Add silence audio stream

examples/audio.cpp

@@ -1,4 +1,5 @@
 #include <psemek/audio/engine.hpp>
+#include <psemek/audio/wave/silence.hpp>
 #include <psemek/audio/wave/sine.hpp>
 #include <psemek/audio/wave/sawtooth.hpp>
 #include <psemek/audio/wave/square.hpp>

libs/audio/include/psemek/audio/wave/silence.hpp

@@ -0,0 +1,10 @@
+#pragma once
+
+#include <psemek/audio/stream.hpp>
+
+namespace psemek::audio
+{
+
+	stream_ptr silence();
+
+}

libs/audio/source/wave/silence.cpp

@@ -0,0 +1,26 @@
+#include <psemek/audio/wave/silence.hpp>
+
+namespace psemek::audio
+{
+
+	namespace
+	{
+
+		struct silence_impl
+			: stream
+		{
+			std::size_t read(float * data, std::size_t sample_count) override
+			{
+				std::fill(data, data + sample_count, 0.f);
+				return sample_count;
+			}
+		};
+
+	}
+
+	stream_ptr silence()
+	{
+		return std::make_shared<silence_impl>();
+	}
+
+}