From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Thu, 20 Oct 2016 22:53:56 +0000 (-0500)
Subject: Fix GridIn::read_vtk().
X-Git-Tag: v8.5.0-rc1~552^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=05ad2b9a9c7fe9e63bcf2c23757e42fe37c3f01a;p=dealii.git

Fix GridIn::read_vtk().

The function reads a section of VTK files of the form

CELL_DATA 4
SCALARS MaterialID double 1
LOOKUP_TABLE default
1.000000
2.000000
3.000000
4.000000

but internally (despite the fact that the field is declared
as 'double' above) reads them as integers. This leads to
wrong results if they are given as floating point numbers,
as in the case above.

While there also add an assertion an clean things up
slightly.
---

diff --git a/source/grid/grid_in.cc b/source/grid/grid_in.cc
index 97de9881dd..b101d32742 100644
--- a/source/grid/grid_in.cc
+++ b/source/grid/grid_in.cc
@@ -307,8 +307,27 @@ void GridIn<dim, spacedim>::read_vtk(std::istream &in)
 
       if (keyword == "CELL_DATA")
         {
-          int no_ids;
-          in>>no_ids;
+          unsigned int no_ids;
+          in >> no_ids;
+
+          AssertThrow (no_ids == no_cells + (dim == 3 ?
+                                             no_quads :
+                                             (dim == 2 ?
+                                              no_lines
+                                              :
+                                              0)),
+                       ExcMessage ("The VTK reader found a CELL_DATA statement "
+                                   "that lists a total of "
+                                   + Utilities::int_to_string (no_ids) +
+                                   " cell data objects, but this needs to "
+                                   "equal the number of cells (which is "
+                                   + Utilities::int_to_string (no_cells) +
+                                   ") plus the number of quads ("
+                                   + Utilities::int_to_string (no_quads) +
+                                   " in 3d or the number of lines ("
+                                   + Utilities::int_to_string (no_lines) +
+                                   ") in 2d."));
+
 
           std::string linenew;
           std::string textnew[2];
@@ -331,7 +350,7 @@ void GridIn<dim, spacedim>::read_vtk(std::istream &in)
 
           for (unsigned int i = 0; i < no_cells; i++) //assigning IDs to cells.
             {
-              int id;
+              double id;
               in>>id;
               cells[cell_indices[i]].material_id = id;
             }
@@ -340,8 +359,8 @@ void GridIn<dim, spacedim>::read_vtk(std::istream &in)
             {
               for (unsigned int i = 0; i < no_quads; i++) //assigning IDs to bounds.
                 {
-                  int id;
-                  in>>id;
+                  double id;
+                  in >> id;
                   subcelldata.boundary_quads[quad_indices[i]].material_id = id;
                 }
             }
@@ -349,8 +368,8 @@ void GridIn<dim, spacedim>::read_vtk(std::istream &in)
             {
               for (unsigned int i = 0; i < no_lines; i++) //assigning IDs to bounds.
                 {
-                  int id;
-                  in>>id;
+                  double id;
+                  in >> id;
                   subcelldata.boundary_lines[line_indices[i]].material_id = id;
                 }
             }
diff --git a/tests/grid/grid_in_vtk_3d_03.output b/tests/grid/grid_in_vtk_3d_03.output
index 2293dc9500..80c3135d2d 100644
--- a/tests/grid/grid_in_vtk_3d_03.output
+++ b/tests/grid/grid_in_vtk_3d_03.output
@@ -24,75 +24,75 @@ DEAL::	20	4
 0.0 10. 10. 0 1
 0.0 10. 0.0 0 1
 
-10. 0.0 10. 0 0
-20. 0.0 10. 0 0
-20. 10. 10. 0 0
-10. 10. 10. 0 0
-10. 0.0 10. 0 0
+10. 0.0 10. 0 2
+20. 0.0 10. 0 2
+20. 10. 10. 0 2
+10. 10. 10. 0 2
+10. 0.0 10. 0 2
 
-10. 0.0 0.0 0 0
-20. 0.0 0.0 0 0
-20. 10. 0.0 0 0
-10. 10. 0.0 0 0
-10. 0.0 0.0 0 0
+10. 0.0 0.0 0 2
+20. 0.0 0.0 0 2
+20. 10. 0.0 0 2
+10. 10. 0.0 0 2
+10. 0.0 0.0 0 2
 
-10. 0.0 10. 0 0
-10. 0.0 0.0 0 0
+10. 0.0 10. 0 2
+10. 0.0 0.0 0 2
 
-20. 0.0 10. 0 0
-20. 0.0 0.0 0 0
+20. 0.0 10. 0 2
+20. 0.0 0.0 0 2
 
-20. 10. 10. 0 0
-20. 10. 0.0 0 0
+20. 10. 10. 0 2
+20. 10. 0.0 0 2
 
-10. 10. 10. 0 0
-10. 10. 0.0 0 0
+10. 10. 10. 0 2
+10. 10. 0.0 0 2
 
-10. 10. 10. 0 0
-20. 10. 10. 0 0
-20. 20. 10. 0 0
-10. 20. 10. 0 0
-10. 10. 10. 0 0
+10. 10. 10. 0 3
+20. 10. 10. 0 3
+20. 20. 10. 0 3
+10. 20. 10. 0 3
+10. 10. 10. 0 3
 
-10. 10. 0.0 0 0
-20. 10. 0.0 0 0
-20. 20. 0.0 0 0
-10. 20. 0.0 0 0
-10. 10. 0.0 0 0
+10. 10. 0.0 0 3
+20. 10. 0.0 0 3
+20. 20. 0.0 0 3
+10. 20. 0.0 0 3
+10. 10. 0.0 0 3
 
-10. 10. 10. 0 0
-10. 10. 0.0 0 0
+10. 10. 10. 0 3
+10. 10. 0.0 0 3
 
-20. 10. 10. 0 0
-20. 10. 0.0 0 0
+20. 10. 10. 0 3
+20. 10. 0.0 0 3
 
-20. 20. 10. 0 0
-20. 20. 0.0 0 0
+20. 20. 10. 0 3
+20. 20. 0.0 0 3
 
-10. 20. 10. 0 0
-10. 20. 0.0 0 0
+10. 20. 10. 0 3
+10. 20. 0.0 0 3
 
-20. 10. 10. 0 0
-30. 10. 10. 0 0
-30. 20. 10. 0 0
-20. 20. 10. 0 0
-20. 10. 10. 0 0
+20. 10. 10. 0 4
+30. 10. 10. 0 4
+30. 20. 10. 0 4
+20. 20. 10. 0 4
+20. 10. 10. 0 4
 
-20. 10. 0.0 0 0
-30. 10. 0.0 0 0
-30. 20. 0.0 0 0
-20. 20. 0.0 0 0
-20. 10. 0.0 0 0
+20. 10. 0.0 0 4
+30. 10. 0.0 0 4
+30. 20. 0.0 0 4
+20. 20. 0.0 0 4
+20. 10. 0.0 0 4
 
-20. 10. 10. 0 0
-20. 10. 0.0 0 0
+20. 10. 10. 0 4
+20. 10. 0.0 0 4
 
-30. 10. 10. 0 0
-30. 10. 0.0 0 0
+30. 10. 10. 0 4
+30. 10. 0.0 0 4
 
-30. 20. 10. 0 0
-30. 20. 0.0 0 0
+30. 20. 10. 0 4
+30. 20. 0.0 0 4
 
-20. 20. 10. 0 0
-20. 20. 0.0 0 0
+20. 20. 10. 0 4
+20. 20. 0.0 0 4