June 29, 2001: Here's a little geometry/trig
problem from an old ACM programming contest. The
FlatLand Piano Movers need a program to determine if they can
deliver a piano of a given size around the corners at a
destination with hallways of known width. I found it
challenging, and never did find an analytical solution, although I'm sure
one exists. This program uses a "try it and see if it fits"
June 26, 2001: We're on a one week break
between grandkid visits - just enough time to get some lawn mowing and
garden work done. For the past few days I've spent more time than was
justified shopping for new PC pieces. Components are now all
ordered - $450 for an 800mhz Celeron. No mouse, hard drive or
monitor, which I already have. But including 256mb memory, a 9-bay
mid-tower case, an 8X CDRW drive, 32mb AGP video card and a multimedia
keyboard! I'll post a page with the details when the pieces
arrive and I get them hooked up.
The TAstronomy component & demo are
working! It turned out to be pretty large though, 4000 or so lines of
code, so I guess it'll be a while before I get around to documenting and
posting it. If anyone is really interested in getting a copy "as
is", send me a note.
June 14, 2001: As you might guess, I
couldn't resist adding planet position prediction to the forthcoming TAstronomy
component, so now everything is there and working. Well,
Pluto isn't there because it's position isn't predictable over the long
term using simple curve fitting. No big loss - it's the smallest
planet, smaller than our moon, about 100 times dimmer than the next dimmest
planet, Neptune and it's about 4 billion miles away. But I do
need a program that does more than just display where the rest are at
any point in time.
I found a neat, free, Delphi OpenGL 3D graphics
component this week. (Computer Geometry, CGLib, from Delphi3D).
I came across this while working on the idea for a 3D planetary model
to go with TAstronomy. So here's a prototype
Planet Viewer based on OpenGL/CGLib. It's adapted
from a demo program I found at the Delphi3D site. Most of it I don't
really understand yet, but it does look cool.
June 12, 2001: I wrote this Canvas
drawing demo the other day to help
someone who needed some help saving and restoring canvas drawings.
It's posted in the Delphi Techniques section. It also
illustrates the starting point to get the little images posted
occasionally with these program descriptions.
June 3, 2001: I finally got eclipse
prediction working, but it was probably
more effort than it was worth. Only stubbornness kept me at it, long
past the fun stage. I'll come back and clean it up and post it in a
week or so. (Unless I recover enough to tackle the planets.)
But here's a
river crossing puzzle that was fun. This is the
fox-duck-corn variation of the 1200 year old wolf-goose-cabbage
original. A graphics interface allows the user or
the program to solve the puzzle. A simple puzzle, but I