From 0b2df4f7d486ff31ca3d33475fe2f0fa5821e660 Mon Sep 17 00:00:00 2001
From: tildearrow <tildearrow@protonmail.com>
Date: Mon, 6 Feb 2023 14:14:50 -0500
Subject: [PATCH] SoundUnit: enough of bitfields, part 2

---
 src/engine/platform/sound/su.cpp | 42 ++++++++++++++++----------------
 src/engine/platform/sound/su.h   | 11 +++------
 2 files changed, 24 insertions(+), 29 deletions(-)

diff --git a/src/engine/platform/sound/su.cpp b/src/engine/platform/sound/su.cpp
index d74377cd..0a0b38b4 100644
--- a/src/engine/platform/sound/su.cpp
+++ b/src/engine/platform/sound/su.cpp
@@ -160,15 +160,15 @@ void SoundUnit::NextSample(short* l, short* r) {
     if (chan[i].flags1&32) {
       if (--swvolt[i]<=0) {
         swvolt[i]=chan[i].swvol.speed;
-        if (chan[i].swvol.dir) {
-          chan[i].vol+=chan[i].swvol.amt;
-          if (chan[i].vol>chan[i].swvol.bound && !chan[i].swvol.loop) {
+        if (chan[i].swvol.amt&32) {
+          chan[i].vol+=chan[i].swvol.amt&31;
+          if (chan[i].vol>chan[i].swvol.bound && !(chan[i].swvol.amt&64)) {
             chan[i].vol=chan[i].swvol.bound;
           }
           if (chan[i].vol&0x80) {
-            if (chan[i].swvol.loop) {
-              if (chan[i].swvol.loopi) {
-                chan[i].swvol.dir=!chan[i].swvol.dir;
+            if (chan[i].swvol.amt&64) {
+              if (chan[i].swvol.amt&128) {
+                chan[i].swvol.amt^=32;
                 chan[i].vol=0xff-chan[i].vol;
               } else {
                 chan[i].vol&=~0x80;
@@ -178,11 +178,11 @@ void SoundUnit::NextSample(short* l, short* r) {
             }
           }
         } else {
-          chan[i].vol-=chan[i].swvol.amt;
+          chan[i].vol-=chan[i].swvol.amt&31;
           if (chan[i].vol&0x80) {
-            if (chan[i].swvol.loop) {
-              if (chan[i].swvol.loopi) {
-                chan[i].swvol.dir=!chan[i].swvol.dir;
+            if (chan[i].swvol.amt&64) {
+              if (chan[i].swvol.amt&128) {
+                chan[i].swvol.amt^=32;
                 chan[i].vol=-chan[i].vol;
               } else {
                 chan[i].vol&=~0x80;
@@ -191,7 +191,7 @@ void SoundUnit::NextSample(short* l, short* r) {
               chan[i].vol=0x0;
             }
           }
-          if (chan[i].vol<chan[i].swvol.bound && !chan[i].swvol.loop) {
+          if (chan[i].vol<chan[i].swvol.bound && !(chan[i].swvol.amt&64)) {
             chan[i].vol=chan[i].swvol.bound;
           }
         }
@@ -200,20 +200,20 @@ void SoundUnit::NextSample(short* l, short* r) {
     if (chan[i].flags1&16) {
       if (--swfreqt[i]<=0) {
         swfreqt[i]=chan[i].swfreq.speed;
-        if (chan[i].swfreq.dir) {
-          if (chan[i].freq>(0xffff-chan[i].swfreq.amt)) {
+        if (chan[i].swfreq.amt&128) {
+          if (chan[i].freq>(0xffff-(chan[i].swfreq.amt&127))) {
             chan[i].freq=0xffff;
           } else {
-            chan[i].freq=(chan[i].freq*(0x80+chan[i].swfreq.amt))>>7;
+            chan[i].freq=(chan[i].freq*(0x80+(chan[i].swfreq.amt&127)))>>7;
             if ((chan[i].freq>>8)>chan[i].swfreq.bound) {
               chan[i].freq=chan[i].swfreq.bound<<8;
             }
           }
         } else {
-          if (chan[i].freq<chan[i].swfreq.amt) {
+          if (chan[i].freq<(chan[i].swfreq.amt&127)) {
             chan[i].freq=0;
           } else {
-            chan[i].freq=(chan[i].freq*(0xff-chan[i].swfreq.amt))>>8;
+            chan[i].freq=(chan[i].freq*(0xff-(chan[i].swfreq.amt&127)))>>8;
             if ((chan[i].freq>>8)<chan[i].swfreq.bound) {
               chan[i].freq=chan[i].swfreq.bound<<8;
             }
@@ -224,20 +224,20 @@ void SoundUnit::NextSample(short* l, short* r) {
     if (chan[i].flags1&64) {
       if (--swcutt[i]<=0) {
         swcutt[i]=chan[i].swcut.speed;
-        if (chan[i].swcut.dir) {
-          if (chan[i].cutoff>(0xffff-chan[i].swcut.amt)) {
+        if (chan[i].swcut.amt&128) {
+          if (chan[i].cutoff>(0xffff-(chan[i].swcut.amt&127))) {
             chan[i].cutoff=0xffff;
           } else {
-            chan[i].cutoff+=chan[i].swcut.amt;
+            chan[i].cutoff+=chan[i].swcut.amt&127;
             if ((chan[i].cutoff>>8)>chan[i].swcut.bound) {
               chan[i].cutoff=chan[i].swcut.bound<<8;
             }
           }
         } else {
-          if (chan[i].cutoff<chan[i].swcut.amt) {
+          if (chan[i].cutoff<(chan[i].swcut.amt&127)) {
             chan[i].cutoff=0;
           } else {
-            chan[i].cutoff=((2048-(unsigned int)chan[i].swcut.amt)*(unsigned int)chan[i].cutoff)>>11;
+            chan[i].cutoff=((2048-(unsigned int)(chan[i].swcut.amt&127))*(unsigned int)chan[i].cutoff)>>11;
             if ((chan[i].cutoff>>8)<chan[i].swcut.bound) {
               chan[i].cutoff=chan[i].swcut.bound<<8;
             }
diff --git a/src/engine/platform/sound/su.h b/src/engine/platform/sound/su.h
index 502aabac..51c769e3 100644
--- a/src/engine/platform/sound/su.h
+++ b/src/engine/platform/sound/su.h
@@ -72,22 +72,17 @@ class SoundUnit {
       unsigned short pcmrst;
       struct {
         unsigned short speed;
-        unsigned char amt: 7;
-        unsigned char dir: 1;
+        unsigned char amt;
         unsigned char bound;
       } swfreq;
       struct {
         unsigned short speed;
-        unsigned char amt: 5;
-        unsigned char dir: 1;
-        unsigned char loop: 1;
-        unsigned char loopi: 1;
+        unsigned char amt;
         unsigned char bound;
       } swvol;
       struct {
         unsigned short speed;
-        unsigned char amt: 7;
-        unsigned char dir: 1;
+        unsigned char amt;
         unsigned char bound;
       } swcut;
       unsigned char special1C;