acad的向量/矩阵函数

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (dest As Any, Source As Any, ByVal numBytes As Long)
Sub Test()
Dim P1(2) As Double
Dim P2(2) As Double
'P1(0) = 1: P1(1) = 2: P1(2) = 3
CopyArray P1, P2
MsgBox (P2(2))
End Sub
Sub CopyArray(Source() As Double, Target() As Double)
    Dim NumOfBytes As Long
    
    On Error GoTo NoElements
    NumOfBytes = (UBound(Source) + 1) * LenB(Source(0))
    ReDim Target(UBound(Source))                              'no need for a diffrent number of items to be a
                                                            'true copy and save checking if the target is large enough...
    
        
    CopyMemory Target(0), Source(0), NumOfBytes
    
NoElements:
MsgBox "Empty Source array in Sub CopySourceArray() at " & Format$(Now(), "hh:nn ss"), vbCritical + vbOKOnly + vbMsgBoxSetForeground, "Void Array."
On Error GoTo 0
Exit Sub
End Sub

Option Explicit
Type TPoint
    Coord(0 To 2) As Double
End Type
Sub AnotherDemo ( )
    Dim P1 As TPoint
    
    P1.Coord(0) = 10
    P1.Coord(1) = 20
    Dim P2 As TPoint
    
    P2 = P1
    
    Debug.Print P2.Coord(0)
    Debug.Print P2.Coord(1)
End Sub

Sub PassTheDoubly()
    Dim P1(2) As Double
    Dim P2(2) As Double
    Dim V As Variant
    Dim i As Long, j As Integer
    Dim T As Single
    
    T = Timer
    P1(0) = 23: P1(1) = 23: P1(2) = 23
    For i = 0 To 1000000
        For j = 0 To 2
            P2(j) = P1(j)
        Next j
    Next i
    
    Debug.Print "double time=" & Timer - T
    
    T = Timer
    For i = 0 To 1000000
      V = P1
    Next i
     Debug.Print "Var time=" & Timer - T
    
End Sub