Data commit

Task/Dragon-curve/Delphi/dragon-curve.delphi

@@ -0,0 +1,86 @@
+program Dragon_curve;
+
+{$APPTYPE CONSOLE}
+
+uses
+  Winapi.Windows,
+  System.SysUtils,
+  System.Classes,
+  Vcl.Graphics;
+
+type
+  TDragon = class
+  private
+    p: TColor;
+    _sin: TArray<double>;
+    _cos: TArray<double>;
+    s: double;
+    b: TBitmap;
+    FAsBitmap: TBitmap;
+    const
+      sep = 512;
+      depth = 14;
+    procedure Dragon(n, a, t: Integer; d, x, y: Double; var b: TBitmap);
+  public
+    constructor Create;
+    destructor Destroy; override;
+    property AsBitmap: TBitmap read b;
+  end;
+
+{ TDragon }
+
+procedure TDragon.Dragon(n, a, t: Integer; d, x, y: Double; var b: TBitmap);
+begin
+  if n <= 1 then
+  begin
+    with b.Canvas do
+    begin
+      Pen.Color := p;
+      MoveTo(Trunc(x + 0.5), Trunc(y + 0.5));
+      LineTo(Trunc(x + d * _cos[a] + 0.5), Trunc(y + d * _sin[a] + 0.5));
+      exit;
+    end;
+  end;
+
+  d := d * s;
+  var a1 := (a - t) and 7;
+  var a2 := (a + t) and 7;
+
+  dragon(n - 1, a1, 1, d, x, y, b);
+  dragon(n - 1, a2, -1, d, x + d * _cos[a1], y + d * _sin[a1], b);
+end;
+
+constructor TDragon.Create;
+begin
+  s := sqrt(2) / 2;
+  _sin := [0, s, 1, s, 0, -s, -1, -s];
+  _cos := [1.0, s, 0.0, -s, -1.0, -s, 0.0, s];
+  p := Rgb(64, 192, 96);
+  b := TBitmap.create;
+
+  var width := Trunc(sep * 11 / 6);
+  var height := Trunc(sep * 4 / 3);
+  b.SetSize(width, height);
+  with b.Canvas do
+  begin
+    Brush.Color := clWhite;
+    Pen.Width := 3;
+    FillRect(Rect(0, 0, width, height));
+  end;
+  dragon(14, 0, 1, sep, sep / 2, sep * 5 / 6, b);
+end;
+
+destructor TDragon.Destroy;
+begin
+  b.Free;
+  inherited;
+end;
+
+var
+  Dragon: TDragon;
+
+begin
+  Dragon := TDragon.Create;
+  Dragon.AsBitmap.SaveToFile('dragon.bmp');
+  Dragon.Free;
+end.