1 files changed, 115 insertions, 0 deletions

diff --git a/src/audio_core/hle/filter.cpp b/src/audio_core/hle/filter.cpp
new file mode 100644
index 000000000..2c65ef026
--- /dev/null
+++ b/src/audio_core/hle/filter.cpp
@@ -0,0 +1,115 @@
+// Copyright 2016 Citra Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <array>
+#include <cstddef>
+
+#include "audio_core/hle/common.h"
+#include "audio_core/hle/dsp.h"
+#include "audio_core/hle/filter.h"
+
+#include "common/common_types.h"
+#include "common/math_util.h"
+
+namespace DSP {
+namespace HLE {
+
+void SourceFilters::Reset() {
+    Enable(false, false);
+}
+
+void SourceFilters::Enable(bool simple, bool biquad) {
+    simple_filter_enabled = simple;
+    biquad_filter_enabled = biquad;
+
+    if (!simple)
+        simple_filter.Reset();
+    if (!biquad)
+        biquad_filter.Reset();
+}
+
+void SourceFilters::Configure(SourceConfiguration::Configuration::SimpleFilter config) {
+    simple_filter.Configure(config);
+}
+
+void SourceFilters::Configure(SourceConfiguration::Configuration::BiquadFilter config) {
+    biquad_filter.Configure(config);
+}
+
+void SourceFilters::ProcessFrame(StereoFrame16& frame) {
+    if (!simple_filter_enabled && !biquad_filter_enabled)
+        return;
+
+    if (simple_filter_enabled) {
+        FilterFrame(frame, simple_filter);
+    }
+
+    if (biquad_filter_enabled) {
+        FilterFrame(frame, biquad_filter);
+    }
+}
+
+// SimpleFilter
+
+void SourceFilters::SimpleFilter::Reset() {
+    y1.fill(0);
+    // Configure as passthrough.
+    a1 = 0;
+    b0 = 1 << 15;
+}
+
+void SourceFilters::SimpleFilter::Configure(SourceConfiguration::Configuration::SimpleFilter config) {
+    a1 = config.a1;
+    b0 = config.b0;
+}
+
+std::array<s16, 2> SourceFilters::SimpleFilter::ProcessSample(const std::array<s16, 2>& x0) {
+    std::array<s16, 2> y0;
+    for (size_t i = 0; i < 2; i++) {
+        const s32 tmp = (b0 * x0[i] + a1 * y1[i]) >> 15;
+        y0[i] = MathUtil::Clamp(tmp, -32768, 32767);
+    }
+
+    y1 = y0;
+
+    return y0;
+}
+
+// BiquadFilter
+
+void SourceFilters::BiquadFilter::Reset() {
+    x1.fill(0);
+    x2.fill(0);
+    y1.fill(0);
+    y2.fill(0);
+    // Configure as passthrough.
+    a1 = a2 = b1 = b2 = 0;
+    b0 = 1 << 14;
+}
+
+void SourceFilters::BiquadFilter::Configure(SourceConfiguration::Configuration::BiquadFilter config) {
+    a1 = config.a1;
+    a2 = config.a2;
+    b0 = config.b0;
+    b1 = config.b1;
+    b2 = config.b2;
+}
+
+std::array<s16, 2> SourceFilters::BiquadFilter::ProcessSample(const std::array<s16, 2>& x0) {
+    std::array<s16, 2> y0;
+    for (size_t i = 0; i < 2; i++) {
+        const s32 tmp = (b0 * x0[i] + b1 * x1[i] + b2 * x2[i] + a1 * y1[i] + a2 * y2[i]) >> 14;
+        y0[i] = MathUtil::Clamp(tmp, -32768, 32767);
+    }
+
+    x2 = x1;
+    x1 = x0;
+    y2 = y1;
+    y1 = y0;
+
+    return y0;
+}
+
+} // namespace HLE
+} // namespace DSP