Snake.h

class Snake{

  #define MAX_SNAKE_LENGTH 255
  
  cLEDText ScrollingMsg;
  CRGBPalette16 snakePalette;
  unsigned char txtSnake[17];
  unsigned long previousMillis;
  uint8_t interval, startIndex, fruitHue;
  uint32_t count10ms;
  uint8_t snakeLength, snakeX[MAX_SNAKE_LENGTH], snakeY[MAX_SNAKE_LENGTH];
  uint8_t fruitX, fruitY;  
  struct Explode{
    uint8_t x, y, r, hue;
  } ex;
  boolean paused;
  uint16_t PlasmaTime, PlasmaShift;
  const uint8_t PlasmaLowHue = 100;
  const uint8_t PlasmaHighHue = 150;
  
  public:
  Snake(){
    previousMillis = 0;
    interval = 250;
    snakeLength = 1;
    snakePalette = RainbowColors_p;
    startIndex = 0;
    fruitHue = 0;
    ex.r = 10;
    count10ms = 0;
    paused = false;
  };

  void setup() {
    sprintf((char *)txtSnake, "                ");
    ScrollingMsg.SetFont(MatriseFontData);
    ScrollingMsg.Init(&leds, leds.Width(), ScrollingMsg.FontHeight() + 1, 0, 5);
    ScrollingMsg.SetBackgroundMode(BACKGND_ERASE);
    ScrollingMsg.SetScrollDirection(SCROLL_LEFT);
    ScrollingMsg.SetFrameRate(1);
    ScrollingMsg.SetTextColrOptions(COLR_RGB | COLR_SINGLE, 0x00, 0x99, 0x33);
    
    currentInput = NONE;

    PlasmaShift = (random8(0, 5) * 32) + 64;
    PlasmaTime = 0;

    // Start snake in the middle
    snakeX[0] = leds.Width() / 2;
    snakeY[0] = leds.Height() / 2;
  
    makeFruit();
  }

  boolean loop() {
    // Fill background with dim plasma
    #define PLASMA_X_FACTOR  48
    #define PLASMA_Y_FACTOR  48
    for (int16_t x=0; x<leds.Width(); x++)
    {
      for (int16_t y=0; y<leds.Height(); y++)
      {
        int16_t r = sin16(PlasmaTime) / 256;
        int16_t h = sin16(x * r * PLASMA_X_FACTOR + PlasmaTime) + cos16(y * (-r) * PLASMA_Y_FACTOR + PlasmaTime) + sin16(y * x * (cos16(-PlasmaTime) / 256) / 2);
        int16_t hue = ((h / 256) + 128);
        leds(x, y) = CHSV((uint8_t)hue, 255, 64);
      }
    }
    uint16_t OldPlasmaTime = PlasmaTime;
    PlasmaTime += PlasmaShift;
    if (OldPlasmaTime > PlasmaTime) {
      PlasmaShift = (random8(0, 5) * 32) + 64;
    }
    
    EVERY_N_MILLISECONDS(10){
      count10ms++;
    }
    
    unsigned long currentMillis = millis();
    
    if(paused) {
      //Black bar behind text
      for (int i = 48; i<191; i++) {
        leds(i) = CRGB::Black;
      }
      if(ScrollingMsg.UpdateText() == -1) {
        ScrollingMsg.SetText((unsigned char *)txtSnake, sizeof(txtSnake)-1);
      }
      if (SerialBT.available()) {
        reset();
      }
    }
    else {
      //FastLED.clear();
      explodeFruit();
      drawFruit();
      FillSnakeWithColour( startIndex );
      if(currentMillis - previousMillis >= interval) {
        previousMillis = currentMillis;
        nextStep();
      }

      if (SerialBT.available()) {
        char keyPress = (char)SerialBT.read();
        switch(keyPress) {
          case 'w':
            currentInput = UP;
            break;
          case 'a':
            currentInput = LEFT;
            break;
          case 's':
            currentInput = DOWN;
            break;
          case 'd':
            currentInput = RIGHT;
            break;
          case 'm':
            currentApp = -1;
            return false;
        }
      }
    }
    
    FastLED.show();
    delay(10);
    
    return true;
  }

  private:  
  void drawFruit(){
    leds(fruitX, fruitY) = CHSV(fruitHue, 255, 255);
  }
  
  void nextStep(){
    for(int i=snakeLength-1; i>0; i--){
      snakeX[i] = snakeX[i-1];
      snakeY[i] = snakeY[i-1];
    }
    switch(currentInput){
      case UP:
        snakeY[0] = snakeY[0]+1;
        break;
      case RIGHT:
        snakeX[0] = snakeX[0]+1;
        break;
      case DOWN:
        snakeY[0] = snakeY[0]-1;
        break;
      case LEFT:
        snakeX[0] = snakeX[0]-1;
        break;
    }
    
    // Check if head has hit fruit
    if((snakeX[0] == fruitX) && (snakeY[0] == fruitY)){
      snakeLength++;
      interval -= 5;
      if(interval < 100) interval = 100;

      //Store current fruit values to make explosion
      ex.x = snakeX[0];
      ex.y = snakeY[0];
      ex.r = 1;
      ex.hue = fruitHue;
      
      if(snakeLength < MAX_SNAKE_LENGTH){      
        makeFruit();
      }
    }
  
    // Check if head has hit body or left play area
    if(isPartOfSnakeBody(snakeX[0], snakeY[0]) || !inPlayField(snakeX[0], snakeY[0])){
      currentInput = NONE;
      FastLED.clear();
      paused = true;
      sprintf((char *)txtSnake, "   SCORE %u   ", snakeLength-1);
      ScrollingMsg.SetText(txtSnake, strlen((const char *)txtSnake));
    }
  }
  
  void reset() {
    snakeLength = 1;
    currentInput = UP;
    interval = 250;
    snakeX[0] = leds.Width() / 2;
    snakeY[0] = leds.Height() / 2;
    for(int i=1; i<MAX_SNAKE_LENGTH; i++){
      snakeX[i] = snakeY[i] = -1;
    }
    paused = false;
  }
  
  boolean inPlayField(int x, int y){
    return (x>=0) && (x<leds.Width()) && (y>=0) && (y<leds.Height());
  }
  
  void makeFruit(){
    uint8_t x, y;
    x = random(0, leds.Width());
    y = random(0, leds.Height());
    while(isPartOfSnake(x, y)){
      x = random(0, leds.Width());
      y = random(0, leds.Height());
    }
    fruitX = x;
    fruitY = y;
    // Pick a new fruit color
    fruitHue = random8();
  }
  
  boolean isPartOfSnake(int x, int y){
    for(int i=0; i<snakeLength-1; i++){
      if((x == snakeX[i]) && (y == snakeY[i])){
        return true;
      }
    }
    return false;
  }
  
  boolean isPartOfSnakeBody(int x, int y){
    for(int i=1; i<snakeLength-1; i++){
      if((x == snakeX[i]) && (y == snakeY[i])){
        return true;
      }
    }
    return false;
  }

  void FillSnakeWithColour(uint8_t colourIndex) {
    startIndex = startIndex + 1;
    for (int i = 0; i < snakeLength; i++) {
      leds(snakeX[i], snakeY[i]) = ColorFromPalette( snakePalette, colourIndex );
      colourIndex += 3;
    }
  }

  void explodeFruit() {
    if(ex.r < 7) {
      leds.DrawCircle(ex.x, ex.y, ex.r, CHSV(ex.hue, 255, 255-(ex.r*40)));
      if(count10ms % 2 == 0) ex.r++;
    }
  }
};