Audio stuff

libs/audio/include/psemek/audio/detail/white_noise.hpp

@@ -2,7 +2,7 @@
 
 #include <vector>
 
-namespace psemek::audio
+namespace psemek::audio::detail
 {
 
 	std::vector<float> white_noise(std::size_t sample_count);

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

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

libs/audio/source/detail/white_noise.cpp

@@ -3,7 +3,7 @@
 #include <psemek/random/generator.hpp>
 #include <psemek/random/uniform.hpp>
 
-namespace psemek::audio
+namespace psemek::audio::detail
 {
 
 	std::vector<float> white_noise(std::size_t sample_count)

libs/audio/source/wave/karplus_strong.cpp

@@ -17,7 +17,7 @@ namespace psemek::audio
 			: stream
 		{
 			karplus_strong_impl(float frequency)
-				: buffer_(white_noise(2 * std::round(audio::frequency / frequency)))
+				: buffer_(detail::white_noise(2 * std::round(audio::frequency / frequency)))
 			{}
 
 			std::optional<std::size_t> length() const override

libs/audio/source/wave/white_noise.cpp

@@ -0,0 +1,61 @@
+#include <psemek/audio/wave/white_noise.hpp>
+#include <psemek/audio/constants.hpp>
+#include <psemek/audio/detail/white_noise.hpp>
+
+#include <vector>
+#include <atomic>
+
+namespace psemek::audio
+{
+
+	namespace
+	{
+
+		struct white_noise_impl
+			: stream
+		{
+			white_noise_impl(float frequency)
+				: buffer_(detail::white_noise(2 * std::round(audio::frequency / frequency)))
+			{}
+
+			std::optional<std::size_t> length() const override
+			{
+				return std::nullopt;
+			}
+
+			std::size_t read(util::span<float> samples) override
+			{
+				std::size_t const size = buffer_.size();
+
+				for (std::size_t i = 0; i < samples.size(); i += 2)
+				{
+					samples[i + 0] = buffer_[buffer_pos_ + 0];
+					samples[i + 1] = buffer_[buffer_pos_ + 1];
+
+					buffer_pos_ += 2;
+					buffer_pos_ %= size;
+				}
+
+				return samples.size();
+			}
+
+			std::size_t played() const override
+			{
+				return played_.load();
+			}
+
+		private:
+			std::vector<float> buffer_;
+			std::size_t buffer_pos_{0};
+
+			std::atomic<std::size_t> played_;
+		};
+
+	}
+
+	stream_ptr white_noise(float frequency)
+	{
+		return std::make_shared<white_noise_impl>(frequency);
+	}
+
+}