1 files changed, 276 insertions, 0 deletions
diff --git a/Ryujinx.Audio.Renderer/Server/Mix/MixContext.cs b/Ryujinx.Audio.Renderer/Server/Mix/MixContext.cs
new file mode 100644
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+++ b/Ryujinx.Audio.Renderer/Server/Mix/MixContext.cs
@@ -0,0 +1,276 @@
+//
+// 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.Server.Splitter;
+using Ryujinx.Audio.Renderer.Utils;
+using System;
+using System.Diagnostics;
+
+namespace Ryujinx.Audio.Renderer.Server.Mix
+{
+    /// <summary>
+    /// Mix context.
+    /// </summary>
+    public class MixContext
+    {
+        /// <summary>
+        /// The total mix count.
+        /// </summary>
+        private uint _mixesCount;
+
+        /// <summary>
+        /// Storage for <see cref="MixState"/>.
+        /// </summary>
+        private Memory<MixState> _mixes;
+
+        /// <summary>
+        /// Storage of the sorted indices to <see cref="MixState"/>.
+        /// </summary>
+        private Memory<int> _sortedMixes;
+
+        /// <summary>
+        /// Graph state.
+        /// </summary>
+        public NodeStates NodeStates { get; }
+
+        /// <summary>
+        /// The instance of the adjacent matrix.
+        /// </summary>
+        public EdgeMatrix EdgeMatrix { get; }
+
+        /// <summary>
+        /// Create a new instance of <see cref="MixContext"/>.
+        /// </summary>
+        public MixContext()
+        {
+            NodeStates = new NodeStates();
+            EdgeMatrix = new EdgeMatrix();
+        }
+
+        /// <summary>
+        /// Initialize the <see cref="MixContext"/>.
+        /// </summary>
+        /// <param name="sortedMixes">The storage for sorted indices.</param>
+        /// <param name="mixes">The storage of <see cref="MixState"/>.</param>
+        /// <param name="nodeStatesWorkBuffer">The storage used for the <see cref="NodeStates"/>.</param>
+        /// <param name="edgeMatrixWorkBuffer">The storage used for the <see cref="EdgeMatrix"/>.</param>
+        public void Initialize(Memory<int> sortedMixes, Memory<MixState> mixes, Memory<byte> nodeStatesWorkBuffer, Memory<byte> edgeMatrixWorkBuffer)
+        {
+            _mixesCount = (uint)mixes.Length;
+            _mixes = mixes;
+            _sortedMixes = sortedMixes;
+
+            if (!nodeStatesWorkBuffer.IsEmpty && !edgeMatrixWorkBuffer.IsEmpty)
+            {
+                NodeStates.Initialize(nodeStatesWorkBuffer, mixes.Length);
+                EdgeMatrix.Initialize(edgeMatrixWorkBuffer, mixes.Length);
+            }
+
+            int sortedId = 0;
+            for (int i = 0; i < _mixes.Length; i++)
+            {
+                SetSortedState(sortedId++, i);
+            }
+        }
+
+        /// <summary>
+        /// Associate the given <paramref name="targetIndex"/> to a given <paramref cref="id"/>.
+        /// </summary>
+        /// <param name="id">The sorted id.</param>
+        /// <param name="targetIndex">The index to associate.</param>
+        private void SetSortedState(int id, int targetIndex)
+        {
+            _sortedMixes.Span[id] = targetIndex;
+        }
+
+        /// <summary>
+        /// Get a reference to the final <see cref="MixState"/>.
+        /// </summary>
+        /// <returns>A reference to the final <see cref="MixState"/>.</returns>
+        public ref MixState GetFinalState()
+        {
+            return ref GetState(RendererConstants.FinalMixId);
+        }
+
+        /// <summary>
+        /// Get a reference to a <see cref="MixState"/> at the given <paramref name="id"/>.
+        /// </summary>
+        /// <param name="id">The index to use.</param>
+        /// <returns>A reference to a <see cref="MixState"/> at the given <paramref name="id"/>.</returns>
+        public ref MixState GetState(int id)
+        {
+            return ref SpanIOHelper.GetFromMemory(_mixes, id, _mixesCount);
+        }
+
+        /// <summary>
+        /// Get a reference to a <see cref="MixState"/> at the given <paramref name="id"/> of the sorted mix info.
+        /// </summary>
+        /// <param name="id">The index to use.</param>
+        /// <returns>A reference to a <see cref="MixState"/> at the given <paramref name="id"/>.</returns>
+        public ref MixState GetSortedState(int id)
+        {
+            Debug.Assert(id >= 0 && id < _mixesCount);
+
+            return ref GetState(_sortedMixes.Span[id]);
+        }
+
+        /// <summary>
+        /// Get the total mix count.
+        /// </summary>
+        /// <returns>The total mix count.</returns>
+        public uint GetCount()
+        {
+            return _mixesCount;
+        }
+
+        /// <summary>
+        /// Update the internal distance from the final mix value of every <see cref="MixState"/>.
+        /// </summary>
+        private void UpdateDistancesFromFinalMix()
+        {
+            foreach (ref MixState mix in _mixes.Span)
+            {
+                mix.ClearDistanceFromFinalMix();
+            }
+
+            for (int i = 0; i < GetCount(); i++)
+            {
+                ref MixState mix = ref GetState(i);
+
+                SetSortedState(i, i);
+
+                if (mix.IsUsed)
+                {
+                    uint distance;
+
+                    if (mix.MixId != RendererConstants.FinalMixId)
+                    {
+                        int mixId = mix.MixId;
+
+                        for (distance = 0; distance < GetCount(); distance++)
+                        {
+                            if (mixId == RendererConstants.UnusedMixId)
+                            {
+                                distance = MixState.InvalidDistanceFromFinalMix;
+                                break;
+                            }
+
+                            ref MixState distanceMix = ref GetState(mixId);
+
+                            if (distanceMix.DistanceFromFinalMix != MixState.InvalidDistanceFromFinalMix)
+                            {
+                                distance = distanceMix.DistanceFromFinalMix + 1;
+                                break;
+                            }
+
+                            mixId = distanceMix.DestinationMixId;
+
+                            if (mixId == RendererConstants.FinalMixId)
+                            {
+                                break;
+                            }
+                        }
+
+                        if (distance > GetCount())
+                        {
+                            distance = MixState.InvalidDistanceFromFinalMix;
+                        }
+                    }
+                    else
+                    {
+                        distance = MixState.InvalidDistanceFromFinalMix;
+                    }
+
+                    mix.DistanceFromFinalMix = distance;
+                }
+            }
+        }
+
+        /// <summary>
+        /// Update the internal mix buffer offset of all <see cref="MixState"/>.
+        /// </summary>
+        private void UpdateMixBufferOffset()
+        {
+            uint offset = 0;
+
+            foreach (ref MixState mix in _mixes.Span)
+            {
+                mix.BufferOffset = offset;
+
+                offset += mix.BufferCount;
+            }
+        }
+
+        /// <summary>
+        /// Sort the mixes using distance from the final mix.
+        /// </summary>
+        public void Sort()
+        {
+            UpdateDistancesFromFinalMix();
+
+            int[] sortedMixesTemp = _sortedMixes.Slice(0, (int)GetCount()).ToArray();
+
+            Array.Sort(sortedMixesTemp, (a, b) =>
+            {
+                ref MixState stateA = ref GetState(a);
+                ref MixState stateB = ref GetState(b);
+
+                return stateB.DistanceFromFinalMix.CompareTo(stateA.DistanceFromFinalMix);
+            });
+
+            sortedMixesTemp.AsSpan().CopyTo(_sortedMixes.Span);
+
+            UpdateMixBufferOffset();
+        }
+
+        /// <summary>
+        /// Sort the mixes and splitters using an adjacency matrix.
+        /// </summary>
+        /// <param name="splitterContext">The <see cref="SplitterContext"/> used.</param>
+        /// <returns>Return true, if no errors in the graph were detected.</returns>
+        public bool Sort(SplitterContext splitterContext)
+        {
+            if (splitterContext.UsingSplitter())
+            {
+                bool isValid = NodeStates.Sort(EdgeMatrix);
+
+                if (isValid)
+                {
+                    ReadOnlySpan<int> sortedMixesIndex = NodeStates.GetTsortResult();
+
+                    int id = 0;
+
+                    for (int i = sortedMixesIndex.Length - 1; i >= 0; i--)
+                    {
+                        SetSortedState(id++, sortedMixesIndex[i]);
+                    }
+
+                    UpdateMixBufferOffset();
+                }
+
+                return isValid;
+            }
+            else
+            {
+                UpdateMixBufferOffset();
+
+                return true;
+            }
+        }
+    }
+}