Fixed compile error related to example projects

[simbaforrest]

Related issues:

#1313

#1314

[taketwo]

Can you please explain the first fix (in "example_difference_of_normals.cpp")? Everything else looks good.

[simbaforrest]

Without the change, the line 206 and the line 114 will lead to unresolved external symbols since only core point types were instantiated in the pcl's dll.

[taketwo]

This is strange, I'll need to test this. But anyway, we should not manipulate PCL_NO_PRECOMPILE inside source files, this is something that is set by CMake when configuring the project.

[simbaforrest]

I guess then the other way is to add

#include <pcl/features/impl/normal_3d_omp.hpp>

below line 19

and add

#include <pcl/segmentation/impl/extract_clusters.hpp>

below line 22

since without this "PCL_NO_PRECOMPILE", this two hpp files will not be included and in the example project, the types

typedef pcl::PointNormal PointNT;
typedef pcl::PointNormal PointOutT;

will leave some functions of

pcl::NormalEstimationOMP<PointT, PointNT> ne;

and

pcl::EuclideanClusterExtraction<PointOutT> ec;

undefined.

[taketwo]

How about other example programs though? Shouldn't the same problem manifest in them as well?

[simbaforrest]

Other examples are built just fine. I guess they don't use any non-default point types.

BTW, just want to note that I built with the PCL_NO_PRECOMPILE off. So maybe this example project should add some compile time switch...

[taketwo]

Ok, I also get the error with PCL_NO_PRECOMPILE=OFF and PCL_ONLY_CORE_POINT_TYPES=ON.

I think the right way to solve this is to include the corresponding headers from impl/ as you suggested. However I would wrap them in #ifdef PCL_ONLY_CORE_POINT_TYPES.

[simbaforrest]

Sure, I'll update and submit another pull request then.

[taketwo]

You don't need to make another PR. Just rewrite your last commit locally and push with --force flag.

[taketwo]

Can you actually join both #ifdefs so we have cleaner code? And one last thing will be to squash the commits in this pull request so that we do not pollute the history.

git rebase -i HEAD~2

Mark the second commit as "fixup", save and exit. Once rebasing is done, git push --force, and this PR will be automatically updated. Thank you!

[simbaforrest]

This will be cleaned up code

#include <string>

#include <pcl/point_types.h>
#include <pcl/io/pcd_io.h>
#include <pcl/kdtree/kdtree_flann.h>
#include <pcl/common/point_operators.h>
#include <pcl/common/io.h>
#include <pcl/search/organized.h>
#include <pcl/search/octree.h>
#include <pcl/search/kdtree.h>
#include <pcl/features/normal_3d_omp.h>
#include <pcl/filters/conditional_removal.h>
#include <pcl/segmentation/sac_segmentation.h>
#include <pcl/segmentation/extract_clusters.h>
#include <pcl/io/vtk_io.h>
#include <pcl/filters/voxel_grid.h>

#include <pcl/features/don.h>

#ifdef PCL_ONLY_CORE_POINT_TYPES
#include <pcl/features/impl/normal_3d_omp.hpp>
#include <pcl/segmentation/impl/extract_clusters.hpp>
#endif

Sorry I'm not that familiar with git rebase, I tried "git rebase -i HEAD~2" but nothing seems to happen. Should I do this after this new commit or before?

[simbaforrest]

Got it, since with the interactive rebase, I have to setup my git to work with my notepad++ like this...

[taketwo]

Apparently working with terminal Git is a bit more complicated on Windows :D
Sorry again, but could you please squash these two commits into a single one? Then I'll merge.

[simbaforrest]

Now there should be only one commit :)

[taketwo]

Perfect! Thank you.