SetAlphaMask
fDrawState->SetAlphaMask(mask);
SetAlphaMask(mask);
void SetAlphaMask(AlphaMask* mask);
next->SetAlphaMask(fAlphaMask);
SetAlphaMask(mask);
void SetAlphaMask(AlphaMask* mask);
fCanvas->SetAlphaMask(mask);
fCurrentView->SetAlphaMask(NULL);
fCurrentView->SetAlphaMask(mask);