Falcon 4.0 Flight Simulator was released at late 1998, so it's no surprise how complicated the code behind it is, especially if we consider that, those days, every bit of memory that could be spared was valuable. With this principle in mind, the terrain storage and display is a very complicated procedure, involving low resolution pcx graphics (paletted) and various mechanisms to spare memory and storage space.
In general, all the terrain information are stored into files with the extension *.lx, where x =0,1,2,3,4,5. These files represent a given LOD (Level Of Detail), which kicks in, at a given distance between the player and the terrain, with *.l0 is the maximum detail. The smallest data information in the *.lx file is a Tile, which represents a 1km by 1km area in l2 LOD. The tiles are stored by packets inside *.lx files, called Segments, where a Segment contains an area of 16×16 Tiles. These *.lx files come together with a pair *.ox file, where x is again 0,1,2,3,4 and 5, which represent the actual terrain map and contain the position in the *.lx file of the Segment that needs to be loaded in the specific position. The Tile record contains information about the altitude of the terrain at the specific point, the number of the texture to be used, a reference to a color from a palette inside a *.map file (the exact function for that is unclear to me, it has to do something with vertex coloring and fog) and some other info (for terrain normals).
The control file for terrain textures is a file with extension *.bin. In there, all the texture information is stored, in a form of Sets. Each set can contain up to 16 Tiles and has a specific type (e.g. Water, Plains etc). Each Tile in this file holds information about the filename of the texture and about Areas and Paths that are drawn on it and used by the program (e.g. for calculating roads and ground troops movement or be aware that there is water on this Tile).
Finally, the textures themselves, were stored in a file called texture.zip, which is a normal zip file containing the the textures in pcx format. The latest versions of Falcon 4.0 (made by user communities) use the dds texture format, which has better quality than pcx.
Terrain Editor (TE for the rest of the manual) is a program developed by me in order to edit the terrain and texture data of Falcon 4.0 (described above). The whole program was created with Visual Basic 6 and C++ and the coding was done by me, using the FreeImage Library.
The need for this software came from the fact that we needed a tool to see the whole terrain of Falcon at once (not in chunks of 16×16 tiles) to evaluate how it's going to be looking inside the sim. Furthermore, we needed some tools to edit some special files of Falcon (such as theater.map and texture.bin).
With time passing, more features were added to the software, trying to create an almost complete tool to edit Falcon's terrain.
The needs and inputs for this tool came initially from the emf theater building community.
Some features of this program are:
And much more…