moving picture in a perfect circle.

This doesn't help much, but I remember that Fox posted some code to move a label in an elipse...I'll do a search and see if anything pops up.

This also might not help much but here it is anyhow...

It runs on a timer control so your other code can still run while the control rotates in a circle. Change the settings for radius, speed (milliseconds) and step to see if it will do what you want.

Code:

---

' add a timer, command button and picturebox to a form.
Option Explicit
Dim mControl As Control
Dim mRadius As Integer
Dim xStart As Long
Dim yStart As Long
Dim mInc As Single
Dim pi As Single

Private Sub Command1_Click()
  MoveObjectInCircle Picture1, 50, 10, 1
End Sub

Sub MoveObjectInCircle(ctl As Control, radius As Integer, speed As Integer, inc As Single)
  ' use degrees not radians for the inc parameter because
  ' most people think of a circle as 360 degrees rather than
  ' 2 * pi radians
  Set mControl = ctl
  mRadius = radius
  mInc = inc
  ' get the centre of the control
  xStart = ctl.Left
  yStart = ctl.Top
 
  Timer1.Interval = speed
  Timer1.Enabled = True
End Sub


Private Sub Form_Load()
  pi = Atn(1) * 4
End Sub

Private Sub Timer1_Timer()
  ' each time the timer event happens, we move the object a little bit
  MoveObject
End Sub

Private Sub MoveObject()
  ' assumed the form is in pixels but it doesn't matter really
  ' spped represents how quickly the object is moved
  Dim x, y As Single
  Static lastX, lastY As Single
  Static angle As Single
 
  'initialise the lastX
  If lastX = x Then
    lastX = 0
  Else
    lastX = x
    lastY = y
  End If
 
  ' get the new angle to rotate (in radians)
  angle = angle + mInc / 180# * pi
 
  x = xStart - mRadius * Cos(angle) + mRadius
  y = yStart - mRadius * Sin(angle)
 
  mControl.Left = x
  mControl.Top = y

End Sub

---

Cheers

This may help a bit more ;)
The idea is to use sin() and cos() as Paul already showed:

Put a Picture box into a new project and add this code:

Code:

---

Sub Form_Load()
  'A (the angle) is 0 - 2Pi instead of 360°!
  Dim A as Single
  Dim Radius as Long

  'Position of center
  Dim X As Long
  Dim Y As Long

  'Initialize
  X = Me.ScaleWidth / 2
  Y = Me.ScaleHeight / 2
  Radius = Me.ScaleHeight / 4

  Me.Show

  'The main loop
  While 1
      Picture1.Move Sin(A) * Radius + X, Cos(A) * Radius + Y
      A = A + 0.01
     
      DoEvents
  Wend
End Sub

---

Hope this helps... And don't forget to put "End" into Form_Unload()! :)