1 files changed, 103 insertions, 0 deletions
diff --git a/Ryujinx.Audio/Renderer/Dsp/Command/DepopForMixBuffersCommand.cs b/Ryujinx.Audio/Renderer/Dsp/Command/DepopForMixBuffersCommand.cs
new file mode 100644
index 00000000..c6feacfb
--- /dev/null
+++ b/Ryujinx.Audio/Renderer/Dsp/Command/DepopForMixBuffersCommand.cs
@@ -0,0 +1,103 @@
+//
+// Copyright (c) 2019-2021 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 System;
+
+namespace Ryujinx.Audio.Renderer.Dsp.Command
+{
+    public class DepopForMixBuffersCommand : ICommand
+    {
+        public bool Enabled { get; set; }
+
+        public int NodeId { get; }
+
+        public CommandType CommandType => CommandType.DepopForMixBuffers;
+
+        public ulong EstimatedProcessingTime { get; set; }
+
+        public uint MixBufferOffset { get; }
+
+        public uint MixBufferCount { get; }
+
+        public float Decay { get; }
+
+        public Memory<float> DepopBuffer { get; }
+
+        private const int FixedPointPrecisionForDecay = 15;
+
+        public DepopForMixBuffersCommand(Memory<float> depopBuffer, uint bufferOffset, uint mixBufferCount, int nodeId, uint sampleRate)
+        {
+            Enabled = true;
+            NodeId = nodeId;
+            MixBufferOffset = bufferOffset;
+            MixBufferCount = mixBufferCount;
+            DepopBuffer = depopBuffer;
+
+            if (sampleRate == 48000)
+            {
+                Decay = 0.962189f;
+            }
+            else // if (sampleRate == 32000)
+            {
+                Decay = 0.943695f;
+            }
+        }
+
+        private float ProcessDepopMix(Span<float> buffer, float depopValue, uint sampleCount)
+        {
+            if (depopValue <= 0)
+            {
+                for (int i = 0; i < sampleCount; i++)
+                {
+                    depopValue = FloatingPointHelper.MultiplyRoundDown(Decay, depopValue);
+
+                    buffer[i] -= depopValue;
+                }
+
+                return -depopValue;
+            }
+            else
+            {
+                for (int i = 0; i < sampleCount; i++)
+                {
+                    depopValue = FloatingPointHelper.MultiplyRoundDown(Decay, depopValue);
+
+                    buffer[i] += depopValue;
+                }
+
+                return depopValue;
+            }
+
+        }
+
+        public void Process(CommandList context)
+        {
+            uint bufferCount = Math.Min(MixBufferOffset + MixBufferCount, context.BufferCount);
+
+            for (int i = (int)MixBufferOffset; i < bufferCount; i++)
+            {
+                float depopValue = DepopBuffer.Span[i];
+                if (depopValue != 0)
+                {
+                    Span<float> buffer = context.GetBuffer(i);
+
+                    DepopBuffer.Span[i] = ProcessDepopMix(buffer, depopValue, context.SampleCount);
+                }
+            }
+        }
+    }
+}