cython._binary_reader: cells_with_*_nodes: Generalize and simplify by…

… directly using `offset` for next cell offset; close: `_file_out` does not exist; correct pyvista version check for version 0.32.dev0 (#74)

* Result._plot_point_scalars: Use argument return_cpos in any case

... before, it was used only, when `if animate`. Now, it used in any case of the call `plotter.show`.

* Result._plot_point_scalars: fix screenshot function on Windows OS

pyvista\plotting\plotting.py:4882: On Windows OS "in the event that the user hits
the exit-button on the GUI then it must be finalized and deleted as accessing it
will kill the kernel... proper screenshots cannot be saved if this happens"
Therefore, when you used ´_plot_point_scalars(..., screenshot=...)´, you got at
ansys\mapdl\reader\rst.py:2830:
´RuntimeError: This plotter is closed and unable to save a screenshot.´

The only solution is, to pass the ´screenshot´ argument to ´plotter.show´
as done in this patch.

* Result._plot_point_scalars: future-safe pyvista version check

... the old version would break with version 1.0.0.
I used the same compare operation as in
<https://github.com/rbarrois/python-semanticversion/blob/master/semantic_version/base.py>
tested manually.

* cython._binary_reader.cells_with_*_nodes: Generalize and simplify by directly using `offset` for next cell offset

- Therefore the function `cell_lookup`, which was limited to 3D cells, is no longer necessary.
- Now, all cell types are supported, while the functions has even been simplified.
- Now, the functions do not need the parameter `celltypes` any more. Since they are only used in rst.py in the private method `Result._extract_node_components`, I took the liberty to remove the parameter A in the respective definition und the respective call.

Remark: Only tested with a pure python version of the functions, please test the cython function of the commit!

* cython._binary_reader.cells_with_*_nodes: correct expression for `ncells`

* _binary.reader: _file_out does not exist

When you called `AnsysFile.close()` you got at line 255

   'ansys.mapdl.reader._binary_reader.AnsysFile' object has no attribute '_file_out'

as `_file_out` is never created (this line is the only occurrence).

* Result._plot_point_scalars: correct pyvista version check for version 0.32.dev0

The actual development version is 0.32.dev0: `pv._version.version_info = (0, 32, "dev0")`. There, the string `"dev0"` can not be compared with `0`, so that comparison failed for this version. To solve this, I removed the last element on the right-hand side expression of the comparison. The new comparison `(0, 32, "dev0") > (0, 32)` works now as expected. Tested manually.

ansys/mapdl/reader/cython/_binary_reader.pyx

@@ -252,7 +252,6 @@ cdef class AnsysFile:
     def close(self):
         """Close the file"""
         del self._file
-        del self._file_out
 
     def read_element_data(self, int64_t [::1] ele_ind_table, int table_index,
                           int64_t ptr_off):
@@ -1638,61 +1637,45 @@ def affline_transform(float_or_double [:, ::1] points, float_or_double [:, ::1]
         points[i, 2] = t20*x + t21*y + t22*z + t23
 
 
-cdef inline int cell_lookup(uint8 celltype) nogil:
-    if celltype == VTK_HEXAHEDRON or celltype == VTK_QUADRATIC_HEXAHEDRON:
-        return 8
-    elif celltype == VTK_TETRA or celltype == VTK_QUADRATIC_TETRA:
-        return 4
-    elif celltype == VTK_PYRAMID or celltype == VTK_QUADRATIC_PYRAMID:
-        return 5
-    elif celltype == VTK_WEDGE or celltype == VTK_QUADRATIC_WEDGE:
-        return 6
-
-
 def cells_with_all_nodes(index_type [::1] offset, index_type [::1] cells,
-                         uint8 [::1] celltypes, uint8 [::1] point_mask):
+                         uint8 [::1] point_mask):
     """
     Updates mask of cells containing all points in the point indices
     or mask.
     """
-    cdef int ncells = celltypes.size
-    cdef uint8 celltype
-    cdef int ncell_points, i, j
-    cdef index_type cell_offset
+    cdef int ncells = offset.size - 1
+    cdef int i, j
+    cdef index_type cell_offset, next_cell_offset
     cdef uint8 [::1] cell_mask = np.ones(ncells, np.uint8)
 
     with nogil:
         for i in range(ncells):
-            celltype = celltypes[i]
-            ncell_points = cell_lookup(celltype)
             cell_offset = offset[i] + 1
-            for j in range(cell_offset, cell_offset + ncell_points):
+            next_cell_offset = offset[i+1] + 1
+            for j in range(cell_offset, next_cell_offset):
                 if point_mask[cells[j]] != 1:
                     cell_mask[i] = 0
 
     return np.asarray(cell_mask, dtype=np.bool)
 
 
 def cells_with_any_nodes(index_type [::1] offset, index_type [::1] cells,
-                         uint8 [::1] celltypes, uint8 [::1] point_mask):
+                         uint8 [::1] point_mask):
     """
     Updates mask of cells containing at least one point in the point
     indices or mask.
     """
-    cdef int ncells = celltypes.size
-    cdef uint8 celltype
-    cdef int ncell_points
-    cdef index_type cell_offset
+    cdef int ncells = offset.size - 1
+    cdef index_type cell_offset, next_cell_offset
     cdef int i, j
 
     cdef uint8 [::1] cell_mask = np.zeros(ncells, np.uint8)
 
     with nogil:
         for i in range(ncells):
-            celltype = celltypes[i]
-            ncell_points = cell_lookup(celltype)
             cell_offset = offset[i] + 1
-            for j in range(cell_offset, cell_offset + ncell_points):
+            next_cell_offset = offset[i+1] + 1
+            for j in range(cell_offset, next_cell_offset):
                 if point_mask[cells[j]] == 1:
                     cell_mask[i] = 1
                     break

ansys/mapdl/reader/rst.py

@@ -723,10 +723,10 @@ def _extract_node_components(self, node_components,
         # need to extract the mesh
         cells, offset = vtk_cell_info(grid)
         if sel_type_all:
-            cell_mask = cells_with_all_nodes(offset, cells, grid.celltypes,
+            cell_mask = cells_with_all_nodes(offset, cells,
                                              mask.view(np.uint8))
         else:
-            cell_mask = cells_with_any_nodes(offset, cells, grid.celltypes,
+            cell_mask = cells_with_any_nodes(offset, cells,
                                              mask.view(np.uint8))
 
         if not cell_mask.any():
@@ -2754,7 +2754,7 @@ def _plot_point_scalars(self, scalars, rnum=None, grid=None,
 
         # camera position added in 0.32.0
         show_kwargs = {}
-        if pv._version.version_info >= (0, 32, 0):
+        if pv._version.version_info >= (0, 32):
             show_kwargs['return_cpos'] = return_cpos
 
         if animate: