Delphi的绘图功能[7] - PolyBezier、PolyBezierTo

Delphi的绘图功能[7] - PolyBezier、PolyBezierTo2011-12-15 cnblogs 万一

unit Unit1;
interface
uses
 Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
 Dialogs, StdCtrls;
type
 TForm1 = class（TForm）
  Button1: TButton;
  Button2: TButton;
  procedure Button1Click（Sender: TObject）;
  procedure Button2Click（Sender: TObject）;
 end;
var
 Form1: TForm1;
implementation
{$R *.dfm}

{PolyBezier 至少需要四个点做参数; 不改变画笔的当前位置}

procedure TForm1.Button1Click（Sender: TObject）;
var
 pts: array[0..3] of TPoint;
begin
 Canvas.Pen.Width := 2;
 Canvas.Pen.Color := clRed;
 pts[0].X := 10; pts[0].Y := 10; {起点}
 pts[1].X := 60; pts[1].Y := 10; {控制点1}
 pts[2].X := 10; pts[2].Y := 100; {控制点2}
 pts[3].X := 60; pts[3].Y := 100; {终点}
 Canvas.PolyBezier（pts）;
 Canvas.Pen.Width := 1;
 Canvas.Pen.Color := clWhite;
 Canvas.LineTo（ClientWidth, ClientHeight）;
end;

{PolyBezierTo 最少只需要需要三个点, 它把当前位置当作第一点; 会改变画笔的当前位置}

procedure TForm1.Button2Click（Sender: TObject）;
var
 pts: array[1..3] of TPoint; {从 1 开始的, 就 3 个元素}
begin
 Canvas.Pen.Width := 2;
 Canvas.Pen.Color := clRed;
 Canvas.MoveTo（10 + 82, 10）;      {起点}
 //pts[0].X := 10; pts[0].Y := 10;
 pts[1].X := 60 + 82; pts[1].Y := 10; {控制点1}
 pts[2].X := 10 + 82; pts[2].Y := 100; {控制点2}
 pts[3].X := 60 + 82; pts[3].Y := 100; {终点}
 Canvas.PolyBezierTo（pts）;
 Canvas.Pen.Width := 1;
 Canvas.Pen.Color := clBlue;
 Canvas.LineTo（ClientWidth, ClientHeight）;
end;
end.