demo.ray

Demo of graphics applications built by Fexl

Running the demos

First go into the source code directory:

cd src

In this demo, you fly through a rolling 3D landscape of random blocks:

fexl demo_0462.fxl

In these demos, you walk around a 3D landscape of random blocks:

fexl demo_9457.fxl
fexl demo_6611.fxl

The only difference is that demo_9457 builds the scene as completely static code all in one object file, and demo_6611 uses dynamic lists of objects whose types are defined in auxiliary object files such as plane.o, cube.o, etc. So those demos should produce exactly the same experience, but they illustrate different code generation techniques.

The advantage of demo_6611 going forward is that new objects could be created at run time, and the attributes of existing objects could be changed. That is not possible in the static demo_9457.

Run from any directory

All these demos are position-independent, meaning they can be run from any directory on the file system by specifying a full path. For example, let's say you installed demo.ray in your ~/project/demo.ray directory. Then you could do this:

cd ~
fexl project/demo.ray/src/demo_0462.fxl

Run on Windows

I was able to run the demos on Windows by means of Windows Subsystem for Linux (WSL). After installing WSL on the Windows machine, I could bring up the Ubuntu app through the Start menu, which put me into a shell prompt, where I cloned this demo.ray project and built the prequisites (see below). Then from a Windows command prompt I ran:

wsl.exe ~/code/fexl/bin/fexl project/demo.ray/src/demo_0462.fxl

I also tried that in a demo_0462.bat file and it worked fine.

Utilities

I created a "splitter" utility which helps with converting an existing block of hand-written C code into a Fexl function which reproduces that C code. This helped me convert the old static demo.c into the new demo_6611.fxl.

Here's an example of running the splitter:

fexl splitter.fxl cube.c

Prerequisites

Fexl

Install Fexl from https://github.com/chkoreff/Fexl . My preference is to build it in my own ~/code/fexl directory and then make it available from the command line with a shell alias in ~/.bash_aliases:

alias fexl=~/code/fexl/bin/fexl

Raylib

Here are some instructions on installing raylib:

https://github.com/raysan5/raylib/wiki/Working-on-GNU-Linux

Typically:

sudo apt install libasound2-dev mesa-common-dev libx11-dev libxrandr-dev libxi-dev xorg-dev libgl1-mesa-dev libglu1-mesa-dev

git clone https://github.com/raysan5/raylib.git raylib
cd raylib
mkdir build && cd build
cmake -DBUILD_SHARED_LIBS=ON ..
make
sudo make install

cd src
make