fixes issue #7

[floriandeboissieu]

I had to touch to LASlib lasreadermerged, but it works.

[Jean-Romain]

Well I'm not comfortable with touching LASlib. Could you explain me why you need to touch LASlib. I don't know the exact role of the lines you commented but they look important. I can't believe LASlib is not able to read several 1.4 file natively.

Each time we touch LASlib we make the update more difficult and we are likely to add bugs.

Could you also send be some tiny files in 1.4. Actually I can't search on my side because I don't have this kind of file.

[floriandeboissieu]

A small comment to explain the changes. Two things were wrong for extra byte reading of merged LAS:

• header->number_attributes was 0 in lasreadermerged the opener was resetted extra byte attributes in the header. I did not managed to understand why, maybe because the coherence of extra bytes field between LAS files is not checked? Commenting those lines in lasreadermerged kept the attributes info of the first file header used for the following files.
• lasreader->point .attributer is empty (not initialized?) and thus in lasread->point.get_attribute_as_float() attributer->attribute_starts [index] is also empty. I did not managed to understand why. Thus I made the same trick as in las2txt, taking the attributes info from the header instead of the point.

I'll try to have more precisions from Martin Isenburg about the why it was implemented like this.

[floriandeboissieu]

I'm not confortable neither, every line of code had a reason until now, that is why I asked Martin Isenburg about it. Let see what he answers.

Unfortunately I don't have LAS 1.4 files neither, maybe ASPRS has that kind of file format samples. But if you are looking for extra byte files, there is one in the inst/extdata directory. The extra byte format is formalised in LAS 1.4 specs but it was used before (since LAS 1.1 by Riegl, see http://www.riegl.com/uploads/tx_pxpriegldownloads/Whitepaper_-_LAS_extrabytes_implementation_in_Riegl_software_01.pdf).

Cheers

Florian

On 23/11/2017 14:26, Jean-Romain Roussel wrote:

Well I'm not comfortable with touching LASlib. Could you explain me why you need to touch LASlib. I don't know the exact role of the lines you commented but they look important. I can't believe LASlib is not able to read several 1.4 file natively.

Each time we touch LASlib we make the update more difficult and we are likely to add bugs.

Could you also send be some tiny files in 1.4. Actually I can't search on my side because I don't have this kind of file.

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