4 files changed, 509 insertions, 0 deletions
diff --git a/src/audio_core/renderer/mix/mix_context.cpp b/src/audio_core/renderer/mix/mix_context.cpp
new file mode 100644
index 000000000..2427c83ed
--- /dev/null
+++ b/src/audio_core/renderer/mix/mix_context.cpp
@@ -0,0 +1,141 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include <ranges>
+
+#include "audio_core/renderer/mix/mix_context.h"
+#include "audio_core/renderer/splitter/splitter_context.h"
+
+namespace AudioCore::AudioRenderer {
+
+void MixContext::Initialize(std::span<MixInfo*> sorted_mix_infos_, std::span<MixInfo> mix_infos_,
+                            const u32 count_, std::span<s32> effect_process_order_buffer_,
+                            const u32 effect_count_, std::span<u8> node_states_workbuffer,
+                            const u64 node_buffer_size, std::span<u8> edge_matrix_workbuffer,
+                            const u64 edge_matrix_size) {
+    count = count_;
+    sorted_mix_infos = sorted_mix_infos_;
+    mix_infos = mix_infos_;
+    effect_process_order_buffer = effect_process_order_buffer_;
+    effect_count = effect_count_;
+
+    if (node_states_workbuffer.size() > 0 && edge_matrix_workbuffer.size() > 0) {
+        node_states.Initialize(node_states_workbuffer, node_buffer_size, count);
+        edge_matrix.Initialize(edge_matrix_workbuffer, edge_matrix_size, count);
+    }
+
+    for (s32 i = 0; i < count; i++) {
+        sorted_mix_infos[i] = &mix_infos[i];
+    }
+}
+
+MixInfo* MixContext::GetSortedInfo(const s32 index) {
+    return sorted_mix_infos[index];
+}
+
+void MixContext::SetSortedInfo(const s32 index, MixInfo& mix_info) {
+    sorted_mix_infos[index] = &mix_info;
+}
+
+MixInfo* MixContext::GetInfo(const s32 index) {
+    return &mix_infos[index];
+}
+
+MixInfo* MixContext::GetFinalMixInfo() {
+    return &mix_infos[0];
+}
+
+s32 MixContext::GetCount() const {
+    return count;
+}
+
+void MixContext::UpdateDistancesFromFinalMix() {
+    for (s32 i = 0; i < count; i++) {
+        mix_infos[i].distance_from_final_mix = InvalidDistanceFromFinalMix;
+    }
+
+    for (s32 i = 0; i < count; i++) {
+        auto& mix_info{mix_infos[i]};
+        sorted_mix_infos[i] = &mix_info;
+
+        if (!mix_info.in_use) {
+            continue;
+        }
+
+        auto mix_id{mix_info.mix_id};
+        auto distance_to_final_mix{FinalMixId};
+
+        while (distance_to_final_mix < count) {
+            if (mix_id == FinalMixId) {
+                break;
+            }
+
+            if (mix_id == UnusedMixId) {
+                distance_to_final_mix = InvalidDistanceFromFinalMix;
+                break;
+            }
+
+            auto distance_from_final_mix{mix_infos[mix_id].distance_from_final_mix};
+            if (distance_from_final_mix != InvalidDistanceFromFinalMix) {
+                distance_to_final_mix = distance_from_final_mix + 1;
+                break;
+            }
+
+            distance_to_final_mix++;
+            mix_id = mix_infos[mix_id].dst_mix_id;
+        }
+
+        if (distance_to_final_mix >= count) {
+            distance_to_final_mix = InvalidDistanceFromFinalMix;
+        }
+        mix_info.distance_from_final_mix = distance_to_final_mix;
+    }
+}
+
+void MixContext::SortInfo() {
+    UpdateDistancesFromFinalMix();
+
+    std::ranges::sort(sorted_mix_infos, [](const MixInfo* lhs, const MixInfo* rhs) {
+        return lhs->distance_from_final_mix > rhs->distance_from_final_mix;
+    });
+
+    CalcMixBufferOffset();
+}
+
+void MixContext::CalcMixBufferOffset() {
+    s16 offset{0};
+    for (s32 i = 0; i < count; i++) {
+        auto mix_info{sorted_mix_infos[i]};
+        if (mix_info->in_use) {
+            const auto buffer_count{mix_info->buffer_count};
+            mix_info->buffer_offset = offset;
+            offset += buffer_count;
+        }
+    }
+}
+
+bool MixContext::TSortInfo(const SplitterContext& splitter_context) {
+    if (!splitter_context.UsingSplitter()) {
+        CalcMixBufferOffset();
+        return true;
+    }
+
+    if (!node_states.Tsort(edge_matrix)) {
+        return false;
+    }
+
+    std::vector<s32> sorted_results{node_states.GetSortedResuls()};
+    const auto result_size{std::min(count, static_cast<s32>(sorted_results.size()))};
+    for (s32 i = 0; i < result_size; i++) {
+        sorted_mix_infos[i] = &mix_infos[sorted_results[i]];
+    }
+
+    CalcMixBufferOffset();
+    return true;
+}
+
+EdgeMatrix& MixContext::GetEdgeMatrix() {
+    return edge_matrix;
+}
+
+} // namespace AudioCore::AudioRenderer
diff --git a/src/audio_core/renderer/mix/mix_context.h b/src/audio_core/renderer/mix/mix_context.h
new file mode 100644
index 000000000..da3aa2829
--- /dev/null
+++ b/src/audio_core/renderer/mix/mix_context.h
@@ -0,0 +1,124 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <span>
+
+#include "audio_core/renderer/mix/mix_info.h"
+#include "audio_core/renderer/nodes/edge_matrix.h"
+#include "audio_core/renderer/nodes/node_states.h"
+#include "common/common_types.h"
+
+namespace AudioCore::AudioRenderer {
+class SplitterContext;
+
+/*
+ * Manages mixing states, sorting and building a node graph to describe a mix order.
+ */
+class MixContext {
+public:
+    /**
+     * Initialize the mix context.
+     *
+     * @param sorted_mix_infos - Buffer for the sorted mix infos.
+     * @param mix_infos - Buffer for the mix infos.
+     * @param effect_process_order_buffer - Buffer for the effect process orders.
+     * @param effect_count - Number of effects in the buffer.
+     * @param node_states_workbuffer - Buffer for node states.
+     * @param node_buffer_size - Size of the node states buffer.
+     * @param edge_matrix_workbuffer - Buffer for edge matrix.
+     * @param edge_matrix_size - Size of the edge matrix buffer.
+     */
+    void Initialize(std::span<MixInfo*> sorted_mix_infos, std::span<MixInfo> mix_infos, u32 count_,
+                    std::span<s32> effect_process_order_buffer, u32 effect_count,
+                    std::span<u8> node_states_workbuffer, u64 node_buffer_size,
+                    std::span<u8> edge_matrix_workbuffer, u64 edge_matrix_size);
+
+    /**
+     * Get a sorted mix at the given index.
+     *
+     * @param index - Index of sorted mix.
+     * @return The sorted mix.
+     */
+    MixInfo* GetSortedInfo(s32 index);
+
+    /**
+     * Set the sorted info at the given index.
+     *
+     * @param index    - Index of sorted mix.
+     * @param mix_info - The new mix for this index.
+     */
+    void SetSortedInfo(s32 index, MixInfo& mix_info);
+
+    /**
+     * Get a mix at the given index.
+     *
+     * @param index - Index of mix.
+     * @return The mix.
+     */
+    MixInfo* GetInfo(s32 index);
+
+    /**
+     * Get the final mix.
+     *
+     * @return The final mix.
+     */
+    MixInfo* GetFinalMixInfo();
+
+    /**
+     * Get the current number of mixes.
+     *
+     * @return The number of active mixes.
+     */
+    s32 GetCount() const;
+
+    /**
+     * Update all of the mixes' distance from the final mix.
+     * Needs to be called after altering the mix graph.
+     */
+    void UpdateDistancesFromFinalMix();
+
+    /**
+     * Non-splitter sort, sorts the sorted mixes based on their distance from the final mix.
+     */
+    void SortInfo();
+
+    /**
+     * Re-calculate the mix buffer offsets for each mix after altering the mix.
+     */
+    void CalcMixBufferOffset();
+
+    /**
+     * Splitter sort, traverse the splitter node graph and sort the sorted mixes from results.
+     *
+     * @param splitter_context - Splitter context for the sort.
+     * @return True if the sort was successful, othewise false.
+     */
+    bool TSortInfo(const SplitterContext& splitter_context);
+
+    /**
+     * Get the edge matrix used for the mix graph.
+     *
+     * @return The edge matrix used.
+     */
+    EdgeMatrix& GetEdgeMatrix();
+
+private:
+    /// Array of sorted mixes
+    std::span<MixInfo*> sorted_mix_infos{};
+    /// Array of mixes
+    std::span<MixInfo> mix_infos{};
+    /// Number of active mixes
+    s32 count{};
+    /// Array of effect process orderings
+    std::span<s32> effect_process_order_buffer{};
+    /// Number of effects in the process ordering buffer
+    u64 effect_count{};
+    /// Node states used in splitter sort
+    NodeStates node_states{};
+    /// Edge matrix for connected nodes used in splitter sort
+    EdgeMatrix edge_matrix{};
+};
+
+} // namespace AudioCore::AudioRenderer
diff --git a/src/audio_core/renderer/mix/mix_info.cpp b/src/audio_core/renderer/mix/mix_info.cpp
new file mode 100644
index 000000000..cc18e57ee
--- /dev/null
+++ b/src/audio_core/renderer/mix/mix_info.cpp
@@ -0,0 +1,120 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "audio_core/renderer/behavior/behavior_info.h"
+#include "audio_core/renderer/effect/effect_context.h"
+#include "audio_core/renderer/mix/mix_info.h"
+#include "audio_core/renderer/nodes/edge_matrix.h"
+#include "audio_core/renderer/splitter/splitter_context.h"
+
+namespace AudioCore::AudioRenderer {
+
+MixInfo::MixInfo(std::span<s32> effect_order_buffer_, s32 effect_count_, BehaviorInfo& behavior)
+    : effect_order_buffer{effect_order_buffer_}, effect_count{effect_count_},
+      long_size_pre_delay_supported{behavior.IsLongSizePreDelaySupported()} {
+    ClearEffectProcessingOrder();
+}
+
+void MixInfo::Cleanup() {
+    mix_id = UnusedMixId;
+    dst_mix_id = UnusedMixId;
+    dst_splitter_id = UnusedSplitterId;
+}
+
+void MixInfo::ClearEffectProcessingOrder() {
+    for (s32 i = 0; i < effect_count; i++) {
+        effect_order_buffer[i] = -1;
+    }
+}
+
+bool MixInfo::Update(EdgeMatrix& edge_matrix, const InParameter& in_params,
+                     EffectContext& effect_context, SplitterContext& splitter_context,
+                     const BehaviorInfo& behavior) {
+    volume = in_params.volume;
+    sample_rate = in_params.sample_rate;
+    buffer_count = static_cast<s16>(in_params.buffer_count);
+    in_use = in_params.in_use;
+    mix_id = in_params.mix_id;
+    node_id = in_params.node_id;
+    mix_volumes = in_params.mix_volumes;
+
+    bool sort_required{false};
+    if (behavior.IsSplitterSupported()) {
+        sort_required = UpdateConnection(edge_matrix, in_params, splitter_context);
+    } else {
+        if (dst_mix_id != in_params.dest_mix_id) {
+            dst_mix_id = in_params.dest_mix_id;
+            sort_required = true;
+        }
+        dst_splitter_id = UnusedSplitterId;
+    }
+
+    ClearEffectProcessingOrder();
+
+    // Check all effects, and set their order if they belong to this mix.
+    const auto count{effect_context.GetCount()};
+    for (u32 i = 0; i < count; i++) {
+        const auto& info{effect_context.GetInfo(i)};
+        if (mix_id == info.GetMixId()) {
+            const auto processing_order{info.GetProcessingOrder()};
+            if (processing_order > effect_count) {
+                break;
+            }
+            effect_order_buffer[processing_order] = i;
+        }
+    }
+
+    return sort_required;
+}
+
+bool MixInfo::UpdateConnection(EdgeMatrix& edge_matrix, const InParameter& in_params,
+                               SplitterContext& splitter_context) {
+    auto has_new_connection{false};
+    if (dst_splitter_id != UnusedSplitterId) {
+        auto& splitter_info{splitter_context.GetInfo(dst_splitter_id)};
+        has_new_connection = splitter_info.HasNewConnection();
+    }
+
+    // Check if this mix matches the input parameters.
+    // If everything is the same, don't bother updating.
+    if (dst_mix_id == in_params.dest_mix_id && dst_splitter_id == in_params.dest_splitter_id &&
+        !has_new_connection) {
+        return false;
+    }
+
+    // Reset the mix in the graph, as we're about to update it.
+    edge_matrix.RemoveEdges(mix_id);
+
+    if (in_params.dest_mix_id == UnusedMixId) {
+        if (in_params.dest_splitter_id != UnusedSplitterId) {
+            // If the splitter is used, connect this mix to each active destination.
+            auto& splitter_info{splitter_context.GetInfo(in_params.dest_splitter_id)};
+            auto const destination_count{splitter_info.GetDestinationCount()};
+
+            for (u32 i = 0; i < destination_count; i++) {
+                auto destination{
+                    splitter_context.GetDesintationData(in_params.dest_splitter_id, i)};
+
+                if (destination) {
+                    const auto destination_id{destination->GetMixId()};
+                    if (destination_id != UnusedMixId) {
+                        edge_matrix.Connect(mix_id, destination_id);
+                    }
+                }
+            }
+        }
+    } else {
+        // If the splitter is not used, only connect this mix to its destination.
+        edge_matrix.Connect(mix_id, in_params.dest_mix_id);
+    }
+
+    dst_mix_id = in_params.dest_mix_id;
+    dst_splitter_id = in_params.dest_splitter_id;
+    return true;
+}
+
+bool MixInfo::HasAnyConnection() const {
+    return dst_mix_id != UnusedMixId || dst_splitter_id != UnusedSplitterId;
+}
+
+} // namespace AudioCore::AudioRenderer
diff --git a/src/audio_core/renderer/mix/mix_info.h b/src/audio_core/renderer/mix/mix_info.h
new file mode 100644
index 000000000..b5fa4c0c7
--- /dev/null
+++ b/src/audio_core/renderer/mix/mix_info.h
@@ -0,0 +1,124 @@
+// SPDX-FileCopyrightText: Copyright 2022 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include <array>
+#include <span>
+
+#include "audio_core/common/common.h"
+#include "common/common_types.h"
+
+namespace AudioCore::AudioRenderer {
+class EdgeMatrix;
+class SplitterContext;
+class EffectContext;
+class BehaviorInfo;
+
+/**
+ * A single mix, which may feed through other mixes in a chain until reaching the final output mix.
+ */
+class MixInfo {
+public:
+    struct InParameter {
+        /* 0x000 */ f32 volume;
+        /* 0x004 */ u32 sample_rate;
+        /* 0x008 */ u32 buffer_count;
+        /* 0x00C */ bool in_use;
+        /* 0x00D */ bool is_dirty;
+        /* 0x010 */ s32 mix_id;
+        /* 0x014 */ u32 effect_count;
+        /* 0x018 */ s32 node_id;
+        /* 0x01C */ char unk01C[0x8];
+        /* 0x024 */ std::array<std::array<f32, MaxMixBuffers>, MaxMixBuffers> mix_volumes;
+        /* 0x924 */ s32 dest_mix_id;
+        /* 0x928 */ s32 dest_splitter_id;
+        /* 0x92C */ char unk92C[0x4];
+    };
+    static_assert(sizeof(InParameter) == 0x930, "MixInfo::InParameter has the wrong size!");
+
+    struct InDirtyParameter {
+        /* 0x00 */ u32 magic;
+        /* 0x04 */ s32 count;
+        /* 0x08 */ char unk08[0x18];
+    };
+    static_assert(sizeof(InDirtyParameter) == 0x20,
+                  "MixInfo::InDirtyParameter has the wrong size!");
+
+    MixInfo(std::span<s32> effect_order_buffer, s32 effect_count, BehaviorInfo& behavior);
+
+    /**
+     * Clean up the mix, resetting it to a default state.
+     */
+    void Cleanup();
+
+    /**
+     * Clear the effect process order for all effects in this mix.
+     */
+    void ClearEffectProcessingOrder();
+
+    /**
+     * Update the mix according to the given parameters.
+     *
+     * @param edge_matrix      - Updated with new splitter node connections, if supported.
+     * @param in_params        - Input parameters.
+     * @param effect_context   - Used to update the effect orderings.
+     * @param splitter_context - Used to update the mix graph if supported.
+     * @param behavior        - Used for checking which features are supported.
+     * @return True if the mix was updated and a sort is required, otherwise false.
+     */
+    bool Update(EdgeMatrix& edge_matrix, const InParameter& in_params,
+                EffectContext& effect_context, SplitterContext& splitter_context,
+                const BehaviorInfo& behavior);
+
+    /**
+     * Update the mix's connection in the node graph according to the given parameters.
+     *
+     * @param edge_matrix      - Updated with new splitter node connections, if supported.
+     * @param in_params        - Input parameters.
+     * @param splitter_context - Used to update the mix graph if supported.
+     * @return True if the mix was updated and a sort is required, otherwise false.
+     */
+    bool UpdateConnection(EdgeMatrix& edge_matrix, const InParameter& in_params,
+                          SplitterContext& splitter_context);
+
+    /**
+     * Check if this mix is connected to any other.
+     *
+     * @return True if the mix has a connection, otherwise false.
+     */
+    bool HasAnyConnection() const;
+
+    /// Volume of this mix
+    f32 volume{};
+    /// Sample rate of this mix
+    u32 sample_rate{};
+    /// Number of buffers in this mix
+    s16 buffer_count{};
+    /// Is this mix in use?
+    bool in_use{};
+    /// Is this mix enabled?
+    bool enabled{};
+    /// Id of this mix
+    s32 mix_id{UnusedMixId};
+    /// Node id of this mix
+    s32 node_id{};
+    /// Buffer offset for this mix
+    s16 buffer_offset{};
+    /// Distance to the final mix
+    s32 distance_from_final_mix{InvalidDistanceFromFinalMix};
+    /// Array of effect orderings of all effects in this mix
+    std::span<s32> effect_order_buffer;
+    /// Number of effects in this mix
+    const s32 effect_count;
+    /// Id for next mix in the chain
+    s32 dst_mix_id{UnusedMixId};
+    /// Mixing volumes for this mix used when this mix is chained with another
+    std::array<std::array<f32, MaxMixBuffers>, MaxMixBuffers> mix_volumes{};
+    /// Id for next mix in the graph when splitter is used
+    s32 dst_splitter_id{UnusedSplitterId};
+    /// Is a longer pre-delay time supported for the reverb effect?
+    const bool long_size_pre_delay_supported;
+};
+
+} // namespace AudioCore::AudioRenderer