Hypocycloid is essentially an electronic Spirograph inspired by the article
Five Original Graphics in February 1984 BYTE.  Also, see articles in
May-June 1984 Creative Computing for background on the hypocycloid and basic
formula for drawing these.

Hypocycloid has been modifed for improved performance and now functions as
a fairly effective cycloid construction set.

About the changes. . .

The main menu:

A dialog window retrieves new values for large and small radii, when you
select the 'new' option from the main menu.  Clicking on okay causes the
program to recalulate its initialization values and thereby sustains the
drawing indefinitely.  Cancel restores the values in the radii boxes to
their previous values.  You use this option to start a new figure based on
the other menus, even if you didn't change the values in the large and small
radius gadgets.

'Go' begins the iteration process and continues to draw until either stopped
with 'Stop' or the figure goes through 360 degrees of rotation.
'Go' no longer initiates a new series of iterations with different colors
each time without going back to where 'stopped'. Stopping and starting will
work with the same figure, as long as you don't exceed the 360 degrees of
rotation.  Actually, you could enter the same values into the 'new'
gadgets, hit 'go' and the drawing would proceed again, but it would draw the
same figure again from the same starting point.  New figures can be drawn on
old ones, each limited to 360 degrees of rotation.  The limit is 360 degrees
because more rotation does not develop most patterns any further but only
serves to muddle them.

'Stop' stops the iteration after completing the current iteration.  This
now works correctly (Hit 'stop', anytine and the program automatically
finishes the current iteration.)

'Color' -- new item -- adds a color palette for changing the startup
defaults.  This is the Microsmiths palette from Charlie Heath. The program
no longer alters the current colors each time 'new' or 'go' is selected.

'Cycle' -- new item -- cycles through the 32 color table, using the custom
color map set up by the palette routine.  This results in smoother color
cycling than setting each color individually.  Cycling only occurs when the
drawing has been stopped or stops after 360 degrees of rotation.

'Save' saves drawing in iff.ilbm format, uncompressed, each picture taking
about 40k disk space.  Now uses a dialog window to get filenames instead of
closing down the drawing window and using the workbench console.  This
enables saving and resuming on the same figure without starting the drawing
all over at the beginning.  The pointer changes to a yield sign while the
disk operations are taking place.  This alerts the user to the possible
harmful effects of doing something while the save is proceeding.

Known bug:  Saving to a full disk will crash the computer.  The SavePicture
routine doesn't know what to do with a disk full message from the system and
everything freezes.  Will somebody please study iffwriter2.c and tell me how
to work around this?!

'Clear' clears the screen at any time the plotting has finished an iteration.

'Quit' exits program.

Reduce:--default changed to 1.0--

The ratio of reduction of the first iteration to the last iteration, 1.0
being 100% reduction. That is, the final iteration of the hypocycloid will be
100% smaller than the first iteration.

Begin:--default changed to .1--

(Hard to explain) The beginning reduction factor as part of the reduction
ratio.  Increasing this produces more circular patterns or curls in the ends
of the hypocycloid.  Starting at 0 makes the hypocycloid more pointed.
Default is .1.

End:--default changed to .5--

The end reduction factor as part of the reduction ratio.  If less than the
beginning reduction factor, the result is a figure that grows outward
instead of inward (hard to believe, ain't it?). Experiment with this and the
others!

Angle:--default changed to 9--

The angle of rotation where each iteration is offset from each other by this
amount. Takes more rotation to produce significant displacement of the
figure when the reduction factor is under 1.0.

#COL: new menu

Allows you to specify how many colors you want the program to use (1-10) to
draw the figure.  Colors alternate with each new iteration. Default is 4.

Correspondence on this and any of my programs shoud be addressed to

      Terry W. Gintz
      4430 Pinecrest Drive
      Eugene, Or 97405