A Pong implementation for the UMass CICS 290M Makerboard

pong.ino

// Imports
#include <Adafruit_SSD1306.h>

// Globals
#define UP_BUTTON 34
#define DOWN_BUTTON 0
#define RESET_BUTTON 35
#define BUZZER 17

// Game State
int score = 0;

// Paddle
int paddle_pos = 32;
int paddle_velocity = 1;
int paddle_height = 16;
int paddle_width = 4;

// Ball
volatile int ball_x = random(10, 80);
volatile int ball_y = random(16, 48);
volatile int ball_radius = 3;
volatile int ball_velocity_x = random(1, 3);
volatile int ball_velocity_y = random(1, 3);


Adafruit_SSD1306 lcd(128, 64); // create display object

// Callbacks
void IRAM_ATTR moveUp() {
  if (paddle_pos >= 0) {
    paddle_pos -= 1;
  }
}

void IRAM_ATTR moveDown() {
  if (paddle_pos + paddle_height <= 64) {
    paddle_pos += 1;
  }
}

void IRAM_ATTR restart() {
  if (gameOver()) {
    score = 0;
    ball_x = random(10, 80);
    ball_y = random(16, 48);
    ball_velocity_x = random(1, 3);
    ball_velocity_y = random(1, 3);
  }
}
void setup() {
  Serial.begin(9600);
  pinMode(BUZZER, OUTPUT);
  pinMode(UP_BUTTON, INPUT);
  pinMode(DOWN_BUTTON, INPUT);
  pinMode(RESET_BUTTON, INPUT);
  lcd.begin(SSD1306_SWITCHCAPVCC, 0x3C); // init
  lcd.setTextColor(WHITE);
  lcd.clearDisplay(); // clear software buffer
  lcd.display();
  attachInterrupt(RESET_BUTTON, restart, FALLING);
}

// Test if coordinates are out of bounds
boolean yIsOutOfBounds(int y) {return y > 63 || y < 0;}
boolean xIsOutOfBounds(int x) {return x > 127 || x < 0;}
boolean outOfBounds(int x, int y) {return xIsOutOfBounds(x) || yIsOutOfBounds(y);}
boolean gameOver() {return ball_x + ball_radius >= 127;}
boolean ballPaddleCollision(int x, int y) {
  return (x > 128 - paddle_width) && (y < paddle_pos + paddle_height && y > paddle_pos);
}

void drawPaddle(int x, int y, int width, int height) {
  lcd.fillRect(x, y, width, height, WHITE);
}

void ding() {
  ledcSetup(0, 5000, 8);
  ledcAttachPin(BUZZER, 0);
  ledcWriteTone(0, 500);
  delay(50); // 500Hz for 0.05 second
  ledcWriteTone(0, 0); // buzzer off
}

void drawBall() {
  lcd.fillCircle(ball_x, ball_y, ball_radius, BLACK);
  if (xIsOutOfBounds(ball_x + ball_radius) || xIsOutOfBounds(ball_x - ball_radius)) {
    ball_velocity_x *= -1;
    ding();
  }
  if (yIsOutOfBounds(ball_y + ball_radius) || yIsOutOfBounds(ball_y - ball_radius)) {ball_velocity_y *= -1;}
  if (ballPaddleCollision(ball_x + ball_radius, ball_y) || ballPaddleCollision(ball_x - ball_radius, ball_y)) {
    ball_velocity_x *= -1;
    ding();
    score++;
  }
  ball_x += ball_velocity_x;
  ball_y += ball_velocity_y;
  lcd.fillCircle(ball_x, ball_y, ball_radius, WHITE);
}

void loop() {
  // Check if Game is over
  if (gameOver()) {
    lcd.clearDisplay();
    lcd.setCursor(0,0);
    lcd.print("Score: " + String(score) + "\nPress bottom button \nto restart.");
    lcd.display();
    return;
  }
  // Check for button presses
  if (!digitalRead(UP_BUTTON)) {
    moveUp();
  }
  if (!digitalRead(DOWN_BUTTON)) {
    moveDown();
  }
  lcd.clearDisplay();
  drawPaddle(0, ball_y - (paddle_height / 2), paddle_width, paddle_height);
  drawPaddle(127 - paddle_width, paddle_pos + paddle_velocity, paddle_width, paddle_height); 
  drawBall();
  lcd.display();
}