[Gdal-dev] Anything changed on reading Geo-Information from G eoTiff?

[Winkler, Roland]

You are right!

I had Revision 1.23 were CPLFGets() was just introduced. I update the [prot]
files now the problem is vanished! I will have another test on your test
system tomorrow, but I'm pretty sure that this will work. If I have any
problem on this issue I will report immediatly.

Thanks for your support!
Roland

> -----Original Message-----
> From: Frank Warmerdam [mailto:warmerdam at pobox.com] 
> Sent: Mittwoch, 19. November 2003 16:17
> To: gdal-dev at remotesensing.org
> Subject: Re: [Gdal-dev] Anything changed on reading 
> Geo-Information from G eoTiff?
> 
> 
> Winkler, Roland wrote:
> > I debugged now GDALReadWorldFile() and I finally I found 
> whats wrong 
> > with this .tfw file. The .tfw has after the 6.line 
> containing the last 
> > coordintate another line containing something at the first 
> position. 
> > If I remove this line everything works fine and I get the correct 
> > coordinates. I don't know if this .twf file is simply 
> shitty, but on 
> > the other hand the older version of gdal could read it correctly
> > 
> > The problem isn't the atof in GDALReadWorldFile(), it's the 
> > CPLReadLine which already reads this coordintates without 
> the "-". For 
> > this 5.line the file pointer in *CPLFGets is positioned 
> after the "-" 
> > an therefore it isn't read. If you place there any number 
> this will be 
> > skipped, because the filepointer isn't corrrect. While reading the 
> > first time the file into the pszBuffer I saw the value -83 was read 
> > for this last position. Maybe it is really a problem on the 
> different 
> > linefeeds on Linux that you can't reproduce.
> > 
> > Was anything changed on the reading from a stream recently?
> 
> Roland,
> 
> Ahh. I think this is related to the problems we have had with 
> CPLFGets(). In late August Andrey added a CPLFGets() 
> function, and changed CPLReadLine() to use it.  However, the 
> CPLFGets() didn't work properly if the file being read was 
> opened in text mode on win32 systems (since seeking on a text 
> file doesn't generally work well).
> 
> About September 12th or so I fixed the problems, largely 
> re-implementing CPLFGets().
> 
> Can you check your gdal/port/cpl_conv.cpp file and verify 
> that you have version 1.29 or more recent?  If so, you 
> shouldn't be having problems, but it certainly possible there 
> are bugs in my logic.  I tried reproducing the problem with 
> the current CVS source and your .tfw file and was not 
> successful. I am not sure if that is because the linefeeds 
> were altered "in the mail" or whether it is because you are 
> working with slightly out of date code that is buggy.
> 
> If you verify that you are working with the most recent code, 
> I would appreciate your emailing the .tfw file to me within a 
> zip file to preserve it's exact contents and I will try again.
> 
> > Just tell me if you need more informations. For me it's ok now, 
> > because with the edited file the image works, so I didn't 
> examine what 
> > happend in detail with the file pointer positions.
> 
> If there are still bugs in the system they could strike 
> anyone unexpectedly. I would very much like to isolate them 
> and fix them.
> 
> Best regards,
> -- 
> ---------------------------------------+----------------------
> ----------
> ---------------------------------------+------
> I set the clouds in motion - turn up   | Frank Warmerdam, 
> warmerdam at pobox.com
> light and sound - activate the windows | http://pobox.com/~warmerdam
> and watch the world go round - Rush    | Geospatial 
> Programmer for Rent
> 
> 
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