SkyMap Release History
----------------------

29-May-93 v1.3

New features:

The program can now display non-stellar objects.  The database used is the
Revised New General Catalogue (RNGC).

Constellation boundaries can now be displayed.

The printing options have been greatly expanded.  When a map is printed the
user can now select whether to print the entire map, or the current zoomed
view, and also whether to print in black and white or colour.  For colour
maps a dialog allows the user to select the colour of each component of
the map.

All map features are now present on both the horizon and sky area maps
(eg star labels can now be displayed on the horizon map).  The user interface
has been made more consistent between the map types.

The program now has an optional ToolBar at the top of the screen, which
provides short-cuts for the commands on the "View" menu.

The program now (finally!) has a complete on-line help system.  This is
basically a copy of the manual.

Bug fixes:

I'd forgotten to apply the correction for diurnal parallax to planetary
positions on the Sky Area map.  Consequently, the planets were being shown
in their geocentric, rather than topocentric positions, resulting in errors
of up to 2 degrees in the apparent position of the Moon.  Fixed.

The size of the image of the Sun and Moon on the Sky Area map was being
incorrectly calculated, resulting in images that were about 50% too large
when the map was printed on a portrait orientation page.  Fixed.


07-Mar-93 v1.2

New features:

Added a new "Sky Area" map type, centred on a right ascension and
declination.  This is intended to be used to draw a detailed map of a
small region of the sky.

Added the ability to display photographic images in either GIF or BMP
format.  Images can either be explicitly opened, or associated with specific
objects (currently planets) and automatically displayed.

Bugs fixed:

Single pixel stars were being printed on the printer in the screen colour,
which almost certainly mapped to white on the printer, resulting in them
not being printed.  On a mono print, single pixel stars are now correctly
printed black.

When the right mouse button was pressed over a horizon map to display the
pop-up menu, then the *right*, rather than the *left* button pressed (ie,
a user input error!) an incorrect cursor position was stored.  If the left
button was subsequently used to select an information dialog a wildly
inaccurate position or a GPF resulted.  This is probably the cause of all
the "random number" errors previously reported.  Thanks to Don Munro for
tracking down a reproducable case of this puzzling error!  Fixed.

Removed the incorrect, uninitialized data displayed on the information dialogs
for the Sun and Moon. (Eg phase 0.000 for the Sun.)


05-Feb-93 v1.11

When the start of a constellation figure was off the edge of the map,
the first visible line of the constellation was being drawn incorrectly in
certain circumstances.  Fixed.

The correction for refraction was being correctly calculated and correctly
displayed in the "About" box for a star, but not applied to the plotted
position of the stars on the map.  This led to stars being plotted with
slightly too low an altitude (the maximum error being about half a degree
at the horizon).  Fixed.

If the star position calculation was aborted by the user pressing the "Cancel"
button, the subsequent constellation figure setup calculation code displayed
an error message for each star it was unable to find.  Pressing the "Cancel"
button now aborts the map calculation cleanly.


31-Jan-93 v1.1

Test release to BIX only for testing.

In the "Observer" dialog, the "Time Difference" edit field was only wide
enough to allow two digits to be entered, making the program not too
useful for anyone outside the GMT time zone.  Fixed.

Version 1.0 of SkyMap simply plotted stars in their mean catalog position.
This version now rigorously calculates the apparent place for the time of
observation, correcting for proper motion, aberration, precession, nutation,
and refraction.

Added code to verify that dates are in the range 4000BC-8000AD (the
range over which the planetary position equations are valid.



24-Jan-93 v1.0

Release of SkyMap 1.0, with basic facilities for drawing horizon map and
plotting planetary and lunar positions.