bezirview.cpp

Draw bezier with visual c++!

// bezirView.cpp : implementation of the CBezirView class
//

#include "stdafx.h"
#include "bezir.h"

#include "bezirDoc.h"
#include "bezirView.h"
#include "math.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CBezirView

IMPLEMENT_DYNCREATE(CBezirView, CView)

BEGIN_MESSAGE_MAP(CBezirView, CView)
	//{{AFX_MSG_MAP(CBezirView)
	ON_WM_LBUTTONDOWN()
	ON_WM_MOUSEMOVE()
	ON_WM_RBUTTONDOWN()
	ON_COMMAND(clear, Onclear)
	ON_COMMAND(result, Onresult)
	//}}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()

/////////////////////////////////////////////////////////////////////////////
// CBezirView construction/destruction

CBezirView::CBezirView()
{
n=0;
k=0;
flag=0;
flag2=0;	
// TODO: add construction code here

}

CBezirView::~CBezirView()
{
}

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

	return CView::PreCreateWindow(cs);
}

/////////////////////////////////////////////////////////////////////////////
// CBezirView drawing

void CBezirView::OnDraw(CDC* pDC)
{
	CBezirDoc* pDoc = GetDocument();
	ASSERT_VALID(pDoc);
    pDC->SetTextColor(0xff0000);
	pDC->TextOut(700,50,"按鼠标左键开始");
    pDC->TextOut(700,80,"按鼠标右键结束");
	CPen pen(0,3,0xff0000);
	pDC->SelectObject(&pen);
	if(flag2) 
	{
		pDC->MoveTo(b(h-1,0,p));
        for(int i=0;i<=50;i++)
        pDC->LineTo(b(h-1,(float)i/50,p));
        flag2=0;
	}
}

/////////////////////////////////////////////////////////////////////////////
// CBezirView printing

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

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

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

/////////////////////////////////////////////////////////////////////////////
// CBezirView diagnostics

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

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

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

/////////////////////////////////////////////////////////////////////////////
// CBezirView message handlers

void CBezirView::OnLButtonDown(UINT nFlags, CPoint point) 
{   
	CClientDC dc(this);
	flag=1;
    CPoint y[100];
	static n1;
	y[n1]=point;
	p[n]=y[n1];
	x0=xm=point;
	dc.MoveTo(y[n1-1]);
    dc.LineTo(y[n1]);
    n1++;n++;
	CView::OnLButtonDown(nFlags, point);
}

void CBezirView::OnMouseMove(UINT nFlags, CPoint point) 
{
CClientDC dc(this);
if(flag)
{
	dc.SetROP2(R2_NOT);
	dc.MoveTo(x0);
	dc.LineTo(xm);
	dc.MoveTo(x0);
	dc.LineTo(point);
	xm=point;
}
	CView::OnMouseMove(nFlags, point);
}

void CBezirView::OnRButtonDown(UINT nFlags, CPoint point) 
{
flag=0;
CPen pen1(0,3,255),pen2(0,3,0xff0000),pen3(0,3,0x00ff00);
CClientDC dc(this);
switch(k%3)
{
case 0:
dc.SelectObject(&pen1);
break;
case 1:
dc.SelectObject(&pen2);
break;
case 2:
dc.SelectObject(&pen3);
break;
}
k++;
dc.MoveTo(b(n-1,0,p));
for(int i=0;i<=30;i++)
  dc.LineTo(b(n-1,(float)i/30,p));
h=n;
n=0;
     CView::OnRButtonDown(nFlags, point);
}



float CBezirView::c(int n, int i,float t)
{
int j;
float a=1;
for(j=i+1;j<=n;j++)
a*=j;
for(j=1;j<=n-i;j++)
a/=j;
a*=pow(t,i);
a*=pow(1-t,n-i);
return a;
}

CPoint CBezirView::b(int n, float t, CPoint p[])
{
int i,j;
CPoint q;
float x=0,y=0;
for(i=0;i<=n;i++)
{
	x=x+p[i].x*c(n,i,t);
	y=y+p[i].y*c(n,i,t);
}
q.x=x;
q.y=y;
return q;
}

void CBezirView::Onclear() 
{
n=0;
k=0;
Invalidate();	
}

void CBezirView::Onresult() 
{
	flag2=1;
Invalidate();	
	
}