VB.NET Collision oF 2 Graph Rectangles in bitmap

Question

I'm pretty new to programming. I'm trying to code OOP as much as possible .

Problem: How can I detected if two graphics make a collision with each other in a single picturebox?

Now here are the questions:

1. Is there anyway I can do this with graphics on a bitmap. I have seen a lot of examples where two separate picterbox are used to make a collision with each, but how to do this with my example?

2. How can I improve my current code?

   Public Class RechtHoek
   
   'property
   
   Public Property Y As Integer
       Set(value As Integer)
           _y = value
       End Set
       Get
           Return _y
       End Get
   End Property
   
   Public Property X As Integer
       Set(value As Integer)
           _x = value
       End Set
       Get
           Return _x
       End Get
   End Property
   
   'Variables
   
   Dim _y As Integer
   Dim _x As Integer
   Dim _maxY As Integer
   Dim _maxX As Integer   
   
   
   'Variabele om kleur te wijzingen
   Dim kleur As Color = RandomKleur()
   Dim VeranderKleur As Boolean = False
   Dim brush2 As New SolidBrush(RandomKleur)
   
   
   'variablen om rechthoek te draaien
   
   'Variabelen voor bewegen van de rechthoeken
   Dim goingUp As Boolean = False
   Dim goingRight As Boolean = False
   'constructor 
   Public Sub New(x As Integer, y As Integer, maxX As Integer, MaxY As Integer)
   
       _y = y
       _x = x
       _maxX = maxX
       _maxY = MaxY
   End Sub
   
   Public Sub DrawRechthoekHorizontaal(graph As Graphics)
   
   
       Dim pen As New Pen(Color.Black)
       Dim rect As New Rectangle(_x, Y, 40, 100)
   
   
       graph.FillRectangle(brush2, rect)
       graph.DrawRectangle(pen, rect)
   
   End Sub
   
   Public Sub DrawRechthoekVerticaal(graph As Graphics)
   
   
       Dim pen As New Pen(Color.Black)
       Dim rect As New Rectangle(_x, Y, 100, 40)
   
   
   
       graph.FillRectangle(brush2, rect)
       graph.DrawRectangle(pen, rect)
   
   End Sub  
   
   
   Public Function RandomKleur() As Color
   
   
       Dim myAlpha As Integer = 0
       Dim myRed As Integer = 0
       Dim myGreen As Integer = 0
       Dim myBlue As Integer = 0
   
       Randomize()
   
   
       myAlpha = CInt(Int((254 * Rnd()) + 0))
       Randomize()
       myGreen = CInt(Int((254 * Rnd()) + 0))
       Randomize()
       myRed = CInt(Int((254 * Rnd()) + 0))
       Randomize()
       myBlue = CInt(Int((254 * Rnd()) + 0))
   
       'Color.FromArgb(myAlpha, myRed, myGreen, myBlue)
   
       Return Color.FromArgb(myAlpha, myRed, myGreen, myBlue)
   
   
   End Function
   
   Public Sub Up()
       Y -= 10
   End Sub
   
   Public Sub Down()
       Y += 10
   End Sub
   
   Public Sub Right()
       X -= 10
   End Sub
   
   Public Sub Left()
       X += 10
   End Sub
   
   
   Public Sub MoveX()
   
       If goingRight Then
   
           Right()
   
       Else
   
           Left()
       End If
   
       If X < 0 Then
   
           goingRight = False
   
           'verander van kleur 
           If X = -10 Then
               VeranderKleur = True
               brush2.Color = RandomKleur()
           End If
   
       ElseIf X > 1600 Then
   
   
           goingRight = True
   
           'verander van kleur 
           If X = 1610 Then
               VeranderKleur = False
               brush2.Color = RandomKleur()
           End If
   
       End If
   
   
   End Sub
   
   Public Sub MoveY()
   
       If goingUp Then
   
           Up()
   
       Else
   
           Down()
   
       End If
   
       If Y < 0 Then
   
           goingUp = False
   
           'verander van kleur 
           If Y = -10 Then
               VeranderKleur = True
               brush2.Color = RandomKleur()
           End If
   
       ElseIf Y > 900 Then
   
           goingUp = True
   
           'verander van kleur 
           If Y = 910 Then
               VeranderKleur = True
               brush2.Color = RandomKleur()
           End If
   
       End If
   
   End Sub
   
   End Class
   
   Public Class FormBewegendeRechtHoeken
   
   Dim rectY As RechtHoek
   Dim rectX As RechtHoek
   
   Dim bitmap As Bitmap
   
   Private img As Image
   
   Private Sub FormRechtHoek_Load(sender As Object, e As EventArgs) Handles MyBase.Load
   
       bitmap = New Bitmap(PictureBox.Width, PictureBox.Height)
   
       'X = plaats waar rechthoek start op x as , Y = plaats waar rechthoekstart op y as 'Max x hoogete &' Max Y hoogte 
       rectY = New RechtHoek(PictureBox.Width \ 2, PictureBox.Height, PictureBox.Width, PictureBox.Height)
   
       rectX = New RechtHoek(PictureBox.Width, PictureBox.Height \ 2, PictureBox.Width, PictureBox.Height)
   
   
       Draw()
   
       TheTimer.Start()
   
   End Sub
   
   Private Sub Botsing()
   
   
   End Sub
   
   Private Sub Draw()
   
       Using graph As Graphics = Graphics.FromImage(bitmap)
   
           graph.Clear(Color.Yellow)
   
   
   
           rectX.DrawRechthoekHorizontaal(graph)
   
   
           'Omkeren van de rechthoek in het midden
           If rectY.Y < 450 Then
               rectY.DrawRechthoekHorizontaal(graph)
           End If
   
           If rectY.Y > 450 Then
   
               rectY.DrawRechthoekVerticaal(graph)
   
           End If
   
   
   
       End Using
   
       PictureBox.Image = bitmap
   
   End Sub
   
   Private Sub TheTimer_Tick(sender As Object, e As EventArgs) Handles TheTimer.Tick
   
   
       rectY.MoveY()
       rectX.MoveX()
       Draw()
   
   End Sub
   
   End Class
   

Answer 1

If you save the rectangle structures you draw in an array or a list, you can check a collision like this:

The rectangles collide when one rectangle contains at least one edge point of the other rectangle. So you can define a function:

Function CheckRectCollision(Rect1 as Rectangle, Rect2 as Rectangle) as Boolean
   If Rect1.Contains(New Point(Rect2.Left, Rect2.Top) Orelse _
      Rect1.Contains(New Point(Rect2.Left, Rect2.Bottom) Orelse _
      Rect1.Contains(New Point(Rect2.Right, Rect2.Top) Orelse _
      Rect1.Contains(New Point(Rect2.Right, Rect2.Bottom) Then
      Return True
    Else
      Return False
    End If
End Function

That way you can check if two rectangles collide. Find exclusive permutations for all rectangle pairs you have and call the function for each pair.