* Adjusted pan computing function from original game (2D sound should work correctly)

* Set max sound distance to 110.0f to match original colobot (for issue #123)

3 files changed, 91 insertions, 31 deletions

diff --git a/src/sound/oalsound/alsound.cpp b/src/sound/oalsound/alsound.cpp
index 21f11b7..a5a6989 100644
--- a/src/sound/oalsound/alsound.cpp
+++ b/src/sound/oalsound/alsound.cpp
@@ -28,6 +28,8 @@ ALSound::ALSound()
     mMusicVolume = 1.0f;
     mMute = false;
     mCurrentMusic = nullptr;
+    mEye.LoadZero();
+    mLookat.LoadZero();
 }
 
 
@@ -82,7 +84,7 @@ bool ALSound::Create(bool b3D)
     }
     alcMakeContextCurrent(mContext);
     alListenerf(AL_GAIN, mAudioVolume);
-    alDistanceModel(AL_LINEAR_DISTANCE);
+    alDistanceModel(AL_LINEAR_DISTANCE_CLAMPED);
 
     mCurrentMusic = new Channel();
     GetLogger()->Info("Done.\n");
@@ -94,18 +96,6 @@ bool ALSound::Create(bool b3D)
 void ALSound::SetSound3D(bool bMode)
 {
     m3D = bMode;
-    
-    if (!m3D) {
-        float orientation[] = {0.0f, 0.0f, 0.0f, 0.f, 1.f, 0.f};   
-        alListener3f(AL_POSITION, 0.0f, 0.0f, 0.0f); 
-        alListenerfv(AL_ORIENTATION, orientation);
-        
-        for (auto c : mChannels) {
-            if (c.second->IsPlaying()) {
-                c.second->SetPosition(Math::Vector(0.0f, 0.0f, 0.0f));
-            }
-        }
-    }
 }
 
 
@@ -326,6 +316,9 @@ int ALSound::Play(Sound sound, Math::Vector pos, float amplitude, float frequenc
         }
     }
     Position(channel, pos);
+    if (!m3D) {
+        ComputeVolumePan2D(channel, pos);
+    }
 
     // setting initial values
     mChannels[channel]->SetStartAmplitude(amplitude);
@@ -384,6 +377,8 @@ bool ALSound::Position(int channel, Math::Vector pos)
 
     if (m3D) {
         mChannels[channel]->SetPosition(pos);
+    } else {
+        ComputeVolumePan2D(channel, pos);
     }
     return true;
 }
@@ -447,6 +442,7 @@ bool ALSound::MuteAll(bool bMute)
     return true;
 }
 
+
 void ALSound::FrameMove(float delta)
 {
     if (!mEnabled)
@@ -507,6 +503,8 @@ void ALSound::FrameMove(float delta)
 
 void ALSound::SetListener(Math::Vector eye, Math::Vector lookat)
 {
+    mEye = eye;
+    mLookat = lookat;
     if (m3D) {
         float orientation[] = {lookat.x, lookat.y, lookat.z, 0.f, 1.f, 0.f};   
         alListener3f(AL_POSITION, eye.x, eye.y, eye.z); 
@@ -600,3 +598,49 @@ void ALSound::SuspendMusic()
     
     mCurrentMusic->Stop();
 }
+
+
+void ALSound::ComputeVolumePan2D(int channel, Math::Vector &pos)
+{
+    float dist, a, g;
+
+    if (VectorsEqual(pos, mEye)) {
+        mChannels[channel]->SetVolume(1.0f);  // maximum volume
+        mChannels[channel]->SetPosition(Math::Vector());  // at the center
+        return;
+    }
+
+    dist = Distance(pos, mEye);
+    if ( dist >= 110.0f ) { // very far?
+        mChannels[channel]->SetVolume(0.0f);  // silence
+        mChannels[channel]->SetPosition(Math::Vector());  // at the center
+        return;
+    } else if ( dist <= 10.0f ) { // very close?
+        mChannels[channel]->SetVolume(1.0f);   // maximum volume
+        mChannels[channel]->SetPosition(Math::Vector());  // at the center
+        return;
+    }
+    mChannels[channel]->SetVolume(1.0f - ((dist - 10.0f) / 100.0f));
+
+    a = fmodf(Angle(mLookat, mEye), Math::PI * 2.0f);
+    g = fmodf(Angle(pos, mEye), Math::PI * 2.0f);
+    
+    if ( a < 0.0f ) {
+        a += Math::PI * 2.0f;
+    }
+    if ( g < 0.0f ) {
+        g += Math::PI * 2.0f;
+    }
+    
+    if ( a < g ) {
+        if (a + Math::PI * 2.0f - g < g - a ) {
+            a += Math::PI * 2.0f;
+        }
+    } else {
+        if ( g + Math::PI * 2.0f - a < a - g ) {
+            g += Math::PI * 2.0f;
+        }
+    }
+    
+    mChannels[channel]->SetPosition( Math::Vector(sinf(g - a), 0.0f, 0.0f) );
+}
diff --git a/src/sound/oalsound/alsound.h b/src/sound/oalsound/alsound.h
index bdf06b1..725aa2a 100644
--- a/src/sound/oalsound/alsound.h
+++ b/src/sound/oalsound/alsound.h
@@ -81,6 +81,7 @@ class ALSound : public CSoundInterface
         void CleanUp();
         int GetPriority(Sound);
         bool SearchFreeBuffer(Sound sound, int &channel, bool &bAlreadyLoaded);
+        void ComputeVolumePan2D(int channel, Math::Vector &pos);
 
         bool mEnabled;
         bool m3D;
@@ -93,4 +94,6 @@ class ALSound : public CSoundInterface
         std::map<int, Channel*> mChannels;
         std::deque<Buffer*> mMusicCache;
         Channel *mCurrentMusic;
+        Math::Vector mEye;
+        Math::Vector mLookat;
 };
diff --git a/src/sound/oalsound/channel.cpp b/src/sound/oalsound/channel.cpp
index f5967ab..746282e 100644
--- a/src/sound/oalsound/channel.cpp
+++ b/src/sound/oalsound/channel.cpp
@@ -49,20 +49,25 @@ Channel::~Channel() {
 
 
 bool Channel::Play() {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return false;
+    }
 
     alSourcei(mSource, AL_LOOPING, static_cast<ALint>(mLoop));
+    alSourcei(mSource, AL_REFERENCE_DISTANCE, 10.0f);
+    alSourcei(mSource, AL_MAX_DISTANCE, 110.0f);
     alSourcePlay(mSource);
-    if (alCheck())
+    if (alCheck()) {
         GetLogger()->Warn("Could not play audio sound source. Code: %d\n", alGetCode());
+    }
     return true;
 }
 
 
 bool Channel::SetPosition(Math::Vector pos) {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return false;
+    }
     
     alSource3f(mSource, AL_POSITION, pos.x, pos.y, pos.z);
     if (alCheck()) {
@@ -75,8 +80,9 @@ bool Channel::SetPosition(Math::Vector pos) {
 
 bool Channel::SetFrequency(float freq)
 {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return false;
+    }
 
     alSourcef(mSource, AL_PITCH, freq);
     if (alCheck()) {
@@ -90,8 +96,9 @@ bool Channel::SetFrequency(float freq)
 float Channel::GetFrequency()
 {
     ALfloat freq;
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return 0;
+    }
     
     alGetSourcef(mSource, AL_PITCH, &freq);
     if (alCheck()) {
@@ -105,8 +112,9 @@ float Channel::GetFrequency()
 
 bool Channel::SetVolume(float vol)
 {
-    if (!mReady || vol < 0 || mBuffer == nullptr)
+    if (!mReady || vol < 0 || mBuffer == nullptr) {
         return false;
+    }
     
     alSourcef(mSource, AL_GAIN, vol);
     if (alCheck()) {
@@ -120,8 +128,9 @@ bool Channel::SetVolume(float vol)
 float Channel::GetVolume()
 {
     ALfloat vol;
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return 0;
+    }
     
     alGetSourcef(mSource, AL_GAIN, &vol);
     if (alCheck()) {
@@ -201,8 +210,9 @@ void Channel::ResetOper()
 
 
 Sound Channel::GetSoundType() {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return SOUND_NONE;
+    }
     
     return mBuffer->GetSoundType();
 }
@@ -230,10 +240,7 @@ bool Channel::SetBuffer(Buffer *buffer) {
 
 
 bool Channel::FreeBuffer() {
-    if (!mReady)
-        return false;
-    
-    if (!mBuffer) {
+    if (!mReady || !mBuffer) {
         return false;
     }
 
@@ -247,8 +254,9 @@ bool Channel::FreeBuffer() {
 
 bool Channel::IsPlaying() {
     ALint status;
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return false;
+    }
     
     alGetSourcei(mSource, AL_SOURCE_STATE, &status);
     if (alCheck()) {
@@ -270,8 +278,9 @@ bool Channel::IsLoaded() {
 
 
 bool Channel::Stop() {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return false;
+    }
     
     alSourceStop(mSource);
     if (alCheck()) {
@@ -284,8 +293,9 @@ bool Channel::Stop() {
 
 float Channel::GetCurrentTime()
 {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return 0.0f;
+    }
     
     ALfloat current;
     alGetSourcef(mSource, AL_SEC_OFFSET, &current);
@@ -299,19 +309,22 @@ float Channel::GetCurrentTime()
 
 void Channel::SetCurrentTime(float current)
 {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return;
+    }
     
     alSourcef(mSource, AL_SEC_OFFSET, current);
-    if (alCheck())
+    if (alCheck()) {
         GetLogger()->Warn("Could not get source current play time. Code: %d\n", alGetCode());
+    }
 }
 
 
 float Channel::GetDuration()
 {
-    if (!mReady || mBuffer == nullptr)
+    if (!mReady || mBuffer == nullptr) {
         return 0.0f;
+    }
     
     return mBuffer->GetDuration();
 }