Move kissfft to engine/third_party and add AudioMixer class

engine/src/Audio/AudioMixer.cpp

@@ -0,0 +1,84 @@
+#include <XCEngine/Audio/AudioMixer.h>
+#include <algorithm>
+#include <cmath>
+
+namespace XCEngine {
+namespace Audio {
+
+AudioMixer::AudioMixer()
+{
+    for (int i = 0; i < static_cast<int>(AudioChannel::SideRight) + 1; ++i) {
+        m_channelVolumes[static_cast<AudioChannel>(i)] = ChannelVolume{1.0f, false};
+    }
+}
+
+AudioMixer::~AudioMixer() {
+}
+
+void AudioMixer::SetVolume(float volume) {
+    m_volume = std::max(0.0f, std::min(1.0f, volume));
+}
+
+void AudioMixer::SetMute(bool mute) {
+    m_mute = mute;
+}
+
+void AudioMixer::AddEffect(IAudioEffect* effect) {
+    if (effect) {
+        m_effects.push_back(effect);
+    }
+}
+
+void AudioMixer::RemoveEffect(IAudioEffect* effect) {
+    if (!effect) return;
+    auto it = std::find(m_effects.begin(), m_effects.end(), effect);
+    if (it != m_effects.end()) {
+        m_effects.erase(it);
+    }
+}
+
+void AudioMixer::ClearEffects() {
+    m_effects.clear();
+}
+
+void AudioMixer::ProcessAudio(float* buffer, uint32 sampleCount, uint32 channels) {
+    if (!buffer || sampleCount == 0) {
+        return;
+    }
+
+    float effectiveVolume = m_mute ? 0.0f : m_volume;
+
+    if (effectiveVolume < 0.001f) {
+        return;
+    }
+
+    for (size_t i = 0; i < sampleCount * channels; ++i) {
+        buffer[i] *= effectiveVolume;
+    }
+}
+
+void AudioMixer::SetOutputMixer(AudioMixer* mixer) {
+    m_outputMixer = mixer;
+}
+
+void AudioMixer::Set3DParams(const Audio3DParams& params) {
+    m_3DParams = params;
+}
+
+void AudioMixer::SetChannelVolume(AudioChannel channel, float volume) {
+    auto it = m_channelVolumes.find(channel);
+    if (it != m_channelVolumes.end()) {
+        it->second.volume = std::max(0.0f, std::min(1.0f, volume));
+    }
+}
+
+float AudioMixer::GetChannelVolume(AudioChannel channel) const {
+    auto it = m_channelVolumes.find(channel);
+    if (it != m_channelVolumes.end()) {
+        return it->second.volume;
+    }
+    return 1.0f;
+}
+
+} // namespace Audio
+} // namespace XCEngine