Question

Setting up gl3w in my computer: 2 errors that I have no idea how to resolve are being thrown:

Function that’s built by Gl3w script which has the errors:

static void *get_proc(const char *proc)               - line 19
{
void *res;

res = wglGetProcAddress(proc);                    - line 23, first error
if (!res)
    res = GetProcAddress(libgl, proc);        - line 25, second error
return res;
}

Build errors:

||=== LearnOPG, Debug ===|
C:\CodeBlocks\LearnOPG\gl3w.c||In function 'void* get_proc(const char*)':|

C:\CodeBlocks\LearnOPG\gl3w.c|23|error: invalid conversion from 'PROC {aka int (__attribute__((__stdcall__)) *)()}' to 'void*' [-fpermissive]|

C:\CodeBlocks\LearnOPG\gl3w.c|25|error: invalid conversion from 'FARPROC {aka int (__attribute__((__stdcall__)) *)()}' to 'void*' [-fpermissive]|

||=== Build finished: 2 errors, 0 warnings (0 minutes, 0 seconds) ===|

Answer 1

Some compilers/platforms are less picky than others. Implicitly converting function pointers to void* and back is not guaranteed to be possible by C or C++. But GL3W’s code expects it to work; obviously, it was not tested with more strict compilers/platforms.

You should probably file a bug report on it with the GL3W people. Granted, it doesn’t seem to be being actively worked on, but they might fix it.