src/object/ambient_sound.cpp

   1 // ambient_sound.cpp   basti_
   2 //
   3 //  SuperTux
   4 //
   5 //  This program is free software; you can redistribute it and/or
   6 //  modify it under the terms of the GNU General Public License
   7 //  as published by the Free Software Foundation; either version 2
   8 //  of the License, or (at your option) any later version.
   9 //
  10 //  This program is distributed in the hope that it will be useful,
  11 //  but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 //  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 //  GNU General Public License for more details.
  14 //
  15 //  You should have received a copy of the GNU General Public License
  16 //  along with this program; if not, write to the Free Software
  17 //  Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
  18 //  02111-1307, USA.
  19 #include <config.h>
  20
  21 #include <math.h>
  22
  23 #include "ambient_sound.h"
  24 #include "object_factory.h"
  25 #include "lisp/lisp.h"
  26 #include "sector.h"
  27
  28 AmbientSound::AmbientSound(const lisp::Lisp& lisp)
  29 {
  30
  31   position.x=0;
  32   position.y=0;
  33
  34   dimension.x=0;
  35   dimension.y=0;
  36
  37   distance_factor=0;
  38   distance_bias=0;
  39   maximumvolume=1;
  40   sample="";
  41
  42   if (!(lisp.get("x", position.x)&&lisp.get("y", position.y))) {
  43     std::cerr << "No Position in ambient_sound"  << std::endl;
  44   }
  45
  46   lisp.get("width" , dimension.x);
  47   lisp.get("height", dimension.y);
  48
  49   lisp.get("distance_factor",distance_factor);
  50   lisp.get("distance_bias"  ,distance_bias  );
  51   lisp.get("sample"         ,sample         );
  52   lisp.get("volume"         ,maximumvolume  );
  53
  54   // square all distances (saves us a sqrt later)
  55
  56   distance_bias*=distance_bias;
  57   distance_factor*=distance_factor;
  58
  59   // set default silence_distance
  60
  61   if (distance_factor == 0)
  62     silence_distance = 10e99;
  63   else
  64     silence_distance = 1/distance_factor;
  65
  66   lisp.get("silence_distance",silence_distance);
  67
  68   playing=-1; // not playing at the beginning
  69   latency=0;
  70 }
  71
  72 AmbientSound::~AmbientSound() {
  73   stop_playing();
  74 }
  75
  76 void
  77 AmbientSound::hit(Player& )
  78 {
  79 }
  80
  81 void
  82 AmbientSound::stop_playing() {
  83   if (playing>=0) {
  84     Mix_HaltChannel(playing);
  85     playing=-1;
  86   }
  87 }
  88
  89 void
  90 AmbientSound::start_playing()
  91 {
  92   playing=sound_manager->play_sound(sample,-1);
  93   Mix_Volume(playing,0);
  94   currentvolume=targetvolume=1e-20;
  95 }
  96
  97 void
  98 AmbientSound::update(float deltat)
  99 {
 100   if (latency--<=0) {
 101
 102     float px,py;
 103     float rx,ry;
 104
 105     // Player position
 106
 107     px=Sector::current()->player->get_pos().x;
 108     py=Sector::current()->player->get_pos().y;
 109
 110     // Relate to which point in the area
 111
 112     rx=px<position.x?position.x:
 113       (px<position.x+dimension.x?px:position.x+dimension.x);
 114     ry=py<position.y?position.y:
 115       (py<position.y+dimension.y?py:position.y+dimension.y);
 116
 117     // calculate square of distance
 118
 119     float sqrdistance=(px-rx)*(px-rx)+(py-ry)*(py-ry);
 120
 121     sqrdistance-=distance_bias;
 122
 123     // inside the bias: full volume (distance 0)
 124
 125     if (sqrdistance<0)
 126       sqrdistance=0;
 127
 128     // calculate target volume - will never become 0
 129
 130     targetvolume=1/(1+sqrdistance*distance_factor);
 131
 132     float rise=targetvolume/currentvolume;
 133
 134     // rise/fall half life?
 135
 136     currentvolume*=pow(rise,deltat*10);
 137     currentvolume += 1e-6; // volume is at least 1e-6 (0 would never rise)
 138
 139     if (playing>=0) {
 140
 141       // set the volume
 142       Mix_Volume(playing,(int)(currentvolume*maximumvolume*MIX_MAX_VOLUME));
 143
 144       if (sqrdistance>=silence_distance && currentvolume<1e-3)
 145         stop_playing();
 146       latency=0;
 147     } else {
 148       if (sqrdistance<silence_distance) {
 149         start_playing();
 150         latency=0;
 151       }
 152       else // set a reasonable latency
 153         latency=(int)(0.001/distance_factor);
 154       //(int)(10*((sqrdistance-silence_distance)/silence_distance));
 155     }
 156   }
 157
 158   // heuristically measured "good" latency maximum
 159
 160   //  if (latency>0.001/distance_factor)
 161   // latency=
 162 }
 163
 164 void
 165 AmbientSound::draw(DrawingContext &)
 166 {
 167 }
 168
 169 IMPLEMENT_FACTORY(AmbientSound, "ambient_sound");