Adding Sound Effects to the game

[BureauBert]

In the background I am heavily working on MoT-Mod 2.0. I revised almost each and every file, did a lot of cleanup etc. and my latest playtests are promising. I even got rid of all SLIC-errors with DebugSlic on (except for one that apparently has to do with players not yet having founded a city and hence not yet being alive [at least for some part of the exe], which all IsPlayerAlive-checks don't eliminate).

However ... I have achieved a nice success regarding SOUNDS: I thought it would add to the atmosphere of the game to replace the odd "building complete"-audio message by sounds/sound effects that match the character of the building (e.g. flowing water for the aqueduct, some religious atmosphere for the shrine, etc.). Now there is only one explicit sound-function in SLIC, and that's PlaySound.

The disadvantage of PlaySound is, that the sound gets played unconditionally for all players and regardless if the city is visible. I wanted the "building complete"-sound to be played only for the city owner (who naturally can see it), but not for other players (even if they *can* see the city). After quite a while of pondering I came to this solution:

HandleEvent(CreateBuilding) 'BuildingSound' post {
location_t sfxLoc;
int_t sfxBldg;
int_t sfxPlayer;
int_t sfxCurrPlayer;

sfxLoc = city[0].location;
sfxBldg = value[0].value;
sfxPlayer = city[0].owner;
sfxCurrPlayer = g.player;

if(sfxPlayer == sfxCurrPlayer) {
if(sfxBldg == BuildingDB(IMPROVE_SHRINE)) {
AddEffect(sfxLoc, "SPECEFFECT_BLANC", "SOUND_SHRINE");
}
... and so on for all buildings ...

One tricky part of adding an effect just to play a sound is the effect sprite. In the first place I used "SPECEFFECT_NONE" which already exists in speceffectid.txt with sprite number -1. This does not work, obviously because the invalid sprite number causes the exe to omit the entire effect. So I had to create an effect sprite which consists of nothing else but transparency, gave it the number 98 and named it SPECEFFECT_BLANC. And hooray: this works just fine.

I attach "GX98.SPR" (the blanc effect sprite) for those who want to experiment with this method themselves.

[BureauBert]

P.S.: If you wish to use the above code for your own modding please be WARNED, that my first if-clause

if(sfxPlayer == sfxCurrPlayer) { 

is complete and utter nonsense because sfxPlayer is always sfxCurrPlayer. I (1.) mixed up Turns and Rounds in the first place and (2.) even if these were synonyms the clause would still be the same nonsense because g.player doesn't "own" the Round. (In my understanding a "Round" is one pass through all player's "Turns" -- their "container" so to say.)

The only way to achieve what I intend to achieve is

if(IsHumanPlayer(sfxPlayer)) { 

which is just fine for single player games. In multiplayer games all sounds will be played if they are triggered by a HUMAN player's event and they will be heard by any other player (for biological reasons: any other HUMAN player) who witnesses these events. This shouldn't be much of an annoyance -- and in fact multiplayer games seem to have become rare anyway.