Мяч в vba

Формулировка задачи:

Изобразить движение футбольного мяча после удара (задается начальное положение мяча и вектор скорости). В процессе полёта мяч ударяется о пол, потолок и стены,стены поле есть,но не пойму как сделать(

Решение задачи: «Мяч в vba»

textual
                            Листинг программы 
                        

                            Option Explicit
 
Private Type Vector
    Dx As Single
    Dy As Single
End Type
 
Dim Vec As Vector, Pos As Vector
Dim Fri As Single, Loss As Single, Rad As Single
Dim Bf As Boolean
 
Private Sub Form_Load()
    Rad = 20: Loss = 1.2: Fri = 1.01
    Pos.Dx = Me.ScaleWidth / 2
    Pos.Dy = Me.ScaleHeight / 2
End Sub
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Dim Dx As Single, Dy As Single, R As Single
    Dx = X - Pos.Dx: Dy = Y - Pos.Dy
    R = Sqr(Dx * Dx + Dy * Dy)
    If R < Rad Then Bf = True
End Sub
Private Sub Form_MouseMove(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Dim Dx As Single, Dy As Single
    If Not Bf Then Exit Sub
    Dx = X - Pos.Dx: Dy = Y - Pos.Dy
    Vec.Dx = -Dx: Vec.Dy = -Dy
End Sub
Private Sub Form_MouseUp(Button As Integer, Shift As Integer, X As Single, Y As Single)
    Bf = False
End Sub
Private Sub LossVec()
    If Vec.Dx Then Vec.Dx = Vec.Dx / Loss
    If Vec.Dy Then Vec.Dy = Vec.Dy / Loss
End Sub
Private Sub tmrTimer_Timer()
    Me.Cls
    If Bf Then
        Me.Circle (Pos.Dx, Pos.Dy), Rad, vbRed
        Me.Line (Pos.Dx, Pos.Dy)-Step(-Vec.Dx, -Vec.Dy), vbGreen
    Else
        Vec.Dx = Vec.Dx / Fri: Vec.Dy = Vec.Dy / Fri
        Pos.Dx = Pos.Dx + Vec.Dx
        Pos.Dy = Pos.Dy + Vec.Dy
        If Pos.Dx > Me.ScaleWidth - Rad Then Pos.Dx = Me.ScaleWidth - Rad: Vec.Dx = -Vec.Dx: LossVec
        If Pos.Dx < Rad Then Pos.Dx = Rad: Vec.Dx = -Vec.Dx: LossVec
        If Pos.Dy > Me.ScaleHeight - Rad Then Pos.Dy = Me.ScaleHeight - Rad: Vec.Dy = -Vec.Dy:  LossVec
        If Pos.Dy < Rad Then Pos.Dy = Rad: Vec.Dy = -Vec.Dy:  LossVec
        Me.Circle (Pos.Dx, Pos.Dy), Rad
    End If
    Me.Refresh
End Sub
                        