These cell types are inherited from VTK, but they are basically the same
as quad and hexahedron, respectively. The only useful difference is that
pixel and voxel are supposed to be axis aligned, but you cannot
determine that by the cell shape alone (at least not just from the cell
set).
A big issue with these is that their indexing is different that of quad
and hex. The development team had a long discussion about the benefits
of the alternate indexing, but after consulting with Berk Geveci and
Will Schroder from the VTK team, that indexing is not really taken
advantage of at the cell level. Thus, it is really just a nuisance in
VTK-m.
When getting cell indices in a cell to point structured connectivity, it
was previously returning a vtkm::Vec of the maximum size and setting
invalid indices to -1. This is changed to vtkm::VecVariable, which will
reflect the actual number of indices.
I thought I made this change a while ago, but I guess I missed it.
We have been using the term "shape" in the cell set and connectivity
classes. To be consistent, use the term "shape" for the geometric
identify of the cell everywhere.
templating topology worklet to support mappings other than point-to-cell
This adds a FromTopology and ToTopology template type to the topology worklet, removing hard-coded types.
This is a precursor step necessary before we can add other mappings (like cell-to-point, etc.).
See merge request !140
The idea of the PointCoordinate classes was to make it easier to define
new special types of point coordinate arrays. But ultimately you have to
create an array handle type, and the CoordinateSystem class pretty much
handles everything else for you. Thus, these classes where being used
nowhere.
The point of making CoordinateSystem a special type of Field object
was so that it could handle special array types like implicit regular
point coordinates. Overload the GetData and GetBounds methods to
properly handle this type of array.
Originally, DynamicArrayHandle only automatically handled the default
type and storage lists. There was an internal subclass that expanded
that to user defined lists, but it was a bit inaccessible. This change
makes DynamicArrayHandle match the structure of DynamicCellSet. There is
now a templated base class named DynamicArrayHandleBase that can accept
any pair of lists. DynamicArrayHandle itself is really just a typedef of
DynamicArrayHandleBase with the default lists.
Previously, coordinate systems in a DataSet simply pointed to field data
specifying the coordinate information (although the ability to get that
back out of the DataSet was missing). This makes sense since point
coordinates are in fact just fields with a particular semantic meaning
to them.
However, there is an issue with this approach. It turns out that there
are special representations that are very common for point coordinates
and very uncommon for other types of fields. For example, a uniform
(a.k.a. regular or image) grid has point coordinates that are easily
derived from the point index, but such fields are quite uncommon
elsewhere.
Representing this kind of structure in the Field list of a DataSet is
problematic. Either all fields have to check to see if they are this
type, which will cause an explosion of unnecessary generated code, or
you will have to actually write out the coordinates in memory, which is
really wasteful but what was done previously.
However, by storing fields representing coordinate systems in a separate
batch, we can use these special types without the stated explosion.
Move ArrayPortalUniformPointCoordinates to the vtkm::internal namespace
since it is going to be actively used in both control and execution
environments.
Replace usage of extent with simple dimensions. We have decided that
there is not a lot of value in supporting extent in VTK-m.
Variable topology fields
Changes to fetching in topology maps that lets you properly deal with cases where you do not know how many values are being fetched at compile time. For example, explicit cell sets can have any number of cell shapes that have different numbers of nodes.
This change should resolve issue #26.
See merge request !128
Workaround thrust 1.8 inclusive scan issue.
Starting in thrust 1.8 the implementation of scan inclusive inside
thrust became highly optimized by using parallel task groups. This
new implementation has a bug that only exists when using custom
binary operators, large size arrays, release mode, and no
debugger or mem-checker attached.
While I have submitted the issue to thrust, we need to be able
to work around the existing issue. The solution I have chosen is
to mark all vtkm::exec::cuda::interal::WrappedBinaryOperators
as being commutative as far as thrust is concerened. To make
sure we don't get any unexpected behavior I have also had
to create WrappedBinaryPredicate so that we don't mark any
predicate as commutative.
See merge request !129
Starting in thrust 1.8 the implementation of scan inclusive inside
thrust became highly optimized by using parallel task groups. This
new implementation has a bug that only exists when using custom
binary operators, large size arrays, release mode, and no
debugger or mem-checker attached.
While I have submitted the issue to thrust, we need to be able
to work around the existing issue. The solution I have chosen is
to mark all vtkm::exec::cuda::interal::WrappedBinaryOperators
as being commutative as far as thrust is concerened. To make
sure we don't get any unexpected behavior I have also had
to create WrappedBinaryPredicate so that we don't mark any
predicate as commutative.
My version of the PGI compiler was having problems with using
IteratorFromArrayPortal with STL algorithms. I traced the problem to
iterator_facade checking to see if the reference type we gave it was
a real reference (e.g. T&). It is not, iterator_facade downgraded the
iterator trait to a simple input iterator tag even though I declared
it with a random access traversal. I don't know what the reference type
has to do with random access, but in any case the value object is
designed to behave like a reference in that when you assign to it
the value gets propagated to the array. To tell boost this is the case,
I made a specialization of boost::is_reference that declares the
value type as a reference.
I'm not sure why it failed for me but not elsewhere. It might be that
this version of the PGI compiler is using "old-style" iterator traits
whereas other were using newer style that matches better the boost
iterator traits that iterator_facade is actually using.
BOOST_MPL_ASSERT is causing warnings in the PGI compiler. Apparently,
when BOOST_MPL_ASSERT succeeds it declares a static object with a unqiue
name scoped to the file. The problem is that the PGI compiler is pretty
picky about things being declared without being used, so it was emitting
useless warnings about successful BOOST_MPL_ASSERTs. However,
BOOST_STATIC_ASSERT does not seem to have this problem, so for the benefit
of PGI change the compile-time assert method.
We want to be able to get topological connections where it is difficult
to know how many values you get each time. In this change, the type of
the vector holding the from indices is determined from the connectivity
object, and the worklet does not know the type (it must be templated).
Although you do not need to specify the max number for this value set
(you still currently do for field values), we still need to change the
type for explicit sets that uses something that does not rely on the Vec
class. The cell-to-point method also needs a Vec wrapper that allows it
to shorten the vector dynamically.
Previously, all arrays passed to worklets were designated as either
input or output. No in-place operation was permitted. This change adds
the FieldInOut tag for ControlSignature in both WorkletMapField and
WorkletMapTopology that allows you to read and write from the same
array.
Clean up CellSet
Underneath the CellSet implementation is a set of supporting classes that manage the actual structure in both the control and execution environments. However, the implementation of these classes was a bit confusing and inconsistent. The following changes are made:
* Most significantly, there is no longer any Connectivity classes in the control environment. This functionality has been wrapped up into the CellSet classes, which is more consistent and easier to understand. (There was a definite distinction between CellSet and Connectivity, but it was subtle and difficult to understand.) This also means that edits to CellSets happen to CellSets directly.
* The set of classes for structured and explicit cell sets match. There is different functionality within, but the class naming and meaning are consistent.
* Make the class names more consistent with the rest of VTK-m class names. Specifically classes like ExplicitConnectivity become ConnectivityExplicit. Also, the words regular and structured were being used interchangeably. Now, always use structured except when dealing specifically with grids of regular spacing.
* The connectivity classes were using the nomenclature "From" and "To" to specify topological elements of links. The same concept in worklet classes were using the nomenclature "Src" and "Dest." For consistency, all references are changed to "From" and "To".
* Unlike explicit cell sets, structured cell sets have functionality shared between control and execution environments. Rather than duplicate it or create unique exposed classes, have a shared internal implementation in vtkm::internal.
See merge request !117
The storage used will now be aligned to `VTKM_CACHE_LINE_SIZE bytes,
resulting in slightly better cache usage and load/store performance.
This define is set in `StorageBasic.h We also now detect if Posix is
available in Configure.h and will define VTKM_POSIX with _POSIX_VERSION
if it's available.
The AlignedAllocator used by StorageBasic is also STL compatible
and can be used in STL containers so user's can use it in their
std::vector and pass aligned user memory to the storage.
(Re-) Add a helper structure that holds the connectivity information for
a particular topology connection (e.g. from points to cells) to make it
easier to manage connections in multiple different directions in
CellSetExplicit.
Unlike the previous version of connectivity, this structure is
considered "internal" and not exposed through the API so that
CellSetExplicit can better manage the data. Also, many of the helper
methods remain in CellSetExplicit since they were specific for point-to-
Also, CellSetExplicit has a mechanism to take an arbitrary pair of
TopologyElementTags and get the appropriate connectivity. This should
simplify adding connections in the future.
Robert Maynard tells me that the TBB backend has been tried on versions
of TBB back to 4.0. Since the patch appears to work across them, allow
those versions too.
We have a patched version of TBB's parallel_for.h in our files that
fixes a problem with using std::swap. This issue has since been fixed in
TBB, so for newer versions we should revert back to TBB's
implementation.
Most of VTK-m follows the convention of calling the 0D topology elements
"points" (which follows the convention of VTK). However, there were
several places where they were referred to as "nodes." Make things
consistent by calling them points everywhere.
Also merged some redundant ExecutionSignature tags.
Previously there was a Connectivity* structure for both the control
environment and the execution environment. This was necessary before
because the connectivity is explicit to the from and to topology
elements, so you would get this structure from the appropriate call to
CellSet*. However, the symantics are changed so that the type of
connectivity is selected in the worklet's dispatcher. Thus, it is now
much cleaner to manage the CellSet structure in the CellSet class itself
and just have a single set of Connectivity* classes in the execution
environment.
Also moved from vtkm namespace to vtkm::internal namespace. This change
is to then move the structured connectivity classes to the cont and exec
namespaces.
Previously, the items used to identify parts of topology like points,
cells, faces, etc. were in an enumeration. However, they are only really
used in template specialization, and it is easier to use tags in this
case. So, change the enumeration to a set of tag structures. Also made
the following changes:
* Renamed TopologyType to TopologyElement, which is more indicative of
what we are referring to.
* Moved the structures from the vtkm::cont namespace to the vtkm
namespace. There is no reason not to be able to use them from either the
control or execution environments.
* Added a VTKM_IS_TOPOLOGY_ELEMENT_TAG macro to do type checks on
template arguments that are supposed to be topology element tags.
GCC warnings
Attempt to fix any compiler warnings that appear on GCC dashboards.
I also was using a pretty picky compiler, so there is probably several fixes that have no impact on the current dashboard set.
See merge request !110
C and C++ has a funny feature where operations on small integers (char
and short) actually promote the result to a 32 bit integer. Most often
in our code the result is pushed back to the same type, and picky compilers
can then give a warning about an implicit type conversion (that we
inevitably don't care about). Here are a lot of changes to suppress
the warnings.