Thread: Cannot understand this syntax in png.h

I actually get the problem with other functions of the same file but not for variables defined in the same.

Code:

png_byte color_type;
png_byte bit_depth;

png_structp png_ptr;
png_infop info_ptr;

png_bytep * row_pointers;

All of these are recognized. I guess if there was a linking problem to the library they would also be undefined references, or not?

I found in the distribution of pnglib the c file that defines the function. However including it should not be required since I've the libpng.LIB in the lib folder.

I'm using Eclipse with MinGW.

I've tried adding it to the library paths in eclipse, as well as -l libpng, libpng.a, libpng.lib, from the linker options, but in vain.
I've also tried from the prompt:

C:\Documents and Settings\Simpatico\My Documents\ws\Test>make -I C:\MinGW\libpn
\include\libpng12 test test.c -l libpng
gcc test.c -o test
test.c:6:17: png.h: No such file or directory
test.c:20: error: syntax error before "color_type"
test.c:20: warning: data definition has no type or storage class
test.c:21: error: syntax error before "bit_depth"
test.c:21: warning: data definition has no type or storage class
test.c:22: error: syntax error before "png_ptr"
test.c:22: warning: data definition has no type or storage class
test.c:23: error: syntax error before "info_ptr"
test.c:23: warning: data definition has no type or storage class
test.c:25: error: syntax error before '*' token
test.c:25: warning: data definition has no type or storage class
test.c: In function `write_png_file':
test.c:36: error: `PNG_LIBPNG_VER_STRING' undeclared (first use in this functio
)
test.c:36: error: (Each undeclared identifier is reported only once
test.c:36: error: for each function it appears in.)
test.c:56: error: `width' undeclared (first use in this function)
test.c:56: error: `height' undeclared (first use in this function)
test.c:57: error: `PNG_INTERLACE_NONE' undeclared (first use in this function)
test.c:58: error: `PNG_COMPRESSION_TYPE_BASE' undeclared (first use in this fun
tion)
test.c:58: error: `PNG_FILTER_TYPE_BASE' undeclared (first use in this function

test.c:78: warning: passing arg 1 of `free' makes pointer from integer without
cast
make: *** [test] Error 1

C:\Documents and Settings\Simpatico\My Documents\ws\Test>
Please help me getting it to compile at least in the prompt.

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Solved it. I've specified in the linker the name libpng in the -l option and in the -L was specified the path.