Tweak 4-way parallel output to work on pins 12-15 on esp8266 - keep b…

…locked out for now, needs some more testing.

bitswap.cpp

@@ -0,0 +1,28 @@
+#define FASTLED_INTERNAL
+#include "FastLED.h"
+
+/// Simplified form of bits rotating function.  Based on code found here - http://www.hackersdelight.org/hdcodetxt/transpose8.c.txt - rotating
+/// data into LSB for a faster write (the code using this data can happily walk the array backwards)
+void transpose8x1_noinline(unsigned char *A, unsigned char *B) {
+  uint32_t x, y, t;
+
+  // Load the array and pack it into x and y.
+  y = *(unsigned int*)(A);
+  x = *(unsigned int*)(A+4);
+
+  // pre-transform x
+  t = (x ^ (x >> 7)) & 0x00AA00AA;  x = x ^ t ^ (t << 7);
+  t = (x ^ (x >>14)) & 0x0000CCCC;  x = x ^ t ^ (t <<14);
+
+  // pre-transform y
+  t = (y ^ (y >> 7)) & 0x00AA00AA;  y = y ^ t ^ (t << 7);
+  t = (y ^ (y >>14)) & 0x0000CCCC;  y = y ^ t ^ (t <<14);
+
+  // final transform
+  t = (x & 0xF0F0F0F0) | ((y >> 4) & 0x0F0F0F0F);
+  y = ((x << 4) & 0xF0F0F0F0) | (y & 0x0F0F0F0F);
+  x = t;
+
+  *((uint32_t*)B) = y;
+  *((uint32_t*)(B+4)) = x;
+}