BricsCAD is a almost perfect clone for AutoCAD, but many users are missing the GeomCal functionality. This problem is solved with the Lisp-application CADCAL, which can be downloaded for free from
www.archtools.de/cadcal.zip. CADCAL brings the same functionality as GeomCal, including the possibility to use GeomCal calculations in Lisp like in (cal "PLT(end,end,/3)"). You can get an overview of CADCAL at
www.archtools.de/cadcal.html.
CADCAL has some more functions than GeomCAL, i.e. PGR(<p1>,<p2>) which divides the distance between P1 and P2 in the Golden Ratio, oder PCG(<p1>,<p2> ... <pn>) which returns the center of gravity of a polygon over all points in the function's argument.
And now CADCAL also can be used with a dialog and a history od previously calles math expressions. The dialog is called with the command DDCAL and should be self explaining. The history is stored inside the dwg and will be restored when you reopen the dwg. All results of all math expressions in the history are stored too and can be recalled. DDCAL can be called transparently from any running CAD command, and the results of the calculations as well as the recalled results of previous results from the history list can be used directly as input to the running command. The ZIP also contains a demo DWG file with a history of CADCAL expressions for a first view at this functionality.
CADCAL is programmed in Lisp only, and therefore should work in AutoCAD, BricsCAD and all similar CAD applications as well. CADCALs parser first translates the string containing the math expression into an evaluable Lisp expression. The user can do this too using the CC-STR->LISP function, i.e. using (CC-STR->LISP "PLD(end,end,100)"). Because any math expression needs only one single translation within the same DWG-Session, CADCAL is rather fast. In AutoCAD overall CADCAL is about 5 to 10% slower than GeomCal, and in BricsCAD because the very fast Lisp interpreter CADCAL is about 10 times faster than GeomCal.
The DDCAL functionality is new and therefore CADCAL is still in beta stadium. Please let me know what you think of CADCAL. If you have any ideas for additional functionality, then please let me know.