From 89a2407debe74ea5317010d64de3188cb084b093 Mon Sep 17 00:00:00 2001
From: reuk <reuk@users.noreply.github.com>
Date: Mon, 25 Nov 2024 17:06:56 +0000
Subject: [PATCH] AudioFormatReader: Update searchForLevel to work for more
 than two channels

---
 .../format/juce_AudioFormatReader.cpp         | 53 +++++++------------
 1 file changed, 18 insertions(+), 35 deletions(-)

diff --git a/modules/juce_audio_formats/format/juce_AudioFormatReader.cpp b/modules/juce_audio_formats/format/juce_AudioFormatReader.cpp
index 57efbccf7d..5d61027bc5 100644
--- a/modules/juce_audio_formats/format/juce_AudioFormatReader.cpp
+++ b/modules/juce_audio_formats/format/juce_AudioFormatReader.cpp
@@ -299,11 +299,12 @@ int64 AudioFormatReader::searchForLevel (int64 startSample,
         return -1;
 
     const int bufferSize = 4096;
-    HeapBlock<int> tempSpace (bufferSize * 2 + 64);
+    const size_t channels = numChannels;
+    HeapBlock<int> tempSpace (bufferSize * channels + 64);
+    std::vector<int*> channelPointers (channels);
 
-    int* tempBuffer[3] = { tempSpace.get(),
-                           tempSpace.get() + bufferSize,
-                           nullptr };
+    for (auto [index, ptr] : enumerate (channelPointers, size_t{}))
+        ptr = tempSpace + (bufferSize * index);
 
     int consecutive = 0;
     int64 firstMatchPos = -1;
@@ -326,7 +327,7 @@ int64 AudioFormatReader::searchForLevel (int64 startSample,
         if (bufferStart >= lengthInSamples)
             break;
 
-        read (tempBuffer, 2, bufferStart, numThisTime, false);
+        read (channelPointers.data(), (int) channels, bufferStart, numThisTime, false);
         auto num = numThisTime;
 
         while (--num >= 0)
@@ -334,43 +335,25 @@ int64 AudioFormatReader::searchForLevel (int64 startSample,
             if (numSamplesToSearch < 0)
                 --startSample;
 
-            bool matches = false;
             auto index = (int) (startSample - bufferStart);
 
-            if (usesFloatingPointData)
+            const auto matches = std::invoke ([&]
             {
-                const float sample1 = std::abs (((float*) tempBuffer[0]) [index]);
-
-                if (sample1 >= magnitudeRangeMinimum
-                     && sample1 <= magnitudeRangeMaximum)
+                if (usesFloatingPointData)
                 {
-                    matches = true;
+                    return std::any_of (channelPointers.begin(), channelPointers.end(), [&] (const auto& ptr)
+                    {
+                        const float sample = std::abs (((float*) ptr) [index]);
+                        return magnitudeRangeMinimum <= sample && sample <= magnitudeRangeMaximum;
+                    });
                 }
-                else if (numChannels > 1)
-                {
-                    const float sample2 = std::abs (((float*) tempBuffer[1]) [index]);
 
-                    matches = (sample2 >= magnitudeRangeMinimum
-                                 && sample2 <= magnitudeRangeMaximum);
-                }
-            }
-            else
-            {
-                const int sample1 = std::abs (tempBuffer[0] [index]);
-
-                if (sample1 >= intMagnitudeRangeMinimum
-                     && sample1 <= intMagnitudeRangeMaximum)
+                return std::any_of (channelPointers.begin(), channelPointers.end(), [&] (const auto& ptr)
                 {
-                    matches = true;
-                }
-                else if (numChannels > 1)
-                {
-                    const int sample2 = std::abs (tempBuffer[1][index]);
-
-                    matches = (sample2 >= intMagnitudeRangeMinimum
-                                 && sample2 <= intMagnitudeRangeMaximum);
-                }
-            }
+                    const int sample = std::abs (ptr[index]);
+                    return intMagnitudeRangeMinimum <= sample && sample <= intMagnitudeRangeMaximum;
+                });
+            });
 
             if (matches)
             {