<%@CodePage="65001"%>
<script language="vbscript" runat="server">
	Option Explicit '显示声明
	Dim showErrorImg
	showErrorImg = False

	function ChkPost() 
	  dim server_v1,server_v2
	  chkpost=false
	  server_v1=Cstr(Request.ServerVariables("HTTP_REFERER"))
	  server_v2=Cstr(Request.ServerVariables("SERVER_NAME"))
	  If Mid(server_v1,8,Len(server_v2))<>server_v2 then
		chkpost=False
	  else
	   chkpost=True
	  end If
	end Function

	If Not ChkPost() Then
		showErrorImg = true
	End If
	
	Class Com_GifCode_Class
		Public Noisy, Count, Width, Height, Angle, Offset, Border
		Private Graph(), Margin(3)
		Private Sub Class_Initialize()
		 Randomize 
		 Noisy = 7 ' 干扰点出现的概率 
		 Count = 4  ' 字符数量
		 Width = 80 ' 图片宽度
		 Height = 20 ' 图片高度
		 Angle = 3  ' 角度随机变化量
		 Offset = 10 ' 偏移随机变化量
		 Border = 3 ' 边框大小
		End Sub 
		Public Function Create2(str)
		 Dim i
		 Dim vIndex
		 ReDim Graph(Width-1, Height-1)
		 For i = 0 To Count - 1
		  vIndex=CInt(Mid(str,i+1,1)-1)
		  SetDraw vIndex, i
		 Next
		End Function
	
		Sub SetDot(pX, pY)
		 If pX * (Width-pX-1) >= 0 And pY * (Height-pY-1) >= 0 Then
		  Graph(pX, pY) = 1
		 End If
		End Sub
	
		Public Sub SetDraw(pIndex, pNumber)
		 ' 字符数据字典
		 If pIndex=-1 Then pIndex=9
		 Dim DotData(9)
		 DotData(0) = Array(30, 15, 50, 1, 50, 100)
		 DotData(1) = Array(1 ,34 ,30 ,1 ,71, 1, 100, 34, 1, 100, 93, 100, 100, 86) 
		 DotData(2) = Array(1, 1, 100, 1, 42, 42, 100, 70, 50, 100, 1, 70)
		 DotData(3) = Array(100, 73, 6, 73, 75, 6, 75, 100)
		 DotData(4) = Array(100, 1, 1, 1, 1, 50, 50, 35, 100, 55, 100, 80, 50, 100, 1, 95)
		 DotData(5) = Array(100, 20, 70, 1, 20, 1, 1, 30, 1, 80, 30, 100, 70, 100, 100, 80, 100, 60, 70, 50, 30, 50, 1, 60) 
		 DotData(6) = Array(6, 26, 6, 6, 100, 6, 53, 100)
		 DotData(7) = Array(100, 30, 100, 20, 70, 1, 30, 1, 1, 20, 1, 30, 100, 70, 100, 80, 70, 100, 30, 100, 1, 80, 1, 70, 100, 30)
		 DotData(8) = Array(1, 80, 30, 100, 80, 100, 100, 70, 100, 20, 70, 1, 30, 1, 1, 20, 1, 40, 30, 50, 70, 50, 100, 40) 
		 DotData(9) = Array(100, 20, 70, 1, 20, 1, 1, 30, 1, 80, 30, 100, 70, 100, 100, 80, 100, 60, 90, 20, 80,3)
		 
	
		 Dim vExtent : vExtent = Width / Count
		 Margin(0) = Border + vExtent * (Rnd * Offset) / 100 + Margin(1)
		 Margin(1) = vExtent * (pNumber + 1) - Border - vExtent * (Rnd * Offset) / 100
		 Margin(2) = Border + Height * (Rnd * Offset) / 100 
		 Margin(3) = Height - Border - Height * (Rnd * Offset) / 100
		 
		 Dim vStartX, vEndX, vStartY, vEndY
		 Dim vWidth, vHeight, vDX, vDY, vDeltaT
		 Dim vAngle, vLength
		 
		 vWidth =Int(Margin(1) - Margin(0))
		 vHeight =Int(Margin(3) - Margin(2))
		 vStartX = Int((DotData(pIndex)(0)-1) * vWidth / 100)
		 vStartY = Int((DotData(pIndex)(1)-1) * vHeight / 100)
		 
		 Dim i, j
		 For i = 1 To UBound(DotData(pIndex), 1)/2
		  If DotData(pIndex)(2*i-2) <> 0 And DotData(pIndex)(2*i) <> 0 Then 
		   vEndX = (DotData(pIndex)(2*i)-1) * vWidth / 100
		   vEndY = (DotData(pIndex)(2*i+1)-1) * vHeight / 100
		   vDX = vEndX - vStartX
		   vDY = vEndY - vStartY
		   If vDX = 0 Then
			vAngle = Sgn(vDY) * 3.14 /2
		   Else
			vAngle = Atn(vDY / vDX)
		   End If
		   If Sin(vAngle) = 0 Then
			vLength = vDX
		   Else
			vLength = vDY / Sin(vAngle)
		   End If
		   vAngle = vAngle + (Rnd - 0.5) * 2 * Angle * 3.14 * 2 / 100
		   vDX = Int(Cos(vAngle) * vLength)
		   vDY = Int(Sin(vAngle) * vLength)
		   If Abs(vDX) > Abs(vDY) Then vDeltaT = Abs(vDX) Else vDeltaT = Abs(vDY)
		   For j = 1 To vDeltaT
			SetDot Margin(0) + vStartX + j * vDX / vDeltaT, Margin(2) + vStartY + j * vDY / vDeltaT 
		   Next
		   vStartX = vStartX + vDX
		   vStartY = vStartY + vDY
		  End If
		 Next
		End Sub
	
		Public Sub Output()
		 Response.Expires = -9999
		 Response.AddHeader "pragma", "no-cache"
		 Response.AddHeader "cache-ctrol", "no-cache"
		 Response.ContentType = "image/gif" 
		 Response.BinaryWrite ChrB(Asc("G")) & ChrB(Asc("I")) & ChrB(Asc("F"))
		 Response.BinaryWrite ChrB(Asc("8")) & ChrB(Asc("9")) & ChrB(Asc("a")) 
		 Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)
		 Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height \ 256) Mod 256)
		 Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(0) 
		 Response.BinaryWrite ChrB(250) & ChrB(250) & ChrB(250)
		 Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0)
		 Response.BinaryWrite ChrB(Asc(","))
		 Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0) 
		 Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)
		 Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height \ 256) Mod 256)
		 Response.BinaryWrite ChrB(0) & ChrB(7) & ChrB(255) 
	
		 Dim x, y, i : i = 0
		 For y = 0 To Height - 1
		  For x = 0 To Width - 1
		   If Rnd < Noisy / 100 Then
			Response.BinaryWrite ChrB(1-Graph(x, y))
		   ElseIf x * (x-Width) = 0 Or y * (y-Height) = 0 Then 
			Response.BinaryWrite ChrB(Graph(x, y))
		   ElseIf Graph(x-1, y) = 1 Or Graph(x, y) Or Graph(x, y-1) = 1 Then
			Response.BinaryWrite ChrB(1)
		   Else
			Response.BinaryWrite ChrB(0)
		   End If
	
		   If (y * Width + x + 1) Mod 126 = 0 Then
			Response.BinaryWrite ChrB(128)
			i = i + 1
		   End If
		   If (y * Width + x + i + 1) Mod 255 = 0 Then
			If (Width*Height - y * Width - x - 1) > 255 Then 
			 Response.BinaryWrite ChrB(255)
			Else
			 Response.BinaryWrite ChrB(Width * Height Mod 255)
			End If
		   End If
		  Next
		 Next
		 Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(129) & ChrB(0) & ChrB(59) 
		End Sub
	End Class
	'---------------
	Dim mCode
	Set mCode = New Com_GifCode_Class

        Randomize
        Dim code
        code = Int(Rnd * 9000 + 1000)
		If showErrorImg Then
			Session("GetCode") = Int(Rnd * 9000 + 1000)
		else
			Session("GetCode") = code
		End If
		
	mCode.Create2(code)
	mCode.Output()

	Set mCode = Nothing
</script>