Implement a region calculus

.appveyor.yml

@@ -121,7 +121,7 @@ before_build:
 #  - cmd: if "%TARGET_ARCH%"=="x64" "C:\Program Files (x86)\Microsoft Visual Studio 15.9\VC\vcvarsall.bat" amd64
 
   # CMake configure
-  - cmd: cmake -G "%OPENPMD_CMAKE_GENERATOR%" -DCMAKE_BUILD_TYPE=%CONFIGURATION% -DBUILD_SHARED_LIBS=%SHARED% -DBUILD_TESTING=ON -DCMAKE_INSTALL_PREFIX="%CONDA_INSTALL_LOCN%" -DCMAKE_INSTALL_BINDIR="Library\bin" ".."
+  - cmd: cmake -G "%OPENPMD_CMAKE_GENERATOR%" -DopenPMD_USE_REGIONS=OFF -DCMAKE_BUILD_TYPE=%CONFIGURATION% -DBUILD_SHARED_LIBS=%SHARED% -DBUILD_TESTING=ON -DCMAKE_INSTALL_PREFIX="%CONDA_INSTALL_LOCN%" -DCMAKE_INSTALL_BINDIR="Library\bin" ".."
 
 build_script:
   - cmd: cmake --build . --config %CONFIGURATION%

.github/ci/spack-envs/gcc7_py36_ompi_h5_ad1_ad2/spack.yaml

@@ -0,0 +1,61 @@
+# This is a Spack environment file.
+#
+# Activating and installing this environment will provide all dependencies
+# that are needed for full-feature development.
+#   https//spack.readthedocs.io/en/latest/environments.html#anonymous-environments
+#
+spack:
+  specs:
+  - adios
+  - adios2
+  - hdf5
+  - openmpi
+
+  packages:
+    adios:
+      variants: ~zfp ~sz ~lz4 ~blosc
+    adios2:
+      variants: ~zfp ~sz ~png ~dataman ~python ~fortran ~ssc ~shared ~bzip2
+    cmake:
+      externals:
+      - spec: "cmake"
+        prefix: /usr
+      buildable: False
+    openmpi:
+      externals:
+      - spec: "openmpi"
+        prefix: /usr
+      buildable: False
+    perl:
+      externals:
+      - spec: "perl"
+        prefix: /usr
+      buildable: False
+    python:
+      externals:
+      - spec: "python"
+        prefix: /usr
+      buildable: False
+    all:
+      target: ['x86_64']
+      variants: ~fortran
+      compiler: [[email protected]]
+
+  compilers:
+  - compiler:
+      environment: {}
+      extra_rpaths: []
+      flags: {}
+      modules: []
+      operating_system: ubuntu18.04
+      paths:
+        cc: /usr/bin/gcc-7
+        cxx: /usr/bin/g++-7
+        f77: /usr/bin/gfortran
+        fc: /usr/bin/gfortran
+      spec: [email protected]
+      target: x86_64
+
+  config:
+    build_jobs: 2
+