mfc梁友栋算法切割

计算机图形学中的梁友栋算法实现 CClientDC dc(this); int x0=m_nStart.x, y0=m_nStart.y; //起点 int x1=m_nEnd.x,y1=m_nEnd.y; //终点 int x=x0,y=y0; dc.SetPixel(x0,y0,RGB(255,0,255)); double m; m=1.0*(y0-y1)/(x1-x0); if (x0<x1) { if((m>=0&&m<=1)||(m>=-1&&m<0)) { double a=y; for(int i=0;i<abs(x1-x0)-1;i++) { x+=1; a=a-m; dc.SetPixel(x,int(a+0.5),RGB(255,0,255)); } } else if(m>1) { double a=x; for (int i=0;i<abs(y1-y0)-1;i++) { y-=1;a=a+1/m; dc.SetPixel(int(a+0.5),y,RGB(255,0,255)); } } else if(m<-1) { double a=x; for (int i=0;i<abs(y1-y0)-1;i++) { y+=1;a=a-1/m; dc.SetPixel(int(a+0.5),y,RGB(255,0,255)); } } } if(x0==x1) if(y0<y1) for (int i=0;i<abs(y1-y0)-1;i++) { y+=1; dc.SetPixel(x0,y,RGB(255,0,255)); } else for (int i=0;i<abs(y1-y0)-1;i++) { y-=1; dc.SetPixel(x0,y,RGB(255,0,255)); } if (x0>x1) { if((m>=0&&m<=1)||(m>=-1&&m<0)) { double a=y; for(int i=0;i<abs(x1-x0)-1;i++) { x-=1; a=a+m; dc.SetPixel(x,int(a+0.5),RGB(255,0,255)); } } else if(m>1) { double a=x; for (int i=0;i<abs(y1-y0)-1;i++) { y+=1; a=a-1/m; dc.SetPixel(int(a+0.5),y,RGB(255,0,255)); } } else if(m<-1) { double a=x; for (int i=0;i<abs(y1-y0)-1;i++) { y-=1; a=a+1/m; dc.SetPixel(int(a+0.5),y,RGB(255,0,255)); } } } CView::OnLButtonUp(nFlags, point); } void CDDAView::LiangBarsky(CPoint Ps,CPoint Pe,CPoint& Us,CPoint& Ue) { double u1,u2; //要求的u值 int pL,pR,pB,pT,qL,qR,qB,qT; //求pL,pR,pB,pT pL=Ps.x-Pe.x; pR=-pL; pB=Ps.y-Pe.y; pT=-pB; //求qL,qR,qB,qT qL=Ps.x-A.x; qR=D.x-Ps.x; qB=Ps.y-A.y; qT=B.y-Ps.y; double uL,uB,uR,uT; //求uL,uB,uR,uT; if (pL<0) { if(pB<0) { uL=double(qL)/pL; uB=double(qB)/pB; u1=GetMaxU(uL,uB,0.0); uR=double(qR)/pR; uT=double(qT)/pT; u2=GetMinU(uR,uT,1.0); } else { uL=double(qL)/pL; uT=double(qT)/pT; u1=GetMaxU(uL,uT,0.0); uR=double(qR)/pR; uB=double(qB)/pB; u2=GetMinU(uR,uB,1.0); } } else { if (pB>0) { uL=double(qL)/pL; uB=double(qB)/pB; u2=GetMinU(uL,uB,1); uR=double(qR)/pR; uT=double(qT)/pT; u1=GetMaxU(uR,uT,0); } else { uL=double(qL)/pL; uT=double(qT)/pT; u2=GetMinU(uL,uT,1); uR=double(qR)/pR; uB=double(qB)/pB; u1=GetMaxU(uR,uB,0); } } double x1,x2,y1,y2; x1=Ps.x+u1*(Pe.x-Ps.x); y1=Ps.y+u1*(Pe.y-Ps.y); x2=Ps.x+u2*(Pe.x-Ps.x); y2=Ps.y+u2*(Pe.y-Ps.y); Us.x=int(x1+0.5); Us.y=int(y1+0.5); Ue.x=int(x2+0.5); Ue.y=int(y2+0.5); }