From 032ff829554699bcd527926723f121e5e4b70ffa Mon Sep 17 00:00:00 2001
From: tildearrow <me@tildearrow.org>
Date: Mon, 7 Apr 2025 23:12:27 -0500
Subject: [PATCH] fix low quality not working in acquireDirect

performance may be reduced
---
 extern/blip_buf/blip_buf.c       |  5 ++++-
 extern/blip_buf/blip_buf.h       |  5 ++++-
 src/engine/dispatchContainer.cpp | 29 ++++++++---------------------
 src/engine/engine.cpp            |  6 ++++++
 4 files changed, 22 insertions(+), 23 deletions(-)

diff --git a/extern/blip_buf/blip_buf.c b/extern/blip_buf/blip_buf.c
index 63f14a049..0ed95a732 100644
--- a/extern/blip_buf/blip_buf.c
+++ b/extern/blip_buf/blip_buf.c
@@ -299,7 +299,7 @@ possibly-wider fixed_t. On 32-bit platforms, this is likely more efficient.
 And by having pre_shift 32, a 32-bit platform can easily do the shift by
 simply ignoring the low half. */
 
-void blip_add_delta( blip_t* m, unsigned time, int delta )
+void blip_add_delta_slow( blip_t* m, unsigned time, int delta )
 {
 	unsigned fixed = (unsigned) ((time * m->factor + m->offset) >> pre_shift);
 	buf_t* out = SAMPLES( m ) + m->avail + (fixed >> frac_bits);
@@ -350,3 +350,6 @@ void blip_add_delta_fast( blip_t* m, unsigned time, int delta )
 	out [7] += delta * delta_unit - delta2;
 	out [8] += delta2;
 }
+
+/* (tildearrow) ability to change blip_add_delta at runtime */
+void (*blip_add_delta)( blip_t*, unsigned int, int )=blip_add_delta_slow;
\ No newline at end of file
diff --git a/extern/blip_buf/blip_buf.h b/extern/blip_buf/blip_buf.h
index 524d10265..8df664b55 100644
--- a/extern/blip_buf/blip_buf.h
+++ b/extern/blip_buf/blip_buf.h
@@ -35,8 +35,11 @@ blip_max_ratio = 1 << 20 };
 /** Clears entire buffer. Afterwards, blip_samples_avail() == 0. */
 void blip_clear( blip_t* );
 
+/** (tildearrow) ability to change blip_add_delta at runtime */
+extern void (*blip_add_delta)( blip_t*, unsigned int, int );
+
 /** Adds positive/negative delta into buffer at specified clock time. */
-void blip_add_delta( blip_t*, unsigned int clock_time, int delta );
+void blip_add_delta_slow( blip_t*, unsigned int clock_time, int delta );
 
 /** Same as blip_add_delta(), but uses faster, lower-quality synthesis. */
 void blip_add_delta_fast( blip_t*, unsigned int clock_time, int delta );
diff --git a/src/engine/dispatchContainer.cpp b/src/engine/dispatchContainer.cpp
index e594ecc95..23cbde76b 100644
--- a/src/engine/dispatchContainer.cpp
+++ b/src/engine/dispatchContainer.cpp
@@ -194,27 +194,14 @@ void DivDispatchContainer::fillBuf(size_t runtotal, size_t offset, size_t size)
         }
       }
     }
-    if (lowQuality) {
-      for (int i=0; i<outs; i++) {
-        if (bbIn[i]==NULL) continue;
-        if (bb[i]==NULL) continue;
-        for (size_t j=0; j<runtotal; j++) {
-          if (bbIn[i][j]==temp[i]) continue;
-          temp[i]=bbIn[i][j];
-          blip_add_delta_fast(bb[i],j,temp[i]-prevSample[i]);
-          prevSample[i]=temp[i];
-        }
-      }
-    } else {
-      for (int i=0; i<outs; i++) {
-        if (bbIn[i]==NULL) continue;
-        if (bb[i]==NULL) continue;
-        for (size_t j=0; j<runtotal; j++) {
-          if (bbIn[i][j]==temp[i]) continue;
-          temp[i]=bbIn[i][j];
-          blip_add_delta(bb[i],j,temp[i]-prevSample[i]);
-          prevSample[i]=temp[i];
-        }
+    for (int i=0; i<outs; i++) {
+      if (bbIn[i]==NULL) continue;
+      if (bb[i]==NULL) continue;
+      for (size_t j=0; j<runtotal; j++) {
+        if (bbIn[i][j]==temp[i]) continue;
+        temp[i]=bbIn[i][j];
+        blip_add_delta(bb[i],j,temp[i]-prevSample[i]);
+        prevSample[i]=temp[i];
       }
     }
   }
diff --git a/src/engine/engine.cpp b/src/engine/engine.cpp
index 54e0c96ba..cfa922bdc 100644
--- a/src/engine/engine.cpp
+++ b/src/engine/engine.cpp
@@ -3763,6 +3763,12 @@ void DivEngine::initDispatch(bool isRender) {
   lowQuality=getConfInt("audioQuality",0);
   dcHiPass=getConfInt("audioHiPass",1);
 
+  if (lowQuality) {
+    blip_add_delta=blip_add_delta_fast;
+  } else {
+    blip_add_delta=blip_add_delta_slow;
+  }
+
   for (int i=0; i<song.systemLen; i++) {
     disCont[i].init(song.system[i],this,getChannelCount(song.system[i]),got.rate,song.systemFlags[i],isRender);
     disCont[i].setRates(got.rate);