[u0k0]

my problem is the following :

I am making a program, which can manipulate brightness, gamma and contrast through C# code. For brightness and gamma it is ok I have achieved it through code I found in the net, but I can't for contrast. The only thing I have found by now is a CalculateRamp method, which has as input parameters (double level, double brightness, double gamma, double contrast), I know what input to give for brightness gamma and contrast ( the values from the sliders in the interface ) , but I don't know what level is for, the other problem with this method is that when I pass the calculated ramp with random "level" parameter as a parameter to the SetDeviceGammaRamp(IntPtr hDC,ref RAMP rmp) it actually changes the screen contrast, but when I move the brightness slider the changes made from the contrast slider are lost, it may be because of using the same method or I am not sure for what.

I will be very thankful to any help or ideas, no matter if they are changes of my current solution which is not full , or brand new solutions / which I would preffer , because I feel in some way unsure with this / . Thanks in advance to everybody.

Here is the code of the CalculateRamp method, as the function SetDeviceGammaRamp(...) is called by me to manipulate the contrast with the current calculated ramp, I am not sure if I have to use it in this way or not :

public static void CalculateRamp(double level, double gamma, double brightness, double contrast) {

ramp.Red = new ushort[256];
ramp.Green = new ushort[256];
ramp.Blue = new ushort[256];

gamma /= 10;
brightness = 1 + (((brightness - 50) / 100) * 65535);
contrast = 1 + ((contrast - 50) / 100);
level = 1 + ((level - 50) / 100);

for (int i = 0; i < 256; i++)
{
double value = i * 256;
value = (Math.Pow(value / 65535, 1 / gamma) * 65535) + 0.5;
value = ((((value / 65535) - 0.5) * contrast) + 0.5) * 65535;
value = value += brightness;
value *= level;
ramp.Red[i] = ramp.Green[i] = ramp.Blue[i] = (ushort)Math.Min((double)65535, Math.Max((double)0, value));
}
SetDeviceGammaRamp(GetDC(IntPtr.Zero), ref ramp);
}