From 0d54743924d2a6db11df1b37d91f4c6d7150f788 Mon Sep 17 00:00:00 2001
From: Will Miles <will@willmiles.net>
Date: Thu, 5 Sep 2024 19:41:16 -0400
Subject: [PATCH] mode_copy_segment: Map mirror/reverse/transpose

Use a local formulation of getRenderedPixelXY() to copy from the
mirrored, reversed, and transposed output.  Grouping, spacing, and
offset used in the source segment are discarded.
---
 wled00/FX.cpp | 64 ++++++++++++++++++++++++---------------------------
 1 file changed, 30 insertions(+), 34 deletions(-)

diff --git a/wled00/FX.cpp b/wled00/FX.cpp
index ca5a40f721..7bf0be2fa5 100644
--- a/wled00/FX.cpp
+++ b/wled00/FX.cpp
@@ -97,47 +97,43 @@ static const char _data_FX_MODE_STATIC[] PROGMEM = "Solid";
 /*
  * Copy selected segment 
  */
+static CRGB shift_color(CRGB sourcecolor, uint8_t shift) {
+    CHSV pxHSV = rgb2hsv(sourcecolor); //convert to HSV
+    pxHSV.h += shift; // shift hue
+    hsv2rgb_spectrum(pxHSV, sourcecolor); // convert back to RGB 
+    return sourcecolor;
+}
+
+static CRGB getRenderedPixelXY(Segment& seg, int x, int y = 0) {
+  // We read pixels back following mirror/reverse/transpose but ignoring grouping
+  // For every group-length pixels, add spacing
+  x *= seg.groupLength(); // expand to physical pixels
+  y *= seg.groupLength(); // expand to physical pixels
+  if (x >= seg.width() || y >= seg.height()) return 0;  // fill out of range pixels with black
+  return strip.getPixelColorXY(seg.start + seg.offset + x, seg.startY + y);
+}
+
+
 uint16_t mode_copy_segment(void) {
 
   uint32_t sourceid = SEGMENT.custom1;
   SEGMENT.fadeToBlackBy(16); // fades out unused pixels, still allows overlay (also fades out if invalid ID is set)
   if (sourceid >= strip._segments.size() || sourceid == strip.getCurrSegmentId()) return FRAMETIME; // invalid source
-  CRGB sourcecolor;
+
   if (strip._segments[sourceid].isActive()) {
-    // note: copying 1D to 2D as well as 2D to 1D is not supported
-    if(SEGMENT.is2D() && strip._segments[sourceid].is2D()) { // 2D setup
-      uint32_t cx, cy; // sizes to copy
-      cx = std::min(strip._segments[sourceid].virtualWidth(), SEGMENT.virtualWidth()); // get smaller width
-      cy = std::min(strip._segments[sourceid].virtualHeight(), SEGMENT.virtualHeight()); // get smaller height
-      for (unsigned x = 0; x < cx; x++) {
-        for (unsigned y = 0; y < cy; y++) {
-          sourcecolor = strip._segments[sourceid].getPixelColorXY(x, y);   
-          if(SEGMENT.custom2 > 0) // color shifting enabled
-          {
-            CHSV pxHSV = rgb2hsv(sourcecolor); //convert to HSV
-            pxHSV.h += SEGMENT.custom2; // shift hue
-            hsv2rgb_spectrum(pxHSV, sourcecolor); // convert back to RGB 
-            
-          }
-          SEGMENT.setPixelColorXY(x, y, sourcecolor);
-          //SEGMENT.setPixelColorXY(x, y, strip._segments[sourceid].getPixelColorXY(x, y)); //use this for no colorshift option
-        }
-     
-      }
-    }
-    else if(!SEGMENT.is2D() && !strip._segments[sourceid].is2D()) { // 1D strip
+    // note: copying 1D to 2D is not supported
+    if(!strip._segments[sourceid].is2D()) { // 1D source; can be expanded into 2D
       uint32_t cl; // length to copy
-      cl = std::min(strip._segments[sourceid].virtualLength(), SEGMENT.virtualLength()); // get smaller length
-      for (unsigned i = 0; i < cl; i++) {              
-        sourcecolor = strip._segments[sourceid].getPixelColor(i);          
-        if(SEGMENT.custom2 > 0) // color shifting enabled
-        {
-          CHSV pxHSV = rgb2hsv(sourcecolor); //convert to HSV
-          pxHSV.h += SEGMENT.custom2; // shift hue
-          sourcecolor = (CRGB)pxHSV; // convert back to RGB
-        }        
-        SEGMENT.setPixelColor(i,  sourcecolor);
-       // SEGMENT.setPixelColor(i, strip._segments[sourceid].getPixelColor(i)); //use this for no colorshift option
+      for (unsigned i = 0; i < SEGMENT.virtualLength(); i++) {              
+        CRGB sourcecolor = getRenderedPixelXY(strip._segments[sourceid], i);
+        SEGMENT.setPixelColor(i, shift_color(sourcecolor, SEGMENT.custom2));
+      }
+    } else if(SEGMENT.is2D()) { // 2D setup
+      for (unsigned x = 0; x < SEGMENT.virtualWidth(); x++) {
+        for (unsigned y = 0; y <  SEGMENT.virtualHeight(); y++) {
+          CRGB sourcecolor = getRenderedPixelXY(strip._segments[sourceid], x, y);   
+          SEGMENT.setPixelColorXY(x, y, shift_color(sourcecolor, SEGMENT.custom2));
+        }     
       }
     }
   }