Angles for a line

[hypnos]

Yo all,
Here's what I'm wanting to do... I have a form with a picture box, text box and a button. I wanted to be able to enter a degree into the text box and then press the button, which would draw a line in the picture box facing that degree. Unfortunately, it didn't quite turn out that way. My lack of knowledge led me to creating a really lame piece of code that should be on a stand-up comedians jokes list. Now, I'm gonna' show you my code but please...before you start rolling over on the floor in hysterics...remember, I'm an idiot

Const PI As Single = 3.14159

Private Function DtoR(degrees As Double) As Double
    Dim rad As Double
    rad = degrees / PI
    DtoR = rad * 180
End Function


Private Sub cmdGo_Click()
    Dim degrees As Double
    Dim x2 As Double
    Dim y2 As Double
    
    
    face.Cls
    degrees = Val(txtDegrees.Text)
    x2 = Sin(DtoR(degrees))
    y2 = -(Cos(DtoR(degrees)))
    
    face.Line (face.Width / 2, face.Height / 2)-(x2 * 700, y2 * 700)
    
    
End Sub

If somebody could please have a look and correct it for me (after you've stopped laughing) I would be very grateful

[Sastraxi]

Not too sure, but I think your problem lies in your DtoR function. I believe it should be:

DtoR = degrees / (180 / pi)

Once again, not too sure.

[hypnos]

Thanks for trying Sastraxi, but unfortunately, that's not it

[Brykovian]

I'm thinking it might have to do with your last couple parameters on the .Line method ...

Remember that the way you're calc'ing x2 & y2 makes them relative to your origin. And since your origin isn't the upper-left corner (0,0), then you need to do a bit more calc'ing ...

OriginX = face.Width \ 2
OriginY = face.Height \ 2

face.Line (OriginX, OriginY) - (OriginX + (x2 * 700), OriginY + (y2 * 700))

... or something like that. As an aside, notice that I used integer divide ("\") instead of the standard divide ("/") because it's faster and it results in an integer, which you'll need for your pixel coordinates anyway.

Hope that helps.

-Bryk

[hypnos]

I did that Brykovian and the results did change! Unfortunately it's still not working as it should. After making the change you suggested I only needed to go through numbers 1 to 10 for the line to do a complete revolution. It is a start but still, more to do Any more suggestions anybody?

[Zaei]

x2 = Cos(DtoR(degrees))
y2 = Sin(DtoR(degrees))

Z.

[hypnos]

Thanks for trying but that makes it worse

[kedaman]

Private Sub cmdGo_Click()
    Dim rad As Double
    face.Cls
    rad = Val(txtDegrees.Text) * 1.74532925199433E-02 'pi/180
    face.Line (face.Width / 2, face.Height / 2)-Step(Cos(rad) * 700, Sin(rad) * 700)
End Sub

[Brykovian]

Yah, hypnos ... I think Kedaman's code should do it ...

You did have your DtoR function wrong though ... you had the 180 and Pi thing flip-flopped ... shoulda been:

Private Function DtoR(degrees As Double) As Double
    Dim rad As Double
    rad = degrees / 180
    DtoR = rad * PI
End Function

Ked's code takes this into effect, plus puts all of the intermediate steps onto fewer lines.

-Bryk

p.s. I'd forgot about the "step" feature on the .Line method ...

[hypnos]

I'd like to thank all you guys for the help. You was right Brykovian, it was my Degrees to Radians function that was wrong. So, I changed it to the code you mentioned:

Private Function DtoR(degrees As Double) As Double
    Dim rad As Double
    rad = degrees / 180
    DtoR = rad * PI
End Function

Now it's working perfectly! Once again, thank you all for the help!