06-03-2022, 01:24 AM
A few years ago we were making Slinky toys with QB64 and today I was just goofing around with graphics and math and came across this spring that stretches and comes back. Someone probably made this before but I want to show you guys what I did myself. It's non-stop until you end it, back and forth. You can press Esc to end.
Code: (Select All)
_Title "Spring Toy"
Screen _NewImage(800, 600, 32)
xx = 200
yy = 200
length = 100
r = 1
c = _RGB32(0, 255, 0)
Do
If more = 0 Then xx = xx - .5: length = length + .5
If more = 0 Then yy = yy - .5: length = length + .5
If more = 1 Then xx = xx + .5: length = length - .5
If more = 1 Then yy = yy + .5: length = length - .5
If xx < 10 Then more = 1
If xx > 200 Then more = 0
For t = 0 To length Step .01
cx = (Sin(t) * xx) + xx + t
cy = (Cos(t) * yy) + yy + t
fillCircle cx, cy, r, c
Next t
_Delay .05
_Display
Cls
Loop Until InKey$ = Chr$(27)
'from Steve Gold standard
Sub fillCircle (CX As Integer, CY As Integer, R As Integer, C As _Unsigned Long)
Dim Radius As Integer, RadiusError As Integer
Dim X As Integer, Y As Integer
Radius = Abs(R): RadiusError = -Radius: X = Radius: Y = 0
If Radius = 0 Then PSet (CX, CY), C: Exit Sub
Line (CX - X, CY)-(CX + X, CY), C, BF
While X > Y
RadiusError = RadiusError + Y * 2 + 1
If RadiusError >= 0 Then
If X <> Y + 1 Then
Line (CX - Y, CY - X)-(CX + Y, CY - X), C, BF
Line (CX - Y, CY + X)-(CX + Y, CY + X), C, BF
End If
X = X - 1
RadiusError = RadiusError - X * 2
End If
Y = Y + 1
Line (CX - X, CY - Y)-(CX + X, CY - Y), C, BF
Line (CX - X, CY + Y)-(CX + X, CY + Y), C, BF
Wend
End Sub