Rolling coins

[nm7s9]

JUst a simple program, no instructions, just hit some buttons and see what
shapes emerge.

Equations curtesy of mathworld.wolfram.com

Cheers
Nick

[Erel]

Very nice!

[Cableguy]

This brougth back so many memories.....
As I was a kid, aged 6 or 7, there was this brand of chocolate powder, wich came with a scantilion, a ruler by wich we could draw on paper Exactly these shapes...
As I did back then, today a spendt hours playing with the values and seeing the shapes being drwan in my screen....
I was 7 again.... Thank you very much...

[taximania]

Very nice work Nick

[Erel]

There is a subtle bug in your code.
You are using an endless loop and therefore the program will not stop until you close it with task manager (optimized compiled version).
A simple correction is to use a global variable as a flag that breaks the loop when the main form is closing:

Sub Globals
    'Declare the global variables here.
    Dim a, b, h, t, t1
    Dim x, y, xstart, ystart
    Dim showsmall, showlarge, showpole
    Dim waittime, inner
    Dim stop ' <---
End Sub

Sub App_Start

'  Equations curtesy of mathworld.wolfram.com
    stop = False
    Form1.Color = cBlack
    xstart = 120 : ystart = 120 
    xsmall = xstart : ysmall = ystart
    a=40:b=10:h=10:t=0:x=0:y=0
    showsmall=1 : showlarge=1 : showpole=1
    waittime = 20 : inner = 1
    SetTransparentColor(cWhite)
    form1.ForeLayer = True
    Form1.Show
    t1=0
    Do Until stop
        If showlarge = 1 Then
            form1.Circle(xstart,ystart,a,cGray)
        Else
            form1.Circle(xstart,ystart,a,cBlack)    
        End If
        form1.FLine(0,0,400,400,cWhite,BF)
        t=t1*cPI/180
        If inner = 1 Then
            z = a-b
            x=z*Cos(t)+h*Cos(z/b*t)
        Else
            z = a+b
            x=z*Cos(t)-h*Cos(z/b*t)
        End If
        y=z*Sin(t)-h*Sin(z/b*t)
        xsmall=z*Cos(t)
        ysmall=z*Sin(t)
        form1.Line(xstart+x,ystart+y,xstart+x+1,ystart+y+1,cWhite,BF)
        If showsmall = 1 Then
            form1.FCircle(xstart+xsmall,ystart+ysmall,b,cGray)
        End If
        If showpole = 1 Then
            form1.FLine(xstart+xsmall,ystart+ysmall,xstart+x,ystart+y,cRed)
        End If
        DoEvents
        Sleep(waittime)
        t1 = t1 + 1
    Loop
    

End Sub
Sub Form1_Close
    stop = True
End Sub

[specci48]

Originally Posted by Cableguy

This brougth back so many memories.....

Dito!
The "game" I had was called Spirograph.

@nm7s9: Really nice program!


specci48

[nm7s9]

Ok - thanks Erel.

Is there a better way to plot a point than approximate it with a 2x2 block.
A 3x3 block with its centre at the correct point is more accurate than what I've done but is too thick, A 1x1 line didn't show up on my screen at all.

BTW I,40,20,40 shows that if your hula-hoop has a nail in it and is twice as big as your waist, then the nail is going to get you, always in the same place every second time round.

Better get a bigger hula hoop, and better still, make sure it is not a intergral size bigger than your waist.

I,46,20,46 makes some really interesting patterns and ensures that the nail strikes occurr evenly around your waist.

[Erel]

Is there a better way to plot a point than approximate it with a 2x2 block.

You can use Bitmap.SetPixel from the ImageLib library.
However it will be a little bit more complicated.

[Mr_Gee]

Real nice!

Will you be enhancing it?
- different sizes
- different colors (agraham's color picker maybe)
- multiple rings
- a "stop" button
- save as function (I think dzt had a nice image lib)

Originally Posted by specci48

Dito!
The "game" I had was called Spirograph.
@nm7s9: Really nice program!
specci48

Yes!
I always wanted to have it as a kid... but never got it :'(

[klaus]

Nice application.

Reminds me also some souvenirs, having programmed something similar quite some years ago.

Specci48, my daughter, once, got a similar game (also some years ago).

I agree with Mr_Gee, you should continue in adding the features discribed by him.

Another suggestions:
- stop the drawing when it beginns to overlap (drawing the same lines)
- by default when changing the small circle, put the drawing radius at the same value.

Best regards.