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'============================================================
' 程序名称 : ASBLOG
' 程序说明 : AllSheng BLOG
' 程序版本 : v2.0
' 项目主管 : Felix Dong
' 版权所有 : 傲胜网络（AllSheng Studio）
'============================================================
' 文件名称 : Include/AS_CheckCode.Asp
' 文件作用 : 验证码函数
' 最后更新 : 2007.11
'============================================================
' 版权声明 : Copyright 2006-2007 AllSheng All Rights Reserved.
' 官方网站 : Http://Www.AllSheng.Net/
' 技术支持 : Http://bbs.AllSheng.Net/
' 电子邮箱 : Support@AllSheng.Net
'============================================================
Option Explicit
Class Cls_ASCheckCode
	Public Noisy, Count, Width, Height, Angle, Offset, Length, 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	= 72	' 图片宽度
		Height	= 20	' 图片高度
		Angle	= 2		' 角度随机变化量
		Offset	= 20	' 偏移随机变化量
		Border	= 1		' 边框大小
	End Sub

	Public Function Create()

		Const cCharSet = "123456789"

		Dim i, x, y

		Dim vValidCode : vValidCode = ""
		Dim vIndex

		ReDim Graph(Width-1, Height-1)

		For i=0 To Count - 1
			vIndex = Int(Rnd * Len(cCharSet))
			vValidCode = vValidCode + Mid(cCharSet, vIndex+1 , 1)
			SetDraw vIndex, i
		Next

		Create = vValidCode

	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
		Dim DotData(8)
		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)

		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))

		' 起始坐标
		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

				' 终点坐标
				vEndX = (DotData(pIndex)(2*i)-1) * vWidth / 100

				vEndY = (DotData(pIndex)(2*i+1)-1) * vHeight / 100

				' 横向差距
				vDX = vEndX - vStartX
				' 纵向差距
				vDY = vEndY - vStartY

				' 倾斜角度
				If vDX = 0 Then
					vAngle = Sgn(vDY) * 3.14/2
				Else
					vAngle = Atn(vDY / vDX)
				End If

				' 两坐标距离
				If Sin(vAngle) = 0 Then
					vLength = vDX
				Else
					vLength = vDY / Sin(vAngle)
				End If

				' 随机转动角度
				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"

		' 文件类型
		Response.BinaryWrite ChrB(Asc("G")) & ChrB(Asc("I")) & ChrB(Asc("F"))
		' 版本信息
		Response.BinaryWrite ChrB(Asc("8")) & ChrB(Asc("9")) & ChrB(Asc("a"))
		' 逻辑屏幕宽度
		Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)
		' 逻辑屏幕高度
		Response.BinaryWrite ChrB(Height Mod 256) & ChrB((Height \ 256) Mod 256)

		Response.BinaryWrite ChrB(128) & ChrB(0) & ChrB(0)
		' 全局颜色列表
		Response.BinaryWrite ChrB(255) & ChrB(255) & ChrB(255)

		'Response.BinaryWrite ChrB(0) & ChrB(85) & ChrB(255)
		Response.BinaryWrite ChrB(76) & ChrB(113) & ChrB(195)

		' 图象标识符
		Response.BinaryWrite ChrB(Asc(","))

		Response.BinaryWrite ChrB(0) & ChrB(0) & ChrB(0) & ChrB(0)
		' 图象宽度
		Response.BinaryWrite ChrB(Width Mod 256) & ChrB((Width \ 256) Mod 256)
		' 图象高度
		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))
				Else
					If x * (x-Width) = 0 Or y * (y-Height) = 0 Then
						Response.BinaryWrite ChrB(Graph(x, y))
					Else
						If 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
					End If
				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

'显示部分
Dim ASCheckCode
Set ASCheckCode			= New Cls_ASCheckCode
Session("CheckCode")	= ASCheckCode.Create()
ASCheckCode.Output()
Set ASCheckCode			= Nothing
%>