balisticmisisle_1.0.0

    Dim m, d, u, wing_s, cl, cd, theta_launch As Double  ' Input_Param:missile_data as mass, nozzle diameter, jet_vel, wing_cl. wing_cd, launch_angle.
    Dim t, missile_x, missile_y, velo, theta_wind As Double ' Calc_Param: time, x, y, v, windAngle, buffer.
    Dim resolution_t, selfDistrunct As Double  ' Calc_setting_param : how resolute calcuration of Integral
    
    
    ' now v0 is 0
    
    
    
    Function getThrot(d, u, m, resolution_t)
        Dim throt As Double
        throt = d * u * m * resolution_t
        getThrot = throt
    End Function
        
    Function getLift(velo, cl, wing_s)
        lo = 1.293
        Dim lift As Double
        lift = ((v ^ 2) * wing_s * cl) / 2
        getLift = lift
    End Function
    
    Function getDrag(velo, cd, wing_s)
        lo = 1.293
        Dim drag As Double
        drag = ((v ^ 2) * wing_s * cd) / 2
        getDrag = drag
    End Function
         
    Function getGrav(m, g)
        Dim grav As Double
        g = 9.8
        grav = m * g
        getGrav = grav
    End Function
    
    Function getWindAngle(m, wing_s, cl, theta_wind, velo) 'there, a = tan(a) =sin(a)
        Dim delta_theta As Double
        delta_theta = getLift(velo, cl, wing_s) - (getGrav(m, g)) * Cos((Pi / 180) * theta_wind)
        theta_wind = theta_wind + delta_theta
        getWindAngle = theta_wind
    End Function
    
    Function getVelo(m, d, u, wing_s, cl, cd, theta_launch)
        Dim delta_velo As Double
        m = 2  ` should be a garbage of test code, no need
        delta_velo = (getThrot(d, u, m, resolution_t) - getDrag(velo, cd, wing_s)) / m
        velo = velo + delta_velo
        getVelo = velo
    End Function
    
    Function getxPos()
        Dim delta_x As Double
        delta_x = (getVelo(m, d, u, wing_s, cl, cd, theta_wind)) * Cos((Pi / 180) * getWindAngle(m, wing_s, cl, theta_wind, velo)) * resolution_t
        missile_x = missile_x + delta_x
        getxPos = delta_x
        
    End Function
        
    Function getyPos()
        Dim delta_y As Double
        delta_y = (getVelo(m, d, u, wing_s, cl, cd, theta_wind)) * Sin((Pi / 180) * getWindAngle(m, wing_s, cl, theta_wind, velo)) * resolution_t
        missile_y = missile_y + delta_y
        getyPos = deltay
        
    End Function
    Function ifTerm(y)
    Dim impact As Boolean
        impact = False
        If y < 0 Then
            impact = True
        End If
        If t > selfDistrunct Then
            impact = True
        End If
        ifTerm = impact
    End Function
Sub balistic_missile()

    
    m = Cells(2, 2)
    d = Cells(2, 3)
    u = Cells(2, 4)
    wing_s = Cells(2, 5)
    cl = Cells(2, 6)
    cd = Cells(2, 7)
    theta_launch = Cells(2, 8)
    resolution_t = Cells(2, 9)
    
    Do
        x = getxPos()
        y = getyPos()
        t = t + resolution_t
    Loop Until ifTerm(y) = True
    
    Cells(3, 2) = missile_x
    Cells(3, 3) = missile_y
    Cells(3, 4) = velo
    Cells(3, 5) = theta_wind
    missile_x = missile_y = velo = theta_wind = 0
    
    
End Sub