Data commit

Task/Dragon-curve/Visual-Basic-.NET/dragon-curve.vb

@@ -0,0 +1,54 @@
+Option Explicit On
+Imports System.Math
+
+Public Class DragonCurve
+    Dim nDepth As Integer = 12
+    Dim angle As Double
+    Dim MouseX, MouseY As Integer
+    Dim CurrentX, CurrentY As Integer
+    Dim nColor As Color = Color.Black
+
+    Private Sub DragonCurve_Click(sender As Object, e As EventArgs) Handles Me.Click
+        SubDragonCurve()
+    End Sub
+
+    Sub DrawClear()
+        Me.CreateGraphics.Clear(Color.White)
+    End Sub
+
+    Sub DrawMove(ByVal X As Double, ByVal Y As Double)
+        CurrentX = X
+        CurrentY = Y
+    End Sub
+
+    Sub DrawLine(ByVal X As Double, ByVal Y As Double)
+        Dim MyGraph As Graphics = Me.CreateGraphics
+        Dim PenColor As Pen = New Pen(nColor)
+        Dim NextX, NextY As Long
+        NextX = CurrentX + X
+        NextY = CurrentY + Y
+        MyGraph.DrawLine(PenColor, CurrentX, CurrentY, NextX, NextY)
+        CurrentX = NextX
+        CurrentY = NextY
+    End Sub
+
+    Sub DragonProc(size As Double, ByVal split As Integer, d As Integer)
+        If split = 0 Then
+            DrawLine(-Cos(angle) * size, Sin(angle) * size)
+        Else
+            angle = angle + d * PI / 4
+            DragonProc(size / Sqrt(2), split - 1, 1)
+            angle = angle - d * PI / 2
+            DragonProc(size / Sqrt(2), split - 1, -1)
+            angle = angle + d * PI / 4
+        End If
+    End Sub
+
+    Sub SubDragonCurve()
+        Const xcoefi = 0.74, xcoefl = 0.59
+        DrawClear()
+        DrawMove(Me.Width * xcoefi, Me.Height / 3)
+        DragonProc(Me.Width * xcoefl, nDepth, 1)
+    End Sub
+
+End Class