From 39bf245d1ed0479d70260f03ab37faa2ff9c8815 Mon Sep 17 00:00:00 2001
From: Frank <91616163+softhack007@users.noreply.github.com>
Date: Sun, 3 Nov 2024 21:54:41 +0100
Subject: [PATCH] HUB75 driver optimization

gains up to 3 fps in some effects.
---
 wled00/bus_manager.cpp | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/wled00/bus_manager.cpp b/wled00/bus_manager.cpp
index 68066a36..fc07909f 100644
--- a/wled00/bus_manager.cpp
+++ b/wled00/bus_manager.cpp
@@ -11,14 +11,14 @@
 
 // WLEDMM functions to get/set bits in an array - based on functions created by Brandon for GOL
 //  toDo : make this a class that's completely defined in a header file
-bool getBitFromArray(const uint8_t* byteArray, size_t position) { // get bit value
+inline bool getBitFromArray(const uint8_t* byteArray, size_t position) { // get bit value
     size_t byteIndex = position / 8;
     unsigned bitIndex = position % 8;
     uint8_t byteValue = byteArray[byteIndex];
     return (byteValue >> bitIndex) & 1;
 }
 
-void setBitInArray(uint8_t* byteArray, size_t position, bool value) {  // set bit - with error handling for nullptr
+inline void setBitInArray(uint8_t* byteArray, size_t position, bool value) {  // set bit - with error handling for nullptr
     //if (byteArray == nullptr) return;
     size_t byteIndex = position / 8;
     unsigned bitIndex = position % 8;
@@ -1018,19 +1018,13 @@ void __attribute__((hot)) BusHub75Matrix::setPixelColor(uint16_t pix, uint32_t c
 }
 
 uint32_t BusHub75Matrix::getPixelColor(uint16_t pix) const {
-  if (!_valid || pix >= _len) return BLACK;
-  if (_ledBuffer)
-    return uint32_t(_ledBuffer[pix].scale8(_bri)) & 0x00FFFFFF;  // scale8() is needed to mimic NeoPixelBus, which returns scaled-down colours
-  else
-    return BLACK;   // we don't know anything about the pixel
+  if (!_valid || pix >= _len || !_ledBuffer) return BLACK;
+  return uint32_t(_ledBuffer[pix].scale8(_bri)) & 0x00FFFFFF;  // scale8() is needed to mimic NeoPixelBus, which returns scaled-down colours
 }
 
 uint32_t __attribute__((hot)) BusHub75Matrix::getPixelColorRestored(uint16_t pix) const {
-  if (!_valid || pix >= _len) return BLACK;
-  if (_ledBuffer)
-    return uint32_t(_ledBuffer[pix]) & 0x00FFFFFF;
-  else
-    return BLACK;   // we don't know anything about the pixel
+  if (!_valid || pix >= _len || !_ledBuffer) return BLACK;
+  return uint32_t(_ledBuffer[pix]) & 0x00FFFFFF;
 }
 
 void BusHub75Matrix::setBrightness(uint8_t b, bool immediate) {
@@ -1056,19 +1050,23 @@ void __attribute__((hot)) BusHub75Matrix::show(void) {
     unsigned height = isFourScan ? fourScanPanel->height() : display->height();
     unsigned width = _panelWidth;
 
+    // Cache pointers to LED array and bitmask array, to avoid repeated accesses
+    const byte* ledsDirty = _ledsDirty;
+    const CRGB* ledBuffer = _ledBuffer;
+
     //while(!previousBufferFree) delay(1);   // experimental - Wait before we allow any writing to the buffer. Stop flicker.
 
     size_t pix = 0; // running pixel index
     for (int y=0; y<height; y++) for (int x=0; x<width; x++) {
-      if (getBitFromArray(_ledsDirty, pix) == true) {        // only repaint the "dirty"  pixels
+      if (getBitFromArray(ledsDirty, pix) == true) {        // only repaint the "dirty"  pixels
         #ifndef NO_CIE1931
-        uint32_t c = uint32_t(_ledBuffer[pix]) & 0x00FFFFFF; // get RGB color, removing FastLED "alpha" component 
+        uint32_t c = uint32_t(ledBuffer[pix]) & 0x00FFFFFF; // get RGB color, removing FastLED "alpha" component 
         c = unGamma24(c); // to use the driver linear brightness feature, we first need to undo WLED gamma correction
         uint8_t r = R(c);
         uint8_t g = G(c);
         uint8_t b = B(c);
         #else
-        const CRGB c = _ledBuffer[pix];  // we stay on CRGB, instead of packing/unpacking the color value to uint32_t
+        const CRGB c = ledBuffer[pix];  // we stay on CRGB, instead of packing/unpacking the color value to uint32_t
         uint8_t r = c.r;
         uint8_t g = c.g;
         uint8_t b = c.b;