Use correct field size for t8_vtk_data_field_t

Project.toml

@@ -1,7 +1,7 @@
 name = "T8code"
 uuid = "d0cc0030-9a40-4274-8435-baadcfd54fa1"
 authors = ["Johannes Markert <johannes.markert@dlr.de>"]
-version = "0.9.1"
+version = "0.9.2-DEV"
 
 [deps]
 CEnum = "fa961155-64e5-5f13-b03f-caf6b980ea82"

examples/t8_step5_element_data.jl

@@ -194,9 +194,10 @@ function t8_step5_output_data_to_vtu(forest, element_data, prefix)
 
     # WARNING: This code hangs for Julia v1.8.* or older. Use at least Julia v1.9.
     # For each user defined data field we need one t8_vtk_data_field_t variable.
-    vtk_data = t8_vtk_data_field_t(T8_VTK_SCALAR, # Set the type of this variable. Since we have one value per element, we pick T8_VTK_SCALAR.
-                                   NTuple{8192, Cchar}(rpad("Element volume\0", 8192, ' ')), # The name of the field as should be written to the file.
-                                   pointer(element_volumes))
+    # We set the type of this variable. Since we have one value per element, we pick
+    # T8_VTK_SCALAR.
+    # We also set the name of the field as should be written to the file.
+    vtk_data = [t8_vtk_data_field_t(T8_VTK_SCALAR, "Element volume", element_volumes)]
 
     # To write user defined data, we need to extended output function
     # t8_forest_vtk_write_file from t8_forest_vtk.h. Despite writin user data,
@@ -208,7 +209,7 @@ function t8_step5_output_data_to_vtu(forest, element_data, prefix)
     write_ghosts = 0
     t8_forest_write_vtk_ext(forest, prefix, write_treeid, write_mpirank,
                             write_level, write_element_id, write_ghosts,
-                            0, 0, num_data, Ref(vtk_data))
+                            0, 0, num_data, pointer(vtk_data))
 end
 
 # The prefix for our output files.
@@ -277,11 +278,9 @@ if t8_forest_get_num_ghosts(forest) > 0
 end
 
 # Output the volume data to vtu.
-if !(CI_ON_WINDOWS || CI_ON_MACOS)
-    t8_step5_output_data_to_vtu(forest, element_data, prefix_forest_with_data)
-    t8_global_productionf(" [step5] Wrote forest and volume data to %s*.\n",
-                          prefix_forest_with_data)
-end
+t8_step5_output_data_to_vtu(forest, element_data, prefix_forest_with_data)
+t8_global_productionf(" [step5] Wrote forest and volume data to %s*.\n",
+                      prefix_forest_with_data)
 
 #
 # Clean-up.

examples/t8_step6_stencil.jl

@@ -338,15 +338,9 @@ function t8_step6_output_data_to_vtu(forest, element_data, prefix)
 
     # WARNING: This code hangs for Julia v1.8.* or older. Use at least Julia v1.9.
     vtk_data = [
-        t8_vtk_data_field_t(T8_VTK_SCALAR,
-                            NTuple{8192, Cchar}(rpad("height\0", 8192, ' ')),
-                            pointer(heights)),
-        t8_vtk_data_field_t(T8_VTK_SCALAR,
-                            NTuple{8192, Cchar}(rpad("schlieren\0", 8192, ' ')),
-                            pointer(schlieren)),
-        t8_vtk_data_field_t(T8_VTK_SCALAR,
-                            NTuple{8192, Cchar}(rpad("curvature\0", 8192, ' ')),
-                            pointer(curvature))
+        t8_vtk_data_field_t(T8_VTK_SCALAR, "height", heights),
+        t8_vtk_data_field_t(T8_VTK_SCALAR, "schlieren", schlieren),
+        t8_vtk_data_field_t(T8_VTK_SCALAR, "curvature", curvature)
     ]
 
     # The number of user defined data fields to write.
@@ -402,10 +396,8 @@ t8_step6_exchange_ghost_data(forest, element_data)
 t8_step6_compute_stencil(forest, element_data)
 
 # Output the data to vtu files.
-if !(CI_ON_WINDOWS || CI_ON_MACOS)
-    t8_step6_output_data_to_vtu(forest, element_data, prefix_forest_with_data)
-    t8_global_productionf(" Wrote forest and data to %s*.\n", prefix_forest_with_data)
-end
+t8_step6_output_data_to_vtu(forest, element_data, prefix_forest_with_data)
+t8_global_productionf(" Wrote forest and data to %s*.\n", prefix_forest_with_data)
 
 #
 # Clean-up

src/Libt8.jl

@@ -12866,9 +12866,9 @@ A data field for VTK output. This struct is used to store data that is written t
 | type        | Describes of which type the data array is  |
 | description | String that describes the data.            |
 """
-struct t8_vtk_data_field_t
+struct t8_vtk_data_field_t{BUFSIZ}
     type::t8_vtk_data_type_t
-    description::NTuple{8192, Cchar}
+    description::NTuple{BUFSIZ, Cchar}
     data::Ptr{Cdouble}
 end
 
@@ -12880,8 +12880,8 @@ end
 int t8_forest_write_vtk_ext (t8_forest_t forest, const char *fileprefix, const int write_treeid, const int write_mpirank, const int write_level, const int write_element_id, const int write_ghosts, const int write_curved, int do_not_use_API, const int num_data, t8_vtk_data_field_t *data);
 ```
 """
-function t8_forest_write_vtk_ext(forest, fileprefix, write_treeid, write_mpirank, write_level, write_element_id, write_ghosts, write_curved, do_not_use_API, num_data, data)
-    @ccall libt8.t8_forest_write_vtk_ext(forest::t8_forest_t, fileprefix::Cstring, write_treeid::Cint, write_mpirank::Cint, write_level::Cint, write_element_id::Cint, write_ghosts::Cint, write_curved::Cint, do_not_use_API::Cint, num_data::Cint, data::Ptr{t8_vtk_data_field_t})::Cint
+function t8_forest_write_vtk_ext(forest, fileprefix, write_treeid, write_mpirank, write_level, write_element_id, write_ghosts, write_curved, do_not_use_API, num_data, data::Ptr{DataFieldType}) where DataFieldType
+    @ccall libt8.t8_forest_write_vtk_ext(forest::t8_forest_t, fileprefix::Cstring, write_treeid::Cint, write_mpirank::Cint, write_level::Cint, write_element_id::Cint, write_ghosts::Cint, write_curved::Cint, do_not_use_API::Cint, num_data::Cint, data::Ptr{DataFieldType})::Cint
 end
 
 """

src/T8code.jl

@@ -258,6 +258,26 @@ macro T8_ASSERT(q)
     :($(esc(q)) ? nothing : throw(AssertionError($(string(q)))))
 end
 
+# platform specific BUFSIZ used in t8_vtk_data_field_t
+# TODO: Just a guess!
+if Sys.isapple()
+    const T8_BUFSIZ = 1024
+elseif Sys.iswindows()
+    const T8_BUFSIZ = 512
+else
+    const T8_BUFSIZ = 8192
+end
+
+# convenience constructor
+# - adds 0 termination and padding to description string
+# - takes pointer of data
+function Libt8.t8_vtk_data_field_t(type, description::String, data)
+    return t8_vtk_data_field_t(type,
+                               NTuple{T8_BUFSIZ, Cchar}(rpad(description * "\0", T8_BUFSIZ,
+                                                             ' ')),
+                               pointer(data))
+end
+
 function t8_free(ptr)
     Libt8.sc_free(t8_get_package_id(), ptr)
 end

test/test_all.jl

@@ -12,11 +12,6 @@ MPI.Init()
 
 comm = MPI.COMM_WORLD
 
-# Check whether we run CI in the cloud with Windows or Mac, see also
-# https://docs.github.com/en/actions/learn-github-actions/environment-variables
-CI_ON_WINDOWS = (get(ENV, "GITHUB_ACTIONS", false) == "true") && Sys.iswindows()
-CI_ON_MACOS = (get(ENV, "GITHUB_ACTIONS", false) == "true") && Sys.isapple()
-
 @testset "init" begin
     include("test_init.jl")
 end

test/test_examples.jl

@@ -22,11 +22,8 @@ end
     include("../examples/t8_step4_partition_balance_ghost.jl")
 end
 
-# Unfortunately, step 5 and step 6 currently crash (1.) in Windows, (2.) in MacOS,
-# and (3.) with Julia older than 1.9, see related issues
-# https://github.com/DLR-AMR/T8code.jl/issues/26,
-# https://github.com/DLR-AMR/T8code.jl/issues/30,
-# https://github.com/DLR-AMR/T8code.jl/issues/104.
+# Step 5 and step 6 crash with Julia older than 1.9, see related issue
+# https://github.com/DLR-AMR/T8code.jl/issues/26
 
 @testset "t8_step5_element_data" begin
     include("../examples/t8_step5_element_data.jl")