First example to actually use smesh

.github/workflows/Documenter.yml

@@ -27,6 +27,24 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
+      # BEGIN - Build smesh locally - remove once JLL package is available
+      - name: Get smesh
+        uses: actions/checkout@v4
+        with:
+          repository: trixi-framework/smesh
+          path: smesh
+      - name: Build smesh (Linux)
+        run: |
+          mkdir smesh/build && cd smesh/build
+          cmake .. -DCMAKE_INSTALL_PREFIX=../install
+          cmake --build .
+          cmake --install .
+          cd ../../docs
+          cat << EOF > LocalPreferences.toml
+          [Smesh]
+          libsmesh = "$(pwd)/smesh/install/lib/libsmesh.so"
+          EOF
+      # END - Build smesh locally - remove once JLL package is available
       - uses: julia-actions/setup-julia@v1
         with:
           version: '1'

.github/workflows/ci.yml

@@ -49,6 +49,55 @@ jobs:
           - windows-latest
     steps:
       - uses: actions/checkout@v4
+      # BEGIN - Build smesh locally - remove once JLL package is available
+      - uses: msys2/setup-msys2@v2
+        if: ${{ matrix.os == 'windows-latest' }}
+        with:
+          update: true
+          install: git base-devel mingw-w64-x86_64-toolchain mingw-w64-x86_64-cmake
+      - name: Get smesh
+        uses: actions/checkout@v4
+        with:
+          repository: trixi-framework/smesh
+          path: smesh
+      - name: Build smesh (Linux)
+        if: ${{ matrix.os == 'ubuntu-latest' }}
+        run: |
+          mkdir smesh/build && cd smesh/build
+          cmake .. -DCMAKE_INSTALL_PREFIX=../install
+          cmake --build .
+          cmake --install .
+          cd ../..
+          cat << EOF > LocalPreferences.toml
+          [Smesh]
+          libsmesh = "$(pwd)/smesh/install/lib/libsmesh.so"
+          EOF
+      - name: Build smesh (macOS)
+        if: ${{ matrix.os == 'macos-latest' }}
+        run: |
+          mkdir smesh/build && cd smesh/build
+          FC=gfortran-13 cmake .. -DCMAKE_INSTALL_PREFIX=../install
+          cmake --build .
+          cmake --install .
+          cd ../..
+          cat << EOF > LocalPreferences.toml
+          [Smesh]
+          libsmesh = "$(pwd)/smesh/install/lib/libsmesh.dylib"
+          EOF
+      - name: Build smesh
+        if: ${{ matrix.os == 'windows-latest' }}
+        run: |
+          mkdir smesh/build && cd smesh/build
+          FC=gfortran cmake .. -DCMAKE_INSTALL_PREFIX=../install
+          cmake --build .
+          cmake --install .
+          cd ../..
+          cat << EOF > LocalPreferences.toml
+          [Smesh]
+          libsmesh = "D:\\\\a\\\\Smesh.jl\\\\Smesh.jl\\\\smesh\\\\install\\\\bin\\\\libsmesh.dll"
+          EOF
+        shell: 'msys2 {0}'
+      # END - Build smesh locally - remove once JLL package is available
       - uses: julia-actions/setup-julia@v1
         with:
           version: ${{ matrix.version }}

.gitignore

@@ -1,2 +1,3 @@
 Manifest.toml
+LocalPreferences.toml
 run/

README.md

@@ -12,6 +12,68 @@ a simple Fortran package for generating and handling unstructured triangular and
 meshes.
 
 
+## Getting started
+### Prerequisites
+If you have not yet installed Julia, please [follow the instructions for your
+operating system](https://julialang.org/downloads/platform/).
+[Smesh.jl](https://github.com/trixi-framewor/Smesh.jl) works with Julia v1.8
+and later on Linux, macOS and Windows platforms.
+
+To use Smesh.jl, you currently need to manually install the underlying Fortran package smesh
+(note that this is subject to change in the near future). For installation instructions,
+please follow the README in the [smesh](https://github.com/trixi-framework/smesh)
+repository.
+
+### Installation
+Since Smesh.jl is a not registered Julia package yet, you can install it by executing
+the following commands in the Julia REPL:
+```julia
+julia> import Pkg; Pkg.add("https://github.com/trixi-framework/Smesh.jl")
+```
+
+To make use of the local smesh build, you need to tell Smesh.jl where to find the library.
+For this, create a `LocalPreferences.toml` file next to your `Project.toml` for the project
+in which you use Smesh.jl. It should have the following content:
+
+* On Linux:
+  ```toml
+  [Smesh]
+  libsmesh = "<smesh-install-prefix>/lib/libsmesh.so"
+  ```
+* On macOS:
+  ```toml
+  [Smesh]
+  libsmesh = "<smesh-install-prefix>/lib/libsmesh.dylib"
+  ```
+* On Windows:
+  ```toml
+  [Smesh]
+  libsmesh = "<smesh-install-prefix>/bin/libsmesh.dll"
+  ```
+
+Where `<smesh-install-prefix>` is where you have installed the local smesh build.
+
+### Usage
+The easiest way to get started is to run one of the examples from the
+[`examples`](https://github.com/trixi-framework/Smesh.jl/tree/main/examples) directory by
+`include`ing them in Julia, e.g.,
+```
+julia> using Smesh
+
+julia> include(joinpath(pkgdir(Smesh), "examples", "build_delaunay_triangulation.jl"))
+Computing Delaunay triangulation.
+Triangulation elements:          2
+Total flipped edges:             0
+Average search time:          1.25
+Flips/triangle:               0.00
+Flips/node:                   0.00
+3×2 Matrix{Int64}:
+ 3  1
+ 1  3
+ 2  4
+ ```
+
+
 ## Authors
 Smesh.jl was initiated by
 [Simone Chiocchetti](https://www.mi.uni-koeln.de/NumSim/dr-simone-chiocchetti/)

examples/build_delaunay_triangulation.jl

@@ -0,0 +1,12 @@
+using Smesh
+
+# Create data points
+# Note: the transpose + collect is just such that we can write the matrix in human readable
+# form here
+data_points = collect([0.0 0.0
+                       1.0 0.0
+                       1.0 1.0
+                       0.0 1.0]')
+
+# Create triangulation
+ve = build_delaunay_triangulation(data_points; verbose = true)

src/Smesh.jl

@@ -1,10 +1,49 @@
 module Smesh
 
-"""
-    greet()
+using Preferences: @load_preference, @has_preference 
+
+export build_delaunay_triangulation
+
+if !@has_preference("libsmesh")
+    error("""
+          Missing preference `libsmesh` for package Smesh.jl. Please add a
+          `LocalPreferences.toml` file to your current Julia project with the following
+          content, where `path/to/libsmesh.{ext}` is the path to your local build of
+          libsmesh and `{ext}` is the appropriate extension for shared libraries on your
+          system (e.g., `so` on Linux, `dylib` on macOS, `dll` on Windows). Afterwards,
+          you need to restart Julia.
+
+          Content of `LocalPreferences.toml` (between the '```' marks):
+
+          ```
+          [Smesh]
+          libsmesh = "path/to/libsmesh.{ext}"
+          ```
+          """)
+end
+const libsmesh = @load_preference("libsmesh")
 
-Say hello to the world.
+
+"""
 """
-greet() = print("Hello World!")
+function build_delaunay_triangulation(data_points; shuffle = false, verbose = false)
+    # Pre-allocate output array
+    npoints = size(data_points, 2)
+    ve_max = @ccall libsmesh.delaunay_triangulation_temparray_size_c(npoints::Cint)::Cint
+    ve_internal = Matrix{Cint}(undef, 3, ve_max)
+
+    # Perform triangulation
+    ntriangles = @ccall libsmesh.build_delaunay_triangulation_c(ve_internal::Ref{Cint},
+                                                                data_points::Ref{Float64},
+                                                                npoints::Cint,
+                                                                ve_max::Cint,
+                                                                shuffle::Cint,
+                                                                verbose::Cint)::Cint
+
+    # Copy to array of appropriate size and convert to Julia `Int`s for convenience
+    ve_out = convert(Matrix{Int}, ve_internal[:, 1:ntriangles])
+
+    return ve_out
+end
 
 end # module Smesh

test/test_examples.jl

@@ -5,8 +5,8 @@ using Smesh
 
 @testset verbose=true showtiming=true "test_examples.jl" begin
 
-@testset verbose=true showtiming=true "examples/dummy.jl" begin
-    @test_nowarn include("../examples/dummy.jl")
+@testset verbose=true showtiming=true "examples/build_delaunay_triangulation.jl" begin
+    @test_nowarn include("../examples/build_delaunay_triangulation.jl")
 end
 
 end # @testset "test_examples.jl"

test/test_unit.jl

@@ -5,8 +5,13 @@ using Smesh
 
 @testset verbose=true showtiming=true "test_unit.jl" begin
 
-@testset verbose=true showtiming=true "greet" begin
-    @test_nowarn Smesh.greet()
+@testset verbose=true showtiming=true "build_delaunay_triangulation" begin
+    data_points = collect([0.0 0.0
+                           1.0 0.0
+                           1.0 1.0
+                           0.0 1.0]')
+
+    @test build_delaunay_triangulation(data_points) == [3 1; 1 3; 2 4]
 end
 
 end # @testset "test_unit.jl"