Merge branch '2.3' of github.com:mixxxdj/mixxx

2 files changed, 30 insertions, 13 deletions

diff --git a/src/util/sample.cpp b/src/util/sample.cpp
index d657979773..ba79d67ab9 100644
--- a/src/util/sample.cpp
+++ b/src/util/sample.cpp
@@ -446,19 +446,37 @@ void SampleUtil::deinterleaveBuffer(CSAMPLE* M_RESTRICT pDest1,
 }
 
 // static
-void SampleUtil::linearCrossfadeBuffers(CSAMPLE* pDest,
-        const CSAMPLE* pSrcFadeOut, const CSAMPLE* pSrcFadeIn,
+void SampleUtil::linearCrossfadeBuffersOut(
+        CSAMPLE* pDestSrcFadeOut,
+        const CSAMPLE* pSrcFadeIn,
         SINT numSamples) {
+    // M_RESTRICT unoptimizes the function for some reason.
     const CSAMPLE_GAIN cross_inc = CSAMPLE_GAIN_ONE
             / CSAMPLE_GAIN(numSamples / 2);
     // note: LOOP VECTORIZED. only with "int i"
     for (int i = 0; i < numSamples / 2; ++i) {
         const CSAMPLE_GAIN cross_mix = cross_inc * i;
-        pDest[i * 2] = pSrcFadeIn[i * 2] * cross_mix
-                + pSrcFadeOut[i * 2] * (CSAMPLE_GAIN_ONE - cross_mix);
-        pDest[i * 2 + 1] = pSrcFadeIn[i * 2 + 1] * cross_mix
-                + pSrcFadeOut[i * 2 + 1] * (CSAMPLE_GAIN_ONE - cross_mix);
+        pDestSrcFadeOut[i * 2] *= (CSAMPLE_GAIN_ONE - cross_mix);
+        pDestSrcFadeOut[i * 2] += pSrcFadeIn[i * 2] * cross_mix;
+        pDestSrcFadeOut[i * 2 + 1] *= (CSAMPLE_GAIN_ONE - cross_mix);
+        pDestSrcFadeOut[i * 2 + 1] += pSrcFadeIn[i * 2 + 1] * cross_mix;
+    }
+}
 
+// static
+void SampleUtil::linearCrossfadeBuffersIn(
+        CSAMPLE* pDestSrcFadeIn,
+        const CSAMPLE* pSrcFadeOut,
+        SINT numSamples) {
+    // M_RESTRICT unoptimizes the function for some reason.
+    const CSAMPLE_GAIN cross_inc = CSAMPLE_GAIN_ONE / CSAMPLE_GAIN(numSamples / 2);
+    // note: LOOP VECTORIZED. only with "int i"
+    for (int i = 0; i < numSamples / 2; ++i) {
+        const CSAMPLE_GAIN cross_mix = cross_inc * i;
+        pDestSrcFadeIn[i * 2] *= cross_mix;
+        pDestSrcFadeIn[i * 2] += pSrcFadeOut[i * 2] * (CSAMPLE_GAIN_ONE - cross_mix);
+        pDestSrcFadeIn[i * 2 + 1] *= cross_mix;
+        pDestSrcFadeIn[i * 2 + 1] += pSrcFadeOut[i * 2 + 1] * (CSAMPLE_GAIN_ONE - cross_mix);
     }
 }
 
diff --git a/src/util/sample.h b/src/util/sample.h
index fbf5510fb1..4ccabe13c0 100644
--- a/src/util/sample.h
+++ b/src/util/sample.h
@@ -223,13 +223,12 @@ class SampleUtil {
     static void deinterleaveBuffer(CSAMPLE* pDest1, CSAMPLE* pDest2,
             const CSAMPLE* pSrc, SINT numSamples);
 
-    // Crossfade two buffers together and put the result in pDest.  All the
-    // buffers must be the same length.  pDest may be an alias of the source
-    // buffers.  It is preferable to use the copyWithRamping functions, but
-    // sometimes this function is necessary.
-    static void linearCrossfadeBuffers(CSAMPLE* pDest,
-            const CSAMPLE* pSrcFadeOut, const CSAMPLE* pSrcFadeIn,
-            SINT numSamples);
+    /// Crossfade two buffers together. All the buffers must be the same length.
+    /// pDest is in one version the Out and in the other version the In buffer.
+    static void linearCrossfadeBuffersOut(
+            CSAMPLE* pDestSrcFadeOut, const CSAMPLE* pSrcFadeIn, SINT numSamples);
+    static void linearCrossfadeBuffersIn(
+            CSAMPLE* pDestSrcFadeIn, const CSAMPLE* pSrcFadeOut, SINT numSamples);
 
     // Mix a buffer down to mono, putting the result in both of the channels.
     // This uses a simple (L+R)/2 method, which assumes that the audio is