From fa10dcfd29e3a39103c5f7ba13ebba652c631307 Mon Sep 17 00:00:00 2001
From: Silent <zdanio95@gmail.com>
Date: Wed, 14 Oct 2020 23:52:01 +0200
Subject: [PATCH] Refactor SetMixBinVolumes

* Clears the code up
* Picks the buffer volume from the maximum speaker volume
---
 .../DSOUND/DirectSound/DirectSoundInline.hpp  | 67 ++++++++-----------
 1 file changed, 27 insertions(+), 40 deletions(-)

diff --git a/src/core/hle/DSOUND/DirectSound/DirectSoundInline.hpp b/src/core/hle/DSOUND/DirectSound/DirectSoundInline.hpp
index ad8e2be47..c8cd34af9 100644
--- a/src/core/hle/DSOUND/DirectSound/DirectSoundInline.hpp
+++ b/src/core/hle/DSOUND/DirectSound/DirectSoundInline.hpp
@@ -27,6 +27,7 @@
 #pragma once
 
 #include <mutex>
+#include <optional>
 
 #include "common/XADPCM.h"
 #include "core/hle/DSOUND/XbDSoundTypes.h"
@@ -1289,49 +1290,35 @@ static inline HRESULT HybridDirectSoundBuffer_SetMixBinVolumes_8(
 {
     HRESULT hRet = DSERR_INVALIDPARAM;
 
-    if (pMixBins != xbox::zeroptr) {
-        DWORD counter = pMixBins->dwCount, count = pMixBins->dwCount;
-        LONG volume = 0;
-        if (pMixBins->lpMixBinVolumePairs != xbox::zeroptr) {
-            // Let's normalize audio level except for low frequency (subwoofer)
-            for (DWORD i = 0; i < count; i++) {
-                // Update the mixbin volume only, do not reassign volume pair array.
-                for (DWORD i = 0; i < count; i++) {
-                    const auto& it_in = pMixBins->lpMixBinVolumePairs[i];
-                    for (DWORD ii = 0; ii < Xb_VoiceProperties.dwMixBinCount; ii++) {
-                        auto& it_internal = Xb_VoiceProperties.MixBinVolumePairs[ii];
-
-                        // Once found a match, set the volume.
-                        // NOTE If titles input duplicate with different volume,
-                        //      it will override previous value.
-                        if (it_in.dwMixBin == it_internal.dwMixBin) {
-                            it_internal.lVolume = it_in.lVolume;
-                        }
-                    }
-                }
-
-#if 0 // This code isn't ideal for DirectSound, since it's not possible to set volume for each speakers.
-                if (pMixBins->lpMixBinVolumePairs[i].dwMixBin != XDSMIXBIN_LOW_FREQUENCY
-                    // We only want to focus on speaker volumes, nothing else.
-                    && pMixBins->lpMixBinVolumePairs[i].dwMixBin < XDSMIXBIN_SPEAKERS_MAX) {
-#endif
-                if (pMixBins->lpMixBinVolumePairs[i].dwMixBin == XDSMIXBIN_FRONT_LEFT
-                    // We only want to focus on front speaker volumes, nothing else.
-                    || pMixBins->lpMixBinVolumePairs[i].dwMixBin == XDSMIXBIN_FRONT_RIGHT) {
-                    volume += pMixBins->lpMixBinVolumePairs[i].lVolume;
-                } else {
-                    counter--;
-                }
+    if (pMixBins != xbox::zeroptr && pMixBins->lpMixBinVolumePairs != xbox::zeroptr) {
+        LONG maxVolume = DSBVOLUME_MIN;
+        // Let's normalize audio level except for low frequency (subwoofer)
+        for (DWORD i = 0; i < pMixBins->dwCount; i++) {
+            // Update the mixbin volume only, do not reassign volume pair array.
+            const auto& it_in = pMixBins->lpMixBinVolumePairs[i];
+            auto it_out = std::find_if(Xb_VoiceProperties.MixBinVolumePairs, Xb_VoiceProperties.MixBinVolumePairs+Xb_VoiceProperties.dwMixBinCount,
+                [&it_in](const auto& e) {
+                    return e.dwMixBin == it_in.dwMixBin;
+                });
+            // Once found a match, set the volume.
+            // NOTE If titles input duplicate with different volume,
+            //      it will override previous value.
+            if (it_out != Xb_VoiceProperties.MixBinVolumePairs+Xb_VoiceProperties.dwMixBinCount) {
+                it_out->lVolume = it_in.lVolume;
             }
-            if (counter > 0) {
-                Xb_volumeMixBin = volume / (LONG)counter;
-                int32_t Xb_volume = Xb_Voice->GetVolume() + Xb_Voice->GetHeadroom();
-                hRet = HybridDirectSoundBuffer_SetVolume(pDSBuffer, Xb_volume, EmuFlags,
-                                                         Xb_volumeMixBin, Xb_Voice);
-            } else {
-                hRet = DS_OK;
+
+            // Since we cannot set per-channel volumes, we want to pick "dominant" volume
+            if (it_in.dwMixBin != XDSMIXBIN_LOW_FREQUENCY && it_in.dwMixBin < XDSMIXBIN_SPEAKERS_MAX) {
+                if (it_in.lVolume > maxVolume) {
+                    maxVolume = it_in.lVolume;
+                }
             }
         }
+
+        Xb_volumeMixBin = maxVolume;
+        int32_t Xb_volume = Xb_Voice->GetVolume() + Xb_Voice->GetHeadroom();
+        hRet = HybridDirectSoundBuffer_SetVolume(pDSBuffer, Xb_volume, EmuFlags,
+                                                    Xb_volumeMixBin, Xb_Voice);
     }
 
     return hRet;