I am new in FastLED, have used Adafruit_Neopixel library before.

Archive FastLED Archive
1

I am new in FastLED, have used Adafruit_Neopixel library before.
I have some difficulties searching needed functionality and trying to understand how all those functions are really working.
For example, I am running DemoReel100 sample code, effect rainbowWithGliter():

void rainbowWithGlitter()
{
// built-in FastLED rainbow, plus some random sparkly glitter
fill_rainbow( leds, NUM_LEDS, gHue, 7);
addGlitter(50);
}
void addGlitter( fract8 chanceOfGlitter)
{
if( random8() < chanceOfGlitter) {
leds[ random16(NUM_LEDS) ] += CRGB::White;
}
}

How to make rainbow to be constantly darker, saving rainbow animation, but still use full brightness for glitter?

2

Try using fadeToBlackBy after the fill_rainbow line and before the addGlitter line.

//fade all pixels about 19% (50/256th)
fadeToBlackBy( leds, NUM_LEDS, 50);

//fade all pixels by 50% (128/256th)
fadeToBlackBy( leds, NUM_LEDS, 128);

3

@marmil , yes, it works thank you. Somehow have missed that function.