边相关扫描线多边形填充算法.doc

边相关扫描线多边形填充算法M文件代码：function scanedge(X,Y)s,sY=size(Y);maxY=max(Y);minY=min(Y);%奇异点Y1=Y;if (Y(sY)Y(1)&Y(2)Y(1)|(Y(sY)Y(1) Y1(1)=Y(1)-1;endif (Y(sY-1)Y(sY)&Y(1)Y(sY)|(Y(sY-1)Y(sY) Y1(sY)=Y(sY)-1;endfor i=2:sY-1 if (Y(i-1)Y(i)&Y(i+1)Y(i)|(Y(i-1)Y(i) Y1(i)=Y(i)-1; endend%画出多边形hold on;plot(X(1),X(sY),Y(1),Y(sY),r);plot(X,Y,r);axis equal;grid on;%建ET表Edge=zeros(sY);ET=cell(maxY,1);for i=minY:maxY A=find(Y=i); sA=size(A); k=1; for j=1:sA(2) %扫描到P1点时 if A(j)=1 if X(sY)X(2) if Edge(sY)=0 if Y(sY)=Y(1) if X(sY)=X(1) ETi,k=max(Y1(sY),Y1(1),X(1),0; else ETi,k=max(Y1(sY),Y1(1),X(1),. (X(1)-X(sY)/(Y(1)-Y(sY); end k=k+1; end Edge(sY)=1; end if Edge(1)=0 if Y(2)=Y(1) if X(2)=X(1) ETi,k=max(Y1(2),Y1(1),X(1),0; else ETi,k=max(Y1(2),Y1(1),X(1),. (Y(2)-Y(1)/(X(2)-X(1); end k=k+1; end Edge(1)=1; end else if Edge(1)=0 if Y(2)=Y(1) if X(2)=X(1) ETi,k=max(Y1(2),Y1(1),X(1),0; else ETi,k=max(Y1(2),Y1(1),X(1),. (Y(2)-Y(1)/(X(2)-X(1); end k=k+1; end Edge(1)=1; end if Edge(sY)=0 if Y(sY)=Y(1) if X(sY)=X(1) ETi,k=max(Y1(sY),Y1(1),X(1),0; else ETi,k=max(Y1(sY),Y1(1),X(1),. (Y(1)-Y(sY)/(X(1)-X(sY); end k=k+1; end Edge(sY)=1; end end end %扫描到P1以外的点时 if A(j)=1 X1=X;X1(sY+1)=X(1); if X(A(j)-1)AET1,2(1,2) Change=AET1,1; AET1,1=AET1,2; AET1,2=Change;endfor i=ceil(AET1,1(1,2):floor(AET1,2(1,2) plot(i,1,b.,markersize,60);endm=2;for i=minY+1:maxY if isempty(ETi,1) for j=1:m; Change1,j=AETi-1,j; end k=2; while k=m if Change1,k-1(1,2)=Change1,k(1,2) for j=k-1:m-2 Change1,j=Change1,j+2; end k=k-2; m=m-2; end k=k+2; end for j=1:m AETi,j=Change1,j; AETi,j(1,2)=Change1,j(1,2)+Change1,j(1,3); end else if isempty(ETi,2) if AETi-1,1(1,2)+AETi-1,1(1,3)=ETi,1(1,2) AETi,1=ETi,1; for j=2:m AETi,j=AETi-1,j; AETi,j(1,2)=AETi-1,j(1,2)+AETi-1,j(1,3); end end if AETi-1,m(1,2)+AETi-1,m(1,3)=ETi,1(1,2) AETi,m=ETi,1; for j=1:m-1 AETi,j=AETi-1,j; AETi,j(1,2)=AETi-1,j(1,2)+AETi-1,j(1,3); end end if AETi-1,1(1,2)+AETi-1,1(1,3)ETi,1(1,2) for j=1:m; Change1,j=AETi-1,j; end k=2; while k=m if Change1,k-1(1,2)=Change1,k(1,2) for j=k-1:m-2 Change1,j=Change1,j+2; end k=k-2; m=m-2; end k=k+2; end for j=1:m AETi,j=Change1,j; AETi,j(1,2)=Change1,j(1,2)+Change1,j(1,3); end end else if AETi-1,1(1,2)+AETi-1,1(1,3)ETi,2(1,2) if m=2 m=4; AETi,1=AETi-1,1; AETi,1(1,2)=AETi-1,1(1,2)+AETi-1,1(1,3); AETi,2=ETi,1; AETi,3=ETi,2; AETi,4=AETi-1,2; AETi,4(1,2)=AETi-1,2(1,2)+AETi-1,2(1,3); else for j=2:2:m if AETi-1,j-1(1,2)+AETi-1,j-1(1,3)ETi,2(1,2) m=m+2; for k=1:j-1 AETi,k=AETi-1,k; AETi,k(1,2)=AETi-1,k(1,2)+AETi-1,k(1,3); end AETi,j=ETi,1; AETi,j+1=ETi,2; for k=j+2:m AETi,k=AETi-1,k-2; AETi,k(1,2)=AETi-1,k-2(1,2)+AETi-1,k-2(1,3); end j=m; end end end end end end for j=2:2:m for k=ceil(AETi,j-1(1,2):floor(AETi,j(1,2) plot(k,i,b.,markersize,60); end endend测试代码与输出图像：X=6,8,6,2,2;Y=7,5,1,3,6;scanedge(X,Y)figure 1X=2,6,10,10,4,2;Y=1,1,3,8,5,7;scanedge(X,Y)figure 2X=2,6,10,10,4,2,1;Y=1,1,3,8,5,7,6;scanedge(X,Y)figure 3X=2,6,10,10,8,6,4,2;Y=1,1,3,7,6,7,5,7;scane