private static bool GetToken(string input, out Token token)
{
if (string.IsNullOrWhiteSpace(input))
{
token = null;
return(false);
}
switch (input)
{
case "+":
token = new OperatorToken(TokenType.Addition, 2);
return(true);
case "-":
token = new OperatorToken(TokenType.Subtraction, 2);
return(true);
case "*":
token = new OperatorToken(TokenType.Multiplication, 3);
return(true);
case "/":
token = new OperatorToken(TokenType.Division, 3);
return(true);
case "(":
token = new OperatorToken(TokenType.OpenPar, 2);
return(true);
case ")":
token = new OperatorToken(TokenType.ClosePar, 2);
return(true);
}
if (!input.StartsWith('-') && !input.StartsWith('+') && double.TryParse(input, System.Globalization.NumberStyles.AllowDecimalPoint, CultureInfo.InvariantCulture, out var d))
{
token = new ValueToken(d);
return(true);
}
if (input.All(c => char.IsLetter(c)))
{
switch (input)
{
case "inf":
case "infinity":
token = new ValueToken(double.PositiveInfinity);
break;
case "e":
token = new ValueToken(Math.E);
break;
case "tau":
case "τ":
token = new ValueToken(Math.Tau);
break;
case "φ":
token = new ValueToken(1.6180339887498948482d);
break;
case "pi":
case "π":
token = new ValueToken(Math.PI);
break;
case "rand":
case "random":
token = new ValueToken(rand.NextDouble());
break;
default:
token = new FunctionToken(input);
break;
}
return(true);
}
token = null;
return(false);
}
private static void PerformFunction(Stack <double> numbers, FunctionToken f)
{
switch (f.Value)
{
case "lerp":
case "mix":
{
var t = numbers.Pop();
var b = numbers.Pop();
var a = numbers.Pop();
numbers.Push(a * (1 - t) + b * t);
}
break;
case "atan2":
{
var rhs = numbers.Pop();
var lhs = numbers.Pop();
numbers.Push(Math.Atan2(rhs, lhs));
}
break;
case "max":
{
var rhs = numbers.Pop();
var lhs = numbers.Pop();
numbers.Push(Math.Max(rhs, lhs));
}
break;
case "min":
{
var rhs = numbers.Pop();
var lhs = numbers.Pop();
numbers.Push(Math.Min(rhs, lhs));
}
break;
case "sq":
case "square":
{
var vv = numbers.Pop();
numbers.Push(Math.Pow(vv, 2));
}
break;
case "pow":
{
var rhs = numbers.Pop();
var lhs = numbers.Pop();
numbers.Push(Math.Pow(lhs, rhs));
}
break;
case "saturate":
{
var vv = numbers.Pop();
numbers.Push(Math.Clamp(vv, 0, 1d));
}
break;
case "round":
{
var vv = numbers.Pop();
numbers.Push(Math.Round(vv));
}
break;
case "log":
{
var vv = numbers.Pop();
numbers.Push(Math.Log10(vv));
}
break;
case "logn":
{
var rhs = numbers.Pop();
var lhs = numbers.Pop();
numbers.Push(Math.Log(lhs, rhs));
}
break;
case "ceil":
{
var vv = numbers.Pop();
numbers.Push(Math.Ceiling(vv));
}
break;
case "floor":
{
var vv = numbers.Pop();
numbers.Push(Math.Floor(vv));
}
break;
case "exp":
{
var vv = numbers.Pop();
numbers.Push(Math.Exp(vv));
}
break;
case "sqrt":
{
var vv = numbers.Pop();
numbers.Push(Math.Sqrt(vv));
}
break;
case "sin":
case "sine":
{
var vv = numbers.Pop();
numbers.Push(vv % Math.PI == 0 ? 0 : Math.Sin(vv));
}
break;
case "cos":
case "cosine":
{
var vv = numbers.Pop();
numbers.Push(Math.Cos(vv));
}
break;
case "tan":
case "tangent":
{
var vv = numbers.Pop();
numbers.Push(Math.Tan(vv));
}
break;
case "tanh":
{
var vv = numbers.Pop();
numbers.Push(Math.Tanh(vv));
}
break;
case "atan":
{
var vv = numbers.Pop();
numbers.Push(Math.Atan(vv));
}
break;
case "atanh":
{
var vv = numbers.Pop();
numbers.Push(Math.Atanh(vv));
}
break;
case "frac":
case "fract":
{
var vv = numbers.Pop();
numbers.Push(vv - Math.Floor(vv));
}
break;
}
}
