From 1cd4a952462f27fe26fb970561702ec26e4f5f8a Mon Sep 17 00:00:00 2001
From: paulfd <paulfd@outlook.fr>
Date: Wed, 28 Aug 2019 17:23:36 +0200
Subject: [PATCH] Tracking the phase of the sine directly instead of
 recomputing it

---
 sources/Voice.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/sources/Voice.h b/sources/Voice.h
index c2dce465..07e8d885 100644
--- a/sources/Voice.h
+++ b/sources/Voice.h
@@ -165,9 +165,10 @@ public:
             return;
 
         float step = baseFrequency * twoPi<float> / sampleRate;
-        ::linearRamp<float>(tempSpan1.first(buffer.size()), sourcePosition * step, step);
-        ::sin<float>(tempSpan1, buffer.left());
+        phase = ::linearRamp<float>(tempSpan1, phase, step);
+        ::sin<float>(tempSpan1.first(buffer.size()), buffer.left());
         absl::c_copy(buffer.left(), buffer.right().begin());
+        
         sourcePosition += buffer.size();
     }
 
@@ -238,6 +239,7 @@ private:
     float pitchRatio { 1.0 };
     float baseGain { 1.0 };
     float baseFrequency { 440.0 };
+    float phase { 0.0f };
 
     uint32_t sourcePosition { 0 };
     uint32_t initialDelay { 0 };