function DistancePoint_line takes real PointX, real PointY, real Line1X,real Line1Y,real Line2X, real Line2Y returns real
local real Vx = Line2X - Line1X
local real Vy = Line2Y - Line1Y

local real Wx = PointX - Line1X
local real Wy = PointY - Line1Y

local real Cxy = Vx*Wx + Vy*Wy
local real Mxy = Vx*Vx + Vy*Vy

if Cxy <= 0 then
    return SquareRoot( (PointX-Line1X)*(PointX-Line1X)  +  (PointY-Line1Y)*(PointY-Line1Y) )
endif
if Mxy <= Cxy then
    return SquareRoot( (PointX-Line2X)*(PointX-Line2X)  +  (PointY-Line2Y)*(PointY-Line2Y) )
endif

set Line1X = Line1X +  (Cxy*Vx)/Mxy
set Line1Y = Line1Y +  (Cxy*Vy)/Mxy
return SquareRoot( (PointX-Line1X)*(PointX-Line1X)  +  (PointY-Line1Y)*(PointY-Line1Y) )

endfunction