Audio: implemented ALC_ENUMERATION_EXT.

doc/openal-support.dox

@@ -38,7 +38,7 @@ functions and enum values are exposed through the API.
 
 Extension                                   | Status
 ------------------------------------------- | ------
-@alc_extension{ENUMERATION,EXT}             | |
+@alc_extension{ENUMERATION,EXT}             | done
 @al_extension{EXT,double}                   | done
 @al_extension{EXT,float32}                  | done
 @al_extension{EXT,ALAW}                     | done

src/Magnum/Audio/Context.cpp

@@ -30,6 +30,7 @@
 
 #include <al.h>
 #include <alc.h>
+#include <cstring>
 
 #include <Corrade/Utility/Assert.h>
 #include <Corrade/Utility/Debug.h>
@@ -75,6 +76,15 @@ Debug& operator<<(Debug& debug, const Context::HrtfStatus value) {
 
 Context* Context::_current = nullptr;
 
+std::vector<std::string> Context::deviceSpecifierStrings() {
+    std::vector<std::string> list;
+    const char* const devices = alcGetString(nullptr, ALC_DEVICE_SPECIFIER);
+    for(const char* device = devices; *device; device += std::strlen(device) + 1)
+        list.push_back(device);
+
+    return list;
+}
+
 bool Context::hasCurrent() { return _current; }
 
 Context& Context::current() {
@@ -87,11 +97,10 @@ Context::Context(): Context{Configuration{}} {}
 Context::Context(const Configuration& config) {
     CORRADE_ASSERT(!_current, "Audio::Context: context already created", );
 
-    /* Open default device */
-    const ALCchar* const defaultDevice = alcGetString(nullptr, ALC_DEFAULT_DEVICE_SPECIFIER);
-    _device = alcOpenDevice(defaultDevice);
-    if(!_device) {
-        Error() << "Audio::Context: cannot open sound device" << defaultDevice;
+    /* Open the device */
+    const ALCchar* const deviceSpecifier = config.deviceSpecifier().empty() ? alcGetString(nullptr, ALC_DEFAULT_DEVICE_SPECIFIER) : config.deviceSpecifier().data();
+    if(!(_device = alcOpenDevice(deviceSpecifier))) {
+        Error() << "Audio::Context: cannot open sound device" << deviceSpecifier;
         std::exit(1);
     }
 
@@ -189,4 +198,17 @@ bool Context::tryCreateContext(const Configuration& config) {
     return !!_context;
 }
 
+Context::Configuration::Configuration() = default;
+Context::Configuration::~Configuration() = default;
+
+Context::Configuration& Context::Configuration::setDeviceSpecifier(const std::string& specifier) {
+    _deviceSpecifier = specifier;
+    return *this;
+}
+
+Context::Configuration& Context::Configuration::setDeviceSpecifier(std::string&& specifier) {
+    _deviceSpecifier = std::move(specifier);
+    return *this;
+}
+
 }}

src/Magnum/Audio/Context.h

@@ -83,7 +83,6 @@ class MAGNUM_AUDIO_EXPORT Extension {
  */
 class MAGNUM_AUDIO_EXPORT Context {
     public:
-
         /**
          * @brief HRTF status
          *
@@ -127,6 +126,14 @@ class MAGNUM_AUDIO_EXPORT Context {
             UnsupportedFormat = ALC_HRTF_UNSUPPORTED_FORMAT_SOFT
         };
 
+        /**
+         * @brief All device specifier strings
+         *
+         * @see @ref deviceSpecifierString(), @ref Configuration::setDeviceSpecifier()
+         *      @fn_al{GetString} with @def_alc{DEVICE_SPECIFIER}
+         */
+        static std::vector<std::string> deviceSpecifierStrings();
+
         /**
          * @brief Whether there is any current context
          *
@@ -202,17 +209,27 @@ class MAGNUM_AUDIO_EXPORT Context {
             return alcGetString(_device, ALC_HRTF_SPECIFIER_SOFT);
         }
 
+        /**
+         * @brief Device specifier string
+         *
+         * @see @ref deviceSpecifierStrings(), @ref vendorString(), @ref rendererString(),
+         *      @fn_al{GetString} with @def_alc{DEVICE_SPECIFIER}
+         */
+        std::string deviceSpecifierString() const { return alcGetString(_device, ALC_DEVICE_SPECIFIER); }
+
         /**
          * @brief Vendor string
          *
-         * @see @ref rendererString(), @fn_al{GetString} with @def_al{VENDOR}
+         * @see @ref deviceSpecifierString(), @ref rendererString(),
+         *      @fn_al{GetString} with @def_al{VENDOR}
          */
         std::string vendorString() const { return alGetString(AL_VENDOR); }
 
         /**
          * @brief Renderer string
          *
-         * @see @ref vendorString(), @fn_al{GetString} with @def_al{RENDERER}
+         * @see @ref deviceSpecifierString(), @ref vendorString(),
+         *      @fn_al{GetString} with @def_al{RENDERER}
          */
         std::string rendererString() const { return alGetString(AL_RENDERER); }
 
@@ -314,8 +331,22 @@ class MAGNUM_AUDIO_EXPORT Context::Configuration {
             Disabled = 2    /**< Disabled */
         };
 
-        /** @brief Constructor */
-        explicit Configuration() {}
+        explicit Configuration();
+        ~Configuration();
+
+        /** @brief Device specifier */
+        const std::string& deviceSpecifier() const { return _deviceSpecifier; }
+
+        /**
+         * @brief Set device specifier
+         * @return Reference to self (for method chaining)
+         *
+         * If set to empty string (the default), default device specifier is
+         * used.
+         * @see @ref Context::deviceSpecifierStrings()
+         */
+        Configuration& setDeviceSpecifier(const std::string& specifier);
+        Configuration& setDeviceSpecifier(std::string&& specifier); /**< @overload */
 
         /** @brief Sampling rate in Hz */
         Int frequency() const { return _frequency; }
@@ -392,6 +423,8 @@ class MAGNUM_AUDIO_EXPORT Context::Configuration {
         }
 
     private:
+        std::string _deviceSpecifier;
+
         Int _frequency{-1};
         Hrtf _hrtf{};
 

src/Magnum/Audio/magnum-al-info.cpp

@@ -88,6 +88,10 @@ int main(const int argc, const char** const argv) {
     Debug() << "";
 
     Audio::Context c;
+    Debug() << "Available devices:";
+    for(const auto& device: Audio::Context::deviceSpecifierStrings())
+        Debug() << "   " << device;
+    Debug() << "Current device:" << c.deviceSpecifierString();
 
     if(args.isSet("extension-strings")) {
         Debug() << "Extension strings:" << Debug::newline