[讨论]矩阵

雪山飞狐_lzh

才开始研究矩阵，发个矩阵实现移动、旋转、缩放的例子 三维的矩阵旋转还没想通，应该怎么实现？ Public Sub Test()
Dim dot(2) As Double
Dim pnt(2) As Double
pnt(0) = 2
pnt(1) = 3
pnt(2) = 3 ScaleByTransMat ThisDrawing.ModelSpace(0), pnt, 10
End Sub Public Sub RotateByTransMat(ByVal Obj As AcadEntity, ByVal BasePoint As Variant, ByVal Angle As Double)
Dim pTransMat(3, 3) As Double
Dim pAngle As Double, pDistance As Double
pAngle = ThisDrawing.Utility.AngleFromXAxis(pnt, BasePoint)
pDistance = Sqr(BasePoint(0) ^ 2 + BasePoint(1) ^ 2)
pTransMat(0, 0) = Cos(Angle): pTransMat(0, 1) = -Sin(Angle): pTransMat(0, 3) = BasePoint(0) - Cos(pAngle + Angle) * pDistance
pTransMat(1, 0) = Sin(Angle): pTransMat(1, 1) = Cos(Angle): pTransMat(1, 3) = BasePoint(1) - Sin(pAngle + Angle) * pDistance
pTransMat(2, 2) = 1
pTransMat(3, 3) = 1
TestTrans pTransMat
Obj.TransformBy pTransMat
Obj.Update
End Sub
Public Sub ScaleByTransMat(ByVal Obj As AcadEntity, ByVal BasePoint As Variant, ByVal ScaleFactor As Double)
Dim pTransMat(3, 3) As Double
pTransMat(0, 0) = ScaleFactor: pTransMat(0, 3) = BasePoint(0) * (1 - ScaleFactor)
pTransMat(1, 1) = ScaleFactor: pTransMat(1, 3) = BasePoint(1) * (1 - ScaleFactor)
pTransMat(2, 2) = ScaleFactor: pTransMat(2, 3) = BasePoint(2) * (1 - ScaleFactor)
pTransMat(3, 3) = 1
TestTrans pTransMat
Obj.TransformBy pTransMat
Obj.Update
End Sub Public Sub MoveByTransMat(ByVal Obj As AcadEntity, ByVal StartPoint As Variant, ByVal EndPoint As Variant)
Dim pTransMat(3, 3) As Double
pTransMat(0, 0) = 1: pTransMat(0, 3) = EndPoint(0) - StartPoint(0)
pTransMat(1, 1) = 1: pTransMat(1, 3) = EndPoint(1) - StartPoint(1)
pTransMat(2, 2) = 1: pTransMat(2, 3) = EndPoint(2) - StartPoint(2)
pTransMat(3, 3) = 1
TestTrans pTransMat
Obj.TransformBy pTransMat
Obj.Update
End Sub
Public Sub TestTrans(ByVal TransMat As Variant)
For i = 0 To 3
Debug.Print TransMat(i, 0) & "," & TransMat(i, 1) & "," & TransMat(i, 2) & "," & TransMat(i, 3)
Next i
End Sub

今晚打老虎

可不可以生成个临时的块对象然后旋转后打碎呢？~~~~


是不是有些跑题~~~~


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