1 files changed, 221 insertions, 0 deletions
diff --git a/Ryujinx.Audio.Renderer/Dsp/State/ReverbState.cs b/Ryujinx.Audio.Renderer/Dsp/State/ReverbState.cs
new file mode 100644
index 00000000..31b03dd6
--- /dev/null
+++ b/Ryujinx.Audio.Renderer/Dsp/State/ReverbState.cs
@@ -0,0 +1,221 @@
+//
+// Copyright (c) 2019-2020 Ryujinx
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+//
+
+using Ryujinx.Audio.Renderer.Common;
+using Ryujinx.Audio.Renderer.Dsp.Effect;
+using Ryujinx.Audio.Renderer.Parameter.Effect;
+using System;
+
+namespace Ryujinx.Audio.Renderer.Dsp.State
+{
+    public class ReverbState
+    {
+        private static readonly float[] FdnDelayTimes = new float[20]
+        {
+            // Room
+            53.953247f, 79.192566f, 116.238770f, 130.615295f,
+            // Hall
+            53.953247f, 79.192566f, 116.238770f, 170.615295f,
+            // Plate
+            5f, 10f, 5f, 10f,
+            // Cathedral
+            47.03f, 71f, 103f, 170f,
+            // Max delay (Hall is the one with the highest values so identical to Hall)
+            53.953247f, 79.192566f, 116.238770f, 170.615295f,
+        };
+
+        private static readonly float[] DecayDelayTimes = new float[20]
+        {
+            // Room
+            7f, 9f, 13f, 17f,
+            // Hall
+            7f, 9f, 13f, 17f,
+            // Plate (no decay)
+            1f, 1f, 1f, 1f,
+            // Cathedral
+            7f, 7f, 13f, 9f,
+            // Max delay (Hall is the one with the highest values so identical to Hall)
+            7f, 9f, 13f, 17f,
+        };
+
+        private static readonly float[] EarlyDelayTimes = new float[50]
+        {
+            // Room
+            0.0f, 3.5f, 2.8f, 3.9f, 2.7f, 13.4f, 7.9f, 8.4f, 9.9f, 12.0f,
+            // Chamber
+            0.0f, 11.8f, 5.5f, 11.2f, 10.4f, 38.1f, 22.2f, 29.6f, 21.2f, 24.8f,
+            // Hall
+            0.0f, 41.5f, 20.5f, 41.3f, 0.0f, 29.5f, 33.8f, 45.2f, 46.8f, 0.0f,
+            // Cathedral
+            33.1f, 43.3f, 22.8f, 37.9f, 14.9f, 35.3f, 17.9f, 34.2f, 0.0f, 43.3f,
+            // Disabled
+            0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f, 0.0f
+        };
+
+        private static readonly float[] EarlyGainBase = new float[50]
+        {
+            // Room
+            0.70f, 0.68f, 0.70f, 0.68f, 0.70f, 0.68f, 0.70f, 0.68f, 0.68f, 0.68f,
+            // Chamber
+            0.70f, 0.68f, 0.70f, 0.68f, 0.70f, 0.68f, 0.68f, 0.68f, 0.68f, 0.68f, 
+            // Hall
+            0.50f, 0.70f, 0.70f, 0.68f, 0.50f, 0.68f, 0.68f, 0.70f, 0.68f, 0.00f,
+            // Cathedral
+            0.93f, 0.92f, 0.87f, 0.86f, 0.94f, 0.81f, 0.80f, 0.77f, 0.76f, 0.65f,
+            // Disabled
+            0.00f, 0.00f, 0.00f, 0.00f, 0.00f, 0.00f, 0.00f, 0.00f, 0.00f, 0.00f
+        };
+
+        private static readonly float[] PreDelayTimes = new float[5]
+        {
+            // Room
+            12.5f,
+            // Chamber
+            40.0f,
+            // Hall
+            50.0f,
+            // Cathedral
+            50.0f,
+            // Disabled
+            0.0f
+        };
+
+        public IDelayLine[] FdnDelayLines { get; }
+        public DecayDelay[] DecayDelays { get; }
+        public IDelayLine PreDelayLine { get; }
+        public IDelayLine BackLeftDelayLine { get; }
+        public uint[] EarlyDelayTime { get; }
+        public float[] EarlyGain { get; }
+        public uint PreDelayLineDelayTime { get; private set; }
+
+        public float[] HighFrequencyDecayDirectGain { get; }
+        public float[] HighFrequencyDecayPreviousGain { get; }
+        public float[] PreviousFeedbackOutput { get; }
+
+        public const int EarlyModeCount = 10;
+
+        private const int FixedPointPrecision = 14;
+
+        private ReadOnlySpan<float> GetFdnDelayTimesByLateMode(ReverbLateMode lateMode)
+        {
+            return FdnDelayTimes.AsSpan().Slice((int)lateMode * 4, 4);
+        }
+
+        private ReadOnlySpan<float> GetDecayDelayTimesByLateMode(ReverbLateMode lateMode)
+        {
+            return DecayDelayTimes.AsSpan().Slice((int)lateMode * 4, 4);
+        }
+
+        public ReverbState(ref ReverbParameter parameter, ulong workBuffer, bool isLongSizePreDelaySupported)
+        {
+            FdnDelayLines = new IDelayLine[4];
+            DecayDelays = new DecayDelay[4];
+            EarlyDelayTime = new uint[EarlyModeCount];
+            EarlyGain = new float[EarlyModeCount];
+            HighFrequencyDecayDirectGain = new float[4];
+            HighFrequencyDecayPreviousGain = new float[4];
+            PreviousFeedbackOutput = new float[4];
+
+            ReadOnlySpan<float> fdnDelayTimes = GetFdnDelayTimesByLateMode(ReverbLateMode.Limit);
+            ReadOnlySpan<float> decayDelayTimes = GetDecayDelayTimesByLateMode(ReverbLateMode.Limit);
+
+            uint sampleRate = (uint)FixedPointHelper.ToFloat((uint)parameter.SampleRate, FixedPointPrecision);
+
+            for (int i = 0; i < 4; i++)
+            {
+                FdnDelayLines[i] = new DelayLine(sampleRate, fdnDelayTimes[i]);
+                DecayDelays[i] = new DecayDelay(new DelayLine(sampleRate, decayDelayTimes[i]));
+            }
+
+            float preDelayTimeMax = 150.0f;
+
+            if (isLongSizePreDelaySupported)
+            {
+                preDelayTimeMax = 350.0f;
+            }
+
+            PreDelayLine = new DelayLine(sampleRate, preDelayTimeMax);
+            BackLeftDelayLine = new DelayLine(sampleRate, 5.0f);
+
+            UpdateParameter(ref parameter);
+        }
+
+        public void UpdateParameter(ref ReverbParameter parameter)
+        {
+            uint sampleRate = (uint)FixedPointHelper.ToFloat((uint)parameter.SampleRate, FixedPointPrecision);
+
+            float preDelayTimeInMilliseconds = FixedPointHelper.ToFloat(parameter.PreDelayTime, FixedPointPrecision);
+            float earlyGain = FixedPointHelper.ToFloat(parameter.EarlyGain, FixedPointPrecision);
+            float coloration = FixedPointHelper.ToFloat(parameter.Coloration, FixedPointPrecision);
+            float decayTime = FixedPointHelper.ToFloat(parameter.DecayTime, FixedPointPrecision);
+
+            for (int i = 0; i < 10; i++)
+            {
+                EarlyDelayTime[i] = Math.Min(IDelayLine.GetSampleCount(sampleRate, EarlyDelayTimes[i] + preDelayTimeInMilliseconds), PreDelayLine.SampleCountMax) + 1;
+                EarlyGain[i] = EarlyGainBase[i] * earlyGain;
+            }
+
+            if (parameter.ChannelCount == 2)
+            {
+                EarlyGain[4] = EarlyGain[4] * 0.5f;
+                EarlyGain[5] = EarlyGain[5] * 0.5f;
+            }
+
+            PreDelayLineDelayTime = Math.Min(IDelayLine.GetSampleCount(sampleRate, PreDelayTimes[(int)parameter.EarlyMode] + preDelayTimeInMilliseconds), PreDelayLine.SampleCountMax);
+
+            ReadOnlySpan<float> fdnDelayTimes = GetFdnDelayTimesByLateMode(parameter.LateMode);
+            ReadOnlySpan<float> decayDelayTimes = GetDecayDelayTimesByLateMode(parameter.LateMode);
+
+            float highFrequencyDecayRatio = FixedPointHelper.ToFloat(parameter.HighFrequencyDecayRatio, FixedPointPrecision);
+            float highFrequencyUnknownValue = FloatingPointHelper.Cos(1280.0f / sampleRate);
+
+            for (int i = 0; i < 4; i++)
+            {
+                FdnDelayLines[i].SetDelay(fdnDelayTimes[i]);
+                DecayDelays[i].SetDelay(decayDelayTimes[i]);
+
+                float tempA = -3 * (DecayDelays[i].CurrentSampleCount + FdnDelayLines[i].CurrentSampleCount);
+                float tempB = tempA / (decayTime * sampleRate);
+                float tempC;
+                float tempD;
+
+                if (highFrequencyDecayRatio < 0.995f)
+                {
+                    float tempE = FloatingPointHelper.Pow10((((1.0f / highFrequencyDecayRatio) - 1.0f) * 2) / 100 * (tempB / 10));
+                    float tempF = 1.0f - tempE;
+                    float tempG = 2.0f - (tempE * 2 * highFrequencyUnknownValue);
+                    float tempH = MathF.Sqrt((tempG * tempG) - (tempF * tempF * 4));
+
+                    tempC = (tempG - tempH) / (tempF * 2);
+                    tempD = 1.0f - tempC;
+                }
+                else
+                {
+                    // no high frequency decay ratio
+                    tempC = 0.0f;
+                    tempD = 1.0f;
+                }
+
+                HighFrequencyDecayDirectGain[i] = FloatingPointHelper.Pow10(tempB / 1000) * tempD * 0.7071f;
+                HighFrequencyDecayPreviousGain[i] = tempC;
+                PreviousFeedbackOutput[i] = 0.0f;
+
+                DecayDelays[i].SetDecayRate(0.6f * (1.0f - coloration));
+            }
+        }
+    }
+}