[RESOLVED] Monitor Brightness

[HanneSThEGreaT]

It's no problem at all

I'll have a look at it over the weekend

Hannes

[HanneSThEGreaT]

Hi Stin

I am looking for external help on this issue. I know what to use and what should be done, but, for the love of me, I can't manage to get it working. perhaps I'm too stupid

Hang in there...

Hannes

[stin]

I really appreciate your help. It's not urgent, and I could get by with a hard coded number.

[dglienna]

This might steer someone in the right direction. Seems that it's been solved before. Looks like C++ though.

http://www.autohotkey.com/forum/topic32034.html

[DataMiser]

That is not C code.. As far as I can tell it is a script for AutoHotKey

[HanneSThEGreaT]

OK, I haven't received any response yt on any of the forums I have posted this question to

I did try this :

Imports System

Imports System.Runtime.InteropServices

Imports System.Windows.Forms


Public Class SetBrightness
    Inherits Form


    <StructLayout(LayoutKind.Sequential, CharSet:=CharSet.Ansi)> _
    Private Structure RAMP

        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=256)> _
        Public Red As UInt16()


        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=256)> _
        Public Green As UInt16()


        <MarshalAs(UnmanagedType.ByValArray, SizeConst:=256)> _
        Public Blue As UInt16()

    End Structure

    <DllImport("gdi32.dll")> _
    Private Shared Function SetDeviceGammaRamp(ByVal hDC As IntPtr, ByRef lpRamp As RAMP) As Boolean
    End Function

    <DllImport("user32.dll")> _
    Private Shared Function GetDC(ByVal hWnd As IntPtr) As IntPtr
    End Function

    <DllImport("gdi32.dll")> _
    Private Shared Function GetDeviceGammaRamp(ByVal hdc As Int32, ByVal lpv As Int32) As Int32
    End Function

    Private WithEvents TrackBar1 As System.Windows.Forms.TrackBar

    Private Shared Ramp1(0 To 255, 0 To 2) As Integer

    Private Shared s_ramp As New RAMP()

    Private Shared MyRamp As New RAMP()

    Private Shared Sub SetGamma(ByVal gamma As Integer)


        s_ramp.Red = New UShort(255) {}

        s_ramp.Green = New UShort(255) {}

        s_ramp.Blue = New UShort(255) {}


        For i As Integer = 1 To 255


            ' gamma is a value between 3 and 44 


            s_ramp.Red(i) = InlineAssignHelper(s_ramp.Green(i), InlineAssignHelper(s_ramp.Blue(i), CUShort((Math.Min(65535, Math.Max(0, Math.Pow((i + 1) / 256.0R, gamma * 0.1) * 65535 + 0.5))))))
        Next

        ' Now set the value. 


        SetDeviceGammaRamp(GetDC(IntPtr.Zero), s_ramp)
    End Sub

    Private Shared Sub RestoreGamma(ByVal gamma As Integer)

        MyRamp.Red = New UShort(255) {}

        MyRamp.Green = New UShort(255) {}

        MyRamp.Blue = New UShort(255) {}

        For x = 0 To 255
            MyRamp.Red(x) = Ramp1(x, 0)
            MyRamp.Green(x) = Ramp1(x, 1)
            MyRamp.Blue(x) = Ramp1(x, 2)
        Next

        SetDeviceGammaRamp(GetDC(IntPtr.Zero), MyRamp)
    End Sub

    Private Shared Function InlineAssignHelper(Of T)(ByRef target As T, ByVal value As T) As T
        target = value
        Return value
    End Function


    Private Sub TrackBar1_Scroll(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TrackBar1.Scroll
        SetGamma(TrackBar1.Value)
    End Sub

    Private Sub SetBrightness_FormClosing(ByVal sender As Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles Me.FormClosing

        RestoreGamma(Ramp1(0, 0))

    End Sub

    Private Sub SetBrightness_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        GetDeviceGammaRamp(GetDC(IntPtr.Zero), Ramp1(0, 0))
    End Sub


End Class

But it doesn't restore the screen back. either the settings doesn't get stored into my array ( which I think is the most likely explanation ), or the SetDeviceGammaRamp doesn't want to get the right values to apply. I'm feeling out of my league here....

[stin]

Yikes. If you're out of your league...

[TT(n)]

I didn't originally realize how popular this question was.
I mean the question of brightness, instead of temp.

Since this is pretty interesting, and possibly useful to me as well, I'll take a look into it.
I've seen alot online about it, and several programs that apparently do it.

[stin]

Another set of eyes is always welcome.

[TT(n)]

got it!

I found the vb6 version kickin around in the API-Guide.
Made it work for the desktop with the right Device context.

It will take a few moments to convert this to .NET, so I'll post back.
For giggles, here is the vb6 example.

Option Explicit
Private Ramp1(0 To 255, 0 To 2) As Integer
Private Ramp2(0 To 255, 0 To 2) As Integer
Private Declare Function apiGetDeviceGammaRamp Lib "gdi32" Alias "GetDeviceGammaRamp" (ByVal hdc As Long, ByRef lpv As Any) As Long
Private Declare Function apiSetDeviceGammaRamp Lib "gdi32" Alias "SetDeviceGammaRamp" (ByVal hdc As Long, ByRef lpv As Any) As Long
Private Declare Function apiCopyMemory Lib "kernel32" Alias "RtlMoveMemory" (ByRef Destination As Any, ByRef Source As Any, ByVal Length As Long) As Long
Private Declare Function apiGetWindowDC Lib "user32" Alias "GetWindowDC" (ByVal hwnd As Long) As Long
Private Declare Function apiGetDesktopWindow Lib "user32" Alias "GetDesktopWindow" () As Long
Private Sub Form_Load()
   Dim iCtr As Integer
   Dim lVal As Long
   Call apiGetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp1(0, 0))
      For iCtr = 0 To 255
         lVal = Int2Lng(Ramp1(iCtr, 0))
         Ramp2(iCtr, 0) = Lng2Int(Int2Lng(Ramp1(iCtr, 0)) / 2)
         Ramp2(iCtr, 1) = Lng2Int(Int2Lng(Ramp1(iCtr, 1)) / 2)
         Ramp2(iCtr, 2) = Lng2Int(Int2Lng(Ramp1(iCtr, 2)) / 2)
      Next iCtr
   Call apiSetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp2(0, 0))
End Sub
Private Sub Form_Unload(Cancel As Integer)
   Call apiSetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp1(0, 0))
End Sub

Public Function Int2Lng(IntVal As Integer) As Long
   Call apiCopyMemory(Int2Lng, IntVal, 2)
End Function
Public Function Lng2Int(Value As Long) As Integer
   Call apiCopyMemory(Lng2Int, Value, 2)
End Function

[HanneSThEGreaT]

Just when I was starting too lose all hope, the Honourable mr TT(n) pops in!

Let us hope for the best

Hannes

[stin]

I just found a vb6 project too at CodeProject.com that I was starting to look at!

[HanneSThEGreaT]

Sad to say, but VB 6 wins .NET hands down here!! Amzingly surprisingly easy in VB 6 - unbelievable!!

Look at this. Add 2 buttons on a VB 6 form, and a checkbox. If the Checkbox is checked and command1 is clicked it dims. And when the second commandbutton is clicked, it restores everything!

I am flabbergasted! This is one more reason why I'll probably never leave VB 6!

Hannes

[TT(n)]

Here is a basic .NET example, which works to start from. {XP only, Vista/7 solution shown later in this thread}

Option Strict On
Option Explicit On
Public Class Form1
    Private Ramp1(255, 2) As Short
    Private Ramp2(255, 2) As Short
    Private Declare Function apiGetDeviceGammaRamp Lib "gdi32" Alias "GetDeviceGammaRamp" (ByVal hdc As Int32, ByRef lpv As Short) As Int32
    Private Declare Function apiSetDeviceGammaRamp Lib "gdi32" Alias "SetDeviceGammaRamp" (ByVal hdc As Int32, ByRef lpv As Short) As Int32
    Private Declare Function apiCopyMemoryIntShrt Lib "kernel32" Alias "RtlMoveMemory" (ByRef Destination As Int32, ByRef Source As Short, ByVal Length As Int32) As Int32
    Private Declare Function apiCopyMemoryShrtInt Lib "kernel32" Alias "RtlMoveMemory" (ByRef Destination As Short, ByRef Source As Int32, ByVal Length As Int32) As Int32
    Private Declare Function apiGetWindowDC Lib "user32" Alias "GetWindowDC" (ByVal hwnd As Int32) As Int32
    Private Declare Function apiGetDesktopWindow Lib "user32" Alias "GetDesktopWindow" () As Int32

    Private Sub Form1_Load(ByVal eventSender As System.Object, ByVal eventArgs As System.EventArgs) Handles MyBase.Load
        Dim iCtr As Short
        Dim lVal As Int32
        apiGetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp1(0, 0))
        For iCtr = 0 To 255
            lVal = Shr2Int(Ramp1(iCtr, 0))
            Ramp2(iCtr, 0) = Int2Shr(CInt(Shr2Int(Ramp1(iCtr, 0)) / 2))
            Ramp2(iCtr, 1) = Int2Shr(CInt(Shr2Int(Ramp1(iCtr, 1)) / 2))
            Ramp2(iCtr, 2) = Int2Shr(CInt(Shr2Int(Ramp1(iCtr, 2)) / 2))
        Next
        apiSetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp2(0, 0))
    End Sub
    Private Sub Form1_FormClosed(ByVal eventSender As System.Object, ByVal eventArgs As System.Windows.Forms.FormClosedEventArgs) Handles Me.FormClosed
        apiSetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp1(0, 0))
    End Sub

    Public Function Shr2Int(ByRef shrVal As Short) As Int32
        apiCopyMemoryIntShrt(Shr2Int, shrVal, 2)
    End Function
    Public Function Int2Shr(ByRef Value As Int32) As Short
        apiCopyMemoryShrtInt(Int2Shr, Value, 2)
    End Function
End Class

[HanneSThEGreaT]

Great work TT(n)!

I do get a red squiggly at this line though :

apiSetDeviceGammaRamp(apiGetWindowDC(apiGetDesktopWindow), Ramp1(0, 0))

And it tells me that it cannot convert Short to Type RAMP

Coincidentally, That is the error I have been battling with the whole time, before I got to the code I had in post # 21