improved speed and fixed issue

- fixed issue: blending was also done when color was on a key-index-color which is now skipped
- speed improvement: conversion is skipped if color is key-color

Author: DedeHai

wled00/colors.cpp

@@ -87,29 +87,31 @@ uint32_t color_fade(uint32_t c1, uint8_t amount, bool video)
 uint32_t ColorFromPaletteWLED(const CRGBPalette16& pal, unsigned index, uint8_t brightness, TBlendType blendType)
 {
   if (blendType == LINEARBLEND_NOWRAP) {
-    index = (index*240) >> 8; // Blend range is affected by lo4 blend of values, remap to avoid wrapping
+    index = (index * 0xF0) >> 8; // Blend range is affected by lo4 blend of values, remap to avoid wrapping
   }
+  uint32_t clr32;
   unsigned hi4 = byte(index) >> 4;
-  const CRGB* entry = (CRGB*)((uint8_t*)(&(pal[0])) + (hi4 * sizeof(CRGB)));
-  unsigned red1   = entry->r;
-  unsigned green1 = entry->g;
-  unsigned blue1  = entry->b;
-  if (blendType != NOBLEND) {
+  unsigned lo4 = (index & 0x0F);
+  const CRGB* entry = (CRGB*)&(pal[0]) + hi4;
+  if(lo4 && blendType != NOBLEND) {
+    unsigned red1   = entry->r;
+    unsigned green1 = entry->g;
+    unsigned blue1  = entry->b;
     if (hi4 == 15) entry = &(pal[0]);
     else ++entry;
-    unsigned f2 = ((index & 0x0F) << 4) + 1; // +1 so we scale by 256 as a max value, then result can just be shifted by 8
-    unsigned f1 = (257 - f2); // f2 is 1 minimum, so this is 256 max
-    red1   = (red1 * f1 + (unsigned)entry->r * f2) >> 8;
+    unsigned f2 = (lo4 << 4);
+    unsigned f1 = 256 - f2;
+    red1   = (red1 * f1 + (unsigned)entry->r * f2) >> 8; // note: using  color_blend() is 20% slower
     green1 = (green1 * f1 + (unsigned)entry->g * f2) >> 8;
     blue1  = (blue1 * f1 + (unsigned)entry->b * f2) >> 8;
+    clr32 = RGBW32(red1, green1, blue1, 0);
   }
+  else
+    clr32 = RGBW32(entry->r, entry->g, entry->b, 0);
   if (brightness < 255) { // note: zero checking could be done to return black but that is hardly ever used so it is omitted
-    uint32_t scale = brightness + 1; // adjust for rounding (bitshift)
-    red1   = (red1 * scale) >> 8;
-    green1 = (green1 * scale) >> 8;
-    blue1  = (blue1 * scale) >> 8;
+    clr32 = color_fade(clr32, brightness);
   }
-  return RGBW32(red1,green1,blue1,0);
+  return clr32;
 }
 
 void setRandomColor(byte* rgb)