The Powder Toy

plypencil

I'm making another physics toy, this is the loop which transmits air pressure to the surrounding squares. However The whole screen almost instantly fills up with air as soon as I put 1 bit of air into the simulation and the program crashes, the number is too high for the int64. I cannot see where I am going wrong, maybe one of you can see?

For x As Integer = 1 To 78
For y As Integer = 1 To 58
If terrain(x, y).type = "air" Then
Dim possiblemove As Integer = 1
Dim pressuretotal As Decimal
If terrain(x + 1, y).type = "air" Then possiblemove += 1 : pressuretotal += terrain(x + 1, y).pressure
If terrain(x - 1, y).type = "air" Then possiblemove += 1 : pressuretotal += terrain(x - 1, y).pressure
If terrain(x, y + 1).type = "air" Then possiblemove += 1 : pressuretotal += terrain(x, y + 1).pressure
If terrain(x, y - 1).type = "air" Then possiblemove += 1 : pressuretotal += terrain(x, y - 1).pressure
Dim unitpressure As Decimal = (pressuretotal / possiblemove)
terrain(x, y).tpressure += unitpressure
If terrain(x + 1, y).type = "air" Then terrain(x + 1, y).tpressure += unitpressure
If terrain(x - 1, y).type = "air" Then terrain(x - 1, y).tpressure += unitpressure
If terrain(x, y + 1).type = "air" Then terrain(x, y + 1).tpressure += unitpressure
If terrain(x, y - 1).type = "air" Then terrain(x, y - 1).tpressure += unitpressure
End If
Next
Next

For x As Integer = 1 To 78
For y As Integer = 1 To 58
terrain(x, y).pressure = terrain(x, y).tpressure
terrain(x, y).tpressure = 0
Next
Next

Felix

I am thinking infinite loops. Add some debugging stuff, like print out variable contents to console and such.

plypencil

Its not an infinite loop, the screen does update but because im running 60fps....

The problem is the math in that block, somehow I am getting MORE out than im putting in

Sorry Einstein

Felix

terrain(x + 1, y).pressure
Together with:
For y As Integer = 1 To 58
For x As Integer = 1 To 78

This is a loop, right? I don't know VB. I think that in there is your problem

plypencil

Its cycling through the x and y axis of the screen, spreading any air out there is in the simulation.

Felix

Then that is probably the problem.

Then possiblemove += 1
That also adds one to possiblemove, can't see a reason for this. Without knowing your code atleast.

plypencil

Because itself is a position.

If it can move only right, it can still have air in itself. So its 1 + 1 direction. So if you have 100 it will be split between the 2 with 50 each. if there were 3 possible directions it would be 33 each.

Its basically air physics but without wind

TPTlover1012

This post is hidden because the user is banned

A bit of coding help