rem                            EQ_PLPT.CDL

rem        Copy Right by International Technology Transfer Corp.
rem        revision 1.0-7/30/99   


rem        Equation of Plane with the same distance from 2 points




clear
defopt = 2
array mtx[9]
acc = 0.00001

:start
getpos "Indicate First Point",defopt

on (@key + 3) goto exit, start, start,
defopt=@key
wx1 = @xworld
wy1 = @yworld
wz1 = @zworld

:second
getpos "Indicate Second Point",defopt

on (@key + 3) goto exit, start, second, 
defopt=@key
wx2 = @xworld
wy2 = @yworld
wz2 = @zworld

f = wx2 - wx1
g = wy2 - wy1
h = wz2 - wz1
ref = f * f + g * g  + h * h

if (ref>acc)
	goto next
pause "Selection Is Not Correct (Press Return)"
goto start

:next
wxc = (wx2 + wx1) / 2
wyc = (wy2 + wy1) / 2
wzc = (wz2 + wz1) / 2


a = f
b = g
c = h
d = - ( a * wxc + b * wyc + c * wzc )

pause " (%.5f) x + (%.5f) y + (%.5f) z + (%.5f) = 0", a, b ,c, d
redraw

:exit
clear