static public VFXExpression TanH(VFXExpression input)
{
//(1-e^2x)/(1+e^2x)
var two = TwoExpression[input.valueType];
var one = OneExpression[input.valueType];
var minusOne = MinusOneExpression[input.valueType];
var e = E_NapierConstantExpression[input.valueType];
var E_minusTwoX = new VFXExpressionPow(e, minusOne * two * input);
return((one - E_minusTwoX) / (one + E_minusTwoX));
}
static public VFXExpression LinearToGamma(VFXExpression linear)
{
var components = ExtractComponents(linear).ToArray();
if (components.Length != 3 && components.Length != 4)
{
throw new ArgumentException("input expression must be a 3 or 4 components vector");
}
VFXExpression exp = VFXValue.Constant(1.0f / 2.2f);
for (int i = 0; i < 3; ++i)
{
components[i] = new VFXExpressionPow(components[i], exp);
}
return(new VFXExpressionCombine(components));
}