Code with perpendicluar

[Anonymous]

I have 3 point A, B, C

and then I calculate another point - D,  then D on AB, and CD perpendicluar with AB

In this Code, Mypoint is a class,like Point-class, with some attributes was added, 

so you dont need care about it

Function perpendicularPointAndLine(startPoint As MyPoint, endPoint As MyPoint, anotherPoint As MyPoint, namePoint As String)

' A B C D

Dim a(0 To 2) As Double
a(0) = startPoint.point.Coordinates(0)
a(1) = startPoint.point.Coordinates(1)
a(2) = startPoint.point.Coordinates(2)

Dim b(0 To 2) As Double
b(0) = endPoint.point.Coordinates(0)
b(1) = endPoint.point.Coordinates(1)
b(2) = endPoint.point.Coordinates(2)

Dim C(0 To 2) As Double
C(0) = anotherPoint.point.Coordinates(0)
C(1) = anotherPoint.point.Coordinates(1)

C(2) = anotherPoint.point.Coordinates(2)

'NOW I HAVE COORDINATE OF POINTS A, B, AND C'

AND THEN I CALCULATE COORIDINATE OF D

Dim vectorCP(0 To 2) As Double
vectorCP(0) = b(0) - a(0)
vectorCP(1) = b(1) - a(1)
vectorCP(2) = b(2) - a(2)

'so D on AB then
' d(0) = a(0) + vectorCP(0) * t
' d(1) = a(1) + vectorCP(1) * t
' d(2)  = a(2) + vectorCP(2) * t

'vector CD  
'd(0) - c(0) =   vectorCP(0) * t+ a(0) - c(0)
'd(1) - c(1) = vectorCP(1) * t+ a(1) - c(1)
'd(2) - c(2) = vectorCP(2) * t+ a(2) - c(2)

Dim c1(0 To 2) As Double

c1(0) = a(0) - C(0)
c1(1) = a(1) - C(1)
c1(2) = a(2) - C(2)

'vector CD
'vectorCP(0) * t+ c1(0)
'vectorCP(1) * t+ c1(1)
'vectorCP(2) * t+ c1(2)

'CD and AB perpendicular

'we have vector(CD) * vector(AB) = 0

'vectorCP(0)^2 *t + c1(0)*vectorCP(0) + vectorCP(1)^2t + c1(1)*vectorCP(1) + vectorCP(2)^2*t +c1(2)*vectorCP(2) = 0
't(vectorCP(0)^2 +vectorCP(1)^2 +vectorCP(2)^2) = -c1(0)*vecCP(0) -c1(1) *vecCP(1) -c1(2) *vectorCP(2)
Dim t As Double
t = (-c1(0) * vectorCP(0) - c1(1) * vectorCP(1) - c1(2) * vectorCP(2))
t = t / (vectorCP(0) * vectorCP(0) + vectorCP(1) * vectorCP(1) + vectorCP(2) * vectorCP(2))

Dim perpenPoint(0 To 2) As Double
perpenPoint(0) = vectorCP(0) * t + a(0)
perpenPoint(1) = vectorCP(1) * t + a(1)
perpenPoint(2) = vectorCP(2) * t + a(2)

'  I think PROBLEM is t variables

'  I think have a wrong when I try to calculate t

' if I set  t = 0.5 it will draw D at Midpoint of AB

Set ArrayPoint(countPoint).point = ThisDrawing.ModelSpace.AddPoint(perpenPoint)



With ArrayPoint(countPoint)
.intID = countPoint
.strName = namePoint
End With
countPoint = countPoint + 1

' twoPoint countPoint - 1, anotherPoint.intID
ThisDrawing.Application.update
'Ket thuc
'
End Function