From fbaab8702e5434a165164c1978901a630c342d22 Mon Sep 17 00:00:00 2001
From: Steve Daulton <Stevethefiddle@users.noreply.github.com>
Date: Fri, 15 May 2015 16:57:29 +0100
Subject: [PATCH] Small optimization - non-linear preview copies only selected
 tracks by default.

---
 src/effects/Effect.cpp | 18 ++++++++++++------
 src/effects/Effect.h   |  6 ++++++
 2 files changed, 18 insertions(+), 6 deletions(-)

diff --git a/src/effects/Effect.cpp b/src/effects/Effect.cpp
index 3564ccdfb..846c54b7a 100644
--- a/src/effects/Effect.cpp
+++ b/src/effects/Effect.cpp
@@ -92,6 +92,7 @@ Effect::Effect()
    mT1 = 0.0;
    mDuration = 0.0;
    mIsLinearEffect = false;
+   mPreviewWithNotSelected = false;
    mNumTracks = 0;
    mNumGroups = 0;
    mProgress = NULL;
@@ -1938,6 +1939,11 @@ void Effect::SetLinearEffectFlag(bool linearEffectFlag)
    mIsLinearEffect = linearEffectFlag;
 }
 
+void Effect::IncludeNotSelectedPreviewTracks(bool includeNotSelected)
+{
+   mPreviewWithNotSelected = includeNotSelected;
+}
+
 bool Effect::TotalProgress(double frac)
 {
    int updateResult = (mProgress ?
@@ -2432,17 +2438,17 @@ void Effect::Preview(bool dryOnly)
       t1 = mixLeft->GetEndTime();
    }
    else {
-      // Copy all tracks as 'some' effects (AutoDuck) may require non-selected tracks.
       TrackListOfKindIterator iter(Track::Wave, saveTracks);
       WaveTrack *src = (WaveTrack *) iter.First();
       while (src)
       {
          WaveTrack *dest;
-         src->Copy(t0, t1, (Track **) &dest);
-         dest->SetSelected(src->GetSelected());
-         dest->SetDisplay(WaveTrack::NoDisplay);
-         mTracks->Add(dest);
-
+         if (src->GetSelected() || mPreviewWithNotSelected) {
+            src->Copy(t0, t1, (Track **) &dest);
+            dest->SetSelected(src->GetSelected());
+            dest->SetDisplay(WaveTrack::NoDisplay);
+            mTracks->Add(dest);
+         }
          src = (WaveTrack *) iter.Next();
       }
    }
diff --git a/src/effects/Effect.h b/src/effects/Effect.h
index 38a61f0c4..f00ebeaa3 100644
--- a/src/effects/Effect.h
+++ b/src/effects/Effect.h
@@ -321,6 +321,11 @@ protected:
    // To allow pre-mixing before Preview, set linearEffectFlag to true.
    void SetLinearEffectFlag(bool linearEffectFlag);
 
+   // Most effects only require selected tracks to be copied for Preview.
+   // If IncludeNotSelectedPreviewTracks(true), then non-linear effects have
+   // preview copies of all wave tracks.
+   void IncludeNotSelectedPreviewTracks(bool includeNotSelected);
+
    // Use these two methods to copy the input tracks to mOutputTracks, if
    // doing the processing on them, and replacing the originals only on success (and not cancel).
    void CopyInputTracks(int trackType = Track::Wave);
@@ -394,6 +399,7 @@ private:
    bool mIsBatch;
 
    bool mIsLinearEffect;
+   bool mPreviewWithNotSelected;
 
    double mDuration;
    // mSetDuration should ONLY be set when SetDuration() is called.