add high and low pass filters

.github/workflows/ci.yml

@@ -1,95 +1,51 @@
-name: ci-pr
-on: [pull_request, workflow_dispatch]
+name: Build
+on: [push, pull_request]
+defaults:
+  run:
+    shell: pwsh
 jobs:
-  x64-linux-gcc:
-    runs-on: ubuntu-latest
+  build:
+    name: ${{ matrix.platform.name }} ${{ matrix.config.name }}
+    runs-on: ${{ matrix.platform.os }}
+    env:
+      CMAKE_BUILD_PARALLEL_LEVEL: 4
+    strategy:
+      fail-fast: false
+      matrix:
+        platform:
+          - { name: "Windows VS2022", os: windows-2022, flags: "" }
+          - { name: "Linux GCC",      os: ubuntu-latest, flags: "" }
+          - { name: "Linux Clang",    os: ubuntu-latest, flags: "-DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++" }
+          - { name: "macOS AppleClang", os: macos-latest, flags: "" }
+        config:
+          - { name: "Static", flags: "-DBUILD_SHARED_LIBS=FALSE" }
     steps:
-      - uses: actions/checkout@v4
-      - name: init
-        run: uname -m; sudo apt update -yqq && sudo apt install -yqq ninja-build mesa-common-dev libwayland-dev libxkbcommon-dev wayland-protocols extra-cmake-modules
-      - name: configure
-        run: cmake -S . --preset=ninja-gcc -B build -DGLFW_BUILD_X11=OFF -DJUKE_USE_LIBXMP=OFF -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14
-      - name: build debug
-        run: cmake --build build --config=Debug -- -v
-      - name: build release
-        run: cmake --build build --config=Release -- -v
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
-  x64-linux-clang:
-    runs-on: ubuntu-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: init
-        run: uname -m; sudo apt update -yqq && sudo apt install -yqq ninja-build clang-19 mesa-common-dev libwayland-dev libxkbcommon-dev wayland-protocols extra-cmake-modules
-      - name: configure
-        run: cmake -S . --preset=ninja-clang -B build -DGLFW_BUILD_X11=OFF -DJUKE_USE_LIBXMP=OFF -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19
-      - name: build debug
-        run: cmake --build build --config=Debug -- -v
-      - name: build release
-        run: cmake --build build --config=Release -- -v
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
-  arm64-linux-gcc:
-    runs-on: ubuntu-24.04-arm
-    steps:
-      - uses: actions/checkout@v4
-      - name: init
-        run: uname -m; sudo apt update -yqq && sudo apt install -yqq ninja-build mesa-common-dev libwayland-dev libxkbcommon-dev wayland-protocols extra-cmake-modules
-      - name: configure
-        run: cmake -S . --preset=ninja-gcc -B build -DGLFW_BUILD_X11=OFF -DJUKE_USE_LIBXMP=OFF -DCMAKE_C_COMPILER=gcc-14 -DCMAKE_CXX_COMPILER=g++-14
-      - name: build debug
-        run: cmake --build build --config=Debug -- -v
-      - name: build release
-        run: cmake --build build --config=Release -- -v
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
-  arm64-linux-clang:
-    runs-on: ubuntu-24.04-arm
-    steps:
-      - uses: actions/checkout@v4
-      - name: init
-        run: uname -m; sudo apt update -yqq && sudo apt install -yqq ninja-build clang-19 mesa-common-dev libwayland-dev libxkbcommon-dev wayland-protocols extra-cmake-modules
-      - name: configure
-        run: cmake -S . --preset=ninja-clang -B build -DGLFW_BUILD_X11=OFF -DJUKE_USE_LIBXMP=OFF -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19
-      - name: build debug
-        run: cmake --build build --config=Debug -- -v
-      - name: build release
-        run: cmake --build build --config=Release -- -v
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
-  x64-windows-vs22:
-    runs-on: windows-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: configure
-        run: cmake -S . --preset=vs22 -B build -DJUKE_USE_LIBXMP=OFF
-      - name: build debug
-        run: cmake --build build --config=Debug --parallel
-      - name: build release
-        run: cmake --build build --config=Release --parallel
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
-  x64-windows-clang:
-    runs-on: windows-latest
-    steps:
-      - uses: actions/checkout@v4
-      - name: configure
-        run: cmake -S . --preset=ninja-clang -B build -DJUKE_USE_LIBXMP=OFF
-      - name: build debug
-        run: cmake --build build --config=Debug -- -v
-      - name: build release
-        run: cmake --build build --config=Release -- -v
-      - name: test debug
-        run: cd build && ctest -V -C Debug
-      - name: test release
-        run: cd build && ctest -V -C Release
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Install Dependencies
+        run: |
+          if ($env:RUNNER_OS -eq 'Windows') {
+            choco install ninja -y
+          } elseif ($env:RUNNER_OS -eq 'Linux') {
+            sudo apt-get update
+            sudo apt-get install -y ninja-build libxrandr-dev libxcursor-dev libxi-dev libudev-dev libflac-dev libvorbis-dev libgl1-mesa-dev libegl1-mesa-dev libfreetype-dev
+          } elseif ($env:RUNNER_OS -eq 'macOS') {
+            brew install ninja
+          } else {
+            Write-Error "Unsupported OS: $env:RUNNER_OS"
+            exit 1
+          }
+      - name: Configure
+        run: |
+          if ($env:RUNNER_OS -eq 'Windows') {
+            . "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\Tools\Launch-VsDevShell.ps1" -Arch amd64 -HostArch amd64
+            Set-Location $env:GITHUB_WORKSPACE
+          }
+          cmake -B build -G "Ninja Multi-Config" ${{ matrix.platform.flags }} ${{ matrix.config.flags }}
+      - name: Build
+        run: |
+          if ($env:RUNNER_OS -eq 'Windows') {
+            . "C:\Program Files\Microsoft Visual Studio\2022\Enterprise\Common7\Tools\Launch-VsDevShell.ps1" -Arch amd64 -HostArch amd64
+            Set-Location $env:GITHUB_WORKSPACE
+          }
+          cmake --build build --config Release

app/src/MediaPlayer.cpp

@@ -26,6 +26,8 @@ void MediaPlayer::handle_input() {
 		static auto gain{1.f};
 		static auto pan{0.f};
 		static auto pitch{1.f};
+		static auto lo_cutoff{sample_rate_v};
+		static auto hi_cutoff{0.f};
 		static float pos[] = {0.f, 0.f, 0.f};
 
 		/* Metadata & Info */
@@ -67,6 +69,11 @@ void MediaPlayer::handle_input() {
 				m_jukebox.set_position(capo::Vec3f{pos[0], pos[1], pos[2]});
 				if (ImGui::Button("reset")) { pos[0] = pos[1] = pos[2] = 0.f; }
 			}
+
+			ImGui::SliderFloat("Low Pass", &lo_cutoff, 0.f, sample_rate_v, "%.1f", ImGuiSliderFlags_Logarithmic);
+			m_jukebox.set_cutoff(FilterType::low, lo_cutoff, sample_rate_v);
+			ImGui::SliderFloat("High Pass:", &hi_cutoff, 0.f, sample_rate_v, "%.1f", ImGuiSliderFlags_Logarithmic);
+			m_jukebox.set_cutoff(FilterType::high, hi_cutoff, sample_rate_v);
 			ImGui::TreePop();
 		}
 	}

library/include/juke/core/AudioFile.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <capo/buffer.hpp>
+#include <juke/core/Common.hpp>
 #include <juke/core/MediaFile.hpp>
 
 namespace juke {
@@ -10,6 +11,7 @@ class AudioFile : public IMediaFile {
 	explicit AudioFile(std::filesystem::path const& path);
 
 	bool bind_to(capo::ISource& source) final { return source.bind_to(m_buffer); }
+	void set_cutoff(FilterType type, float to_cutoff, float sample_rate) override {}
 
   private:
 	std::shared_ptr<capo::Buffer> m_buffer{std::make_shared<capo::Buffer>()};

library/include/juke/core/Common.hpp

@@ -0,0 +1,10 @@
+
+#pragma once
+
+namespace juke {
+
+enum class FilterType : std::uint8_t { high, low };
+
+constexpr auto sample_rate_v = 44100.0f;
+
+} // namespace juke

library/include/juke/core/MediaFile.hpp

@@ -2,6 +2,7 @@
 #pragma once
 
 #include <capo/source.hpp>
+#include <juke/core/Common.hpp>
 #include <filesystem>
 
 namespace juke {
@@ -11,6 +12,7 @@ class IMediaFile : public capo::Polymorphic {
 	explicit IMediaFile(std::filesystem::path const& path) : m_filename(path.filename().string()) {}
 
 	virtual bool bind_to(capo::ISource& source) = 0;
+	virtual void set_cutoff(FilterType type, float to_cutoff, float sample_rate) = 0;
 
 	[[nodiscard]] std::string const& get_filename() const { return m_filename; }
 

library/include/juke/core/XMFile.hpp

@@ -13,6 +13,8 @@ class XMFile : public IMediaFile {
 
 	bool bind_to(capo::ISource& source) final { return source.bind_to(m_stream); }
 
+	void set_cutoff(FilterType type, float to_cutoff, float sample_rate) override { m_stream->set_cutoff(type, to_cutoff, sample_rate); }
+
   private:
 	std::shared_ptr<XMStream> m_stream{};
 };

library/include/juke/core/XMStream.hpp

@@ -2,6 +2,9 @@
 
 #include <capo/buffer.hpp>
 #include <capo/stream_pipe.hpp>
+#include <juke/core/Common.hpp>
+#include <juke/effect/HighPassFilter.hpp>
+#include <juke/effect/LowPassFilter.hpp>
 #include <filesystem>
 #include <memory>
 
@@ -13,6 +16,8 @@ class XMStream : public capo::IStreamPipe {
 
 	explicit XMStream(std::filesystem::path const& path);
 
+	void set_cutoff(FilterType type, float to_cutoff, float sample_rate);
+
   private:
 	struct Impl;
 	struct Deleter {
@@ -25,6 +30,9 @@ class XMStream : public capo::IStreamPipe {
 	auto set_looping(bool looping) -> bool final;
 
 	std::unique_ptr<Impl, Deleter> m_impl{};
+
+	LowPassFilter m_lowpass;
+	HighPassFilter m_highpass;
 };
 
 } // namespace juke

library/include/juke/effect/HighPassFilter.hpp

@@ -0,0 +1,37 @@
+
+#pragma once
+
+#include <numbers>
+
+namespace juke {
+
+class HighPassFilter {
+  public:
+	HighPassFilter(float cutoff_hz, float sample_rate) { set_cutoff(cutoff_hz, sample_rate); }
+
+	void set_cutoff(float cutoff_hz, float sample_rate) {
+		if (cutoff_hz <= 0.0f) {
+			m_alpha = 0.0f;
+			return;
+		}
+
+		auto const dt = 1.0f / sample_rate;
+		auto const rc = 1.0f / (2.0f * std::numbers::pi * cutoff_hz);
+		m_alpha = rc / (rc + dt);
+	}
+
+	float process(float input) {
+		if (m_alpha == 0.0f) return input;
+		auto output = m_alpha * (m_prev_out + input - m_prev_in);
+		m_prev_in = input;
+		m_prev_out = output;
+		return output;
+	}
+
+  private:
+	float m_prev_in{};
+	float m_prev_out{};
+	float m_alpha{};
+};
+
+} // namespace juke

library/include/juke/effect/LowPassFilter.hpp

@@ -0,0 +1,28 @@
+
+#pragma once
+
+#include <numbers>
+
+namespace juke {
+
+class LowPassFilter {
+  public:
+	LowPassFilter(float cutoff_hz, float sample_rate) { set_cutoff(cutoff_hz, sample_rate); }
+
+	void set_cutoff(float cutoff_hz, float sample_rate) {
+		auto const rc = 1.0f / (2.0f * std::numbers::pi * cutoff_hz);
+		auto const dt = 1.0f / sample_rate;
+		m_alpha = dt / (rc + dt);
+	}
+
+	float process(float in) {
+		m_prev_out = m_alpha * in + (1.0f - m_alpha) * m_prev_out;
+		return m_prev_out;
+	}
+
+  private:
+	float m_prev_out{};
+	float m_alpha{};
+};
+
+} // namespace juke

library/include/juke/juke.hpp

@@ -28,6 +28,9 @@ class Jukebox {
 	/// \brief Stop audio and set cursor to beginning. This does not work for XM format.
 	void stop();
 
+	// utility functions
+	void set_cutoff(FilterType type, float cutoff_hz, float sample_rate);
+
 	/* capo API wrapper functions */
 
 	// setters
@@ -39,7 +42,7 @@ class Jukebox {
 	void set_position(capo::Vec3f pos) { m_source->set_position(pos); }
 	void set_spatialized(bool spatialized) { m_source->set_spatialized(spatialized); }
 
-	//getters
+	// getters
 	[[nodiscard]] auto get_gain() const -> float { return m_source->get_gain(); }
 	[[nodiscard]] auto get_pitch() const -> float { return m_source->get_pitch(); }
 	[[nodiscard]] auto get_pan() const -> float { return m_source->get_pan(); }

library/src/core/XMStream.cpp

@@ -24,7 +24,7 @@ void XMStream::Deleter::operator()(Impl* ptr) const noexcept {
 	std::default_delete<Impl>{}(ptr);
 }
 
-XMStream::XMStream(std::filesystem::path const& path) : m_impl(new Impl) {
+XMStream::XMStream(std::filesystem::path const& path) : m_impl(new Impl), m_lowpass{sample_rate_v, sample_rate_v}, m_highpass{0.f, sample_rate_v} {
 	if (!m_impl->load_module(path)) { throw MediaError{"Failed to open XM file: " + path.generic_string()}; }
 	xmp_start_player(m_impl->context, static_cast<int>(capo::Buffer::sample_rate_v), 0);
 }
@@ -43,15 +43,29 @@ void XMStream::push_samples(std::vector<float>& out) {
 	// wrap buffer into strongly-typed span for easy iteration and normalization.
 	auto const src = std::span{static_cast<std::int16_t const*>(frame_info.buffer), static_cast<std::size_t>(frame_info.buffer_size) / sizeof(std::int16_t)};
 	// need to normalize each u16 sample [-32k,32k] to f32 [-1,1].
+
 	static constexpr auto sample_max_v = static_cast<float>(std::numeric_limits<std::int16_t>::max());
-	for (std::int16_t const sample : src) { out.push_back(static_cast<float>(sample) / sample_max_v); }
+	for (std::int16_t const sample : src) {
+		auto normalized = static_cast<float>(sample) / sample_max_v;
+		auto high_passed = m_highpass.process(normalized);
+		auto band_passed = m_lowpass.process(high_passed);
+		out.push_back(band_passed);
+	}
 }
 
 auto XMStream::set_looping(bool const looping) -> bool {
 	m_impl->looping = looping;
 	return true;
 }
 
+void XMStream::set_cutoff(FilterType type, float to_cutoff, float sample_rate) {
+	switch (type) {
+	case FilterType::high: m_highpass.set_cutoff(to_cutoff, sample_rate); break;
+	case FilterType::low: m_lowpass.set_cutoff(to_cutoff, sample_rate); break;
+	default: break;
+	}
+}
+
 #else
 
 void XMStream::Deleter::operator()(Impl* /*ptr*/) const noexcept {}

library/src/juke.cpp

@@ -48,4 +48,6 @@ void Jukebox::stop() {
 	m_source->set_cursor({}); // seek to start. this will do nothing for XM streams
 }
 
+void Jukebox::set_cutoff(FilterType type, float cutoff_hz, float sample_rate) { m_media_file->set_cutoff(type, cutoff_hz, sample_rate); }
+
 } // namespace juke