Drawing Oval!

[parkho]

hi, I have a form which I want to draw 4 Ovals with the same center point but with different directions so it looks like a star. I used the circle command which I can only get two Ovals on the desired direction and I cannot get the other two in right position. Please help me!
Thanks

[douglandmesser]

The best way to do what you want is to use SIN/COS functions. You can adjust the circle to do pretty much whatever you want. Give it a try. You will need to assign a value to PI. Also, use a FOR...NEXT loop for the actual 360 points on the circles. I have some code, but it's written in QB. You should be able to convert it to VB code quite easily. Let me know if you want it.

[Killer42]

The best way to do what you want is to use SIN/COS functions. You can adjust the circle to do pretty much whatever you want. Give it a try. You will need to assign a value to PI. Also, use a FOR...NEXT loop for the actual 360 points on the circles. I have some code, but it's written in QB. You should be able to convert it to VB code quite easily. Let me know if you want it.

Actually, surprisingly enough you don't need to use Pi at all in drawing a circle. You just vary the X and Y coordinates that you draw based on Sin() and Cos() of a value. For example...

Dim S As Single
For S = 0 to 6 Step 0.1
  Me.Pset (50+Sin(S)*25, 50+Cos(S)*25)
Next
 

Sorry if this code isn't quite right, I don't have time to test it. Just typed it straight in here. Anyway, to produce an oval shape, you just change the ratio of what you add to the X and Y coordinates (Eg. add 25 to X and 10 to Y). To slant the oval, I guess you'd need to make a further variation.

[debasisdas]

Please find a related article here .

[parkho]

The best way to do what you want is to use SIN/COS functions. You can adjust the circle to do pretty much whatever you want. Give it a try. You will need to assign a value to PI. Also, use a FOR...NEXT loop for the actual 360 points on the circles. I have some code, but it's written in QB. You should be able to convert it to VB code quite easily. Let me know if you want it.

hi, thanks for the reply. Is it possible for you to post the code so I can some Idea? thanks so much.

[debasisdas]

Have you gone through the article provided in the link.

[parkho]

Have you gone through the article provided in the link.

yes I have. It gives me the basics of the Circle command which I already knew. my problem is that I want all the Ovals with the same center point NOT with different Center points. that looks like a star just like we turn them around at one center point.

Thanks

[debasisdas]

Then what are you expecting the complete code ?

[Killer42]

I think there's one important question that we don't have a definite answer to as yet. You can produce interesting effects quite simply, by varying the aspect ratio of the circle (look up "circle" in the VB doco). That is, by making it taller or wider, so you get an oval shape. But that only makes horizontal/vertical ovals. Do you need tham at other angles as well?

[Killer42]

If anyone's interested, here is some code where I was playing around with doing different offsets from the centre of the circle, depending on which "quarter" you're in. It's not terribly useful, but may inspire some ideas.

It uses a routine I wrote years ago for an analogue clock display, which takes a minute from 0 to 59 and converts it to the appropriate value to produce a point on the circle using Sin and Cos. that's why the code uses numbers from 0 to 59.

Private Sub Form_Click()
  Dim S As Integer, Q As Double
  Dim OffsetX As Single, OffsetY As Single
  For S = 0 To 59
    Q = Converted(S)
    Select Case S
      Case 0 To 14
        OffsetX = (Abs(7 - Abs(7.5 - S))) * 5
        OffsetY = (Abs(7 - Abs(7.5 - S))) * 5
'      Case 15 To 29
'        OffsetX = (Abs(7 - Abs(22.5 - S))) * 5
'        OffsetY = (Abs(7 - Abs(22.5 - S))) * 5
      Case 30 To 44
        OffsetX = (Abs(7 - Abs(37.5 - S))) * 5
        OffsetY = (Abs(7 - Abs(37.5 - S))) * 5
'      Case 45 To 59
'        OffsetX = (Abs(7 - Abs(52.5 - S))) * 5
'        OffsetY = (Abs(7 - Abs(52.5 - S))) * 5
      Case Else
        OffsetX = 0
        OffsetY = 0
    End Select
 
    If S = 0 Then
      Me.PSet (150 + Sin(Q) * (50 + OffsetX), 100 + Cos(Q) * (50 + OffsetY))
    Else
      Me.Line -(150 + Sin(Q) * (50 + OffsetX), 100 + Cos(Q) * (50 + OffsetY))
    End If
  Next
 
End Sub
 
Private Function Converted(What As Integer) As Double
 
  ' Note:
  ' Step size = .105 (roughly)
  ' Starting at 0 points us at 6 on the clock.
  ' Therefore, about 3.15 should put us at 12 o'clock..
 
  Converted = (58 - What) * 0.1067 + 3.15
 
End Function
 

If anyone plans to try it, the other point of note is that I set the form's ScaleMode to "3 - Pixel".