NumberSetting.observe

src/data/setting.h

@@ -3,8 +3,10 @@
 
 #include <limits>
 #include <string>
+#include <vector>
 
 #include "../typedefs.h"
+#include "../delegates.h"
 
 enum class setting_format {
     simple, percent
@@ -34,6 +36,7 @@ protected:
     number_t value;
     number_t min;
     number_t max;
+    std::vector<consumer<number_t>> consumers;
 public:
     NumberSetting(
         number_t value, 
@@ -56,7 +59,13 @@ public:
     }
 
     void set(number_t value) {
+        if (value == this->value) {
+            return;
+        }
         this->value = value;
+        for (auto& callback : consumers) {
+            callback(value);
+        }
     }
 
     number_t getMin() const {
@@ -71,6 +80,10 @@ public:
         return (value - min) / (max - min);
     }
 
+    void observe(consumer<number_t> callback) {
+        consumers.push_back(callback);
+    }
+
     virtual void resetToDefault() override {
         value = initial;
     }

src/delegates.h

@@ -7,6 +7,7 @@
 
 using runnable = std::function<void()>;
 template<class T> using supplier = std::function<T()>;
+template<class T> using consumer = std::function<void(T)>;
 
 // data sources
 using wstringsupplier = std::function<std::wstring()>;

src/engine.cpp

@@ -63,6 +63,22 @@ Engine::Engine(EngineSettings& settings, EnginePaths* paths)
     audio::create_channel("ambient");
     audio::create_channel("ui");
 
+    settings.audio.volumeMaster.observe([=](auto value) {
+        audio::get_channel("master")->setVolume(value*value);
+    });
+    settings.audio.volumeRegular.observe([=](auto value) {
+        audio::get_channel("regular")->setVolume(value*value);
+    });
+    settings.audio.volumeUI.observe([=](auto value) {
+        audio::get_channel("ui")->setVolume(value*value);
+    });
+    settings.audio.volumeAmbient.observe([=](auto value) {
+        audio::get_channel("ambient")->setVolume(value*value);
+    });
+    settings.audio.volumeMusic.observe([=](auto value) {
+        audio::get_channel("music")->setVolume(value*value);
+    });
+
     auto resdir = paths->getResources();
     std::cout << "-- loading assets" << std::endl;
     std::vector<fs::path> roots {resdir};
@@ -128,19 +144,6 @@ void Engine::updateHotkeys() {
     }
 }
 
-inline constexpr float sqr(float x) {
-    return x*x;
-}
-
-static void updateAudio(double delta, const AudioSettings& settings) {
-    audio::get_channel("master")->setVolume(sqr(settings.volumeMaster.get()));
-    audio::get_channel("regular")->setVolume(sqr(settings.volumeRegular.get()));
-    audio::get_channel("ui")->setVolume(sqr(settings.volumeUI.get()));
-    audio::get_channel("ambient")->setVolume(sqr(settings.volumeAmbient.get()));
-    audio::get_channel("music")->setVolume(sqr(settings.volumeMusic.get()));
-    audio::update(delta);
-}
-
 void Engine::mainloop() {
     setScreen(std::make_shared<MenuScreen>(this));
 
@@ -152,7 +155,7 @@ void Engine::mainloop() {
         assert(screen != nullptr);
         updateTimers();
         updateHotkeys();
-        updateAudio(delta, settings.audio);
+        audio::update(delta);
 
         gui->act(delta);
         screen->update(delta);