ChatGPT Boids Simulation: Winforms, WPF versions

It took a few prompts for ChatGPT 3.5 to create it, but I had to fix some of it's mistakes. From Wikipedia, for those who don't know what a boids simulation is, it's an artificial life program, developed by Craig Reynolds in 1986, which simulates the flocking behaviour of birds, and related group motion.

In this boids simulation project you can change the number of boids in the simulation and pause their movement. 4 boids is the smallest size a flock can be. The boids avoid the mouse cursor, so you can observe the new counts of flocks, trios, pairs and lone boids. It runs fine when you resize the form.

Attachment 189367

The capture above is from the 1st version of the boids simulation project. The updated winforms and Wpf versions have filled-in triangles, and can handle up to 1000 boids.

The code below is also from the 1st version. It needs 1 panel docked at the bottom and a PictureBox to fill the remaining space in the Form. It also needs 2 timers named "SimulationTimer" and "CountingTimer", 7 labels, a textbox, and two buttons. Button2 is the pause button.

The code has enough comments to explain everything. All required classes will be in the next two comments.

Main class:

Code:

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Option Strict On

Public Class Form1
    ' Maximum speed of boids
    Private MaxSpeed As Integer = 7

    ' Range within which boids perceive and interact with each other
    Public VisualRange As Integer = 40

    ' Range within which boids avoid collisions
    Private ProtectedRange As Integer = 20

    ' List to store individual boid instances representing the flock.
    Private BoidsList As List(Of Boid)

    ' Buffered bitmap for off-screen rendering
    Private buffer As Bitmap

    ' Variables for mouse cursor avoidance.
    Private BoidsMousePosition As Point
    Private MouseAvoidanceThreshold As Double = 25

    ' Instances for alignment, cohesion, and separation rules for boid behavior.
    ' MaxSpeed parameter is set to the maximum speed allowed for boids.
    Private alignmentRule As New Alignment(MaxSpeed)
    Private cohesionRule As New Cohesion()
    Private separationRule As New Separation()

    ' The initial number of boids to be created and initialized
    Private Const InitialBoidCount As Integer = 400

    ' Flag to track pause state
    Private IsPaused As Boolean = False

    ' BoidCounterInstance represents an instance of the BoidCounter class,
    ' which is responsible for counting various configurations of boids within a specified visual range.
    Public BoidCounterInstance As New BoidCounter()


    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ' Set the DoubleBuffered property to True to enable double buffering
        Me.DoubleBuffered = True

        ' Initialize the buffered bitmap
        buffer = New Bitmap(PictureBox1.ClientSize.Width, PictureBox1.ClientSize.Height)

        ' Set VisualRange for BoidCounterInstance
        BoidCounterInstance.VisualRange = VisualRange

        ' Initialize the list of boids
        BoidsList = New List(Of Boid)()
        InitializeBoids(InitialBoidCount)

        ' Start the simulation timer
        SimulationTimer.Start()
        CountingTimer.Start()
    End Sub


    ' Initializes a specified number of boids with random positions and velocities.
    Private Sub InitializeBoids(ByVal count As Integer)
        ' Create a random number generator.
        Dim random As Random = New Random()

        ' Generate boids with random positions and velocities.
        For i As Integer = 0 To count - 1
            Dim boid As Boid = New Boid()
            boid.Location = New Point(random.Next(0, PictureBox1.ClientSize.Width), random.Next(0, PictureBox1.ClientSize.Height))
            boid.Velocity = New Point(random.Next(-2, 3), random.Next(-2, 3))
            BoidsList.Add(boid)
        Next
    End Sub


    Private Sub SimulationTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles SimulationTimer.Tick
        If Not IsPaused Then
            ' Update boids position
            For Each boid As Boid In BoidsList
                UpdateBoid(boid)
            Next

            ' Draw boids to the buffer
            DrawBoidsToBuffer()
        End If
    End Sub


    ' Updates the position and behavior of a given boid based on its interactions with other boids and the environment.
    Private Sub UpdateBoid(ByVal boid As Boid)
        ' Variables to store averages, counts, and distances for boid interactions
        Dim averageXposition, averageYposition, averageXvelocity, averageYvelocity, neighboringBoids, closeDx, closeDy As Double

        ' Loop through every other boid in the flock
        For Each otherBoid As Boid In BoidsList
            ' Check if the boid is not itself
            If Not boid.Equals(otherBoid) Then
                Dim dx As Double = boid.Location.X - otherBoid.Location.X
                Dim dy As Double = boid.Location.Y - otherBoid.Location.Y
                Dim squaredDistance As Double = dx * dx + dy * dy

                ' Check if the boids are within the protected range
                If squaredDistance < ProtectedRange * ProtectedRange Then
                    closeDx += boid.Location.X - otherBoid.Location.X
                    closeDy += boid.Location.Y - otherBoid.Location.Y
                ElseIf squaredDistance < VisualRange * VisualRange Then
                    ' Update averages for boids within the visual range
                    averageXposition += otherBoid.Location.X
                    averageYposition += otherBoid.Location.Y
                    averageXvelocity += otherBoid.Velocity.X
                    averageYvelocity += otherBoid.Velocity.Y
                    neighboringBoids += 1
                End If
            End If
        Next

        ' Check if there are neighboring boids
        If neighboringBoids > 0 Then
            ' Calculate average velocity and position
            Dim avgVelocity As New Point(CInt(averageXvelocity / neighboringBoids), CInt(averageYvelocity / neighboringBoids))
            Dim avgPosition As New Point(CInt(averageXposition / neighboringBoids), CInt(averageYposition / neighboringBoids))

            ' Calculate distance to the mouse
            Dim mouseDistance As Double = Math.Sqrt((boid.Location.X - BoidsMousePosition.X) ^ 2 + (boid.Location.Y - BoidsMousePosition.Y) ^ 2)

            ' Skip alignment and cohesion when boid is near the mouse
            If mouseDistance > VisualRange Then
                ' Apply alignment rule
                alignmentRule.ApplyAlignmentRule(boid, avgVelocity)
                ' Apply cohesion rule
                cohesionRule.ApplyCohesionRule(boid, avgPosition)
            End If
        End If

        ' Apply separation rule
        separationRule.ApplySeparationRule(boid, closeDx, closeDy)

        ' Move boid
        boid.Location = New Point(boid.Location.X + boid.Velocity.X, boid.Location.Y + boid.Velocity.Y)

        ' Apply mouse avoidance
        Dim distanceToMouse As Double = Math.Sqrt((boid.Location.X - BoidsMousePosition.X) ^ 2 + (boid.Location.Y - BoidsMousePosition.Y) ^ 2)
        If distanceToMouse < MouseAvoidanceThreshold Then
            ' Adjust velocity to avoid the mouse more strongly
            Dim angle As Double = Math.Atan2(boid.Location.Y - BoidsMousePosition.Y, boid.Location.X - BoidsMousePosition.X)
            boid.Velocity = New Point(CInt(boid.Velocity.X + Math.Cos(angle) * 4), CInt(boid.Velocity.Y + Math.Sin(angle) * 4))
        End If

        ' Keep boids within the PictureBox boundaries
        If boid.Location.X < 0 Then
            boid.Location = New Point(0, boid.Location.Y)
            boid.Velocity = New Point(-boid.Velocity.X, boid.Velocity.Y)
        ElseIf boid.Location.X > PictureBox1.ClientSize.Width Then
            boid.Location = New Point(PictureBox1.ClientSize.Width, boid.Location.Y)
            boid.Velocity = New Point(-boid.Velocity.X, boid.Velocity.Y)
        End If

        If boid.Location.Y < 0 Then
            boid.Location = New Point(boid.Location.X, 0)
            boid.Velocity = New Point(boid.Velocity.X, -boid.Velocity.Y)
        ElseIf boid.Location.Y > PictureBox1.ClientSize.Height Then
            boid.Location = New Point(boid.Location.X, PictureBox1.ClientSize.Height)
            boid.Velocity = New Point(boid.Velocity.X, -boid.Velocity.Y)
        End If

        ' Normalize velocity
        Dim length As Double = Math.Sqrt(boid.Velocity.X ^ 2 + boid.Velocity.Y ^ 2)
        If length > MaxSpeed Then
            ' Scale velocity back to the maximum speed
            boid.Velocity = New Point(CInt(MaxSpeed * boid.Velocity.X / length), CInt(MaxSpeed * boid.Velocity.Y / length))
        End If
    End Sub


    Private Sub CountingTimer_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles CountingTimer.Tick
        ' Set the BoidsList property before counting
        BoidCounterInstance.BoidsList = BoidsList

        ' Counts flocks, trios, pairs, and lone boids
        BoidCounterInstance.CountFlocksTriosPairsLoners(BoidsList)

        ' Update labels outside the loop with the calculated counts.
        Label1.Text = "Flocks: " & BoidCounterInstance.FlockCount
        Label2.Text = "Trios: " & BoidCounterInstance.TrioCount
        Label3.Text = "Pairs: " & BoidCounterInstance.PairCount
        Label4.Text = "Loners: " & BoidCounterInstance.LoneCount
    End Sub


    Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
        ' Update mouse position
        BoidsMousePosition = e.Location
    End Sub


    Private Sub DrawBoidsToBuffer()
        ' Draw boids as small narrow triangles on the off-screen buffer
        Using g As Graphics = Graphics.FromImage(buffer)
            g.Clear(Color.White) ' You can choose a different background color if needed

            For Each boid As Boid In BoidsList
                ' Calculate the angle of the velocity vector
                Dim angle As Double = Math.Atan2(boid.Velocity.Y, boid.Velocity.X) ' The angle now directly represents the direction of the top of the triangle

                ' Calculate the points of the triangle
                Dim points As Point() = {
                    New Point(boid.Location.X + CInt(7 * Math.Cos(angle)), boid.Location.Y + CInt(8 * Math.Sin(angle))),
                    New Point(boid.Location.X + CInt(3 * Math.Cos(angle - 2 * Math.PI / 3)), boid.Location.Y + CInt(3 * Math.Sin(angle - 2 * Math.PI / 3))),
                    New Point(boid.Location.X + CInt(3 * Math.Cos(angle + 2 * Math.PI / 3)), boid.Location.Y + CInt(3 * Math.Sin(angle + 2 * Math.PI / 3)))
                }

                ' Draw the triangle (body) on the off-screen buffer
                g.DrawPolygon(Pens.Blue, points)
            Next
        End Using
        ' Trigger the Paint event to display the buffered bitmap on the PictureBox
        PictureBox1.Invalidate()
    End Sub


    Private Sub PictureBox1_Paint(ByVal sender As Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles PictureBox1.Paint
        ' Draw the buffered image onto the PictureBox
        e.Graphics.DrawImage(buffer, 0, 0)
    End Sub


    Private Sub PictureBox1_SizeChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles PictureBox1.SizeChanged
        ' Resize the buffered bitmap when the PictureBox size changes
        buffer = New Bitmap(PictureBox1.ClientSize.Width, PictureBox1.ClientSize.Height)

        ' Update the label displaying the display area size
        Label7.Text = "Display Area: " & PictureBox1.ClientSize.Width & " x " & PictureBox1.ClientSize.Height

        ' Invalidate the form to trigger a redraw
        Me.Invalidate()
    End Sub


    Private Sub Panel1_Paint(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PaintEventArgs) Handles Panel1.Paint
        ' Draw a black line at the top of the panel
        Dim topBorderPen As New Pen(Color.Black)
        e.Graphics.DrawLine(topBorderPen, 0, 0, Panel1.Width, 0)
    End Sub


    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        ' Attempt to parse the input as an integer
        Dim newBoidCount As Integer
        If Integer.TryParse(TextBox1.Text, newBoidCount) Then
            If CInt(TextBox1.Text) > 1000 Then
                ' Input integer value is too high, display an error message
                MessageBox.Show("The integer value is too high")
            Else
                ' Input is a valid integer, reset the list and initialize new boids
                BoidsList = New List(Of Boid)()
                InitializeBoids(newBoidCount)

                ' Check if the simulation is paused and unpause if needed
                If IsPaused Then
                    IsPaused = False
                    ' Update button text when resumed
                    PauseButton.Text = "Pause"
                End If
            End If
        Else
            ' Input is not a valid integer, display an error message
            MessageBox.Show("Invalid input for boid count." & vbCrLf & vbCrLf & "Please enter a valid integer value.")

            ' clears invalid input
            TextBox1.Text = ""
        End If
    End Sub


    Private Sub PauseButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles PauseButton.Click
        ' Toggle the pause state
        IsPaused = Not IsPaused

        ' Update button text based on the pause state
        If IsPaused Then
            ' Update button text when paused
            PauseButton.Text = "Resume"
        Else
            ' Update button text when resumed
            PauseButton.Text = "Pause"
        End If
    End Sub
End Class

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The boids simulation was coded in Visual Basic 2010, Framework 4, but the code provided above and in the next two comments should work with any Framework.

The "ChatGPT Boid Simulation Update.zip" project's and "Wpf Boids Simulation.zip" project's performance is the same. The only thing, when you minimize the ""ChatGPT Boid Simulation Update.zip" version to the taskbar, it crashes. I can't figure out why it does that.

https://www.vbforums.com/images/ieimages/2023/11/19.png

The capture above was taken soon after I changed the boid count. The boids eventually unite into two or 3 flocks. Large flocks sometimes split-up.

Update, Dec 8th:
I updated the WPF boids simulation project zip below. It no longer goes by a previous canvas size when changing the boid count, but the actual canvas size after resizing the window. It also displays the actual canvas size while resizing.

Boid class:

Code:

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' Represents a boid with properties for its location and velocity.
Public Class Boid
    Public Property Location As Point
    Public Property Velocity As Point
End Class

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Alignment class:

Code:

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' For applying the alignment rule to boids.
Public Class Alignment

    Private MaxSpeed As Integer

    ' Constructor to initialize the Alignment class with the maximum speed.
    Public Sub New(ByVal maxSpeed As Integer)
        Me.MaxSpeed = maxSpeed
    End Sub

    ' Applies the alignment rule to adjust the boid's velocity based on the average velocity of neighboring boids.
    Public Sub ApplyAlignmentRule(ByVal boid As Boid, ByVal avgVelocity As Point)
        ' Calculate the angle of the new velocity based on the average velocity.
        Dim newVelocityAngle As Double = Math.Atan2(avgVelocity.Y, avgVelocity.X)

        ' Set the boid's velocity with the adjusted speed in the direction of the new velocity angle.
        boid.Velocity = New Point(CInt(MaxSpeed * Math.Cos(newVelocityAngle)), CInt(MaxSpeed * Math.Sin(newVelocityAngle)))
    End Sub
End Class

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Separation class:

Code:

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' For applying the separation rule to boids.
Public Class Separation

    ' Applies the separation rule to adjust the boid's velocity based on the distances to close neighbors.
    Public Sub ApplySeparationRule(ByVal boid As Boid, ByVal closeDx As Double, ByVal closeDy As Double)
        ' Separation rule logic
        ' The separation factor determines the strength of the separation effect. Adjust as needed.
        Dim separationFactor As Double = 0.1

        ' Adjust the boid's velocity based on the distances to close neighbors and the separation factor.
        boid.Velocity = New Point(CInt(boid.Velocity.X + closeDx * separationFactor), CInt(boid.Velocity.Y + closeDy * separationFactor))
    End Sub
End Class

---

Cohesion class:

Code:

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' For applying the cohesion rule to boids.
Public Class Cohesion

    ' The factor determining the strength of the cohesion effect. Adjust as needed.
    Public Property CenteringFactor As Double = 0.1

    ' Applies the cohesion rule to adjust the boid's velocity based on the average position of neighboring boids.
    Public Sub ApplyCohesionRule(ByVal boid As Boid, ByVal averagePosition As Point)
        ' Cohesion rule logic
        ' The cohesion factor is a combination of the centering factor and a scaling factor. Adjust as needed.
        Dim cohesionFactor As Double = CenteringFactor * 0.4

        ' Adjust the boid's velocity based on the average position of neighboring boids and the cohesion factor.
        boid.Velocity = New Point(CInt(boid.Velocity.X + (averagePosition.X - boid.Location.X) * cohesionFactor),
                                  CInt(boid.Velocity.Y + (averagePosition.Y - boid.Location.Y) * cohesionFactor))
    End Sub
End Class

---

And lastly the BoidCounter class:

Code:

---

' BoidCounter class is responsible for counting various configurations of boids within a specified visual range.

Public Class BoidCounter


    ' Property to set or get the list of boids from the Form1 class.
    Public Property BoidsList As List(Of Boid)

    ' Property to set or get the visual range within which boids are considered neighbors.
    Public Property VisualRange As Integer


    Public FlockCount As Integer = 0 ' Number of flocks
    Public TrioCount As Integer = 0  ' Number of trios
    Public PairCount As Integer = 0  ' Number of pairs
    Public LoneCount As Integer = 0  ' Number of loners


    ' Counts the number of flocks, trios, pairs, and lone boids based on the specified visual range.
    ' Requires the BoidsList property to be set before calling this method.
    Public Sub CountFlocksTriosPairsLoners(ByVal BoidsList As List(Of Boid))

        ' Initialize a set to keep track of visited boids during counting.
        Dim visitedBoids As New HashSet(Of Boid)

        ' Reset count variables to zero.
        FlockCount = 0
        TrioCount = 0
        PairCount = 0
        LoneCount = 0

        ' Iterate through each boid in the BoidsList.
        For Each boid As Boid In BoidsList
            ' Check if the boid has not been visited before.
            If Not visitedBoids.Contains(boid) Then
                ' Find the boids to which the boid belongs and mark the visited boids.
                Dim boids As List(Of Boid) = FindBoidsGroup(boid, visitedBoids)
                visitedBoids.UnionWith(boids)

                ' Update counts based on boids group size.
                If boids.Count > 3 Then
                    FlockCount += 1
                End If

                ' Check if it's a trio.
                If boids.Count = 3 Then
                    TrioCount += 1
                End If

                ' Check if it's a pair.
                If boids.Count = 2 Then
                    PairCount += 1
                End If

                ' Check if it's a lone boid.
                If boids.Count = 1 Then
                    LoneCount += 1
                End If
            End If
        Next
    End Sub

    ' Finds and returns the group of boids to which a given boid belongs.
    ' Uses depth-first search to traverse the boid groups.
    ' Parameters:
    '  - boid: The boid for which to find the group.
    '  - visitedBoids: A set to keep track of visited boids during the traversal.
    ' Returns a List(Of Boid) representing the group of boids.
    Private Function FindBoidsGroup(ByVal boid As Boid, ByVal visitedBoids As HashSet(Of Boid)) As List(Of Boid)
        ' Initialize a list to store the boids in the group.
        Dim group As New List(Of Boid)

        ' Use a stack to perform depth-first search to find the boids group.
        Dim stack As New Stack(Of Boid)
        stack.Push(boid)

        ' Iterate until the stack is empty.
        While stack.Count > 0

            ' Pop the current boid from the stack.
            Dim currentBoid As Boid = stack.Pop()

            ' If the current boid has not been visited, add it to the group and visit its neighbors.
            If Not visitedBoids.Contains(currentBoid) Then
                visitedBoids.Add(currentBoid)
                group.Add(currentBoid)

                ' Visit neighbors and add them to the stack if they are not already visited.
                For Each neighbor As Boid In BoidsList
                    If Not visitedBoids.Contains(neighbor) AndAlso IsNeighbor(currentBoid, neighbor, VisualRange) Then
                        stack.Push(neighbor)
                    End If
                Next
            End If
        End While

        ' Return the final group of boids.
        Return group
    End Function

    ' Determines if two boids are neighbors based on distance.
    Private Function IsNeighbor(ByVal boid1 As Boid, ByVal boid2 As Boid, ByVal visualRange As Double) As Boolean
        ' Calculate the Euclidean distance between the locations of the two boids.
        Dim distance As Double = Math.Sqrt((boid1.Location.X - boid2.Location.X) ^ 2 + (boid1.Location.Y - boid2.Location.Y) ^ 2)

        ' Return true if the distance is less than the visual range.
        Return distance < visualRange ' Adjust the distance as needed
    End Function
End Class

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How does chatGPT come in, you used it to generate the codes?

Quote:

---

Originally Posted by coolcurrent4u

How does chatGPT come in, you used it to generate the codes?

---

Yes, ChatGPPT generated the codes, but I had to tweak it to get it to work.

I mentioned this in the first sentence of the first post above. :lol:

Would you say that using ChatGPT you were not able to kill two boids with one stone?

Quote:

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Originally Posted by jdelano

Would you say that using ChatGPT you were not able to kill two boids with one stone?

---

A little boidie told me to give it a try. :bigyello:

Seriously, I just wanted to see if ChatGPT could code it. I have no use for a boids simulation.