Back in the mid-1990s (when I was young!), programmers who wanted to build their own games didn't have rich frameworks like Unity. Perhaps the closest we got was the WordUp Graphics Toolkit, which I came across on the Hot Sound & Vision CD-ROM - a BBS archive. If you have a moment, perhaps use Google to see what "bulletin board systems" were... nostaglia awaits!
Much like my very simple _fb.c_, the WGT provides a library of graphics routines which can be depended upon for reuse. This library, however, is much more fully-fledged than mine, and makes it easy to build sprite-based games (like Breakout, Space Invaders, Pacman etc.).
The directory structure
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As I port the WGT to my OS (a.k.a. make it work on my OS), I am using the following directories:
* _samples/_ : sample "kernels" for my OS which exercise certain WGT library functions. To build them, copy one of these (and only one at a time) to the same directory as the _Makefile_.
* _wgt/_ : the library itself. Where possible, I have stayed true to the original code, but do bear in mind it was written for the x86 architecture and we're on AArch64!
So... to build the first sample simply type `cp samples/wgt01.c .` from the top-level directory, and then type `make`. When you boot with the generated _kernel8.img_ you will see the screen go into 320x200 (VGA!) mode and draw a white line from corner to corner. If you do, the library is doing its stuff!
We're still booting into a multicore environment (just in case we need it). There are a few significant changes to _boot/boot.S_ though. I will write more on these later, but (for now) they are:
