[RESOLVED] how would i tranfer the velocity or speed of an object into a single angle reading

[flyhigh]

im trying to explain this the best i can .
this way you change the velocity to get the balls angle change ,im trying to hopyfully ,with i havent a clue ,get the angle instead.
thanks all

                 If Image1(i).x + Image1(i).Radius < 35 Then
                     Image1(i).vx = -Image1(i).vx
                 End If
                 If Image1(i).x + Image1(i).Radius > 981 Then
                     Image1(i).vx = -Image1(i).vx
                 End If
                 If Image1(i).y + Image1(i).Radius < 35 Then
                     Image1(i).vy = -Image1(i).vy
                 End If
                 If Image1(i).y + Image1(i).Radius > 693 Then
                     Image1(i).vy = -Image1(i).vy
                 End If

[opus]

Is this still the same question as in your other thread, you try to get the direction (or angle) of the moving object?
The code shown is checking if the object is at a border and then reversing the x or y part of the velocity depending on the border that was hit.

[flyhigh]

yes i think its different .
what i would like to do is put>> Image1(i).vx = -Image1(i).vx << into >>Image1(i).Angle .
and the same with vy.

                    Image1(i).x = Image1(i).x + (Cos(Image1(i).Angle * Rad) * 0.4)
                    Image1(i).y = Image1(i).y + (Sin(Image1(i).Angle * Rad) * 0.4)

[opus]

What do you need?
A.) Calculate the angle out of .VX and .VY?
or
B.) How to change the actual angle when hitting a border?

[flyhigh]

A
thanks

[opus]

As I said in your other thread, have a look into trigonometry.
For all cardinal directions it would be:
VX=0 and VY positve Direction 0° or 360° (I'm using the navigational notation)
VX=0 and VY negative Direction 180°
VX positive and VY=0 Direction 090°
VX negative and VY=0 Direction 270°
all others can be computed out of VX/VY or VY/VX which will give you the sin or cos of the angle.

[flyhigh]

thanks alot im gonna put this in my notes for the future ref
this means divided by right VX/VY ?

on a computer screen this VX positive and VY=0 Direction 090° means 0 or 360 ?

[opus]

I used DY positive for UP, while an increasing Y will move the objects down, my fault SORRY. So you you the turn that around.
DX positive will move objects to the right!

[flyhigh]

hey yall i got this off the web ,but all the degrees are in the wrong places
ive tryed changing it but there still wrong ,need alittle help
thanks

Public Function GetDirection(ByVal xVelocity As Long, ByVal yVelocity As Long) As Single

  Dim Direction As Single

      If yVelocity < 0 Then
        Direction = PI + Atn(xVelocity / yVelocity)
      ElseIf yVelocity > 0 Then
        Direction = Atn(xVelocity / yVelocity)

        If Direction < 0 Then
            Direction = Direction + TwoPi
        End If

      ElseIf xVelocity <= 0 Then
        Direction = ThreePiByTwo
      Else
        Direction = PiByTwo
      End If

    GetDirection = Direction

End Function

[opus]

So you are using Direction in Radians!
The calculations seem correct to me, however they are assuming positive yVelocity is UP and positive xVelocity is to the Rigth.
When you position anything on the screen y increases DOWN and x increases RIGTH.

Which way do you need?

[opus]

I would use it like this:

Public Function GetDirection(ByVal xVelocity As Long, ByVal yVelocity As Long) As Single
  Dim Direction As Single
    If yVelocity <> 0 Then
      Direction = Atn(xVelocity / yVelocity)
      If xVelocity < 0 Then
        'Quadrant III (-/-)   
        Direction = PI + Direction
      Else
        'Quadrant IV (-/+)   
        Direction = 2*PI + Direction
      End If
    Else
      If yVelocity>0 Then
        'Quadrant I (+/+)
        'Direction=Direction
      Else
        'Quadrant II (+/-)
        Direction=PI + Direction
      End If
    End If 
  Else
    If xVelocity > 0 Then
      Direction = PI/2
    Else
      Direction = 3*PI/2
    End If
  End If
  GetDirection = Direction
End Function

[flyhigh]

thanks all hafter wracking my brain i got it ,i think its right now for computer screen.
thanks again

Public Function GetDirection(ByVal xVelocity As Long, ByVal yVelocity As Long) As Single
  Dim Direction As Single
    If yVelocity <> 0 Then
            Direction = Atn(xVelocity / yVelocity)
            If xVelocity = 0 Then
               If yVelocity > 0 Then
                   Direction = 3 * PI / 2
               Else
                   Direction = PI / 2
               End If
            ElseIf yVelocity < 0 Then
             If xVelocity < 0 Then
                Direction = PI - Direction
             Else
                Direction = PI / 2 + Direction
             End If
            ElseIf xVelocity > 0 Then
             If yVelocity < 0 Then
                Direction = PI / 2 + Direction
             Else
                Direction = 3 * PI / 2 + Direction
             End If
            Else
                Direction = 3 * PI / 2 + Direction
            End If
    Else
            If xVelocity > 0 Then
            Else
                Direction = PI + Direction
            End If
    End If
  
    
 
  GetDirection = Direction
End Function

[flyhigh]

hey opus and all
when dealing with velocitis the speed of x and y ,to change the angle an object is flying in,should i change the x and y velocitis or just the angle?
why im asking when i mess with the velocitis ,give them -1 or .1 there angles are wrong.

thanks all