revdep/library/silicate/deldir/ratfor/delseg.r

In mdsumner/gibble: Geometry Decomposition

subroutine delseg(delsgs,ndel,nadj,madj,npd,x,y,ntot,nerror)

# Output the endpoints of the line segments joining the
# vertices of the Delaunay triangles.
# Called by master.

implicit double precision(a-h,o-z)
logical value
dimension nadj(-3:ntot,0:madj), x(-3:ntot), y(-3:ntot)
dimension delsgs(6,ndel)

# For each distinct pair of points i and j, if they are adjacent
# then put their endpoints into the output array.
npd = ntot-4
kseg = 0
do i = 2,npd {
        do j = 1,i-1 {
                call adjchk(i,j,value,nadj,madj,ntot,nerror)
		if(nerror>0){
                    return
                }
                if(value) {
			kseg = kseg+1
			if(kseg > ndel) {
				nerror = 14
				return
			}
			delsgs(1,kseg) = x(i)
			delsgs(2,kseg) = y(i)
			delsgs(3,kseg) = x(j)
			delsgs(4,kseg) = y(j)
			delsgs(5,kseg) = i
			delsgs(6,kseg) = j
                }
        }
}
ndel = kseg

return
end