[vtk-developers] MTime topic

[Bill Lorensen]

Folks,

I'd like to refine/resolve this topic:
https://gitlab.kitware.com/vtk/vtk/merge_requests/1790

The key changes are to:
Common/Core/vtkType.h and Common/Core/vtkTimeStamp.cxx

Please review and provide feedback.

ENH: Introduce vtkMTimeType

Windows applications that run for a long time report that rendered
objects do not change. This is because the modified time on a Windows
system is 32 bits. This causes overflows that defeat the modified time
mechanism. This patch defines a new type, vtkMTimeType that is 64
unsigned integer regardless of the architecture.

A mechanism to provide backward compatibility is introduced. The
preprocessor define "VTK_HAS_MTIME_TYPE" can be used in applications
that must build against VTK versions that use the "unsigned long" type
for MTime's.

Methodology used to find MTime occurences: 1) Identify files as
follows: git grep "unsigned long" | grep ime | cut -d":" -f1,1 | sort
| uniq 2) Hand edit each of those files replacing "unsigned long" with
"vtkMTimeType" where appropriate. 3) Temporarily change typedef for
vtkMTimeType to "double" to detect missing conversions


Thanks,

Bill