mhsw-espurna/code/espurna/garland/animations/anim_fly.h

#if GARLAND_SUPPORT

#include "../anim.h"
#include "../color.h"
#include "../palette.h"

//------------------------------------------------------------------------------
class AnimFly : public Anim {
   public:
    AnimFly() : Anim("Fly") {
    }

    void SetupImpl() override {
        //length of particle tail
        pos = secureRandom(2, 15);
        //probability of the tail
        inc = secureRandom(5, 15);
        if (secureRandom(10) > 5) {
            inc = -inc;
        }
        phase = 0;
    }

    void Run() override {
        byte launchpos;
        if (inc > 0) {
            launchpos = numLeds - 1;
            for (int i = 1; i < numLeds; i++) {
                leds[i - 1] = leds[i];
            }
        } else {
            launchpos = 0;
            for (int i = numLeds - 2; i >= 0; i--) {
                leds[i + 1] = leds[i];
            }
        }

        if (secureRandom(abs(inc)) == 0) {
            curColor = palette->getRndInterpColor();
            phase = pos;
        }

        leds[launchpos] = Color((int)curColor.r * phase / pos, (int)curColor.g * phase / pos, (int)curColor.b * phase / pos);
        if (phase > 0) phase--;
    }
};

#endif  // GARLAND_SUPPORT