* Fixed sound pitch causing segfault

* Sound support should now compile fine with MXE
* Added cache for 3 music files to speedup loading
* Updated howto

CMakeLists.txt

@@ -52,7 +52,7 @@ if ("${CMAKE_CXX_COMPILER_ID}" MATCHES "GNU")
         COMMAND ${CMAKE_CXX_COMPILER} -dumpversion OUTPUT_VARIABLE GCC_VERSION)
     if (GCC_VERSION VERSION_GREATER 4.7 OR GCC_VERSION VERSION_EQUAL 4.7)
         message(STATUS "Detected GCC version 4.7+")
-        set(CXX11_FLAGS "-std=c++11")
+        set(CXX11_FLAGS "-std=gnu++11")
     elseif (GCC_VERSION VERSION_GREATER 4.6 OR GCC_VERSION VERSION_EQUAL 4.6)
         message(STATUS "Detected GCC version 4.6+")
         set(CXX11_FLAGS "-std=c++0x")

HOWTO-MXE.txt

@@ -49,6 +49,10 @@ libraries and tools.
     xz
     zlib
 
+    for audio support:
+    openal
+    libsndfile
+
 4. Now `cd' to colobot directory. To cross-compile a CMake project, you have to specify
    a CMake toolchain file. MXE has such file in MXE's directory:
    usr/i686-pc-mingw32/share/cmake/mxe-conf.cmake

HOWTO.txt

@@ -42,9 +42,11 @@ How to...
     $ cmake .
     $ make
 
-  Note: If you experience problems with OpenGL's extensions, install GLEW library and enable
+  Note #1: If you experience problems with OpenGL's extensions, install GLEW library and enable
            it in compilation by setting USE_GLEW to 1 in CMakeLists.txt
 
+  Note #2: For audio support you need libsndfile and openal.
+
  1.3 Other platforms, compilers, etc.
 
    We haven't checked other platforms yet but the code isn't particularly tied to any compiler or platform, so in theory it should work.

cmake/mxe.cmake

@@ -12,6 +12,19 @@ if((${CMAKE_CROSSCOMPILING}) AND (DEFINED MSYS))
     # Because find package scripts are lame
     set(SDLTTF_INCLUDE_DIR ${CMAKE_FIND_ROOT_PATH}/include/SDL)
     set(SDLIMAGE_INCLUDE_DIR ${CMAKE_FIND_ROOT_PATH}/include/SDL)
+
+    if (${OPENAL_SOUND})
+        set(OPENAL_MXE_LIBS
+            ${CMAKE_FIND_ROOT_PATH}/lib/libFLAC.a
+            ${CMAKE_FIND_ROOT_PATH}/lib/libvorbis.a
+            ${CMAKE_FIND_ROOT_PATH}/lib/libvorbisenc.a
+            ${CMAKE_FIND_ROOT_PATH}/lib/libvorbisfile.a
+            ${CMAKE_FIND_ROOT_PATH}/lib/libogg.a
+            ${CMAKE_FIND_ROOT_PATH}/lib/libwsock32.a
+        )
+    endif()
+
+    set(MXE_CFLAGS "-DAL_LIBTYPE_STATIC")
     set(MXE_LIBS
       # For some reason, these have to be absolute paths
       ${CMAKE_FIND_ROOT_PATH}/lib/libintl.a
@@ -23,6 +36,7 @@ if((${CMAKE_CROSSCOMPILING}) AND (DEFINED MSYS))
       ${CMAKE_FIND_ROOT_PATH}/lib/libwinmm.a
       ${CMAKE_FIND_ROOT_PATH}/lib/libdxguid.a
       ${CMAKE_FIND_ROOT_PATH}/lib/libbz2.a
+      ${OPENAL_MXE_LIBS}
     )
 else()
     set(MXE 0)

src/CMakeLists.txt

@@ -1,5 +1,5 @@
 # Compile flags as defined in global CMakeLists
-set(CMAKE_CXX_FLAGS ${COLOBOT_CXX_FLAGS})
+set(CMAKE_CXX_FLAGS "${COLOBOT_CXX_FLAGS} ${MXE_CFLAGS}")
 set(CMAKE_CXX_FLAGS_RELEASE ${COLOBOT_CXX_FLAGS_RELEASE})
 set(CMAKE_CXX_FLAGS_DEBUG ${COLOBOT_CXX_FLAGS_DEBUG})
 
@@ -27,11 +27,7 @@ endif()
 set(OPTIONAL_LIBS "")
 
 if (${OPENAL_SOUND})
-    if (${MXE})
+    if (${PLATFORM_WINDOWS})
-        set(OPTIONAL_LIBS
-            ${CMAKE_FIND_ROOT_PATH}/lib/libOpenAL32.a
-        )
-    elseif (${PLATFORM_WINDOWS})
         set(OPTIONAL_LIBS
             OpenAL32
         )
@@ -43,8 +39,6 @@ if (${OPENAL_SOUND})
 endif()
 
 # Additional libraries per platform
-set(PLATFORM_LIBS "")
-
 if (${MXE}) # MXE requires special treatment
     set(PLATFORM_LIBS ${MXE_LIBS})  
 elseif (${PLATFORM_WINDOWS})
@@ -201,8 +195,8 @@ ${PNG_LIBRARIES}
 ${GLEW_LIBRARY}
 ${Boost_LIBRARIES}
 ${OPTIONAL_LIBS}
-${PLATFORM_LIBS}
 ${LIBSNDFILE_LIBRARY}
+${PLATFORM_LIBS}
 )
 
 # Local
@@ -210,7 +204,6 @@ include_directories(
 .
 ..
 ${CMAKE_CURRENT_BINARY_DIR}
-${LIBSNDFILE_INCLUDE_DIR}
 )
 
 # System
@@ -223,6 +216,7 @@ ${PNG_INCLUDE_DIRS}
 ${GLEW_INCLUDE_PATH}
 ${Boost_INCLUDE_DIRS}
 ${OPTIONAL_INCLUDE_DIRS}
+${LIBSNDFILE_INCLUDE_DIR}
 )
 
 link_directories(${CMAKE_CURRENT_SOURCE_DIR}/CBot)

src/sound/oalsound/alsound.cpp

@@ -29,7 +29,7 @@ ALSound::ALSound()
     mAudioVolume = 1.0f;
     mMusicVolume = 1.0f;
     mMute = false;
-    mCurrentMusic = new Channel();
+    mCurrentMusic = nullptr;    
     auto pointer = CInstanceManager::GetInstancePointer();
     if (pointer != nullptr)
         CInstanceManager::GetInstancePointer()->AddInstance(CLASS_SOUND, this);
@@ -90,6 +90,7 @@ bool ALSound::Create(bool b3D)
     }
     alcMakeContextCurrent(mContext);
 
+    mCurrentMusic = new Channel();
     GetLogger()->Info("Done.\n");
     mEnabled = true;
     return true;
@@ -125,8 +126,8 @@ bool ALSound::GetEnable()
 
 void ALSound::SetAudioVolume(int volume)
 {
-    alListenerf(AL_GAIN, MIN(static_cast<float>(volume) / MAXVOLUME, 1.0f));
     mAudioVolume = MIN(static_cast<float>(volume) / MAXVOLUME, 1.0f);
+    alListenerf(AL_GAIN, mAudioVolume);
 }
 
 
@@ -141,8 +142,10 @@ int ALSound::GetAudioVolume()
 
 void ALSound::SetMusicVolume(int volume)
 {
-    alListenerf(AL_GAIN, MIN(static_cast<float>(volume) / MAXVOLUME, 1.0f));
     mMusicVolume = MIN(static_cast<float>(volume) / MAXVOLUME, 1.0f);
+    if (mCurrentMusic) {
+        mCurrentMusic->SetVolume(mMusicVolume);
+    }
 }
 
 
@@ -310,29 +313,28 @@ int ALSound::Play(Sound sound, Math::Vector pos, float amplitude, float frequenc
     }
 
     int channel;
-    bool bAlreadyLoaded;
+    bool bAlreadyLoaded = false;
     if (!SearchFreeBuffer(sound, channel, bAlreadyLoaded))
         return -1;
 
-    bAlreadyLoaded = false;
     if (!bAlreadyLoaded) {
         if (!mChannels[channel]->SetBuffer(mSounds[sound])) {
             mChannels[channel]->SetBuffer(nullptr);
             return -1;
         }
     }
-
     Position(channel, pos);
 
     // setting initial values
-    mChannels[channel]->SetStartAmplitude(amplitude);
+    mChannels[channel]->SetStartAmplitude(amplitude * mAudioVolume);
     mChannels[channel]->SetStartFrequency(frequency);
     mChannels[channel]->SetChangeFrequency(1.0f);
     mChannels[channel]->ResetOper();
-    mChannels[channel]->SetFrequency(frequency * mChannels[channel]->GetFrequency());       
+    mChannels[channel]->SetFrequency(frequency);
-    mChannels[channel]->SetVolume(amplitude);
+    mChannels[channel]->SetVolume(amplitude * mAudioVolume);
     mChannels[channel]->SetLoop(bLoop);
     mChannels[channel]->Play();
+
     return channel;
 }
 
@@ -467,7 +469,7 @@ void ALSound::FrameMove(float delta)
        
         // setting volume
         volume = progress * (oper.finalAmplitude - it.second->GetStartAmplitude());
-        it.second->SetVolume(volume + it.second->GetStartAmplitude());
+        it.second->SetVolume((volume + it.second->GetStartAmplitude()) * mAudioVolume);
 
         // setting frequency
         frequency = progress * (oper.finalFrequency - it.second->GetStartFrequency()) * it.second->GetStartFrequency() * it.second->GetChangeFrequency() * it.second->GetInitFrequency();
@@ -506,7 +508,24 @@ bool ALSound::PlayMusic(int rank, bool bRepeat)
     }
     
     if (static_cast<int>(mCurrentMusic->GetSoundType()) != rank) {
+        // check if we have music in cache
+        for (auto music : mMusicCache) {
+            if (static_cast<int>(music->GetSoundType()) == rank) {
+                GetLogger()->Debug("Music loaded from cache\n");
+                mCurrentMusic->SetBuffer(music);
+
+                mCurrentMusic->SetVolume(mMusicVolume);
+                mCurrentMusic->SetLoop(bRepeat);
+                mCurrentMusic->Play();
+                return true;
+            }
+        }
+     
+        // we cache only 3 music files
+        if (mMusicCache.size() == 3) {
             mCurrentMusic->FreeBuffer();
+            mMusicCache.pop_back();
+        }
 
         if (mMusic.find(rank) == mMusic.end()) {
             GetLogger()->Info("Requested music %d was not found.\n", rank);
@@ -514,8 +533,10 @@ bool ALSound::PlayMusic(int rank, bool bRepeat)
         }
 
         Buffer *buffer = new Buffer();
+        mMusicCache.push_front(buffer);
         buffer->LoadFromFile(mMusic.at(rank), static_cast<Sound>(rank));
         mCurrentMusic->SetBuffer(buffer);
+        mMusicCache[rank] = buffer;
     }
     
     mCurrentMusic->SetVolume(mMusicVolume);

src/sound/oalsound/alsound.h

@@ -92,5 +92,6 @@ class ALSound : public CSoundInterface
         ALCcontext* mContext;
         std::map<Sound, Buffer*> mSounds;
         std::map<int, Channel*> mChannels;
+        std::deque<Buffer*> mMusicCache;
         Channel *mCurrentMusic;
 };

src/sound/oalsound/channel.cpp

@@ -224,6 +224,7 @@ bool Channel::SetBuffer(Buffer *buffer) {
     if (!mReady)
         return false;
 
+    Stop();    
     mBuffer = buffer;
     if (buffer == nullptr) {
         alSourcei(mSource, AL_BUFFER, 0);
@@ -276,7 +277,7 @@ bool Channel::IsReady() {
 }
 
 bool Channel::IsLoaded() {
-    return mBuffer == nullptr;
+    return mBuffer != nullptr;
 }