2D Drift: minor optimization

moving "t/20" out of the main loop gives some speedup.

wled00/FX.cpp

@@ -4759,11 +4759,12 @@ uint16_t mode_2DDrift() {              // By: Stepko   https://editor.soulmateli
 
   const uint16_t maxDim = MAX(cols, rows)/2;
   unsigned long t = millis() / (32 - (SEGMENT.speed>>3));
+  unsigned long t_20 = t/20; // softhack007: pre-calculating this gives about 10% speedup
   for (float i = 1; i < maxDim; i += 0.25) {
     float angle = radians(t * (maxDim - i));
     uint16_t myX = (cols>>1) + (uint16_t)(sin_t(angle) * i) + (cols%2);
     uint16_t myY = (rows>>1) + (uint16_t)(cos_t(angle) * i) + (rows%2);
-    SEGMENT.setPixelColorXY(myX, myY, ColorFromPalette(SEGPALETTE, (i * 20) + (t / 20), 255, LINEARBLEND));
+    SEGMENT.setPixelColorXY(myX, myY, ColorFromPalette(SEGPALETTE, (i * 20) + t_20, 255, LINEARBLEND));
   }
   SEGMENT.blur(SEGMENT.intensity>>3);