画图学习[3] 贝塞尔曲线

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    btn1: TButton;
    btn2: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
var
  pts: array [0..6] of TPoint;
begin
  Canvas.Pen.Color := clRed;
  Canvas.Pen.Width := 2;

  pts[0].X := 10;
  pts[0].Y := 10;
  pts[1].X := 200;
  pts[1].Y := 10;
  pts[2].X := 10;
  pts[2].Y := 200;
  pts[3].X := 200;
  pts[3].Y := 200;
  pts[4].X := 130;
  pts[4].Y := 70;
  pts[5].X := 50;
  pts[5].Y := 150;
  pts[6].X := 110;
  pts[6].Y := 190;

  Canvas.PolyBezier(pts);
  Canvas.Pen.Color := clyellow;
  Canvas.Pen.Width := 1;
  Canvas.LineTo(ClientWidth, ClientHeight);

end;

procedure TForm1.btn2Click(Sender: TObject);
var
  pts: array [0..5] of TPoint;
begin
  Canvas.Pen.Color := clRed;
  Canvas.Pen.Width := 2;

  pts[0].X := 10+210;
  pts[0].Y := 10;
  pts[1].X := 200+210;
  pts[1].Y := 10;
  pts[2].X := 10+210;
  pts[2].Y := 200;
  pts[3].X := 200+210;
  pts[3].Y := 200;
  pts[4].X := 130+210;
  pts[4].Y := 70;
  pts[5].X := 50+210;
  pts[5].Y := 150;


  Canvas.MoveTo(220,10);
  Canvas.PolyBezierTo(pts);
  Canvas.Pen.Color := clBlue;
  Canvas.Pen.Width := 1;
  Canvas.LineTo(ClientWidth, ClientHeight);

end;
end.

unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    btn1: TButton;
    btn2: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.btn1Click(Sender: TObject);
var
  pts: array [0..3] of TPoint;
begin
  Canvas.Pen.Color := clRed;
  Canvas.Pen.Width := 2;

  pts[0].X := 10;
  pts[0].Y := 10;
  pts[1].X := 200;
  pts[1].Y := 10;
  pts[2].X := 10;
  pts[2].Y := 200;
  pts[3].X := 200;
  pts[3].Y := 200;

  Canvas.PolyBezier(pts);
  Canvas.Pen.Color := clyellow;
  Canvas.Pen.Width := 1;
  Canvas.LineTo(ClientWidth, ClientHeight);

end;

procedure TForm1.btn2Click(Sender: TObject);
var
  pts: array [0..2] of TPoint;
begin
  Canvas.Pen.Color := clRed;
  Canvas.Pen.Width := 2;

  pts[0].X := 410;
  pts[0].Y := 10;
  pts[1].X := 220;
  pts[1].Y := 200;
  pts[2].X := 410;
  pts[2].Y := 200;

  Canvas.MoveTo(220,10);
  Canvas.PolyBezierTo(pts);
  Canvas.Pen.Color := clBlue;
  Canvas.Pen.Width := 1;
  Canvas.LineTo(ClientWidth, ClientHeight);

end;
end.