! This program generates a micro-strucutre mask and applies it to
! an existing mesh.
! J.Grogan 05/08/11
program Corrosion_Preprocessor
!
!	Parameters
	parameter(max_elements=100000,max_cells=20000,max_fc=100,max_faces=10000)
	parameter(max_elem_in_cell=50000,max_neigh_per_elem=6,max_neighbours=50)
!	
!	Variables 
	character(len=256)input
	character(len=256)input2(2)
	integer,allocatable,dimension(:)::num_faces   
	integer,dimension(max_elements,max_neighbours)::neighbour
	integer mesh_type
	double precision,allocatable,dimension(:,:)::distance
	double precision,allocatable,dimension(:,:)::nbr_dist
	double precision,allocatable,dimension(:,:)::cor_faces
	double precision,dimension(max_elements)::cor_dist
	double precision,allocatable,dimension(:,:)::ele_centroid
!    
!	Mesh Type: 2 = 2D, 3 = 3D
	mesh_type=3
!
	allocate(ele_centroid(max_elements,3))
!	Get element centroids
	call elem_centroids(num_elements,ele_centroid,mesh_type)
!
!	Get neighbouring elements
	allocate(nbr_dist(max_elements,max_neighbours))
	do i=1,num_elements
		icount=1
		do j=1,num_elements
			if(icount>max_neighbours)then
				rmaxdist=0.
				do k=1,max_neighbours
					if(nbr_dist(i,k)>rmaxdist)then
						rmaxdist=nbr_dist(i,k)
						index_max_dist=k
					endif
				enddo
			endif
			cent1x=ele_centroid(i,1)
			cent1y=ele_centroid(i,2)
			cent1z=ele_centroid(i,3)			
			cent2x=ele_centroid(j,1)
			cent2y=ele_centroid(j,2)
			cent2z=ele_centroid(j,3)			
			dist=sqrt((cent1x-cent2x)*(cent1x-cent2x)+(cent1y-cent2y)*(cent1y-cent2y)&
				&+(cent1z-cent2z)*(cent1z-cent2z))
			if(icount>max_neighbours)then
				if(dist<rmaxdist)then
					nbr_dist(i,index_max_dist)=dist
					neighbour(i,index_max_dist)=j
				endif
			else
				nbr_dist(i,j)=dist
				neighbour(i,j)=j
			endif											
			icount=icount+1
		enddo
		print *,float(i)/float(num_elements)
	enddo
	deallocate(nbr_dist)
!
!	Get corrosion surface distances
	open(unit=22,file='CorSurf.dat',status='unknown')
	allocate(cor_faces(max_faces,3))
	ierr=0
	inum_faces=1
	do while (ierr==0)
		read(22,*,iostat=ierr)cor_faces(inum_faces,1),cor_faces(inum_faces,2),&
			&cor_faces(inum_faces,3)
		if(ierr==0)inum_faces=inum_faces+1
	enddo
	close(unit=22)
	do i=1,num_elements
		centx=ele_centroid(i,1)
		centy=ele_centroid(i,2)
		centz=ele_centroid(i,3)
		distmin=1000.
		do j=1,inum_faces-1
			facex=cor_faces(j,1)
			facey=cor_faces(j,2)
			facez=cor_faces(j,3)
			dist=sqrt((centx-facex)*(centx-facex)+(centy-facey)*(centy-facey)&
				&+(centz-facez)*(centz-facez))
			if(dist<distmin)distmin=dist
		enddo
		cor_dist(i)=distmin
	enddo	
	deallocate(cor_faces)
!
	rewind(10)
	open(unit=13,file='GeomGenINP.inp',status='unknown')
    input2(1)='**'
    do while (index(input2(1),'*End Assembly')==0)
		read(10,'(a)')input2(2)
        write(13,'(a)')input2(1)
        input2(1)=input2(2)
	enddo
	write(13,'(a)')'*End Assembly' 
    write(13,*)'*INITIAL CONDITIONS,TYPE=SOLUTION'
	do i=1,num_elements
		write(13,'(3(a,i6),2(a,f18.6),3(i6,a))')'Assembly.CorPart.',i,',' &
			& ,i,',',max_neighbours,',',0.,',',cor_dist(i,j),0,',',1.,',',0,','		
		do k=1,	max_neighbours
			if(mod(k,8)/=0)then
				if(k/=max_neighbours)then
					write(13,'(i6,a)',advance='no')neighbour(i,k),','
				else
					write(13,'(i6)')neighbour(i,k)
				endif
			else
				if(k/=max_neighbours)then
					write(13,'(i6,a)')neighbour(i,k),','
				else
					write(13,'(i6)')neighbour(i,k)
				endif
			endif
		enddo
	enddo
	ierr=0
    do while (ierr==0)
		read(10,'(a)',iostat=ierr)input2(1)
        if(ierr==0)write(13,'(a)')input2(1)          
	enddo
end program	
!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
!	Get Element Centroids
!~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
subroutine elem_centroids(ne,ele_centroid,mesh_type)
!
!	Parameters
	parameter(max_nodes=1000000,max_elements=100000,max_node_in_elem=8)
!	
!	Variables 
	character(len=256)input
	integer,dimension(max_elements,max_node_in_elem)::elements
	double precision,dimension(max_nodes,3)::nodes
	double precision,dimension(max_elements,3)::ele_centroid
!	
!	Open Input File	and read node and element co-ordinates
    open(unit=10,file='GeomGenTemp.inp',status='unknown') 
    do while (index(input,'*Node')==0)
		read(10,'(a)')input
	end do
    nn=0
	do while(1==1)
		read(10,'(a)')input								
	 	if(index(input,'*')==0)then
			backspace(10)
			nn=nn+1	
			if(mesh_type==3)then
				read(10,*)dummy,nodes(nn,1),nodes(nn,2),nodes(nn,3)
			else
				read(10,*)dummy,nodes(nn,1),nodes(nn,2)
			endif
		else 
			if(mesh_type==2)then
				nele_type=4
			else
				if(index(input,'C3D8')/=0)nele_type=8
				if(index(input,'C3D4')/=0)nele_type=4
			endif
			exit
		endif
	end do
    ne=0
	do while(1==1)
		read(10,'(a)')input								
	 	if(index(input,'*')==0)then
			backspace(10)
			ne=ne+1	
			if(nele_type==8)then
				read(10,*)dummy,elements(ne,1),elements(ne,2),elements(ne,3),elements(ne,4)&
					& ,elements(ne,5),elements(ne,6),elements(ne,7),elements(ne,8)
			elseif(nele_type==4)then
				read(10,*)dummy,elements(ne,1),elements(ne,2),elements(ne,3),elements(ne,4)		
			endif
		else
			exit
		endif
	end do
!
!	Get element centroid
	do i=1,ne
		centroidx=0.d0
		centroidy=0.d0
		centroidz=0.d0
		do j=1,nele_type
			centroidx=centroidx+nodes(elements(i,j),1)
			centroidy=centroidy+nodes(elements(i,j),2)
			if(mesh_type==3)centroidz=centroidz+nodes(elements(i,j),3)
		enddo
		ele_centroid(i,1)=centroidx/float(nele_type)
		ele_centroid(i,2)=centroidy/float(nele_type)
		if(mesh_type==3)ele_centroid(i,3)=centroidz/float(nele_type)
	enddo
end subroutine