rem                            P_PL.CDL


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

rem        Intersection between Line and Plane



clear
dspflg = 1
acc = 0.0001

:start
getent "Select Line", enttype

on (@key + 3) goto exit, start, start,
if (enttype!=2)
	goto start
x0 = @fltdat[0]
y0 = @fltdat[1]
z0 = @fltdat[2]
f = @fltdat[3] - @fltdat[0]
g = @fltdat[4] - @fltdat[1]
h = @fltdat[5] - @fltdat[2]

getplane "Indicate Plane", dspflg

on (@key + 3) goto exit, start, ,
a = @fltdat[10]
b = @fltdat[11]
c = @fltdat[12]
d = @fltdat[13]

bunbo = a * f + b * g + c * h
if (abs(bunbo)>acc)
	goto next
pause "Selected Line and Plane Are Parallel (Press Return)"
redraw
goto start

:next
t = -(a * x0 + b * y0 + c * z0 + d) / bunbo

x = x0 + f * t
y = y0 + g * t
z = z0 + h * t

point x, y, z

redraw
goto start
:exit