AVRIL release notes - by Devil Master

1- Introduction
2- How to compile
3- How to use AVRIL.EXE


On April 11, 1995, Bernie Roehl released version 2.0 of his VR program for MS-DOS, AVRIL. This included a demo executable to open and explores scenes in the WLD format (with PLG objects), and a number of source code files.
Almost 4 years later, on March 1, 1999, he released the full source code of AVRIL, released under GPL v2.

Both releases, however, have one problem: they won't compile. The first release lacks a large number of source code files, while the second contains a number of files with empty or duplicated functions, calls to functions that don't exist, and it also lacks two header files.

I (Devil Master) have started from the second release, and the first thing I did was to separate all files containing a main() function from the others. Then, I took AV.C from the first release, and attempted to compile the resulting code under Borland C++ 3.1. This is how I discovered the remaining problems.
I further refined the source code by separating every source code file including a nonexistent header and/or with empty or duplicated functions. I did not delete anything; instead, I moved all faulty source files to a new subdirectory I called rejects, for historical preservation. In one case (commented in CFG.C) I had to modify a function so that it would not attempt to call another function which existence depends on a nonexistent #define. The resulting AVRIL.EXE file mimics the behavior of the AV.EXE file that was released by Bernie Roehl (unfortunately, including the bugs).


This section assumes that:
- you have a functional MS-DOS environment (either native or based on DosBox)
- you have already installed Borland C++ 3.1
- you have added the BIN subdirectory of your Borland C++ 3.1 installation to the path, so that entering the command BC from any directory will always cause Borland C++ 3.1 to open.

So, to compile the program:
- reach the directory where you have unzipped the source code (referred herein as the project directory)
- type BC and press Return
- from within Borland C++ 3.1, select the menu option Project -> Open project
- from the window that appears, select AVRIL.PRJ
- select the menu option Compile -> Build all
- Wait for the message informing you that the compilation was successful

Now the project directory will contain a brand new AVRIL.EXE executable, ready to run.


The program will let you explore the .WLD files you load with it (even though there will be graphical glitches because of bugs in the original code).
The project directory includes a subdirectory called SAMPLE, which contains a scene file called SAMPLE.WLD and all the .PLG objects it uses. To access it, enter the command:

avril sample\sample.wld

and press Return. The program will start, displaying what appear to be a pair of 2-dimensional figures. They are actually part of a more complex environment which contains three rooms, a mannequin and some trees, which Rend386 and VR386 can display correctly, but AVRIL never could: the original AV.EXE program, compiled by Bernie Roehl himself, exhibits the same behavior.

VRML is still a great way to create 3D content for the web that can be experienced on computers or Android-based mobile devices. With a head-mounted display and stereoscopic drivers, it can even be experienced in virtual reality!
Would you like to know more about VRML or create 3D web content? These books may be exactly what you are looking for.