From b1638646edaa5719d919fcfd5316e21b1b938a7b Mon Sep 17 00:00:00 2001
From: paulfd <paulfd@outlook.fr>
Date: Sun, 29 Sep 2019 03:27:32 +0200
Subject: [PATCH 1/2] The processing has to apply on the real buffer, not the
 delayed data one.

---
 sfizz/Voice.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sfizz/Voice.cpp b/sfizz/Voice.cpp
index fff07961..470273a1 100644
--- a/sfizz/Voice.cpp
+++ b/sfizz/Voice.cpp
@@ -248,9 +248,9 @@ void sfz::Voice::renderBlock(AudioSpan<float> buffer) noexcept
         fillWithData(delayed_buffer);
 
     if (region->isStereo())
-        processStereo(delayed_buffer);
+        processStereo(buffer);
     else
-        processMono(delayed_buffer);
+        processMono(buffer);
 
     if (!egEnvelope.isSmoothing())
         reset();

From ae6f10650ddee7831bb42b902ef817eb2087b8fd Mon Sep 17 00:00:00 2001
From: paulfd <paulfd@outlook.fr>
Date: Sun, 29 Sep 2019 03:27:58 +0200
Subject: [PATCH 2/2] Moved the empty span checks in the fill* functions

---
 sfizz/Voice.cpp | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/sfizz/Voice.cpp b/sfizz/Voice.cpp
index 470273a1..cf351ca3 100644
--- a/sfizz/Voice.cpp
+++ b/sfizz/Voice.cpp
@@ -239,8 +239,6 @@ void sfz::Voice::renderBlock(AudioSpan<float> buffer) noexcept
     auto delay = min(static_cast<size_t>(initialDelay), buffer.getNumFrames());
     auto delayed_buffer = buffer.subspan(delay);
     initialDelay -= delay;
-    if (delayed_buffer.getNumFrames() == 0)
-        return;
 
     if (region->isGenerator())
         fillWithGenerator(delayed_buffer);
@@ -350,6 +348,9 @@ void sfz::Voice::processStereo(AudioSpan<float> buffer) noexcept
 
 void sfz::Voice::fillWithData(AudioSpan<float> buffer) noexcept
 {
+    if (buffer.getNumFrames() == 0)
+        return;
+
     auto source { [&]() {
         if (region->canUsePreloadedData())
             return AudioSpan<const float>(*region->preloadedData);
@@ -435,6 +436,9 @@ void sfz::Voice::fillWithGenerator(AudioSpan<float> buffer) noexcept
     if (region->sample != "*sine")
         return;
 
+    if (buffer.getNumFrames() == 0)
+        return;
+
     float step = baseFrequency * twoPi<float> / sampleRate;
     phase = linearRamp<float>(tempSpan1, phase, step);