Daniel/desktop/shift colorset

VortexEngine/VortexLib/VortexLib.cpp

@@ -308,6 +308,7 @@ EMSCRIPTEN_BINDINGS(Vortex) {
     .function("peek", &Colorset::peek)
     .function("peekNext", &Colorset::peekNext)
     .function("numColors", &Colorset::numColors)
+    .function("shift", &Colorset::shift)
     .function("onStart", &Colorset::onStart)
     .function("onEnd", &Colorset::onEnd)
     .function("serialize", &Colorset::serialize)

VortexEngine/src/Colors/Colorset.cpp

@@ -437,6 +437,30 @@ RGBColor Colorset::peek(int32_t offset) const
   return m_palette[nextIndex];
 }
 
+// shift an index to a new destination, dest index before move
+void Colorset::shift(uint8_t idx, uint8_t dest)
+{
+  if (idx >= m_numColors || dest >= m_numColors || idx == dest) {
+    return;
+  }
+  // Backup the color being shifted
+  RGBColor temp = m_palette[idx];
+  // shift the block of colors next to it
+  if (idx < dest) {
+    // Forward shift: Move the block from idx + 1 to dest
+    memmove(m_palette + idx,
+            m_palette + idx + 1,
+            (dest - idx) * sizeof(RGBColor));
+  } else {
+    // Backward shift: Move the block from dest to idx - 1
+    memmove(m_palette + dest + 1,
+            m_palette + dest,
+            (idx - dest) * sizeof(RGBColor));
+  }
+  // Place the saved element at the destination
+  m_palette[dest] = temp;
+}
+
 bool Colorset::onStart() const
 {
   return (m_curIndex == 0);

VortexEngine/src/Colors/Colorset.h

@@ -138,6 +138,9 @@ class Colorset
   // the number of colors in the palette
   uint8_t numColors() const { return m_numColors; }
 
+  // shift an index to a new destination, dest index before move
+  void shift(uint8_t idx, uint8_t dest);
+
   // whether the colorset is currently on the first color or last color
   bool onStart() const;
   bool onEnd() const;