From d2705f033d5826f0b1ffeae9dab11e2d9373e7a0 Mon Sep 17 00:00:00 2001
From: Blaz Kristan <blaz@kristan-sp.si>
Date: Tue, 28 Jun 2022 23:32:29 +0200
Subject: [PATCH] Enhance API - addPixelColorXY() - fadeToBlackBy()

---
 wled00/FX.cpp       |  2 +-
 wled00/FX.h         |  1 +
 wled00/FX_2Dfcn.cpp |  7 +++++++
 wled00/FX_fcn.cpp   | 10 +++++++---
 4 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index 4b506756..9d37d714 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -5067,7 +5067,7 @@ uint16_t WS2812FX::mode_2DLissajous(void) {            // By: Andrew Tuline
   const uint16_t cols = SEGMENT.virtualWidth();
   const uint16_t rows = SEGMENT.virtualHeight();
 
-  fadeToBlackBy(nullptr, SEGMENT.intensity);
+  fadeToBlackBy(SEGMENT.intensity);
   //fade_out(SEGMENT.intensity);
 
   //for (int i=0; i < 4*(cols+rows); i ++) {
diff --git a/wled00/FX.h b/wled00/FX.h
index 9e177537..0675a297 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -1097,6 +1097,7 @@ class WS2812FX {
       setPixelColorXY(uint16_t x, uint16_t y, uint8_t r, uint8_t g, uint8_t b, uint8_t w = 0),
       setPixelColorXY(float x, float y, byte r, byte g, byte b, byte w = 0, bool aa = false),
       blendPixelColorXY(uint16_t x, uint16_t y, uint32_t color, uint8_t blend),
+      addPixelColorXY(uint16_t x, uint16_t y, uint32_t color),
       blur1d(CRGB* leds, fract8 blur_amount),
       blur1d(uint16_t i, bool vertical, fract8 blur_amount, CRGB* leds=nullptr), // 1D box blur (with weight)
       blur2d(CRGB* leds, fract8 blur_amount),
diff --git a/wled00/FX_2Dfcn.cpp b/wled00/FX_2Dfcn.cpp
index e0e73f9c..eac97fd1 100644
--- a/wled00/FX_2Dfcn.cpp
+++ b/wled00/FX_2Dfcn.cpp
@@ -274,6 +274,13 @@ void WS2812FX::blendPixelColorXY(uint16_t x, uint16_t y, uint32_t color, uint8_t
   setPixelColorXY(x, y, color_blend(getPixelColorXY(x,y), color, blend));
 }
 
+/*
+ * Adds the specified color with the existing pixel color perserving color balance.
+ */
+void WS2812FX::addPixelColorXY(uint16_t x, uint16_t y, uint32_t color) {
+  setPixelColorXY(x, y, color_add(getPixelColorXY(x,y), color));
+}
+
 // blurRow: perform a blur on a row of a rectangular matrix
 void WS2812FX::blurRow(uint16_t row, fract8 blur_amount, CRGB* leds) {
   const uint16_t cols = SEGMENT.virtualWidth();
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index d235c9d5..43aceb92 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -968,7 +968,7 @@ void WS2812FX::fade_out(uint8_t rate) {
   int g2 = G(color);
   int b2 = B(color);
 
-  for(uint16_t y = 0; y < rows; y++) for (uint16_t x = 0; x < cols; x++) {
+  for (uint16_t y = 0; y < rows; y++) for (uint16_t x = 0; x < cols; x++) {
     color = isMatrix ? getPixelColorXY(x, y) : getPixelColor(x);
     int w1 = W(color);
     int r1 = R(color);
@@ -993,8 +993,12 @@ void WS2812FX::fade_out(uint8_t rate) {
 
 // fades all pixels to black using nscale8()
 void WS2812FX::fadeToBlackBy(uint8_t fadeBy) {
-  for (uint16_t i = 0; i < SEGLEN; i++) {
-    setPixelColor(i, col_to_crgb(getPixelColor(i)).nscale8(255-fadeBy));
+  const uint16_t cols = isMatrix ? SEGMENT.virtualWidth() : SEGMENT.virtualLength();
+  const uint16_t rows = SEGMENT.virtualHeight(); // will be 1 for 1D
+
+  for (uint16_t y = 0; y < rows; y++) for (uint16_t x = 0; x < cols; x++) {
+    if (isMatrix) setPixelColorXY(x, y, col_to_crgb(getPixelColorXY(x,y)).nscale8(255-fadeBy));
+    else          setPixelColor(x, col_to_crgb(getPixelColor(x)).nscale8(255-fadeBy));
   }
 }