[编程交流] 管斜接脚本

  [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]Sub Main()[/font]
 [font=&quot]  Begin Dialog TUBEMITERDIALOG 50,47, 160, 96, "Tube Miter"[/font]
 [font=&quot]    Text         4  ,12,120,12, "Diameter of intersecting tube (mm)"[/font]
 [font=&quot]    TextBox      120,12,25 ,12, .IDD_D1[/font]
 [font=&quot]    Text         4  ,24,120,12, "Diameter of mitered tube (mm)"[/font]
 [font=&quot]    TextBox      120,24,25 ,12, .IDD_D2[/font]
 [font=&quot]    Text         4  ,36,120,12, "included angle"[/font]
 [font=&quot]    TextBox      120,36,25 ,12, .IDD_PHI[/font]
 [font=&quot]    Text         4  ,48,120,12, "Offset (mm)"[/font]
 [font=&quot]    TextBox      120,48,25 ,12, .IDD_OFFSET[/font]
 [font=&quot]    OKButton     4,80,37,12[/font]
 [font=&quot]    CancelButton 45,80,37,12[/font]
 [font=&quot]  End Dialog[/font]
 [font=&quot]  Dim dlg As TUBEMITERDIALOG [/font]
 [font=&quot]  Dim ot As Long[/font]
 
 [font=&quot]  If(dcSelectAll) Then dcEraseSelObjs[/font]
 
 [font=&quot]  dcSetDrawingScale 25.4[/font]
 [font=&quot]  dcSetLineParms dcBLACK, dcSOLID, dcTHIN[/font]
 [font=&quot]  dcSetSplineParms dcBLACK, dcSOLID, dcTHIN[/font]
 
 
 [font=&quot]  dlg.IDD_D1 = "25.4"[/font]
 [font=&quot]  dlg.IDD_D2 = "25.4"[/font]
 [font=&quot]  dlg.IDD_PHI = "90"[/font]
 [font=&quot]  dlg.IDD_OFFSET= "0.0"[/font]
 
 [font=&quot]  Button = Dialog(dlg)[/font]
 
 [font=&quot]  If Button = -1 Then[/font]
 [font=&quot]    Make_TubeMiter dlg.IDD_d1/2,dlg.IDD_D2/2,rad(90 - dlg.IDD_PHI),dlg.IDD_OFFSET/2[/font]
 [font=&quot]    dcViewAll[/font]
 [font=&quot]  End If[/font]
 [font=&quot]End Sub[/font]
 
 [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]' Square a value[/font]
 [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]Function square(ByVal x As Double)[/font]
 [font=&quot]  square = x * x [/font]
 [font=&quot]End Function[/font]
 
 [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]' Convert from degrees into radians[/font]
 [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]Function rad(ByVal deg As Double)[/font]
 [font=&quot]  rad = (2*3.1415926535/360)*deg[/font]
 [font=&quot]End Function[/font]
 
 [font=&quot]'----------------------------------------------------------------------[/font]
 [font=&quot]' Plot the tube miter[/font]
 [font=&quot]'   R1     = radius of intersecting tube[/font]
 [font=&quot]'   R2     = radius of intersected (cut) tube[/font]
 [font=&quot]'   Phi    = included angle between tubes (in radians)[/font]
 [font=&quot]'   Offset = offset along the z axis between the tubes[/font]
 [font=&quot]'[/font]
 [font=&quot]'[/font]
 [font=&quot]' The generalized equation for a cylinder of radius r about the x axis is 1 = (y/r)^2 + (z/r)^2[/font]
 [font=&quot]' apply the transformation y = y'cos(phi) + x'sin(phi) to rotate the cylinder about the z axis by angle phi[/font]
 [font=&quot]' this gives the equation 1 = ((y cos(phi) + x sin(phi))/r)^2 + (z/r)^2[/font]
 [font=&quot]' now solve for x to get: x = (+- r*sqrt(1-(z/r)^2) - y cos(phi))/sin(phi)[/font]
 
 [font=&quot]' we can now iterate over values of y and z to find the discreet x points that make up our curve and fit them with [/font]
 [font=&quot]' a spline[/font]
 
 [font=&quot]' so we'll find our y and z values by rotating around the mitered cylinder which is along the x axis.  So we get:[/font]
 [font=&quot]' y = R sin(alpha)[/font]
 [font=&quot]' z = R cos(alpha)  for alpha = 0 to 360 [/font]
 [font=&quot]' actually let's not forget the offset, which applies only to the Z axis, so z = R cos(alpha) + Offset[/font]
 [font=&quot]' we can then substitute these back into the above equation for x.[/font]
 
 [font=&quot]' This X dimension is exactly what we want to plot, but the y parmeter for plotting needs to be the circumfrence [/font]
 [font=&quot]' of the mitered cylinder.  so Yplot= R * alpha (if alpha is in radians) [/font]
 
 [font=&quot]' we also need to account for the fact that we support having a mitered cylinder larger than the intersecting cylinder[/font]
 [font=&quot]' so there is some logic there to figure out when a value is valid and not.  [/font]
 
 [font=&quot]'---------------------------------------------------------------------- [/font]
 [font=&quot]Sub Make_TubeMiter(ByVal R1 As Double,ByVal R2 As Double,ByVal Phi As Double,ByVal Offset As Double)[/font]
 [font=&quot]  Dim X As Double ' X(a)[/font]
 [font=&quot]  Dim s(361) As Double 'Array for the spline[/font]
 [font=&quot]  Dim i As Double 'i for for loop[/font]
 [font=&quot]  Dim start As Double 'start of a spline[/font]
 [font=&quot]  Dim sign As Double 'either 1 or -1 to determine the sign in the equation below[/font]
 [font=&quot]  Dim loopCount As Integer 'loop once if the intersecting tube is larger, twice if smaller[/font]
 [font=&quot]  Dim j As Integer[/font]
 [font=&quot]  Dim ya As Double[/font]
 [font=&quot]  Dim za As Double [/font]
 [font=&quot]  Dim alpha As Double[/font]
 [font=&quot]  Dim max As Double[/font]
 
 [font=&quot]  sign = -1[/font]
 [font=&quot]  loopCount = 1[/font]
 [font=&quot]  max = 0[/font]
 
 [font=&quot]  ' If the intersecting tube is smaller, we need to draw both sides[/font]
 [font=&quot]  ' of the intersection since it is making a hole though the tube, Thus we want to run through[/font]
 [font=&quot]  ' the loop twice. [/font]
 
 [font=&quot]  If (R2 + Offset > R1) Then [/font]
 [font=&quot]      loopCount = 2[/font]
 [font=&quot]  End If[/font]
 
 [font=&quot]  For j = 1 to loopCount [/font]
 [font=&quot]    start = -1[/font]
 [font=&quot]    For i=0 To 360 Step 2 'iterate 0 - 360 by 2 degree increments[/font]
 [font=&quot]      alpha = rad(i) 'we need everything in radians[/font]
 [font=&quot]      ya = R2*Sin(alpha)[/font]
 [font=&quot]      za = R2*Cos(alpha)+Offset[/font]
 
 [font=&quot]      'if there is something to cut here[/font]
 [font=&quot]      If square(za/R1) <= 1 Then[/font]
 [font=&quot]        X= (R1 * sign * Sqr(1 - square(za/R1)) - ya * Sin(Phi))/Cos(Phi) ' from the equation derived int he comments above[/font]
 
 [font=&quot]        ' If this is the first good sample in this spline, then record that[/font]
 [font=&quot]        If start = -1 Then [/font]
 [font=&quot]          start = i[/font]
 [font=&quot]        End If[/font]
 [font=&quot]      Else ' we are cutting a hole, and this is outside that hole[/font]
 [font=&quot]        X = 0.0[/font]
 [font=&quot]        ' this is the first sample that is outside the hole, draw the spline[/font]
 [font=&quot]        If start > -1 Then[/font]
 [font=&quot]          dcCreateSpline s(start), (i-start)/2, False[/font]
 [font=&quot]          start = -1[/font]
 [font=&quot]        End If[/font]
 [font=&quot]      End If[/font]
 
 [font=&quot]      ' spline point = (x,R*alpha)[/font]
 [font=&quot]      s(i) = X[/font]
 [font=&quot]      s(i+1) = R2 * alpha [/font]
 
 [font=&quot]      ' record the largest extent for the purpose of drawing reference lines[/font]
 [font=&quot]      If (Abs(X) > max) Then max = Abs(X)[/font]
 
 [font=&quot]    Next i[/font]
 
 [font=&quot]    ' If we stopped the loop while we still had valid values, display the spline[/font]
 [font=&quot]    If start > -1 Then[/font]
 [font=&quot]      dcCreateSpline s(start), (362 - start)/2, False[/font]
 [font=&quot]    End If[/font]
 
 [font=&quot]    ' swap the sign just in case we need to run through the loop again[/font]
 [font=&quot]    sign = 1[/font]
 
 [font=&quot]  Next j[/font]
 
 [font=&quot]  ' Draw reference lines[/font]
 [font=&quot]  dcCreateLine  (-2*max), (R2 * rad(0)  ), (2*max), (R2 * rad(0)  )[/font]
 [font=&quot]  dcCreateLine  (-2*max), (R2 * rad(90) ), (2*max), (R2 * rad(90) )[/font]
 [font=&quot]  dcCreateLine  (-2*max), (R2 * rad(180)), (2*max), (R2 * rad(180))[/font]
 [font=&quot]  dcCreateLine  (-2*max), (R2 * rad(270)), (2*max), (R2 * rad(270))[/font]
 [font=&quot]  dcCreateLine  (-2*max), (R2 * rad(360)), (2*max), (R2 * rad(360))[/font]
 
 [font=&quot]End Sub[/font]