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@KristofferC
Created March 4, 2020 13:58
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# function meshformatparser(str)
#
# end
# const SECTION_PARSER = Dict{String,Function}(
# "MeshFormat" => meshformatparser,
# )
module Gmsh
using Tensors, JuAFEM
function parsenodes(str; version=v"4.1")
m = match(r"\$Nodes(.*)\$EndNodes"s, str)
lines = split(strip(m.captures[1]), '\n')
line = split(popfirst!(lines))
numEntityBlocks, numNodes = parse.(Int, line)
nodes = Vector{Node{3,Float64}}(undef, numNodes)
visited = falses(numNodes)
for nnodeentity in 1:numEntityBlocks
line = split(popfirst!(lines))
tagEntity, dimEntity, parametric, numNodes = parse.(Int, line)
if version == v"4.1"
tag_chunk = Int[]
node_chunk = Node{3,Float64}[]
for node in 1:numNodes
line = split(popfirst!(lines))
tag = parse(Int, line[1])
push!(tag_chunk, tag)
end
for node in 1:numNodes
line = split(popfirst!(lines))
x = parse(Float64, line[1])
y = parse(Float64, line[2])
z = parse(Float64, line[3])
push!(node_chunk, Node{3,Float64}(Vec{3,Float64}((x, y, z))))
end
nodes[tag_chunk] .= node_chunk
visited[tag_chunk] .= true
elseif version == v"4.0"
for node in 1:numNodes
line = split(popfirst!(lines))
tag = parse(Int, line[1])
x = parse(Float64, line[2])
y = parse(Float64, line[3])
z = parse(Float64, line[4])
nodes[tag] = Node{3,Float64}(Vec{3,Float64}((x, y, z)))
visited[tag] = true
end
end
end
@assert all(visited)
return nodes
end
function parseelements(str)
m = match(r"\$Elements(.*)\$EndElements"s, str)
lines = split(strip(m.captures[1]), '\n')
line = split(popfirst!(lines))
numEntityBlocks, numElements = parse.(Int, line)
elements = Tetrahedron[]
for nnodeentity in 1:numEntityBlocks
line = split(popfirst!(lines))
tagEntity, dimEntity, typeEle, numElements = parse.(Int, line)
for element in 1:numElements
line = split(popfirst!(lines))
typeEle === 4 || continue # TODO
tag = parse(Int, line[1])
n1 = parse(Int, line[2])
n2 = parse(Int, line[3])
n3 = parse(Int, line[4])
n4 = parse(Int, line[5])
push!(elements, Tetrahedron((n1, n2, n3, n4)))
end
end
return elements
end
function gmshparser(file)
str = read(file, String)
# Version
m = match(r"\$MeshFormat(.*)\$EndMeshFormat"s, str)
version = VersionNumber(first(split(strip(m.captures[1]))))
# Nodes
nodes = parsenodes(str, version=version)
# Elements
elements = parseelements(str)
return Grid(elements, nodes)
end
end
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