Drawing Ellipsessess...

Okay... here's the deal...
I would like to be able to pick a point on the screen and draw an ellipse with the bottom of the ellipse at the point that was picked.
Here's how I'm doing it with LSP, but I'd like to move it to VBA.
I use this code when creating utility profiles.

Any input will be greatly appreciated!


--------------------------------------------------------------------------------

(defun PROFILEPIPE (intHeight intWidth)
(setq pt1 (getpoint "\n Pick the invert elevation of pipe..."))
(command "ellipse" pt1 (strcat "@0," intHeight) intWidth)
(princ)
)

 

*****
Option Explicit

Public Sub Ellipse()
Dim dblHeight As Double
Dim dblWidth As Double
Dim varPt1 As Variant
Dim dblPt2(2) As Double
Dim varPt2 As Variant
Dim dblRatio As Double
Dim objEnt As AcadEllipse
dblHeight = ThisDrawing.Utility.GetReal("Enter an Height: ")
dblWidth = ThisDrawing.Utility.GetReal("Enter an Width: ")
On Error GoTo ErrorHandler
varPt1 = ThisDrawing.Utility.GetPoint(, "Pick Point: ")
On Error GoTo 0
dblPt2(0) = varPt1(0)
dblPt2(1) = varPt1(1) + dblHeight
dblPt2(2) = varPt1(2)
varPt2 = dblPt2
dblRatio = dblWidth / dblHeight
Set objEnt = ThisDrawing.ModelSpace.AddEllipse(varPt1, varPt2, dblRatio)
objEnt.Move varPt1, varPt2
Exit Sub
ErrorHandler:
Resume
End Sub
*****
Regards - Nathan

 

Wow....VBA required about 5 times amount of code!

 

Why is it that when I run this code, the ellipse is drawn rotated??!?

 

Here you go, Matt.
I was about to defend VBA against jbryant's wisecrack earlier today, but now
I'm glad I didn't. You actually have to compare the height and width to see
which is greater, and use that one in the AddEllipse method. The reason it
was creating a rotated ellipse for you was that the major axis point (2nd
param of AddEllipse) is given relative to the center, not relative to the
origin. The HLP file sure doesn't mention that little factoid....

James


Public Sub Ellipse()
Dim dblHeight As Double
Dim dblWidth As Double
Dim varPt1 As Variant
Dim varPt2 As Variant
Dim dblRatio As Double
Dim objEnt As AcadEllipse
dblHeight = ThisDrawing.Utility.GetReal("Enter an Height: ")
dblWidth = ThisDrawing.Utility.GetReal("Enter an Width: ")
On Error GoTo ErrorHandler
varPt1 = ThisDrawing.Utility.GetPoint(, "Pick Point: ")
On Error GoTo 0
If dblHeight >= dblWidth Then
varPt2 = Point3D(0, dblHeight / 2, 0)
dblRatio = dblWidth / dblHeight
Set objEnt = ThisDrawing.ModelSpace.AddEllipse(varPt1, varPt2, dblRatio)
objEnt.Move Point3D(0, 0, 0), varPt2
Else
varPt2 = Point3D(dblWidth / 2, 0, 0)
dblRatio = dblHeight / dblWidth
Set objEnt = ThisDrawing.ModelSpace.AddEllipse(varPt1, varPt2, dblRatio)
objEnt.Move Point3D(0, 0, 0), Point3D(0, dblHeight / 2, 0)
End If
Exit Sub
ErrorHandler:
Resume
End Sub

Public Function Point3D(x As Double, Y As Double, Optional Z As Double = 0)
As Variant
' courtesy www.acadx.com
Dim retVal(0 To 2) As Double
retVal(0) = x: retVal(1) = Y: retVal(2) = Z
Point3D = retVal
End Function

 

No... the HLP file DOESN'T mention that.
Thanks!

 

Didn't intend for my comment to be taken as a wise-crack, however, this is a perfect example of the beauty of Lisp. No overhead garbage to deal with, just do it. I know there are alot of things Lisp can't do that VBA can, however it has been, and still is, an almost perfct fit language for customizing AutoCAD. The Vlax routines can typically reducelines of code even more.

 

I agree with you somewhat, however we are not exactly comparing apples to
apples here. The VBA code is complete. The lisp code is not. You do not
see the 2 setq's for the values passed to the defun. There is no error
handling in the lisp code and there is in the VBA code. And finally, if you
do not use Option Explicit the code is reduced even more. (Although I would
never, ever recommend programming without Option Explicit).

Anyway, you are correct, though, that lisp will under a lot of circumstances
be shorter. Try adding a form with a couple of text boxes for width and
height and see which is shorter (and quicker to program) - lisp with DCL or
VBA.

 

Hi,

You should watch some new users of AutoCAD starting a command and looking
every where but at the command line. While lisp is wonderful at doing
things, it's command line user interface is unforgiving of errors in user
data entry. Writing interfaces via DCL is more than an order of magnitude
more difficult than with VBA, as well as it cannot provide the same range of
controls.

Also, lisp is far more difficult to debug with the tools supplied by
Autodesk.


--


Laurie Comerford
CADApps
www.cadapps.com.au

a perfect example of the beauty of Lisp. No overhead garbage to deal with,
just do it. I know there are alot of things Lisp can't do that VBA can,
however it has been, and still is, an almost perfct fit language for
customizing AutoCAD. The Vlax routines can typically reducelines of code
even more.