This file is the cornerstone of the internal database for the application. Here all of the data that is read from the input files is built into the data structures that the application actually uses to perform its tasks (these are called the data abstractions of the application). All of the other ``helper'' data structures are simply used as an interface to the data from the files.
This file also assists demfile.c in automatically managing the memory used by the many large pixel maps. See Section 4.1.4 for more information. In addition to memory management of pixel maps, this file also generates all but one of the pixel maps when they are needed. The pixel maps correspond to stand feature information since they determine the color of the patches on the ground in the Forest View. Hence it is likely that for each stand feature, an additional pixel map will be required. With so many pixel maps, the need for automatic memory management of these maps is no longer a question; it's required.