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DrSanent

OpenGL Gamma control in OpenGL

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Hi, I''m trying to change the gamma for my game and I can''t find anything anywhere that will tell me how to do it. I''ve read some functions about DirectX but I don''t want to resort to that to change the gamma. Has anyone been able to accomplish this?

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your in luck, i just finnished coding a gamma control class ...


  

struct Ramp {
WORD r[256];
WORD g[256];
WORD b[256];
}

#define CLAMP(T) {if(T>255) T=255; else if(T<0) T=0;}

GammaControl::GammaControl()
{
ZeroMemory(&NewRamp,sizeof(Ramp));
ZeroMemory(&originalRamp,sizeof(Ramp));
}

GammaControl::~GammaControl()
{
SetDeviceGammaRamp(GetDC(hWnd),&originalRamp);
}

int GammaControl::SetGamma(float Gamma,HWND hWnd)
{
HDC dc = GetDC(hWnd);
GetGamma(hWnd);

float Brightness = 1.9f;
float Overbright = 2.f;
int f = 0;
for (int i=0 ; i<256 ; i++){
f = int(255 * pow ( (float)i/255.0 , 1/.987f ));
f = (f+Brightness) * Overbright;

CLAMP(f);

NewRamp.b[i] =
NewRamp.g[i] =
NewRamp.r[i] =
(WORD) (f<<8);
}

if(!SetDeviceGammaRamp(dc, &NewRamp)){
return 0;
}

return 1;
}

int GammaControl::GetGamma(HWND hWnd)
{
this->hWnd = hWnd;
GetDeviceGammaRamp(GetDC(hWnd),&originalRamp);
return 1;
}

int GammaControl::RestoreGamma()
{
SetDeviceGammaRamp(GetDC(this->hWnd), &originalRamp);
return 1;
}

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