public void CanAddProductions()
{
var gen = new DeterministicStringGenerator();
gen.AddProduction('A', "AB");
Assert.Equal("AB", gen.Generate("A", 1));
}
private static string RunFractal(int width, int height, string name, int generation)
{
var ctx = new SvgContext(width, height);
double initialX;
double initialY;
int stepSize;
double initialAngle;
double turnAngle;
string initialState;
var lsys = new DeterministicStringGenerator();
switch (name)
{
case "koch-curve":
initialX = 0;
initialY = height / 2D;
stepSize = 8;
initialAngle = 0;
turnAngle = 60;
lsys.AddProduction('F', "F+F--F+F");
initialState = "F";
break;
case "koch-curve-right":
initialX = 0;
initialY = height / 2D;
stepSize = 8;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('F', "F+F-F-F+F");
initialState = "F";
break;
case "sierpinski-arrow":
initialX = 0;
initialY = height;
stepSize = 2;
initialAngle = 0;
turnAngle = 60;
lsys.AddProduction('F', "G-F-G");
lsys.AddProduction('G', "F+G+F");
initialState = "F";
break;
case "sierpinski-tri":
initialX = width / 2D;
initialY = height / 4D;
stepSize = 6;
initialAngle = 0;
turnAngle = 60;
lsys.AddProduction('F', "FF");
lsys.AddProduction('X', "--FXF++FXF++FXF--");
initialState = "FXF--FF--FF";
break;
case "plant1":
initialX = width / 2D;
initialY = height;
stepSize = 7;
initialAngle = 75;
turnAngle = 22.5;
lsys.AddProduction('0', "F-[[0]+0]+F[+F0]-0");
lsys.AddProduction('F', "FF");
initialState = "0";
break;
case "plant2":
initialX = width / 2D;
initialY = height;
stepSize = 10;
initialAngle = 80;
turnAngle = 22.5;
lsys.AddProduction('F', "FF-[-F+F+F]+[+F-F-F]");
initialState = "F";
break;
case "dragon-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 4;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('X', "X+YF+");
lsys.AddProduction('Y', "-FX-Y");
initialState = "FX";
break;
case "hex-gosper-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 6;
initialAngle = 60;
turnAngle = 60;
lsys.AddProduction('F', "F-G--G+F++FF+G-");
lsys.AddProduction('G', "+F-GG--G-F++F+G");
initialState = "F";
break;
case "peano-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 4;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('F', "F+F-F-F-F+F+F+F-F");
initialState = "F";
break;
case "quad-koch-island":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 3;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('F', "F-F+F+FFF-F-F+F");
initialState = "F+F+F+F";
break;
case "32-segment-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 2;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('F', "-F+F-F-F+F+FF-F+F+FF+F-F-FF+FF-FF+F+F-FF-F-F+FF-F-F+F+F-F+");
initialState = "F+F+F+F";
break;
case "sierpinski-arrow-alt":
initialX = width / 4D;
initialY = height;
stepSize = 2;
initialAngle = 0;
turnAngle = 60;
lsys.AddProduction('X', "YF+XF+Y");
lsys.AddProduction('Y', "XF-YF-X");
initialState = "YF";
break;
case "peano-gosper-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 4;
initialAngle = 0;
turnAngle = 60;
lsys.AddProduction('X', "X+YF++YF-FX--FXFX-YF+");
lsys.AddProduction('Y', "-FX+YFYF++YF+FX--FX-Y");
initialState = "FX";
break;
case "square-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 4;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('X', "XF-F+F-XF+F+XF-F+F-X");
initialState = "F+XF+F+XF";
break;
case "hilbert-curve":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 6;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('L', "+RF-LFL-FR+");
lsys.AddProduction('R', "-LF+RFR+FL-");
initialState = "L";
break;
case "hilbert-curve-2":
initialX = width / 2D;
initialY = height / 2D;
stepSize = 4;
initialAngle = 0;
turnAngle = 90;
lsys.AddProduction('X', "XFYFX+F+YFXFY-F-XFYFX");
lsys.AddProduction('Y', "YFXFY-F-XFYFX+F+YFXFY");
initialState = "X";
break;
default:
var fileName = $"{name}.lsys";
var files = Directory.GetFiles(Directory.GetCurrentDirectory());
if (files.All(s => Path.GetFileName(s) != fileName))
{
throw new ArgumentException($"Unknown fractal name: '{name}'");
}
var file = File.OpenText(fileName);
var parsed = new FractalDefinitionParser().Parse(file);
initialX = parsed.StartX;
initialY = parsed.StartY;
stepSize = parsed.StepSize;
initialAngle = parsed.StartAngle;
turnAngle = parsed.TurnAngle;
initialState = parsed.Axiom;
foreach (var kvp in parsed.Rules)
{
lsys.AddProduction(kvp.Key, kvp.Value);
}
break;
}
var turtle = new Turtle(ctx, stepSize, initialX, initialY, initialAngle);
var interpreter = new TurtleStringInterpreter(turtle);
interpreter.AddAction('F', t => t.Forward()).AddAction('G', t => t.Forward());
interpreter.AddAction('f', t => t.Move()).AddAction('g', t => t.Move());
interpreter.AddAction('-', t => t.TurnRight(turnAngle));
interpreter.AddAction('+', t => t.TurnLeft(turnAngle));
interpreter.AddAction('[', t => t.PushState());
interpreter.AddAction(']', t => t.PopState());
var derivation = lsys.Generate(initialState, generation);
interpreter.Run(derivation);
return(ctx.ToString());
}