Ubuntu
plotutils package

PNG support?

Asked by Milian Wolff

It seems like PNG support is disabled for plotutils, even though it depends on libpng... I'm lost. I have libplot-dev installed, and examples which do not use PNGPlotter work properly. Take this example:
~~~~
     #include <plotter.h>
     using namespace std;
     int main ()
     {
       // works
       PSPlotter postcript(cin, cout, cerr);
       // fails
       PNGPlotter png(cin, cout, cerr);
       return 0;
     }
~~~~

Now try to compile it:

~~~~
g++ -lplotter -lXaw -lXmu -lXt -lSM -lICE -lXext -lX11 -lpng -lz -lm -ansi -Wall -pedantic test.cpp
test.cpp: In function »int main()«:
test.cpp:8: Fehler: »PNGPlotter« wurde in diesem Gültigkeitsbereich nicht definiert
test.cpp:8: Fehler: expected `;' before »png«
~~~~

I took the -l options from `info:/plotutils/C++ Compiling and Linking`. What am I doing wrong?

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Ubuntu plotutils Edit question
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Milian Wolff
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Harvey Muller (hlmuller) said : 		#1

Milian,

I barely know C. Still learning, so take my recommendation with a grain of salt. But if png is not defined, then it is likely that you are missing the png development headers.

I believe you can find them by searching synaptic for libpng.

Please return to Launchpad and mark this question Solved if this resolves your issue.

Danke,

Harvey

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Milian Wolff (milianw) said : 		#2

It's not C - it is C++. And I have libpng12-dev installed. I found a workaround:

~~~~
g++ -DINCLUDE_PNG_SUPPORT -lplotter -ansi -Wall -pedantic test.cpp
~~~~

That seems to work so far. But I'm not sure this is really required? It is not documented in info... I think this is either a bug _or_ we need to change the documentation. What do you think?

Revision history for this message
Harvey Muller (hlmuller) said : 		#3

Milian, I know your code is C++, I was just remarking that I barely know C.

The manual does not indicate that it is necessary to use the macro on the command line, in the section you referenced. So yes, I would say it is a bug in the documentation.

Or maybe they just consider plotter.h part of the documentation?

Thanks!

Harvey

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Harvey Muller (hlmuller) said : 		#4

Milian,

I am checking to see if the information provided previously resolved your question. If so, please mark the question Solved.

Thanks!

Harvey

Revision history for this message
Milian Wolff (milianw) said : 		#5

Yes, I think I'll report a bug for the documentation. Thank you Harvey!