Enoncé
Visual Basic - Solution 6 ( Projectiles )
Interface graphique :
Il y a très peu à dire au sujet de l'interface, puisqu'il s'agit de dessiner directement sur le fond de la feuille (Form1).
Code de la feuille Form1 :
Dim i As Integer, j As Integer, k As Integer
Dim R As Double 'Force de propulsion du projectile
Dim A As Double 'Angle du lancement
Const Projectiles = 60
Dim F(1 To Projectiles, 1 To 4) As XYPoint
Dim FP(1 To 4) As XYPoint
Dim V As XYPoint
Dim Vh(1 To Projectiles) As XYPoint
Dim T As Double
Const Pi = 3.14159265
Const Tmax = 100
Private Sub Form_Activate()
Form1.Scale (0, 50)-(100, -50)
End Sub
Private Sub Form_MouseDown(Button As Integer, Shift As Integer, X As Single, Y As Single)
Randomize
'Paramétrage des trajectoires des projectiles
For i = 1 To Projectiles
F(i, 1).X = X
F(i, 1).Y = Y
R = Rnd * 20
A = Rnd * 2 * Pi
F(i, 2).X = X + Cos(A) * R
F(i, 2).Y = Y + Sin(A) * R
F(i, 3).X = X + (F(i, 2).X - X) *
1.5
F(i, 3).Y = Y + (F(i, 2).Y - Y) *
1.5
F(i, 4).X = F(i, 3).X
F(i, 4).Y = F(i, 3).Y - R
Vh(i) = F(i, 1)
Next i
'lancement des projectiles
For i = 1 To Tmax
T = i / Tmax
For j = 1 To Projectiles
For k
= 1 To 4
FP(k)
= F(j, k)
Next
k
V =
bezier(FP, T)
Form1.Line
(Vh(j).X, Vh(j).Y)-(V.X, V.Y)
Vh(j)
= V
Next j
Next i
End Sub
Code à placer dans un module :
Public Type XY
X As Integer
Y As Integer
End Type
Public Function bezier(P() As XYPoint, T As Double) As XYPoint
bezier.X = P(1).X * (1 - T) ^ 3 _
+ P(2).X * (1 - T) ^ 2 * 3 * T _
+ P(3).X * (1 - T) * 3 * T ^ 2 _
+ P(4).X * T ^ 3
bezier.Y = P(1).Y * (1 - T) ^ 3 _
+ P(2).Y * (1 - T) ^ 2 * 3 * T _
+ P(3).Y * (1 - T) * 3 * T ^ 2 _
+ P(4).Y * T ^ 3
End Function