Audio fix for Windows

Okay, so I've had problems with "clicks" or "pops" in my sounds when I run the game on Windows using TGB 1.7.4, but no problems on Mac, and after trying lots of things (.ogg versus .wav, and some other things), finally resorted to trying to upgrade OpenAL 1.1 in the engine. It seemed to fix the problem. My steps for how I did this are below in case they are helpful to others.

But I have a question. The final step in upgrading was to remove "OpenAL32.dll" from the game's folder, since OpenAL 1.1 has it as a library built-in to the project. But: I also discovered that by removing this file from *previous* versions of my game (i.e. ones with the older version of OpenAL), this ALSO fixes the sound problems I was having... *without* upgrading to OpenAL. So my questions are: 1) What does a ".dll" file do? (I'm a Mac guy, illiterate to Windows.) 2) By removing this file, was the game simply defaulting to some installed copy of OpenAL on Windows (that I'm assuming was newer). 3) How can I know if I "upgraded" OpenAL in TGB correctly, since removing this the .dll seems to be what "fixed" it, versus the changes I made to the engine?

In any case, here are the steps I followed to upgrade to OpenAL. After doing these steps, if you do not remove OpenAL32.dll from the game's folder before running, the game will crash, which leads me to believe I probably did the upgrade correctly. (i.e. the OpenAL library is now compiled into the TGB app instead of shipping separately as a .dll file.) But this is an assumption, since I don't really know what a .dll file is.

-------------

UPGRADING TGB to OpenAL 1.1

DISCLAIMER: Step 4 gets the engine to compile, but might eliminate some audio functionality used for different "environments." However, I've never seen documented anywhere the ability to set an environment (like "Cave") from within TGB, so as far as I know, if any functionality here is broken by my upgrade steps, it was never exposed to script anyway.


1) Get the OpenAL 1.1 distrubition:

http://connect.creativelabs.com/openal/Downloads/OpenAL11CoreSDK.zip

Or use the link below to get a list of all downloads if the above link doesn't work, and click on "OpenALCore11SDK"

http://connect.creativelabs.com/openal/Downloads/Forms/AllItems.aspx


2 Open up your TGB folder, and open engine/lib/openal/win32/al

Drag all the files inside this folder to some folder on your desktop. (Just in case anything goes wrong, you can restore them instead of deleting them.)

Now drag all the files inside the "include" folder into the Torque engine's "al" folder. Also drag open up "libs/Win32" in the OpenAL distrubion, and drag the stuff here into the Torque "al" folder as well.

3) Open up the Torque Visual C++ project and drag the OpenAL32.lib file into the project.

4) Open audio/AudioDatablock.cc and add this near the top of the file:

// used by DSPROPERTY_EAXLISTENER_ENVIRONMENT

enum
{
EAX_ENVIRONMENT_GENERIC,
EAX_ENVIRONMENT_PADDEDCELL,
EAX_ENVIRONMENT_ROOM,
EAX_ENVIRONMENT_BATHROOM,
EAX_ENVIRONMENT_LIVINGROOM,
EAX_ENVIRONMENT_STONEROOM,
EAX_ENVIRONMENT_AUDITORIUM,
EAX_ENVIRONMENT_CONCERTHALL,
EAX_ENVIRONMENT_CAVE,
EAX_ENVIRONMENT_ARENA,
EAX_ENVIRONMENT_HANGAR,
EAX_ENVIRONMENT_CARPETEDHALLWAY,
EAX_ENVIRONMENT_HALLWAY,
EAX_ENVIRONMENT_STONECORRIDOR,
EAX_ENVIRONMENT_ALLEY,
EAX_ENVIRONMENT_FOREST,
EAX_ENVIRONMENT_CITY,
EAX_ENVIRONMENT_MOUNTAINS,
EAX_ENVIRONMENT_QUARRY,
EAX_ENVIRONMENT_PLAIN,
EAX_ENVIRONMENT_PARKINGLOT,
EAX_ENVIRONMENT_SEWERPIPE,
EAX_ENVIRONMENT_UNDERWATER,
EAX_ENVIRONMENT_DRUGGED,
EAX_ENVIRONMENT_DIZZY,
EAX_ENVIRONMENT_PSYCHOTIC,
EAX_ENVIRONMENT_UNDEFINED,
EAX_ENVIRONMENT_COUNT
};

5) In audio/audio.cc, modify OpenALInit()'s alcOpenDevice() call to use ALChar* instead of ALByte * as seen below:

bool OpenALInit()
{
OpenALShutdown();
if(!OpenALDLLInit())
return false;

// Open a device
#ifdef TORQUE_OS_LINUX
const char* deviceSpecifier =
Con::getVariable("Pref::Unix::OpenALSpecifier");
if (dStrlen(deviceSpecifier) == 0)
// use SDL for audio output by default
deviceSpecifier = "'((devices '(sdl)))";
mDevice = (ALCdevice *)alcOpenDevice((ALubyte*)deviceSpecifier);
#else
mDevice = (ALCdevice *)alcOpenDevice((ALCchar*)NULL); // MODIFIED TO WORK WITH OPENAL 1.1
// mDevice = (ALCdevice *)alcOpenDevice((ALubyte*)NULL);
#endif

6) In platform/platformAL.h, change the beginning if block to this:

#if defined(TORQUE_OS_MAC)
#include <OpenAL/al.h>
#include <OpenAL/alc.h>
#include <OpenAL/altypes.h>
#include <OpenAL/alctypes.h>
#include <OpenAL/eaxtypes.h>
#else
// declare externs of the AL fns here.
#include "al/al.h"
#include "al/alc.h"
#include "al/efx.h"
#include "al/EFX-Util.h"
//#include "al/altypes.h"
//#include "al/alctypes.h"
//#include "al/eaxtypes.h"
#define AL_FUNCTION(fn_return,fn_name,fn_args, fn_value) extern fn_return (FN_CDECL *fn_name)fn_args;
//#include "al/al_func.h"
//#include "al/alc_func.h"
//#include "al/eax_func.h"
#undef AL_FUNCTION

#endif

7) Remove "OpenAL32.dll" from your game's distribution. Do this by opening up tgb/gameData/T2DProject and moving the file somewhere else, like to your desktop.