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1

Audio / Re: Audio Library Pre-Processor Help

« on: November 30, 2018, 03:50:40 pm »

Lately, I've been going back over c++ to get a real fundamental understanding of what is happening and why certain methods are used. There is no goal, I just like knowing everything that happens in a piece of code (low-level understanding). From what I have been able to dig up, AL_LIBTYPE_STATIC is defined in the pre-processor settings in microsoft VS if using a static library. These pre processor directives check to see if this is defined or not when the project is built, if it isn't it tries to check if there is a dynamic library defined. I am not really concerned with licensing as this is a more read and learn project.

2

Audio / Audio Library Pre-Processor Help

« on: November 29, 2018, 10:47:06 pm »

#ifndef AL_AL_H
#define AL_AL_H

#if defined(__cplusplus)
extern "C" {
#endif

#ifndef AL_API
 #if defined(AL_LIBTYPE_STATIC)
  #define AL_API
 #elif defined(_WIN32)
  #define AL_API __declspec(dllimport)
 #else
  #define AL_API extern
 #endif
#endif

#if defined(_WIN32)
 #define AL_APIENTRY __cdecl
#else
 #define AL_APIENTRY
#endif
 

This is probably a simple question but I have been struggling to understand the first 22 lines of al.h in SFML/extlibs/headers/AL/al.h. Specifically line 9, or #if defined(AL_LIBTYPE_STATIC). I am not seeing AL_LIBTYPE_STATIC ever being defined in this whole SFML project, where is this coming from? Is this something that comes up through the linker? What are these lines doing? I understand preprocessor directives and their use but this is something I have not quite seen before. Thanks.