Pixel Chaser Game

/*
---------------------------------------------------------------------------
Pixel Chaser Game - v1.0.0 - 24/03/2019.

AUTHOR/LICENSE:                                                                      
Created by Seon Rozenblum - seon@unexpectedmaker.com
Copyright 2016 License: GNU GPL v3 http://www.gnu.org/licenses/gpl-3.0.html

LINKS:
Blog: unexpectedmaker.com
YOUTUBE: youtube.com/c/unexpectedmaker

DISCLAIMER:
This software is furnished "as is", without technical support, and with no 
warranty, express or implied, as to its usefulness for any purpose.

PURPOSE:
This controller is the software that runs on the Reflow Master toaster oven controller made by Unexpected Maker

HISTORY:
24/03/2019 v1.0.0   - Initial release.

NOTE: This is a work in progress...
---------------------------------------------------------------------------
*/

// We need these libraries installed from library manager
#include <Adafruit_NeoPixel.h>
#include "OneButton.h"

// What GPIO is the strip connected to
#define PIXELPIN       4

// How many NeoPixels in the strip
#define NUMPIXELS      24

// What GPIO is the button connected to?
#define BUTTON_TAP     3

// Initialise the button, with a default low
OneButton buttonTAP(BUTTON_TAP, false);

// Initialise the pixel strip
Adafruit_NeoPixel pixels = Adafruit_NeoPixel(NUMPIXELS, PIXELPIN, NEO_GRB + NEO_KHZ800);

// A bunch of variables
int playerIndex = -1;
int playerIndexTrail = -1;
int playerDirection = 1;
float nextMove = 0;
float currentPlayerSpeed = 150;
unsigned long countdown  = 0;
int enemyIndex = -1;
int coinIndex = -1;
int score = 0;
int bestScore = 0;
int lastScore = 0;
bool gameOver = false;

void setup()
{
  // make the button pin an input
  pinMode( BUTTON_TAP, INPUT );
  
  // Attatch click functions to the button
  buttonTAP.attachClick(singleClick);
  buttonTAP.attachLongPressStart(longClick);

  // Initialise the strip and set it's brightness to 20%
  pixels.begin();
  pixels.setBrightness(20);

  // set a 2 second countdown before the player appears and starts moving
  countdown = millis() + 2000;
}

void loop()
{
  // Every cycle we need to tick the button state
  buttonTAP.tick();

  // If the game is in game over state, exit loop early
  if ( gameOver )
    return;

  // Set the pixel display state of the level
  // This sets the enemy position and the coin position
  SetLevel();

  // wait for a second for the player to get ready
  if ( countdown > millis() )
  {
    pixels.show();
    return;
  }

  // All the player display, movement and game logic is in here
  DisplayPlayer();

   // This sends the updated pixel color to the hardware.
  pixels.show();
}

// Clear the level, setting all pixels to black
void ClearLevel()
{
  for(int i=0;i<NUMPIXELS;i++)
      pixels.setPixelColor(i, pixels.Color(0,0,0)); // Moderately bright green color.

  pixels.show();
}

// Show the best score in yellow and if the last score was less than the best, show that on top in red
void BestScore()
{
  // Best score in yellow
  for(int i=0;i<NUMPIXELS;i++)
  {
    if ( i < bestScore )
      pixels.setPixelColor(i, pixels.Color(255,155,0)); // Moderately bright green color.
    else
      pixels.setPixelColor(i, pixels.Color(0,0,0)); 
  }

  // last score is less than best is in red
  if ( lastScore < bestScore )
  {
    for(int i=0;i<lastScore;i++)
      pixels.setPixelColor(i, pixels.Color(255,0,0)); // Moderately bright green color.
  }
  pixels.show();
}

// Game over animation
void GameOver()
{
  // First pass we animate the strip going red from the enemy position
  int a = enemyIndex;
  int b = enemyIndex;
  
  for(int i=0;i<NUMPIXELS/2;i++)
  {
      pixels.setPixelColor(a, pixels.Color(255,0,0)); // Moderately bright green color.
      pixels.setPixelColor(b, pixels.Color(255,0,0)); // Moderately bright green color.

      a = ( a + 1) % NUMPIXELS;
      b--;
      if ( b == -1 )
        b = NUMPIXELS;

      pixels.show();
      delay(20);
  }

  delay(100);

  // Second pass we animate the strip going back from the enemy position
  a = enemyIndex;
  b = enemyIndex;
  
  for(int i=0;i<NUMPIXELS/2;i++)
  {
      pixels.setPixelColor(a, pixels.Color(0,0,0)); // Black
      pixels.setPixelColor(b, pixels.Color(0,0,0)); // Black

      a = ( a + 1) % NUMPIXELS;
      b--;
      if ( b == -1 )
        b = NUMPIXELS;

        pixels.show();
        delay(20);
  }

  // Now we show the best score
  delay(100);
  BestScore();
}

// Setup the level including the postiion of the enemy and the coin
void SetLevel()
{
  // If the enemy position is -1 (has been reset)
  // Find a new position for the enemy
  if ( enemyIndex < 0 )
  {
    // I fthe player not playing, always start the enemy at the half strip position
    if ( playerIndex < 0 )
    {
      enemyIndex = NUMPIXELS / 2;
    }
    // The player is in the game, so make sure not to place the enemy on or too close to the player
    else
    {
      enemyIndex = random(0, NUMPIXELS);

      while ( abs(enemyIndex - playerIndex ) < ( NUMPIXELS / 4 ) )
        enemyIndex = random(0, NUMPIXELS);
    }
  }
  // If the coin position is -1 (has been reset)
  // Find a new position for the coin
  if ( coinIndex < 0 )
  {
      coinIndex = random(0, NUMPIXELS);

      // pick a coin position somewhere between the player and enemy
      while ( abs(coinIndex - playerIndex ) < 7 || ( abs(coinIndex - enemyIndex ) < 7 ) )
        coinIndex = random(0, NUMPIXELS);
  }

  pixels.setPixelColor(enemyIndex, pixels.Color(255,0,0));
  pixels.setPixelColor(coinIndex, pixels.Color(255,255,0));
}

// This is where all the magic happens
// Player movement happens here as well as game logic for collecting coins or hitting the enemy
void DisplayPlayer()
{
  
  if ( nextMove < millis() )
  {
    nextMove = millis() + currentPlayerSpeed;

    // The player has a visual trail, so these next 2 if statements shows or clears the trail
    if ( playerIndexTrail >= 0 )
        pixels.setPixelColor(playerIndexTrail, pixels.Color(0, 0, 0));

    if ( playerIndex >= 0)
    {
      pixels.setPixelColor(playerIndex, pixels.Color(0, 100, 0));
      playerIndexTrail = playerIndex;
    }

    // Move the player in their current direction
    playerIndex += playerDirection;

    // Wrap the player at the strip edges
    if ( playerIndex < 0 )
      playerIndex = NUMPIXELS - 1;
    else if ( playerIndex == NUMPIXELS )
      playerIndex = 0;
    
    pixels.setPixelColor(playerIndex, pixels.Color(0, 255, 0));

    // Did the player hit the coin?
    // If so, increase the score, reset coin and enemy positions and clear the level
    // Next loop the SetLevel() will reset the enemy and coin
    // Player speed is also increased for every coin hit
    if ( playerIndex == coinIndex )
    {
      enemyIndex = -1;
      coinIndex = -1;
      score++;
      currentPlayerSpeed = constrain( currentPlayerSpeed - 10, 50, 150 );
      ClearLevel();
      pixels.setPixelColor(playerIndex, pixels.Color(0, 255, 0));
    }
    // Did the player hit the enemy?
    // Set the last/best score and call game over
    else if ( playerIndex == enemyIndex )
    {
      lastScore = score;
      if ( score >= bestScore )
        bestScore = score;
        
      GameOver();
      
      gameOver = true;
      enemyIndex = -1;
      coinIndex = -1;
      playerIndex = -1;
    }
  }
}

// Single button click
void singleClick()
{
  // No input until player is visible
  if ( countdown > millis() )
    return;

  // switch the player direction
  playerDirection = -playerDirection;
}
  
// Long button click
void longClick()
{
    // Switch game over state
    // If it was game over, start the game, otherwise cancel a game in progress
    gameOver = !gameOver;
    if ( gameOver )
    {
      enemyIndex = -1;
      coinIndex = -1;
      playerIndex = -1;
      currentPlayerSpeed = 150;
      ClearLevel();
    }
    else
    {
      ClearLevel();
      score = 0;
      currentPlayerSpeed = 150;
      countdown = millis() + 2000;
    }
}