Makefile error including SDL - [NOT RESOLVED]

[sg57]

Im using SDL as a backbone for both sounds and textures, and Im getting undefined references to jpeg and png calls from cygwin when compiling. So i go and set it up by including:

Code: Select all

-lSDL_image -lSDL_mixer -lpng -lz -ljpeg

Im still getting hte exact same error after adding those... Any idea how to get rid of these undefined errors?

(Oh and i have the png and jpeg header included in the source...)

If you need to see the whole makefile, just tell me and ill post it.

[Kojima]

Are you using C++? Alot of libs headers need extern "C" {} added around the code to work in C++.

If not, post the exact error and the makefile.

Also bear in mind order is important. Countless times I've had to add libs twice just to get the order right.

[Raphael]

Also bear in mind order is important. Countless times I've had to add libs twice just to get the order right.

That's most likely it. Permutate through the order of your links until it works.

[dot_blank]

this order work fine for me

-lpng -lz -ljpeg -lm \
-lSDL_image -lSDL_mixer \
-lfreetype -lstdc++ -lsupc++ \

[sg57]

Just tried yours and nothing :(

All im getting is inside SDL_image's IMG_Load function, there are undefined references to jpeg and png calls/functions...

[Kojima]

Did you try the Extern "C" thing? That usually solves unresolved links when using C++ (you havn't stated which you use)

[dot_blank]

is your libraries of images installed

[sg57]

The only thing i havent tried is the extern C thing, but where should i put it? Around the including of SDL?

[dot_blank]

if you are coding in c++ then say you have main.cpp and
wanted to use a texure.c file made from bin2c

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extern "C" {
//c stuff goes here
//ex. if you bin2c a image and your output is a tex_mario.c file
//the object is made into a .c file but you want to use in C++
//to use the image and store array into a buffer and so forth
//you would need to make file known to sources by 
//making that file extern to all sources ....and to do
//this you need to add its use in these braces 
extern unsigned int size_tex_mario;
extern unsigned char tex_mario[];
}; 

and thats one of the ways you can use extern "C"
the undefined errors have nothing to with extern "C" {
the undefined errors have nothing to do with if you include
in C or C++

this is a preproccessor problem ...so check your include
ordering ...tip: sdl_image.h uses png so include png.h earlier
so sdl_image.h can use ....if its not your preproccessor order
then either your linking yet again is wrong or the compiler is
not finding the libraries ....so double check by reconfiguring,
remaking, and then remake installing all the libs needed

if you do all this and yet you have the same problem then come back :P