圓中點Bresenham算法總結(jié)

案例三第5章案例三第5章圓中點Bresenham算法圓中點Bresenham算法本案例知識要點掌握八分法中點Bresenham算法繪制圓的原理設(shè)計八分法繪制圓的中點Bresenham算法編寫八分法繪制圓的CirclePoint(x,y)子函數(shù)編寫繪制整圓的Mbcircle()子函數(shù)一、案例需求1．案例描述使用中點Bresenham算法繪制圓心位于屏幕客戶區(qū)中心的圓。2．案例效果圖案例輸入對話框及效果如圖3-1所示。（a）輸入對話框（b）效果圖3-1圓中點Bresenham算法效果圖3．功能說明（1）要求使用對話框輸入圓的半徑。（2）圓的顏色為藍色。三、算法設(shè)計輸入圓的半徑R。定義圓當(dāng)前點坐標(biāo)x，y、定義中點偏差判別式d、定義像素點顏色rgb。計算，x=0，y=R，rgb＝RGB(0,0,255)。繪制點（x，y）及其在八分圓中的另外7個對稱點。判斷d的符號。若d<0，則（x，y）更新為（x＋1，y），d更新為d+2x＋3；否則（x，y）更新為（x＋1，y－1），d更新為d＋2（x－y）＋5。當(dāng)x小于等于y，重復(fù)步驟⑷和⑸，否則結(jié)束。四、案例實現(xiàn)1．CTestView.h文件//TestView.h:interfaceoftheCTestViewclass/////////////////////////////////////////////////////////////////////////////#if!defined(AFX_TESTVIEW_H__A75FDCFB_621C_4E38_A154_C344803E6372__INCLUDED_)#defineAFX_TESTVIEW_H__A75FDCFB_621C_4E38_A154_C344803E6372__INCLUDED_#if_MSC_VER>1000#pragmaonce#endif//_MSC_VER>1000#include"InputDlg.h"http://包含對話框頭文件classCTestView:publicCView{protected://createfromserializationonly CTestView(); DECLARE_DYNCREATE(CTestView)//Attributespublic: CTestDoc*GetDocument();//Operationspublic: voidGetMaxY();//獲得屏幕的最大x值函數(shù) voidGetMaxX();//獲得屏幕的最大y值函數(shù) voidCirclePoint(doublex,doubley);//八分法畫圓子函數(shù) voidMbcircle();//圓中點Bresenham算法//Overrides //ClassWizardgeneratedvirtualfunctionoverrides //{{AFX_VIRTUAL(CTestView) public: virtualvoidOnDraw(CDC*pDC);//overriddentodrawthisview virtualBOOLPreCreateWindow(CREATESTRUCT&cs); protected: virtualBOOLOnPreparePrinting(CPrintInfo*pInfo); virtualvoidOnBeginPrinting(CDC*pDC,CPrintInfo*pInfo); virtualvoidOnEndPrinting(CDC*pDC,CPrintInfo*pInfo); //}}AFX_VIRTUAL//Implementationpublic: virtual~CTestView();#ifdef_DEBUG virtualvoidAssertValid()const; virtualvoidDump(CDumpContext&dc)const;#endifprotected: intMaxX,MaxY;//屏幕x和y的最大坐標(biāo) doubleR;//圓的半徑//Generatedmessagemapfunctionsprotected: //{{AFX_MSG(CTestView) afx_msgvoidOnMENUMbcircle(); //}}AFX_MSG DECLARE_MESSAGE_MAP()};#ifndef_DEBUG//debugversioninTestView.cppinlineCTestDoc*CTestView::GetDocument(){return(CTestDoc*)m_pDocument;}#endif///////////////////////////////////////////////////////////////////////////////{{AFX_INSERT_LOCATION}}//MicrosoftVisualC++willinsertadditionaldeclarationsimmediatelybeforethepreviousline.#endif//!defined(AFX_TESTVIEW_H__A75FDCFB_621C_4E38_A154_C344803E6372__INCLUDED_)2．CTestView.cpp文件//TestView.cpp:implementationoftheCTestViewclass#include"stdafx.h"#include"Test.h"#include"TestDoc.h"#include"TestView.h"#defineROUND(a)int(a+0.5)//四舍五入#ifdef_DEBUG#definenewDEBUG_NEW#undefTHIS_FILEstaticcharTHIS_FILE[]=__FILE__;#endif///////////////////////////////////////////////////////////////////////////////CTestViewIMPLEMENT_DYNCREATE(CTestView,CView)BEGIN_MESSAGE_MAP(CTestView,CView) //{{AFX_MSG_MAP(CTestView) ON_COMMAND(ID_MENU_Mbcircle,OnMENUMbcircle) //}}AFX_MSG_MAP //Standardprintingcommands 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()///////////////////////////////////////////////////////////////////////////////CTestViewconstruction/destructionCTestView::CTestView(){ //TODO:addconstructioncodehere}CTestView::~CTestView(){}BOOLCTestView::PreCreateWindow(CREATESTRUCT&cs){ //TODO:ModifytheWindowclassorstylesherebymodifying //theCREATESTRUCTcs returnCView::PreCreateWindow(cs);}///////////////////////////////////////////////////////////////////////////////CTestViewdrawingvoidCTestView::OnDraw(CDC*pDC){ CTestDoc*pDoc=GetDocument(); ASSERT_VALID(pDoc);//TODO:adddrawcodefornativedatahere}///////////////////////////////////////////////////////////////////////////////CTestViewprintingBOOLCTestView::OnPreparePrinting(CPrintInfo*pInfo){ //defaultpreparation returnDoPreparePrinting(pInfo);}voidCTestView::OnBeginPrinting(CDC*/*pDC*/,CPrintInfo*/*pInfo*/){ //TODO:addextrainitializationbeforeprinting}voidCTestView::OnEndPrinting(CDC*/*pDC*/,CPrintInfo*/*pInfo*/){ //TODO:addcleanupafterprinting}///////////////////////////////////////////////////////////////////////////////CTestViewdiagnostics#ifdef_DEBUGvoidCTestView::AssertValid()const{ CView::AssertValid();}voidCTestView::Dump(CDumpContext&dc)const{ CView::Dump(dc);}CTestDoc*CTestView::GetDocument()//non-debugversionisinline{ ASSERT(m_pDocument->IsKindOf(RUNTIME_CLASS(CTestDoc))); return(CTestDoc*)m_pDocument;}#endif//_DEBUG///////////////////////////////////////////////////////////////////////////////CTestViewmessagehandlersvoidCTestView::GetMaxX()//得到客戶區(qū)的最大橫坐標(biāo){ CRectRect; GetClientRect(&Rect); MaxX=Rect.right; }voidCTestView::GetMaxY()//得到客戶區(qū)最大縱坐標(biāo){ CRectRect; GetClientRect(&Rect); MaxY=Rect.bottom; }voidCTestView::Mbcircle()//圓中點Bresenham算法{ doublex,y,d; d=1.25-R;x=0;y=R; for(x=0;x<y;x++) { CirclePoint(x,y);//調(diào)用八分法畫圓子函數(shù)if(d<0) d+=2*x+3;else { d+=2*(x-y)+5; y--; }}}voidCTestView::CirclePoint(doublex,doubley)//八分法畫圓子函數(shù){Circlepoint函數(shù)塊的程序請更新Circlepoint函數(shù)塊的程序請更新 COLORREFrgb=RGB(0,0,255);//定義圓的顏色dc.SetPixel(ROUND(x)+MaxX/2,ROUND(y)+MaxY/2,rgb);//x,y dc.SetPixel(ROUND(y)+MaxX/2,ROUND(x)+MaxY/2,rgb);//y,x dc.SetPixel(ROUND(y)+MaxX/2,-ROUND(x)+MaxY/2,rgb);//y,-x dc.SetPixel(ROUND(x)+MaxX/2,-ROUND(y)+MaxY/2,rgb);//x,-y dc.SetPixel(-ROUND(x)+MaxX/2,-ROUND(y)+MaxY/2,rgb);//-x,-y dc.SetPixel(-ROUND(y)+MaxX/2,-ROUND(x)+MaxY/2,rgb);//-y,-x dc.SetPixel(-ROUND(y)+MaxX/2,ROUND(x)+MaxY/2,rgb);//-y,x dc.SetPixel(-ROUND(x)+MaxX/2,ROUND(y)+MaxY/2,rgb);//-x,y}voidCTestView::OnMENUMbcircle()//菜單函數(shù){ //TODO:Addyourcomman