This is a simple program for learning purposes.

Goals:

• Play around and learn some more about the Odin programming language
• Play with the Raylib game programming library
• Learn more about OpenGL shaders

For me, personally, this project has been a lot of fun to develop.

To use this you will need:

• Odin
• A library build of stb
• OpenGL build tools

I developed everything under (Arch-)Linux. You can try to install Odin using one of the AUR packages:

• aur/odin
• aur/odin-dev-bin
• aur/odin-git

However, I just installed LLVM+CLang directly and built Odin from source by cloning the repo:

• https://github.com/odin-lang/Odin

Since Arch is rocking LLVM-13 as of the time of this writing you will need to do some hackery on the Makefile to build:

diff --git a/Makefile b/Makefile
index d3d3c6a2..b3f54ad8 100644
--- a/Makefile
+++ b/Makefile
@@ -42,16 +42,16 @@ ifeq ($(OS), Darwin)
     LDFLAGS:=$(LDFLAGS) -lLLVM-C
 endif
 ifeq ($(OS), Linux)
-    LLVM_CONFIG=llvm-config-11
-    ifneq ($(shell which llvm-config-11 2>/dev/null),)
-        LLVM_CONFIG=llvm-config-11
-    else ifneq ($(shell which llvm-config-11-64 2>/dev/null),)
-        LLVM_CONFIG=llvm-config-11-64
+    LLVM_CONFIG=llvm-config-13
+    ifneq ($(shell which llvm-config-13 2>/dev/null),)
+        LLVM_CONFIG=llvm-config-13
+    else ifneq ($(shell which llvm-config-13-64 2>/dev/null),)
+        LLVM_CONFIG=llvm-config-13-64
     else
-        ifneq ($(shell llvm-config --version | grep '^11\.'),)
+        ifneq ($(shell llvm-config --version | grep '^13\.'),)
             LLVM_CONFIG=llvm-config
         else
-            $(error "Requirement: llvm-config must be version 11")
+            $(error "Requirement: llvm-config must be version 13")
         endif
     endif

With the above you should be able to build Odin:

$ make
clang src/main.cpp src/libtommath.cpp -Wno-switch -Wno-macro-redefined -Wno-unused-value -std=c++14 -DGIT_SHA=\"38725fc0\" -DODIN_VERSION_RAW=\"dev-2022-01\" -I/usr/include -std=c++14   -fno-exceptions -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -L/usr/lib  -g -pthread -ldl -lm -lstdc++ -lLLVM-13 -o odin

1. Clone stb
2. Crete a file: stb_image.c with this in it:

#define STB_IMAGE_IMPLEMENTATION
#include "stb_image.h"

3. Build the library we need:

$ gcc -c -o stb_image.o stb_image.c
$ ar rcs libstb_image.a stb_image.o

I just did a yay -Sy vulkan-devel which should bring in everything you need.

Now, you will need to edit the build.sh file to make sure that you use the path to where you have built Odin and the stb image library:

# Edit the line that looks like this:
<path to where you cloned and built Odin>/odin build tic-tac-toe.odin -vet -debug -extra-linker-flags:'<path to where you built the libstb_image.a file>/libstb_image.a'

After this is all set up building the program should be as easy as:

$ ./build.sh && ./tic-tac-toe

If you see a window that looks like:

Then WOO HOO!

If not: big brain time, and we wish you luck! Better yet: send a PR to help folks out!

This is still a work in progress, so everything is subject to change. And yes, there are bugs!

You can use the mouse or keyboard ... for now.

• Q: Quits the game any time

Mouse:

• Mouse over the space you want (if open)
• Left click

Current keyboard controls:

• Arrow-keys: move the piece around
• SPACE: sets your piece and changes the piece

When the game is over:

• R: Starts a new game

There are problems with using keyboard inputs in that directional movement is often ambiguous. Any kind of search for "something in the direction you want to look" has a bias of some kind. Whatever search you choose will have degenerate cases that are unintuitive. For instance a board that looks like this:

* | X |
---------
X |   | O
---------
  | O |

Where the cursor is at the position marked with *.

What space should be chosen when you hit the RIGHT ARROW? The DOWN ARROW?

My initial search would do a "depth-first" search that would try to stay in the same column or row relative to where the cursor is currently located. This meant that it was impossible to navigate to the center spot in the board.

The current logic will try to do its best to first look 1 column or row away (depending on what arrow key was pressed), which solves the above problem, but because whatever search you implement you're going to preferentially pick something when multiple options are available.

Consider:

  | X |
---------
X | * | O
---------
  | O |

If I hit the RIGHT ARROW what open position should I pick? No matter what I pick there is an argument that it could have been the other option.

As a result of this I'm strongly considering removing keyboard navigation completely.

• Bug fixes
• Add some sounds
• Some more bling
• Some on-screen instructions would be useful