asp无组件生成验证码 GIF图片格式(2)

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)
' 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
Dim mCode
Set mCode = New Com_GifCode_Class
Session("GetCode") = mCode.Create()
mCode.Output()
Set mCode = Nothing
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