//---------------------------------------------------------------------------

#ifndef Unit1H
#define Unit1H
//---------------------------------------------------------------------------
#include <Classes.hpp>
#include <Controls.hpp>
#include <StdCtrls.hpp>
#include <Forms.hpp>
#include <ExtCtrls.hpp>
#include <Gdiplus.h>
//---------------------------------------------------------------------------
class TForm1 : public TForm
{
__published:	// IDE-managed Components
	TTimer *Timer1;
	void __fastcall Timer1Timer(TObject *Sender);
private:	// User declarations
	Gdiplus::GdiplusStartupInput gdiplusStartupInput;
	ULONG_PTR gdiplusToken;
public:		// User declarations
	__fastcall TForm1(TComponent* Owner);
	__fastcall ~TForm1(void);
};
//---------------------------------------------------------------------------
extern PACKAGE TForm1 *Form1;
//---------------------------------------------------------------------------
#endif

//---------------------------------------------------------------------------

#include <vcl.h>
#include <math.h>
#pragma hdrstop

#include <algorithm>
using std::min;
using std::max;

#include "Unit1.h"
//---------------------------------------------------------------------------
#pragma package(smart_init)
#pragma resource "*.dfm"
TForm1 *Form1;

using namespace Gdiplus;
//---------------------------------------------------------------------------
__fastcall TForm1::TForm1(TComponent* Owner)
	: TForm(Owner)
{
	DoubleBuffered = true;

	// 初始化GDI+
	GdiplusStartup(&gdiplusToken, &gdiplusStartupInput, NULL);
}
//---------------------------------------------------------------------------

__fastcall TForm1::~TForm1()
{
	// 闭关GDI+
	GdiplusShutdown(gdiplusToken);
}
//---------------------------------------------------------------------------

void __fastcall TForm1::Timer1Timer(TObject *Sender)
{
	const static int OX = 200, OY = 200;
	const static REAL C = 140;
	const static REAL PI = 3.14;

	static REAL offset = 0;
	POINT p[4];
	REAL k[4];

	// 生成正文形四角的新坐标值
	for (int i=0; i < 4; i++)
	{
		k[i] = offset + (PI / 2) * i;
		p[i].x = (int)OX + C * sin(k[i]);
		p[i].y = (int)OY + C * cos(k[i]);
	}

	Gdiplus::Graphics g(Canvas->Handle);
	g.SetSmoothingMode(SmoothingModeHighQuality); //高画质、低速

	// 重新填充背景
	SolidBrush brush(Color::Color(0,0,0));
	Pen pen(Color::Color(255, 255, 0), 3);

	g.FillRectangle(&brush, 0, 0, ClientWidth, ClientHeight);

	Gdiplus::Point point1(p[0].x, p[0].y);
	Gdiplus::Point point2(p[1].x, p[1].y);
	Gdiplus::Point point3(p[2].x, p[2].y);
	Gdiplus::Point point4(p[3].x, p[3].y);
	Gdiplus::Point point5(p[0].x, p[0].y);

	// 在新坐标绘画正方形
	Gdiplus::Point points[] = {point1, point2, point3, point4, point5};
	g.DrawLines(&pen, points, 5);

	offset += 0.1;
}
//---------------------------------------------------------------------------