A simple and pure win32 Snake game, without any compressor trickery, just under 2,953 bytes!

Context/Credit

The original source code was taken from MattKC's "Can you fit a whole game into a QR code?" video where he attempted to port the classic game of "Snake" into a single QR code using the Win32 API in C. Despite the efforts he failed and decided to use a compressor to complete the challange during the final stretch, which felt very lame and lazy to me. So much so that I took a glance at the source code to see if there were any optimizations to make.

My suspicions were proven correct as I was not only able to fit the program into the QR code threshold without changing its fundamental logic, but I also implememted some fixes and improvements compared to the original.

Most notable changes

• No crinker/compressor is used to reduce the executable size. Only Win32 C code and some MSVC compiler flag shenanigans.
• A few visual and gameplay fixes have been added to the game to make it much closer to the HTML version that was shown in the video.
• You can pause the game now by pressing the enter key instead of the 'pause' or 'P' key.
• You can retry the game by pressing the 'R' key.

Code/smaller changes

To see all of the differences it's best to compare this repository's snake.c and the original side by side. Here is a compiled list of the changes:

Space saving changes

• The input system has been reworked to utilize only 2 variables instead of using an array of valid inputs. This reduces quite a considerable amount of space inside the executable, as the game now does a whole less for the same result.
• The food starts at a constant position instead of calling the rand function at startup.
• All integers are size_t (register-sized instructions are usually preffered in most cases).
• A custom rand is implemented instead of relying on the C standard version.
• Code to change the snake's color depending on the game state (playing/won/lost) has been reworked to be completely branchless.
• WM_TIMER's while loop has been converted to a single if statement.
• Removed the bool moved variable in WM_TIMER and used goto instead.
• Removed the else statement at if (snake_len == MAX_TILE_COUNT).
• Removed GetModuleHandleA and AdjustWindowRect.
• The app now uses stack memory instead of the heap to hold snake_pos (this reduces the amount of OS calls needed to be called).
• Removed if (msg.message == WM_QUIT) in the main loop.
• Removed TranslateMessage in the main loop.

Bug fixes

• The original snake.c leaked memory by continuously not calling DeleteObject when using CreateSolidBrush despite official documentation advising to cleanup after drawing. The only caveat with this is that this unfortunately comes with the cost of additional binary space.

Visual changes

• The apple is now green.

Misc changes

• You can now retry the game at anytime by pressing 'R'.
• The game's performance has been improved (less branching, PosEqual does one check instead of 2, etc).
• The pause button has been changed from VK_PAUSE and P to VK_ENTER.
• Regular WNDCLASSA and CreateWindowA are used instead of the expanded versions.
• The game doesn't overallocate dir_queue like it did in the original.

Building

NOTE: cl.exe is assumed to be x86, not x64. Compiling it in 64-bit will considerably increase the size of the binary.

Windows

Just copy the terminal commands from Makefile and paste them into the terminal.

Linux/*nix OSses

This requires downloading msvc from msvc-wine. After that, just run make and you'll get correct binaries.

Making the QR code

Once you compiled snake.exe, on Unix you can run make qrcode to generate code.png.