计算机图形学实验报告2011-10-12.docx

实验一 直线与圆的绘制(一) 实验目的掌握用Besenham法编程实现直线和圆的绘制。会编程绘制虚线、点划线和具有一定宽度的直线。(二) 实验内容用实现直线和圆的绘制基本要求：（1）数据输入项为：直线的起点与终点坐标，圆心坐标与半径 （2）直线与圆输出在中附加要求：（1）通过用户输入可改变直线的线型（实线、虚线与点划线）（2）通过用户输入可改变直线的线宽（用方刷子处理）（3）通过用户输入可改变直线和圆的颜色(三) 实验所用仪表及设备 使用实验室提供的PC机。使用Visual C+编程。(四) 实验步骤1. 设计思路1) 设计对话框类2) 设计菜单3) 设计CMydrawView 类数据成员protected:double x0,y0,x1,y1,R; /直线始点与终点、圆的半径 int cx,cy; /圆的坐标；成员函数void Mybline(); /直线中点Bresenham函数void CirclePoint(double x,double y); /八分子画圆子函数void Mbcircle(); /圆中点Bresenham函数4) 程序代码 void CMydrawView:Mybline() /中点Bresenham函数CClientDC dc(this);COLORREF rgb=RGB(0,255,0); /定义直线颜色为蓝色double x,y,d,k, t;x=x0;y=y0;if(abs(x1-x0)1e-6) if(y1y0) t=y0;y0=y1;y1=t;for(x=x0,y=y0;y1)if(y1y0)t=y0;y0=y1;y1=t;t=x0;x0=x1;x1=t; d=1-0.5*k; for(x=x0,y=y0;y=0)x+; d+=1-k; else d+=1;if(0=k&kx1)t=x0;x0=x1;x1=t;t=y0;y0=y1;y1=t;d=0.5-k;for(x=x0,y=y0;xx1;x+)dc.SetPixel(ROUND(x),ROUND(y),rgb);if(d=-1&kx1)t=x0;x0=x1;x1=t;t=y0;y0=y1;y1=t;d=-0.5-k;for(x=x0,y=y0;x0)y-;d-=1-k;elsed-=-k;if(k-1)if(y0y1;y-)dc.SetPixel(ROUND(x),ROUND(y),rgb);if(dSetWindowText(基本图形扫描转换：Mybline);/RedrawWindow();Mybline();void CMydrawView:Mbcircle() /圆中点Bresenham函数double x,y,d;d=1.25-R;x=0;y=R;for(x=0;xy;x+)CirclePoint(x,y);if(dSetWindowText(基本图形扫描转换：Mbcircle);Mbcircle();void CMydrawView:OnMENUITEMclear() /清屏菜单函数/ TODO: Add your command handler code hereRedrawWindow();5) 运行结果直线：(五) 思考题如何修改程序使其适合于当直线斜率大于一或小于零时的情况？答：分组讨论大于一和小于零的情况，分别计算机d的值，程序如下：if(k1)if(y1y0)t=y0;y0=y1;y1=t;t=x0;x0=x1;x1=t; d=1-0.5*k; for(x=x0,y=y0;y=0)x+; d+=1-k; else d+=1;if(k=-1&kx1)t=x0;x0=x1;x1=t;t=y0;y0=y1;y1=t;d=-0.5-k;for(x=x0,y=y0;x0)y-;d-=1-k;elsed-=-k;if(k-1)if(y0y1;y-)dc.SetPixel(ROUND(x),ROUND(y),rgb);if(d=1)MemDC.MoveTo(ROUND(Pointx0),ROUND(Pointy0);MemDC.LineTo(ROUND(Pointx1),ROUND(Pointy1);MemDC.SelectObject(pOldPen1);Pen1.DeleteObject();CDC *dc=GetDC();dc-BitBlt(0,0,Rect.Width(),Rect.Height(),&MemDC,0,0,SRCCOPY);MemDC.SelectObject(pBitmap);/ CMyCutView printingBOOL CMyCutView:OnPreparePrinting(CPrintInfo* pInfo)/ default preparationreturn DoPreparePrinting(pInfo);void CMyCutView:OnBeginPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)/ TODO: add extra initialization before printingvoid CMyCutView:OnEndPrinting(CDC* /*pDC*/, CPrintInfo* /*pInfo*/)/ TODO: add cleanup after printing/ CMyCutView diagnostics#ifdef _DEBUGvoid CMyCutView:AssertValid() constCView:AssertValid();void CMyCutView:Dump(CDumpContext& dc) constCView:Dump(dc);CMyCutDoc* CMyCutView:GetDocument() / non-debug version is inlineASSERT(m_pDocument-IsKindOf(RUNTIME_CLASS(CMyCutDoc);return (CMyCutDoc*)m_pDocument;#endif /_DEBUG/ CMyCutView message handlersvoid CMyCutView:OnMENUITEMdrawline() / TODO: Add your command handler code hereif(FALSE=m_attatch)Picture.CreateCompatibleDC(GetDC();CBitmap *Bitmap,*pBitmap;Bitmap=new CBitmap;/Bitmap-LoadBitmap(IDB_BITMAP1);pBitmap=Picture.SelectObject(Bitmap);m_attatch=TRUE;m_draw=TRUE;m_i=0;Invalidate(FALSE);AfxGetMainWnd()-SetWindowText(Cohen-Sutherland直线裁剪算法);/显示标题MessageBox(请使用鼠标在屏幕上绘制直线，然后点击裁剪按钮进行裁剪,提示,MB_OKCANCEL);void CMyCutView:OnMENUITEMclip() /裁剪菜单函数 / TODO: Add your command handler code hereCut();Invalidate(FALSE);void CMyCutView:OnLButtonDown(UINT nFlags, CPoint point) / TODO: Add your message handler code here and/or call defaultif(TRUE=m_draw)if(m_i2)Pointxm_i=point.x;Pointym_i=point.y;m_i+;CView:OnLButtonDown(nFlags, point);void CMyCutView:OnMouseMove(UINT nFlags, CPoint point) / TODO: Add your message handler code here and/or call defaultif(TRUE=m_draw)if(m_i2)Pointxm_i=point.x;Pointym_i=point.y;Invalidate(FALSE);CView:OnMouseMove(nFlags, point);void CMyCutView:Cut()BOOL Change;double x,y;RC0=EnCode(Pointx0,Pointy0);RC1=EnCode(Pointx1,Pointy1);while(TRUE)Change=FALSE;if(0 = (RC0|RC1)/简取之return;else if(0!=(RC0 & RC1)/简弃之return;elseif(0=RC0)/如果P0点在窗口内，交换P0和P1,保证p0点在窗口外/交换点的坐标值double TPointx,TPointy;TPointx=Pointx0;TPointy=Pointy0;Pointx0=Pointx1;Pointy0=Pointy1;Pointx1=TPointx;Pointy1=TPointy;/交换点的编码值unsigned int TRC;TRC=RC0;RC0=RC1;RC1=TRC;/按左、右、下、上的顺序裁剪if(RC0 & LEFT )/P0点位于窗口的左侧x=wxl;/求交点yy=Pointy0+(Pointy1-Pointy0)*(x-Pointx0)/(Pointx1-Pointx0);Pointx0=x;Pointy0=y;Change=TRUE;RC0=EnCode(Pointx0,Pointy0);RC1=EnCode(Pointx1,Pointy1);if(RC0 & RIGHT )/P0点位于窗口的右侧x=wxr;/求交点yy=Pointy0+(Pointy1-Pointy0)*(x-Pointx0)/(Pointx1-Pointx0);Pointx0=x;Pointy0=y;Change=TRUE;RC0=EnCode(Pointx0,Pointy0);RC1=EnCode(Pointx1,Pointy1);if(RC0 & BOTTOM )/P0点位于窗口的下侧y=wyb;/求交点xx=Pointx0+(Pointx1-Pointx0)*(y-Pointy0)/(Pointy1-Pointy0);Pointx0=x;Pointy0=y;Change=TRUE;RC0=EnCode(Pointx0,Pointy0);RC1=EnCode(Pointx1,Pointy1);if(RC0 & TOP )/P0点位于窗口的上侧y=wyt;/求交点xx=Pointx0+(Pointx1-Pointx0)*(y-Pointy0)/(Pointy1-Pointy0);Pointx0=x;Pointy0=y;Change=TRUE;RC0=EnCode(Pointx0,Pointy