position.x=0;
position.y=0;
+
+ dimension.x=0;
+ dimension.y=0;
+
distance_factor=0;
distance_bias=0;
maximumvolume=1;
if (!(lisp.get("x", position.x)&&lisp.get("y", position.y))) {
std::cerr << "No Position in ambient_sound" << std::endl;
}
+
+ lisp.get("width" , dimension.x);
+ lisp.get("height", dimension.y);
+
lisp.get("distance_factor",distance_factor);
lisp.get("distance_bias" ,distance_bias );
lisp.get("sample" ,sample );
lisp.get("volume" ,maximumvolume );
+ // square all distances (saves us a sqrt later)
+
distance_bias*=distance_bias;
distance_factor*=distance_factor;
+ // set default silence_distance
+
if (distance_factor == 0)
silence_distance = 10e99;
else
playing=-1; // not playing at the beginning
latency=0;
-
}
AmbientSound::~AmbientSound() {
}
void
-AmbientSound::action(float deltat)
+AmbientSound::update(float deltat)
{
if (latency--<=0) {
- float dx=Sector::current()->player->get_pos().x-position.x;
- float dy=Sector::current()->player->get_pos().y-position.y;
- float sqrdistance=dx*dx+dy*dy;
+ float px,py;
+ float rx,ry;
+
+ // Player position
+
+ px=Sector::current()->player->get_pos().x;
+ py=Sector::current()->player->get_pos().y;
+
+ // Relate to which point in the area
+
+ rx=px<position.x?position.x:
+ (px<position.x+dimension.x?px:position.x+dimension.x);
+ ry=py<position.y?position.y:
+ (py<position.y+dimension.y?py:position.y+dimension.y);
+
+ // calculate square of distance
+
+ float sqrdistance=(px-rx)*(px-rx)+(py-ry)*(py-ry);
sqrdistance-=distance_bias;
+
+ // inside the bias: full volume (distance 0)
if (sqrdistance<0)
sqrdistance=0;
+ // calculate target volume - will never become 0
+
targetvolume=1/(1+sqrdistance*distance_factor);
+
float rise=targetvolume/currentvolume;
+
+ // rise/fall half life?
+
currentvolume*=pow(rise,deltat*10);
- currentvolume += 1e-30;
+ currentvolume += 1e-6; // volume is at least 1e-6 (0 would never rise)
if (playing>=0) {
+
+ // set the volume
Mix_Volume(playing,(int)(currentvolume*maximumvolume*MIX_MAX_VOLUME));
- if (sqrdistance>=silence_distance && currentvolume<0.05)
+
+ if (sqrdistance>=silence_distance && currentvolume<1e-3)
stop_playing();
latency=0;
} else {
start_playing();
latency=0;
}
- else
- latency=(int)(10*((sqrdistance-silence_distance)/silence_distance));
+ else // set a reasonable latency
+ latency=(int)(0.001/distance_factor);
+ //(int)(10*((sqrdistance-silence_distance)/silence_distance));
}
+ }
- }
- if (latency>0.001/distance_factor)
- latency=(int)(0.001/distance_factor);
+ // heuristically measured "good" latency maximum
+
+ // if (latency>0.001/distance_factor)
+ // latency=
}
void