#include<windows.h>
#include<math.h>
#include<stack>
using namespace std;


LRESULT CALLBACK WndProc(HWND, UINT, WPARAM, LPARAM);

int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance,
                    PSTR szCmdLine, int iCmdShow)
{
     static TCHAR szAppName[] = TEXT ("LINE") ;
     HWND         hwnd ;
     MSG          msg ;
     WNDCLASS     wndclass ;
     
	 memset(&wndclass, 0, sizeof(WNDCLASS));//clear the wndclass

     wndclass.style         = CS_HREDRAW | CS_VREDRAW ;
     wndclass.lpfnWndProc   = WndProc ;
     wndclass.cbClsExtra    = 0 ;
     wndclass.cbWndExtra    = 0 ;
     wndclass.hInstance     = hInstance ;
     wndclass.hIcon         = LoadIcon (NULL, IDI_APPLICATION ) ;
     wndclass.hCursor       = LoadCursor (NULL, IDC_ARROW) ;
     wndclass.hbrBackground = (HBRUSH) (COLOR_WINDOW + 1) ;
     wndclass.lpszMenuName  = NULL;
     wndclass.lpszClassName = szAppName ;
     
     if (!RegisterClass (&wndclass))
     {
          MessageBox (NULL, TEXT ("This program requires Windows NT!"),
                      szAppName, MB_ICONERROR) ;
          return 0 ;
     }
     
     hwnd = CreateWindow (szAppName, TEXT ("填充 sample"),
                          WS_OVERLAPPEDWINDOW,                         
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          CW_USEDEFAULT, CW_USEDEFAULT,
                          NULL, NULL, hInstance, NULL) ;
     
     ShowWindow (hwnd, iCmdShow) ;
     UpdateWindow (hwnd) ;

     while (GetMessage (&msg, NULL, 0, 0))
     {
          TranslateMessage (&msg) ;
          DispatchMessage (&msg) ;
     }
     return msg.wParam ;
}

void Line(HDC hdc,int lxB,int lyB,int lxE,int lyE,COLORREF cr)
{
	int x, y, dx, dy, i, Length;
	if ( abs(lxE - lxB) >= abs(lyE - lyB) )
		Length = abs(lxE - lxB);
	else
		Length = abs(lyE - lyB);
	dx = (lxE - lxB) / Length;
	dy = (lyE - lyB) / Length;

	x = lxB;
	y = lyB;

	i = 1;
	while (i <= Length)
	{
		SetPixel(hdc, x, y, cr);
		x = x + dx;
		y = y + dy;
		i = i + 1;
	}
}

void SimpleSeedFill( HDC hdc, int ix, int iy,
					 COLORREF boundary_color, COLORREF fill_color )
{
	stack<POINT> IntStack;
	int Savex, Xright, Xleft, Pflag, Xenter;

	POINT	tmpPoint;
	tmpPoint.x = ix;
	tmpPoint.y = iy;

#define X tmpPoint.x
#define Y tmpPoint.y

	IntStack.push( tmpPoint );
	while ( IntStack.size() != 0 )
	{
		tmpPoint = IntStack.top();
		IntStack.pop();

		SetPixel( hdc, X, Y, fill_color );

		Savex = X;
		++X;

		while ( GetPixel( hdc, X, Y ) != boundary_color )
		{
			SetPixel( hdc, X, Y, fill_color );
			++X;
		}

		Xright = X - 1;
		X = Savex;
		X = X - 1;

		while ( GetPixel( hdc, X, Y ) != boundary_color )
		{
			SetPixel( hdc, X, Y, fill_color );
			--X;
		}

		Xleft = X + 1;
		X = Savex;

		X = Xleft;
		++Y;

		while ( X <= Xright )
		{
			Pflag = 0;

			while ( ( GetPixel( hdc, X, Y ) != boundary_color ) &&
					( GetPixel( hdc, X, Y ) != fill_color     ) &&
					( X < Xright ) )
			{
				if ( 0 == Pflag )
				{
					Pflag = 1;
				}
				
				++X;
			}

			if ( Pflag == 1 )
			{
				if ( ( X == Xright ) &&
					 ( GetPixel( hdc, X, Y ) != boundary_color ) &&
					 ( GetPixel( hdc, X, Y ) != boundary_color ) )
				{
					POINT point;

					point.x = X;
					point.y = Y;

					IntStack.push( point );
				}
				else
				{
					POINT point;

					point.x = X;
					point.y = Y;

					IntStack.push( point );
				}

				Pflag = 0;
			}

			Xenter = X;
			while ( ( GetPixel( hdc, X, Y ) == boundary_color ||
				    GetPixel( hdc, X, Y ) == fill_color ) && 
					X < Xright )
			{
				++X;
			}

			if ( X = Xenter )
			{
				++X;
			}
		}

		X = Xleft;
		Y -= 2;

		while ( X <= Xright )
		{
			Pflag = 0;

			while ( ( GetPixel( hdc, X, Y ) != boundary_color ) &&
					( GetPixel( hdc, X, Y ) != fill_color     ) &&
					( X < Xright ) )
			{
				if ( 0 == Pflag )
				{
					Pflag = 1;
				}
				
				++X;
			}

			if ( Pflag == 1 )
			{
				if ( ( X == Xright ) &&
					 ( GetPixel( hdc, X, Y ) != boundary_color ) &&
					 ( GetPixel( hdc, X, Y ) != boundary_color ) )
				{
					POINT point;

					point.x = X;
					point.y = Y;

					IntStack.push( point );
				}
				else
				{
					POINT point;

					point.x = X;
					point.y = Y;

					IntStack.push( point );
				}

				Pflag = 0;
			}

			Xenter = X;
			while ( ( GetPixel( hdc, X, Y ) == boundary_color ||
				    GetPixel( hdc, X, Y ) == fill_color ) && 
					X < Xright )
			{
				++X;
			}

			if ( X = Xenter )
			{
				++X;
			}
		}
	}
}

LRESULT CALLBACK WndProc(HWND hwnd, UINT message, WPARAM wParam, LPARAM lParam)
{
	PAINTSTRUCT ps;
	HDC         hdc;

	static BOOL		bDraw = FALSE;

	switch(message)
	{
	case WM_CREATE:
		
		return 0;

	case WM_LBUTTONDOWN:
		bDraw = TRUE;
		InvalidateRect( hwnd, NULL, TRUE );
		return 0;

	case WM_PAINT:
		hdc = BeginPaint(hwnd, &ps);
		
		if ( bDraw )
		{

			//Line drawing
			Line(hdc, 150, 150, 300, 150, RGB(150, 125, 55) );
		    Line(hdc, 150, 150, 150, 200, RGB(150, 125, 55) );
		    Line(hdc, 150, 200, 300, 200, RGB(150, 125, 55) );
		    Line(hdc, 300, 150, 300, 200, RGB(150, 125, 55) );
            
			//填充
			SimpleSeedFill( hdc, 175, 175, RGB(150, 125,55), RGB(0,255,0) );

			bDraw = FALSE;
		}

		EndPaint(hwnd, &ps);
		return 0;

	case WM_DESTROY:
		PostQuitMessage(0);
		return 0;
	}
	return DefWindowProc(hwnd, message, wParam, lParam);
}