利用C语言编写 能够画出任意斜率的直线算法程序（利用中点画线法改编）

将DDA算法改成中点划线乎档宏算法即可

// DDA画线View.cpp : implementation of the CDDAView class

//

#include "stdafx.h"

#include "DDA画线.h"

#include "蠢橘DDA画线Doc.h"

#include "DDA画线View.h"

#ifdef _DEBUG

#define new DEBUG_NEW

#undef THIS_FILE

static char THIS_FILE[] = __FILE__

#endif

/////////////////////////////////////////////////////////////////////////////

// CDDAView

IMPLEMENT_DYNCREATE(CDDAView, CView)

BEGIN_MESSAGE_MAP(CDDAView, CView)

//{{AFX_MSG_MAP(CDDAView)

// 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()

/////////////////////////////////////////////////////////岁册////////////////////

// CDDAView construction/destruction

CDDAView::CDDAView()

{

// TODO: add construction code here

}

CDDAView::~CDDAView()

{

}

BOOL CDDAView::PreCreateWindow(CREATESTRUCT&cs)

{

// TODO: Modify the Window class or styles here by modifying

// the CREATESTRUCT cs

return CView::PreCreateWindow(cs)

}

/////////////////////////////////////////////////////////////////////////////

// CDDAView drawing

void CDDAView::OnDraw(CDC* pDC)

{

CDDADoc* pDoc = GetDocument()

ASSERT_VALID(pDoc)

int xx,yy,x2,y2,m,n

float dx,dy,k,x,y

int x0=50,y0=500,x1=50,y1=50

if(x0>x1)

{

m=x0x0=x1x1=m

m=y0y0=y1y1=m

}

dx=x1-x0

dy=y1-y0

k=dy/dx

if(x0==x1)

{

if(y0>y1)

{

n=y0

y0=y1

y1=n

}

for(y2=y0y2<=y1)

{

for(n=-10n<11)

{

pDC->SetPixel(x0+n,y2,255)

n++

}

y2=y2+3

}

}

if(k>=-1&&k<=1.0)

{

y=y0

for(x2=x0x2<=x1)

{

yy=(int)(y+0.5)

for(n=-10n<11)

{

pDC->SetPixel(x2,yy+n,255)

n++

}

y=y+k

x2++

}

}

else if(k>1)

{

x=x0

k=dx/dy

for(y2=y0y2<=y1)

{

xx=(int)(x+0.5)

for(n=-10n<11)

{

pDC->SetPixel(xx+n,y2,255)

n++

}

x=x+k

y2++

}

}

else if(k<-1)

{

x=x1

k=dx/dy

for(y2=y1y2<=y0)

{

xx=(int)(x+0.5)

for(n=-10n<11)

{

pDC->SetPixel(xx+n,y2,255)

n++

}

x=x+k

y2++

}

}

// TODO: add draw code for native data here

}

/////////////////////////////////////////////////////////////////////////////

// CDDAView printing

BOOL CDDAView::OnPreparePrinting(CPrintInfo* pInfo)

{

// default preparation

return DoPreparePrinting(pInfo)

}

void CDDAView::OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)

{

// TODO: add extra initialization before printing

}

void CDDAView::OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)

{

// TODO: add cleanup after printing

}

/////////////////////////////////////////////////////////////////////////////

// CDDAView diagnostics

#ifdef _DEBUG

void CDDAView::AssertValid() const

{

CView::AssertValid()

}

void CDDAView::Dump(CDumpContext&dc) const

{

CView::Dump(dc)

}

CDDADoc* CDDAView::GetDocument() // non-debug version is inline

{

ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CDDADoc)))

return (CDDADoc*)m_pDocument

}

#endif //_DEBUG

/////////////////////////////////////////////////////////////////////////////

// CDDAView message handlers

DDAline(100,200,300,400,466)

这个函数中的五个数字分别表示x0,y0,x1,y1和颜色。斜率是由x0,y0,x1,y1决定迟型的码启猜。你想改变旁历斜率，只需改变这四个数字即可。

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