From b50e798d55d42b86596cc8e4637849ba968f0510 Mon Sep 17 00:00:00 2001
From: twlare <38672507+twlare@users.noreply.github.com>
Date: Tue, 4 Aug 2020 09:50:16 -0700
Subject: [PATCH] Add segment mirror option

* Add segment mirror option (#1010)

* Update new pull with playlist and palette changes

* Revert "Update new pull with playlist and palette changes"

This reverts commit 9802a7c4e22d408337fc574e031dc49d4265fef3.
---
 wled00/FX.h       | 11 +++++++++--
 wled00/FX_fcn.cpp |  8 +++++++-
 wled00/const.h    |  2 +-
 3 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/wled00/FX.h b/wled00/FX.h
index 7afca48a4..da8a6942d 100644
--- a/wled00/FX.h
+++ b/wled00/FX.h
@@ -84,16 +84,19 @@
 
 // options
 // bit    7: segment is in transition mode
-// bits 3-6: TBD
+// bits 4-6: TBD
+// bit    3: mirror effect within segment
 // bit    2: segment is on
 // bit    1: reverse segment
 // bit    0: segment is selected
 #define NO_OPTIONS   (uint8_t)0x00
 #define TRANSITIONAL (uint8_t)0x80
+#define MIRROR       (uint8_t)0x08
 #define SEGMENT_ON   (uint8_t)0x04
 #define REVERSE      (uint8_t)0x02
 #define SELECTED     (uint8_t)0x01
 #define IS_TRANSITIONAL ((SEGMENT.options & TRANSITIONAL) == TRANSITIONAL)
+#define IS_MIRROR       ((SEGMENT.options & MIRROR      ) == MIRROR      )
 #define IS_SEGMENT_ON   ((SEGMENT.options & SEGMENT_ON  ) == SEGMENT_ON  )
 #define IS_REVERSE      ((SEGMENT.options & REVERSE     ) == REVERSE     )
 #define IS_SELECTED     ((SEGMENT.options & SELECTED    ) == SELECTED    )
@@ -264,7 +267,11 @@ class WS2812FX {
       uint16_t virtualLength()
       {
         uint16_t groupLen = groupLength();
-        return (length() + groupLen -1) / groupLen;
+        uint16_t vLength;
+        vLength = (length() + groupLen - 1) / groupLen;
+        if (options & MIRROR)
+          vLength /= 2;  // divide by 2 if mirror; leaves a blank LED in the middle if length is odd
+        return vLength;
       }
     } segment;
 
diff --git a/wled00/FX_fcn.cpp b/wled00/FX_fcn.cpp
index a1b4096cb..464e9d2aa 100644
--- a/wled00/FX_fcn.cpp
+++ b/wled00/FX_fcn.cpp
@@ -111,7 +111,11 @@ uint16_t WS2812FX::realPixelIndex(uint16_t i) {
 
   /* reverse just an individual segment */
   int16_t realIndex = iGroup;
-  if (IS_REVERSE) realIndex = SEGMENT.length() -iGroup -1;
+  if (IS_REVERSE)
+    if (IS_MIRROR)
+      realIndex = SEGMENT.length() / 2 - iGroup - 1;  //only need to index half the pixels
+    else
+      realIndex = SEGMENT.length() - iGroup - 1;
 
   realIndex += SEGMENT.start;
   /* Reverse the whole string */
@@ -177,6 +181,8 @@ void WS2812FX::setPixelColor(uint16_t i, byte r, byte g, byte b, byte w)
       if (indexSet < customMappingSize) indexSet = customMappingTable[indexSet];
       #endif
       if (indexSetRev >= SEGMENT.start && indexSetRev < SEGMENT.stop) bus->SetPixelColor(indexSet + skip, col);
+      if (IS_MIRROR)  //set the corresponding mirrored pixel
+        bus->SetPixelColor(SEGMENT.stop - (indexSet + skip) + SEGMENT.start - 1, col);
     }
   } else { //live data, etc.
     if (reverseMode) i = _length - 1 - i;
diff --git a/wled00/const.h b/wled00/const.h
index 1ec4caf58..ac3549b5f 100644
--- a/wled00/const.h
+++ b/wled00/const.h
@@ -99,7 +99,7 @@
 #define SEG_OPTION_SELECTED       0
 #define SEG_OPTION_REVERSED       1
 #define SEG_OPTION_ON             2
-#define SEG_OPTION_PAUSED         3            //unused
+#define SEG_OPTION_MIRROR         3            //Indicates that the effect will be mirrored within the segment
 #define SEG_OPTION_NONUNITY       4            //Indicates that the effect does not use FRAMETIME or needs getPixelColor
 #define SEG_OPTION_TRANSITIONAL   7