From 43613e3b100acb8af6cf544efce95b90b8108083 Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Mon, 18 Sep 2023 15:56:50 +0200
Subject: [PATCH] Matrix effect speedup

Typically, more than 50% of pixels are black.
This optimization avoids to fade and rewrite already black pixels.
---
 wled00/FX.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index f0d84c64..6e8e5df0 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -5218,7 +5218,7 @@ uint16_t mode_2Dmatrix(void) {                  // Matrix2D. By Jeremy Williams.
           if (row < rows-1) SEGMENT.setPixelColorXY(col, row+1, spawnColor);
         } else {
           // fade other pixels
-          SEGMENT.setPixelColorXY(col, row, pix.nscale8(fade));
+          if (pix != CRGB::Black) SEGMENT.setPixelColorXY(col, row, pix.nscale8(fade)); // optimization: don't fade black pixels
         }
       }
     }