Snake QR

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

Contenxt/Credit

The original source code was taken from MattKC's "Can you fit a whole game into a QR code?" video. If you haven't watched the video prior, watch it here for context and what not.

Main changes compared to the MattKC version

• No crinker/compressor is used. Just pure C and compiler shenanigans.
• A few visual and gameplay fixes 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.

Primary changes

To see the differences between the original and this version first-hand, it's best to view the original file and see what's different from a programming perspective. Regardless, here is a list of the main changes between the two:

Space saving changes

• The input system has been reworked to utilize only 2 variables instead of using an array of valid/invalid inputs. This rework reduces quite a considerable amount of taken up space inside the executable, as the game now does less interanally for the same result.
• The food starts at a constant position instead of calling the rand function at startup.
• All integers are size_t.
• 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 allocates memory into the stack instead of the heap to allocate snake_pos.
• 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 doing DeleteObject when calling CreateSolidBrush. It's even stated in the official Win32 documentation that you should use DeleteObject once you're done with the brush. This bug fix does come with a caveat, that being it takes up a bit of space in the executable for it to be implemented.

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.