hw4_3view.cpp

给定四个点绘制图4-30所示的不同转角的两个正方形

// hw4_3View.cpp : implementation of the CHw4_3View class
//

#include "stdafx.h"
#include "hw4_3.h"

#include "hw4_3Doc.h"
#include "hw4_3View.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View

IMPLEMENT_DYNCREATE(CHw4_3View, CView)

BEGIN_MESSAGE_MAP(CHw4_3View, CView)
	//{{AFX_MSG_MAP(CHw4_3View)
		// NOTE - the ClassWizard will add and remove mapping macros here.
		//    DO NOT EDIT what you see in these blocks of generated code!
	//}}AFX_MSG_MAP
	// Standard printing commands
	ON_COMMAND(ID_FILE_PRINT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_DIRECT, CView::OnFilePrint)
	ON_COMMAND(ID_FILE_PRINT_PREVIEW, CView::OnFilePrintPreview)
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View construction/destruction

CHw4_3View::CHw4_3View()
{
	// TODO: add construction code here

}

CHw4_3View::~CHw4_3View()
{
}

BOOL CHw4_3View::PreCreateWindow(CREATESTRUCT& cs)
{
	// TODO: Modify the Window class or styles here by modifying
	//  the CREATESTRUCT cs

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View drawing

void CHw4_3View::OnDraw(CDC* pDC)
{
	CHw4_3Doc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);

	// TODO: add draw code for native data here
	CRect rect;
	GetClientRect(&rect);
	pDC->SetMapMode(MM_ANISOTROPIC);
	pDC->SetWindowExt(rect.Width(), rect.Height());
	pDC->SetViewportExt(rect.right, -rect.bottom);
	pDC->SetViewportOrg(rect.right/2, rect.bottom/2);

	// square1
	DrawEdge(pDC, pDoc->square1, RGB(0, 0, 0));
	ScanFill(pDC, pDoc->square1, RGB(255, 0, 0));
	// square2
	DrawEdge(pDC, pDoc->square2, RGB(0, 0, 0));
	ScanFill(pDC, pDoc->square2, RGB(255, 0, 0));
}

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View printing

BOOL CHw4_3View::OnPreparePrinting(CPrintInfo* pInfo)
{
	// default preparation
	return DoPreparePrinting(pInfo);
}

void CHw4_3View::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add extra initialization before printing
}

void CHw4_3View::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)
{
	// TODO: add cleanup after printing
}

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View diagnostics

#ifdef _DEBUG
void CHw4_3View::AssertValid() const
{
	CView::AssertValid();
}

void CHw4_3View::Dump(CDumpContext& dc) const
{
	CView::Dump(dc);
}

CHw4_3Doc* CHw4_3View::GetDocument() // non-debug version is inline
{
	ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CHw4_3Doc)));
	return (CHw4_3Doc*)m_pDocument;
}
#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////
// functions

void CHw4_3View::DrawEdge(CDC *pDC, list<CPoint> &polygon, int color)
{
	list<CPoint>::iterator p_ite;

	p_ite= polygon.begin();
	pDC->MoveTo(p_ite->x, p_ite->y);
	for (++p_ite; p_ite != polygon.end(); ++p_ite, ++num)
		pDC->LineTo(p_ite->x, p_ite->y);
	p_ite = polygon.begin();
	pDC->LineTo(p_ite->x, p_ite->y);
}

void CHw4_3View::ScanFill(CDC *pDC, list<CPoint> &polygon, int color)
{
	int i, x1, y1, x_maxy, miny, scanline;
	list<CPoint>::iterator p_ite;
	list<node>::iterator n_ite;
	list<node> AET_temp;

	if (polygon.size() <= 2)
	{
		pDC->TextOut(0, 0, "Not a polygon!");
		return ;
	}

	p_ite= polygon.begin();
	num = 1;
	y_max = y_min = p_ite->y;
	for (++p_ite; p_ite != polygon.end(); ++p_ite, ++num)
	{
		if (p_ite->y < y_min) y_min = p_ite->y;
		if (p_ite->y > y_max) y_max = p_ite->y;
	}

	m_ET = new list<node>[y_max-y_min+1];
	p_ite = polygon.begin();
	for (i = 1; i <= num; ++i)
	{
		x1 = p_ite->x;
		y1 = p_ite->y;
		++p_ite;
		if (p_ite == polygon.end()) p_ite = polygon.begin();
		if (y1 > p_ite->y)
		{
			x_maxy = x1;
			miny = p_ite->y;
			m_ET[y1-y_min].push_back(node((float)x_maxy, (float)(x1-p_ite->x)/(float)(y1-p_ite->y), miny));
		}
		else if (y1 < p_ite->y)
		{
			x_maxy = p_ite->x;
			miny = y1;
			m_ET[p_ite->y-y_min].push_back(node((float)x_maxy, (float)(x1-p_ite->x)/(float)(y1-p_ite->y), miny));
		}
	}

	// fillrect
	scanline = y_max;
	while (scanline >= y_min)
	{
		for (n_ite = m_ET[scanline-y_min].begin(); n_ite != m_ET[scanline-y_min].end(); ++n_ite)
			AET.push_back(*n_ite);
		AET.sort();

		n_ite = AET.begin();
		while (n_ite != AET.end())
		{
			node node_l = *n_ite;
			++n_ite;
			node node_r = *n_ite;
			for (i = node_l.x; i < node_r.x; ++i)
				pDC->SetPixel(i, scanline, color);
			Sleep(1);
			++n_ite;
		}

		--scanline;

		n_ite = AET.begin();
		while (n_ite != AET.end())
		{
			node temp = *n_ite;
			if (temp.ymin < scanline)
				AET_temp.push_back(node((temp.x-temp.k_r), temp.k_r, temp.ymin));
			++n_ite;
		}
		AET.swap(AET_temp);
		AET_temp.clear();
	}

	delete []m_ET;
}

/////////////////////////////////////////////////////////////////////////////
// CHw4_3View message handlers