I now have “getter” and “setter” functions for the attributes of physical objects, but I still have some work to do. I need a “reset position” for objects in a physical system, which looks to be a little complicated. I need to remove the object’s imprint on the system map (because the new position may overlap the old one), test to see whether it can be added in a new position (because of the system boundaries and interference with other objects), and either add it to the new position, or keep it in the old position if it cannot be moved.
I added a couple of stubs for physical geography and organism biology, and attempted to do something with processing of graphic objects, which somehow introduced a bug. I did manage to introduce a section on approximate arithmetic (rounding), which suggest more functions later.
The work on operator overloading, inheritance, stream i/o, and file processing went slow, and I found that I could create a test file for the file I/O examples, but couldn’t read it. Somehow, my programming brain turned to mush today. I need to do something to sharpen it back up again.