Added support for changing the master SFX volume.

git-svn-id: svn+ssh://svn.code.sf.net/p/supertuxkart/code/main/branches/irrlicht@3384 178a84e3-b1eb-0310-8ba1-8eac791a3b58

src/audio/sfx_base.hpp

@@ -43,6 +43,7 @@ public:
     virtual void       pause()             = 0;
     virtual void       resume()            = 0;
     virtual void       speed(float factor) = 0;
+    virtual void       volume(float gain)  = 0;
     virtual SFXManager::SFXStatus  
                        getStatus()         = 0;
 };   // SfxBase

src/audio/sfx_manager.cpp

@@ -44,6 +44,7 @@ SFXManager::SFXManager()
 {
     // The sound manager initialises OpenAL
     m_initialized = sound_manager->initialized();
+    m_masterGain = 1.0f;
     m_sfx_buffers.resize(NUM_SOUNDS);
     m_sfx_positional.resize(NUM_SOUNDS);
     m_sfx_rolloff.resize(NUM_SOUNDS);
@@ -207,7 +208,8 @@ SFXBase *SFXManager::newSFX(SFXType id)
     if(race_manager->getNumLocalPlayers() < 2)
         positional = m_sfx_positional[id]!=0;
 
-    SFXBase *p=new SFXOpenAL(m_sfx_buffers[id], positional, m_sfx_rolloff[id], m_sfx_gain[id]);
+    SFXBase *p = new SFXOpenAL(m_sfx_buffers[id], positional, m_sfx_rolloff[id], m_sfx_gain[id]);
+    p->volume(m_masterGain);
     m_all_sfx.push_back(p);
     return p;
 }   // newSFX
@@ -261,7 +263,7 @@ void SFXManager::resumeAll()
     }   // for i in m_all_sfx
 }   // resumeAll
 
-//----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
 bool SFXManager::checkError(const std::string &context)
 {
     // Check (and clear) the error flag
@@ -276,6 +278,24 @@ bool SFXManager::checkError(const std::string &context)
     return true;
 }   // checkError
 
+//-----------------------------------------------------------------------------
+void SFXManager::setMasterSFXVolume(float gain)
+{
+    if(gain > 1.0)
+        gain = 1.0f;
+    if(gain < 0.0f)
+        gain = 0.0f;
+
+    m_masterGain = gain;
+
+    for(std::vector<SFXBase*>::iterator i=m_all_sfx.begin();
+        i!=m_all_sfx.end(); i++)
+    {
+        (*i)->volume(m_masterGain);
+    }   // for i in m_all_sfx
+
+}   // setMasterSFXVolume
+
 //-----------------------------------------------------------------------------
 const std::string SFXManager::getErrorString(int err)
 {

src/audio/sfx_manager.hpp

@@ -68,6 +68,7 @@ private:
     std::vector<float>        m_sfx_gain;
     std::vector<SFXBase*>     m_all_sfx;
     bool                      m_initialized;
+    float                     m_masterGain;
     void                      loadSfx();
     void                      loadSingleSfx(const lisp::Lisp *lisp, 
                                             const  char *name, 
@@ -80,6 +81,7 @@ public:
     void                     deleteSFX(SFXBase *sfx);
     void                     pauseAll();
     void                     resumeAll();
+    void                     setMasterSFXVolume(float gain);
     static bool              checkError(const std::string &context);
     static const std::string getErrorString(int err);
 };

src/audio/sfx_openal.cpp

@@ -43,6 +43,7 @@ SFXOpenAL::SFXOpenAL(ALuint buffer, bool positional, float rolloff, float gain)
     m_soundSource = 0;
     m_ok          = false;
     m_positional  = false;
+    m_defaultGain = gain;
 
     alGenSources(1, &m_soundSource );
     if(!SFXManager::checkError("generating a source")) return;
@@ -52,7 +53,7 @@ SFXOpenAL::SFXOpenAL(ALuint buffer, bool positional, float rolloff, float gain)
     alSource3f(m_soundSource, AL_VELOCITY,        0.0, 0.0, 0.0);
     alSource3f(m_soundSource, AL_DIRECTION,       0.0, 0.0, 0.0);
     alSourcef (m_soundSource, AL_ROLLOFF_FACTOR,  rolloff      );
-    alSourcef (m_soundSource, AL_GAIN,            gain         );
+    alSourcef (m_soundSource, AL_GAIN,            m_defaultGain);
     if(positional)
        alSourcei (m_soundSource, AL_SOURCE_RELATIVE, AL_FALSE);
     else
@@ -89,6 +90,18 @@ void SFXOpenAL::speed(float factor)
     SFXManager::checkError("changing the speed");
 }   // speed
 
+//-----------------------------------------------------------------------------
+/** Changes the volume of a sound effect.
+ *  \param gain Volume adjustment between 0.0 (mute) and 1.0 (full volume).
+ */
+void SFXOpenAL::volume(float gain)
+{
+    if(!m_ok) return;
+
+    alSourcef(m_soundSource, AL_GAIN, m_defaultGain * gain);
+    SFXManager::checkError("setting volume");
+}   // volume
+
 //-----------------------------------------------------------------------------
 /** Loops this sound effect.
  */

src/audio/sfx_openal.hpp

@@ -36,6 +36,7 @@ private:
     ALuint       m_soundSource;   // Sources are points emitting sound.
     bool         m_ok;
     bool         m_positional;
+    float        m_defaultGain;
 public:
                                   SFXOpenAL(ALuint buffer, bool positional, float rolloff, float gain);
     virtual                      ~SFXOpenAL();
@@ -46,6 +47,7 @@ public:
     virtual void                  resume();
     virtual void                  speed(float factor);
     virtual void                  position(const Vec3 &position);
+    virtual void                  volume(float gain);
     virtual SFXManager::SFXStatus getStatus();
 	
 };   // SFXOpenAL