Developers, please tell me...

cip2
2005-04-12
2013-03-18
  • cip2

    cip2 - 2005-04-12

    I am the admin from project VisGame and am writing to ask if any of the developers would answer this question.

    Background:
    Mouse Input event MouseMoveDirection( Angle, Force)
    I have a event firing when ever you move the mouse (using DX8 input) but I would like to be able to also have the above event.

    Question:
    How do you get the angle returned by two segments (points-vectors) from a X and Y values back into one angle value?

    Code:
    This is what I am testing out on my computer. (it's in VB but the math is 80% the same - also I suing words in the example code for understanding)

    Type Vector
      X as double
      Y as double
    end type

    U, V, Alpha, Beta, Angle are all of type Vector
    Theta is of type Double

    'Some test values
    U.X = 1: U.Y = 3
    V.X = 4: V.Y = 1
    '||Vector|| = Magnitude = Squar_root ( (Vector.X ^ 2) + (Vector.Y ^2) )

    Alpha.X = cosign( U.x / ||U|| )
    Alpha.Y = sign( U.y / ||U|| )
    Beta.X = cosign( V.x / ||V|| )
    Beta.Y = sign( V.y / ||V|| )

    Now as I understand it you can get the angle between U and V (using a zero vector) like so:

    Theta = Alpha - Beta ' Get the angle

    but this dose not work in VB so you wright it this way

    Angle.X = Alpha.X - Beta.X  ' Get the angle for X
    Angle.Y = Alpha.Y - Beta.Y ' Get the angle for Y

    Again, my question is how do you get these values back into one angle as they should be. If any one can help me please jump in and show me the way.

    --
    Cip2 out

     
    • Dave Brosius

      Dave Brosius - 2005-04-12
       
      • cip2

        cip2 - 2005-04-12

        Hear ye, hear ye!
        Thank you dbrosius!
        I'll dredit you (and the sources) for leading me to the math that alowed the event to happen!
        It works even closer then I had hoped.
        Thank you dbrosius!
        Hear ye!

         

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