waveform: flip Y axis

Fixes #1666
2021-07-08 11:55:35 -07:00
parent dce8ebdf01
commit 558d849d27
1 changed files with 4 additions and 2 deletions
@@ -318,10 +318,12 @@ void AudioVisualWaveform::DrawSample(QPainter *painter, const Sample& sample, in
    } else {
      int channel_mid = y + channel_height * i + channel_half_height;

+      // We subtract the sample so that positive Y values go up on the screen rather than down,
+      // which is how waveforms are usually rendered
      painter->drawLine(x,
-                        channel_mid + qRound(min * static_cast<float>(channel_half_height)),
+                        channel_mid - qRound(min * static_cast<float>(channel_half_height)),
                        x,
-                        channel_mid + qRound(max * static_cast<float>(channel_half_height)));
+                        channel_mid - qRound(max * static_cast<float>(channel_half_height)));
    }
  }
 }