WS2811 / Fast_SPI2 / Bouncing Ball

/* bouncing ball
/* Kelvin Mead Aug/14
/* WS2811 / Fast_SPI2
*/

#include <FastSPI_LED2.h>

#define NUM_LEDS 320

CRGB leds[NUM_LEDS];

  long previousMillis = 0;        // will store last time LED was updated
  long interval = 100;            // interval at which to blink (milliseconds)
  int bright = 255;               // easy adjustable brightness
  const int ledsperstrip = 32;

// for edge definition
  int x = 0;
  int y = 0;
  int rowcount = 10;
  int xdirection = 0;
  int ydirection = 0;
  int boxx = 10;
  int boxy = 32;

void setup() {
  delay(2000);
  LEDS.setBrightness(bright);
  LEDS.addLeds<WS2811, 13>(leds, NUM_LEDS);
}

void loop() {

    unsigned long currentMillis = millis();
  if(currentMillis - previousMillis > interval) {
  previousMillis = currentMillis;

//put programs in here to be controlled by the delay time
// program name (r, g, b, speed)
bouncingball();

  LEDS.setBrightness(bright);
  } // end timed loop
} // end void loop

  void bouncingball() {
  if(xdirection == 0) {
    boxx++;
    if (boxx == 6) {
      xdirection = 1;
      boxx--;
    }
  }
  if(xdirection == 1) {
    boxx--;
    if (boxx == 0) {
      xdirection = 0;
    }
  }
  if(ydirection == 0) {
    boxy++;
    if (boxy == 4) {
      ydirection = 1;
      boxy--;
    }
  }
  if(ydirection == 1) {
    boxy--;
    if (boxy == 0) {
      ydirection = 0;
    }
  }

    if(boxy%2 == 1) { // row is odd
  leds[(boxy * rowcount) + ((rowcount-1)-boxx)].setRGB(255,255,255);
} else { // row is even
  leds[(boxy*rowcount) + boxx].setRGB(255,255,255);
}

  FastSPI_LED.show();
}