course).

More updates coming soon!

Until next time…

Happy coding!

Programming for kids: Developing a chess program in BASIC – Part 1

Advertisements

Programming for kids – How to program a chess program in BASIC

Other Related articles

Programming is fun.

Want to learn? Why not start now?

And what better way there is than to develop an advanced program that makes the computer “think” how to play chess?! Forget about those silly beginners’ example programs which print “Hello world”. Who in his right mind ever spends time to write a program which prints “Hello world” on the screen?

BASIC is fun.

A very easy language for kids to start learning programming. So we will use it here. (Not in the mood for BASIC? Search for the Java and C# relevant tutorials in Harmonia Philosophica!)

And in one day, you will have learnt the basic of how to program a chess program in BASIC! The actual implementation could take a bit longer but in general in some days you will have the knowledge of how the program works, thus being in a position to improve it or write your own!

The BASIC programming language is one of the simplest ones. Especially designed for simplicity, it uses simple commands to perform operations. The commands are easy to learn and use, since they are utilizing English language words which are easily recognizable. Want to print something on the screen? Use the command PRINT! Want to determine what will happen if something else happens? Use the command IF! See what I mean?

IF YOU_UNDERSTAND = "Yes" THEN PRINT "Yes I understand!"

Did you understand the above command? Great!

The only thing that might trouble you if you are new to programming is the notion of variables. A variable is an element which holds values. This element is used in various places of the program. The values could be of different types – the ones we will use are integers (1, 4, 10…) and strings/ characters (e.g. “white pawn”).

Variables could be stored also in arrays. An array is a collection of variables in one or more dimensions. It is also known as a “table”. And yes, you guessed right: we will use an array (table) to store the chessboard. Could you guess the dimensions of that table? Spot on again.

DIM SHARED chessboard$(8, 8)

The command DIM defines a variable. We do all the variable declarations in the beginning of the program. The above command declares an 8×8 array which holds the… you guessed it right: The chessboard!

By the way, we are using QBasic64, a version of Quick Basic that is available for free and pretty popular as well. Check https://www.qb64.org/portal/ to get it. The site also contains excellent tutorials and training material. You will have it as a reference throughout the whole process, so make sure you create a bookmark out of it.

After you download QBasic64 from the site, just click on the QB64.exe file and execute it. You will be presented with the IDE (programming interface) of QBasic where you will write your program. I do not need to explain the “Create new”, “Save” or “Save as” functions…

Just start writing the commands and then press “Save as”. Executing the program is easy as well. Just select Run > Start.

As said above, what is the first thing to do? (Besides the “Create new program” part and saving it in a folder of your choosing with a name of your choosing as well)

Some of the first things to do we already mentioned.

First, declare the variables. BASIC is really simple in the sense that it is not so strict in requiring you to declare all the variables before using them, in contrast to other high level languages like C#. However this is also a downside of the language. Leaving the programmer with some slack makes the programmer careless.

So we will declare all the variables we use…

DEFINT A-Z
OPTION BASE 1 'Make tables dimensions start from 1
DIM SHARED chessboard$(8, 8)
COMMON SHARED startingRank, startingColumn
COMMON SHARED finishingRank, finishingColumn
COMMON SHARED startingRankText$, startingColumnText$
COMMON SHARED finishingRankText$, finishingColumnText$
COMMON SHARED Move$
COMMON SHARED MovingPiece$
COMMON SHARED debugMode

There you go. (Read the QB64 Wiki for what DEFINT A-Z and OPTION BASE 1 commands do – Remember, learning entails the process of… learning)

What is next?

What else?

Ask the user for input!

And what else to ask than his first move! For simplicity purposes we will present the main command which tells the user to put his move. The drawing of the board on the screen will be done by the drawBoard() function. A function is an independent set of code that you can call to perform an action. In our case we call the drawBoard function (with the command… CALL DRAWBOARD – I told you it was simple). For the time being forget how the function works. (Even though reading through it and trying to understand how it works would be a lesson on its own…)

So how would you ask for the user input?

Simple by the command… INPUT!

There you go:

INPUT "Enter your move: ", Move$

This command tells the computer to wait for the user to enter something and press Enter. When this happens, the text entered by the user is saved in the Move$ variable. The dollar sign ($) indicates that the variable is a string (text) and not a number.

Let’s stay there.

For now you have learnt how to…

  • Create a new program.
  • Declare the variables you will use (including the chessboard).
  • Ask from the user to enter his first move.

You have also been acquainted with the notions of variables and functions and with some basic BASIC (get the joke?) commands, like IF… THEN or INPUT and PRINT. Don’t worry if you don’t get everything yet. You will as you program more and more every day.

Next lessons will include the next logical steps:

  • Validate that the user move is valid and legal.
  • Redraw the chessboard with the move of the user.
  • Make the computer think of an answer.

You would be surprised how the last part (the thinking of the computer) is a rather simple one. In essence the computer thinks of all possible moves, validates them (in the same way we will validate the move entered by the user) and then for the valid ones it will calculate a score of the position. The move with the best score will be the move of the computer.

Until next time…

Happy coding!

Next lesson: How to check the legality of the move entered! Check here.

Ultra-fast programming tutorials: How to develop a C# adventure game in one day (without prior programming experience)

Advertisements

Other Related articles

Introduction

Is programming a game difficult?

Don’t be fooled by the title. Yes it is!

However learning the basic principles of programming and making a very simple game is… simple! And the goal of this article is to show how one can learn programming while having fun in just one day.

Yes, you read that right. One day. Do not expect (of course) to be experts. This goes without saying. But you will learn how to create your first program, which will actually do something. This is how I started programming myself. I had bought (my parents actually) a Commodore 16. And there were no games with it. Just a big manual. In which there were the source code of some games I had to type myself into the computer in order to play them! At first I did not know what I typed. But I typed it anyway. And the game was fun.

Next day, I started learning programming.

Because you see, in order to learn something you must LIKE it first! There is absolutely no point in learning programming just by reading big books with incoherent programming exercises which will at the end result in nothing more than code snippets (parts of code) which do nothing important or useful whatsoever. This is how today’s kids learn to hate programming.

The game we will develop is very small and easy: Just an old-times ultra mini text-adventure. Meaning a game with no graphics, which asks for the users to input text commands (e.g. “Open door”) in order to play it.

Sounds fun?

Well, it is!

And most importantly, it is scalable! You can – at your own pace – make it better, more complex, or even add graphics (there will be a lesson for that too). And make it your own super game that will conquer the world! Or at least your friends and parents. 🙂

No more talk. Let us begin!

Setting up the tools

Download Visual Studio from Microsoft. There is a free edition to download. Install it. Figure out how to do that on your own, it is not difficult really – just like installing any other program, just select for now the default configuration suggested by the program.

What you will need is C# to be installed – because there are other languages also supported by Visual Studio (C++, Visual Basic, F# et cetera).

Create the project

Open Visual studio and create a new C# Console Application project.

When first creating the program, Visual Studio will create a lot of code automatically. Your project will look something like the schema below.

This code is the shell of your program. Do not worry about what it does for now. What you need to remember is that the program has a Main class, inside which you should put your code (see the schema above).

Game scenario

What is the scenario of your adventure?

Let us keep it simple: You are a person who have lost his consciousness and is suddenly found inside a locked room. You want to get out. As simple as that. Your goal is to search the room for the key and unlock the outer door!

What will be the solution of the problem?

Again, let us keep it as simple as possible: You search the room. You see a box. You open the box. There is a key inside it. You take the key. You use the key on the door. The door opens. You get out.

It may sound simple – and it is – but this is the basis of a simple game. Remember! You will have time to improve it later on! The point here is to learn the very basics of programming.

The code

Open the newly created project. Now you need to add the code to actually make your game. We will do this by adding the minimum lines of code to make the game. As said above, you will then be able to add additional code and improve the game. What we will show here is the basic principles.

The game has no graphics, so all we need is a way to get user input through text and then present to the user again the results of his action via text.

For a short description of the basic elements of a program (variables, functions etc) check the Huo chess tutorial here.

In short, what we will need is the following programming elements:

Variables: These are elements of different types which hold values. A variable can be an integer variable (which may hold values like 1, 4, 10), a String variable (which may hold values like “key”, “door” etc) or a variable of many other types. We will use the following variables:

  • A variable to hold the command the user has entered. We will call this user_command.
  • A variable to know whether the user has the key or not in his pocket. We will call the variable user_pocket.
  • A variable to determine whether the game must end. We will call this exit_game.

Input/ Output commands: These are the commands we will use to get input from the user (the commands he will issue to do things in the game) and to inform him of the result of his actions with a text message on the screen. There are three major commands we will use for this:

  • Console.Write: This command writes something on the screen, while leaving the cursor at the same line.
  • Console.WriteLine: This command writes a line on the screen and then presses Enter to position the cursor in the next line.
  • Console.ReadLine: This command reads what the user has entered. We will use this command to get the user input and store it in a variable we will call ‘user_command’. Intuitive isn’t it?

All of the above functions are existing functions in C# to process input and output in a program. The fact that they all start with ‘Console.’ simply means that these functions are part of a class called ‘Console’ – look at the class as a large collection of functions. And yes, this is a very simplistic and – to be honest – technically wrong way of putting it. But it will keep your brain from exploding while giving you some time to read in Google what Console is in C#. (remember to check again the basic tutorial for Developing a chess program here, where I have a short description of what a class and a function is)

Decision commands: The program needs to decide what to do when the user does some things. So for example, when the user enters the command “Open door” it needs to be able to decide whether or not the door will open (if the user has the key it will open, if not it will not). We will use the ‘if’ command to perform this kind of operations. The way this command works is very intuitive. You will see in the code how this happens.

The commands the game will accept are the following:

  • Look around
  • Open box
  • Get key
  • Open door
  • Q will exit the game

Loop commands: We need to make the game constantly ask for user input. So after each command the user enters, the program must process it, inform the user of the result of his action and then go back and again ask for input. We will use a do… while look to perform that. With that, every line of code that is within brackets between the ‘do’ and the ‘while’ commands is constantly executed until the condition in the ‘while’ command is met. You will understand when you see the code.

TIP: Google is your friend. Don’t be shy to use it. If you are not sure how a command works just write it into Google search and find out yourself! Not sure how the ‘if’ command works? Google “C# if command” and there you go! (the C# is always needed in the search if you search for C# – but this is rather a tautology and not an advice)

Writing the code

Are you ready to actually write the code?

Well, don’t worry. I have done that for you. Look at code below and write down the program in your own project’s Main method yourself. Go to the static void Main(string[] args) method and write down the below code inside the brackets.

// Declare the variables
String user_command;
String user_pocket = "";
bool exit_game = false;

// Main program loop
do
{
// Ask for user input
Console.Write("What do you want to do? (press Q to exit) ");
user_command = Console.ReadLine();

// Process user input
if ((user_command == "Open door") && (user_pocket == "") )
Console.WriteLine("Door is locked");
else if (user_command == "Look around")
Console.WriteLine("You see a box on a table");
else if (user_command == "Open box")
Console.WriteLine("There is a key inside");
else if (user_command == "Get key")
{   
     Console.WriteLine("You got the key");
     user_pocket = "key";
}
else if ( (user_command == "Open door") && (user_pocket == "key") )
{
     Console.WriteLine("You opened the door! Bravo!");
     user_pocket = "key";
     exit_game = true;
}
else if (user_command == "Q")
     exit_game = true;
else
     Console.WriteLine("Nothing happens");

Console.WriteLine("");
} while (exit_game == false);

There you go!

A game that you wrote!

Your code should look like that.

Important Notes

  • All C# commands end with a semicolon, as you may have noticed. With some exceptions as may have also noticed.
  • The comments are entered after double slash ( // ). They are usually very useful not only for others but mainly for the programmer himself!

Download the code

Ideally you should write the code on your own, so that you practice. However for reference purposes, you can also download the example below.

The file contains the solution as it was developed for this tutorial.

Executing the program

In order to build your code, select Build > Build solution (or Rebuild solution , after you have built it for the first time).

In order to run your program, select Debug > Start without debugging.

The result should look something like this…

That is, if you are smart enough to find the key…

Epilogue

Like when I copied the code from my first Commodore computer manual, you may not know exactly what you write and why. But with what you have read above, you will certainly understand the meaning of the commands and what they do!

You now have a game that you wrote. And potentially a gate to the world of programming. At the end, it is not up to me to teach you anything. It is up to you to learn. As Buddhism says, when the student wants, the teacher appears. I am not your teacher. But I may have instilled in you the desire to search for one…

Happy coding!

APPENDIX – Jurassic Park Adventure Game

When I was a kid, I developed an adventure called “Jussaric Park” based on the known book of Michael Crichton. It was (and still is) a simple yet fun to play text-based adventure writen in QBasic.

You can download the code from below and use your favorite QBasic IDE to view, edit and execute it. The QB64 is a good choice for that.

The user must set the speed when starting the game
Yeap, it is mine!
Graphics are nice… Wait till you hear the crickets…
It’s all Greek to you.
The main screen of the game where you can select the commands
Walk command: Press ‘w’ and simply write where you want to go!
Using the JUPASE (JUrassic PArk Software Emulator)
You made it! You got out of Jurrasic Park!

You can find the code below. Simply copy-paste it into a QBasic editor and execute. The IOURASIO file is the main game. The JUPASE program is called when you reach the Visitors’ Center.

As already mentioned, it is writen in QBasic and it is a playable and enjoyable (at least for those not addicted to ultra-fast 3D graphics) text-based game. It has comments inside the code to help you understand what happens and how it works, so essentially it is an extension of the tutorial you just read.

Note: You will have to update the path in the JUPASE call. (See? Even when having fun, you can alway learn something!)

Have fun!

And keep coding!

Exit mobile version
%%footer%%