// Author: Daniel Kaye

//  URL: http://dnkaye.com/2020_CodingChallenges.html

//

// Based on Daniel Schiffman's (Coding Train) coding challenges

//  URL: https://thecodingtrain.com/CodingChallenges/005-space-invaders-p5.html

//  

// What is this?

//  An attempt to rewrite the classic 'Space Inavders' game using p5.js

//

// How do I do this?

//  I attempt to complete Daniel Schiffman's coding challenges before watching

//  his video, then afterwards I watch and see what he did differently

​

// Things I'm proud of / differences from The Coding Train version:

//  -alien explosions using transformations

//  -original alien sprite useage

//  -resemblenece to original Space Incaders Game.

//    I had no idea Dan's version was going to be so

//    different from the original game  #waterTheFlowers

​

​

//TODO:

// add blockers

​

let canvas;

let player;

let green;

let red;

let white;

let bgColor;

let shots = []; // stores all shots

let aliens = []; // stores all aliens

let redAlienUFOThing;

let lasers = [];

let redLaser;

let score = 0;

let highScore = 0;

// all alien ship images

let alien1_a;

let alien1_b;

let alien2_a;

let alien2_b;

let alien3_a;

let alien3_b;

let alien4; // red alien ship

let speed = 10; // aliens move once ever x frames, lower is faster.

laserSpeed = 10; // speed at which alien laser shots move

let alienDirection = 'left';

let chanceOfFiringLaser = 50; // x% change an alien a random alien shoots a laser every time the aliens moved. Increases slowly to increase difficulty

let pauseMode = false;

let pauseTime = 0;

let gameOverBool = false;

let isThereARedAlien = false;

​

​

​

function preload() {

  alien1_a = loadImage('images/alien1_a.png');

  alien1_b = loadImage('images/alien1_b.png');

  alien2_a = loadImage('images/alien2_a.png');

  alien2_b = loadImage('images/alien2_b.png');

  alien3_a = loadImage('images/alien3_a.png');

  alien3_b = loadImage('images/alien3_b.png');

  alien4 = loadImage('images/alien4.png');

}

​

function setup() {

  canvas = createCanvas(400, 400);

  canvas.id('spaceInvaders');

  noSmooth(); // turns off anti-aliasing

  green = color(51, 255, 0);

  red = color(255, 51, 0);

  white = color(255);

  bgColor = color(50);

  frameRate(10); // 

  player = new MyShip();

  createAllAliens();

  imageMode(CENTER);

  setInterval(createRedAlien, 30000);

}

​

function draw() {

  if (focused || frameCount < 30) {

    background(bgColor);

    player.move();

    player.drawPlayer();

    player.drawExtraLives();

    drawScore();

    if (!pauseMode) { // if the game is not currently in pause mode....

      // run the functions that incrimentally move everything

      moveAllShots();

      moveAllLasers();

      moveRedLaser();

      // events that only occur based on the current speed, not every frame

      if (frameCount % speed == 0) {

        moveAllAliens();

        fireLaser();

      }

      moveRedAlien();

    }

    if (pauseMode) {

      animateNewLife();

    }

    drawAllShots();

    drawAllLasers();

    drawAllAliens();

    drawRedAlien();

    hitAlien();

    hitPlayer();

    hitRedAlien();

    if (allAliensKilled()) {

      print('all aliens killed!');

      resetAliens();

    }

  } else {

    drawUnpauseInstructions();

  }

}

​

function drawUnpauseInstructions() {

  noStroke();

  fill(255);

  textAlign(CENTER);

  textSize(18);

  text('click to play', width / 2, height - height/4);

}

​

function keyPressed() {

  if (key === ' ') {

    if (!pauseMode) {

      print('shot fired!');

      player.fire();

    }

  }

  if (keyCode === LEFT_ARROW) {

    print('directon changes!');

    player.changeDirection('left');

  }

  if (keyCode === RIGHT_ARROW) {

    player.changeDirection('right');

  }

  if ((keyCode === RETURN || keyCode === ENTER) && gameOverBool) {

    reset();

  }

  return false; // prevents default browser behaviors

}

​

function mousePressed() {}

​

function keyReleased() {

  if (keyIsPressed === false) {

    player.changeDirection('none');

  }

}

​

function drawAllShots() {

  for (let shot of shots) {

    shot.draw();

  }

}

​

function moveAllShots() {

  for (let shot of shots) {

    shot.move();

  }

}

​

function createAllAliens() {

  let startingX = 70;

  let startingY = 200;

  // creates bottom two rows of alien 1!

  for (i = 0; i < 22; i++) {

    aliens[i] = new Alien(startingX, startingY, 20, 20, alien1_a, alien1_b, 10);

    startingX += 30;

    if (startingX > width - 30) {

      startingX = 70;

      startingY -= 30;

    }

  }

  // creates middle two rows of alien 2!

  for (i = 22; i < 44; i++) {

    aliens[i] = new Alien(startingX, startingY, 18, 14, alien2_a, alien2_b, 20);

    startingX += 30;

    if (startingX > width - 30) {

      startingX = 70;

      startingY -= 30;

    }

  }

  // creates top two rows of alien 3!

  for (i = 44; i < 55; i++) {

    aliens[i] = new Alien(startingX, startingY, 14, 14, alien3_a, alien3_b, 40);

    startingX += 30;

    if (startingX > width - 30) {

      startingX = 70;

      startingY -= 30;

    }

  }

}

​

function drawAllAliens() {

  for (let alien of aliens) {

    alien.draw();

  }

}

​

// moves all aliens

function moveAllAliens() {

  for (let alien of aliens) {

    alien.moveHorizontal(alienDirection);

  }

  if (checkIfAliensReachedEdge()) {

    reverseAlienDirections();

    moveAllAliensDown();

  }

}

​

function checkIfAliensReachedEdge() {

  let edgeReached = false;

  for (let alien of aliens) {

    if ((alien.x < 15 && alien.alive) || (alien.x > width - 15 && alien.alive)) {

      edgeReached = true;

    }

  }

  return edgeReached;

}

​

// reverse horizontal travel direction of all(most all) aliens & moves them down

function reverseAlienDirections() {

  if (alienDirection === 'left') {

    alienDirection = 'right';

  } else {

    alienDirection = 'left';

  }

}

​

function moveAllAliensDown() {

  for (let alien of aliens) {

    alien.moveVertical();

  }

}

​

function hitAlien() {

  for (let shot of shots) {

    for (let alien of aliens) {

      // if(dist(alien.x, alien.y, shot.x, shot.y) < 10){

      if (shot.x > alien.x - alien.alienWidth / 2 &&

        shot.x < alien.x + alien.alienWidth / 2 &&

        shot.y - shot.length > alien.y - alien.alienHeight / 2 &&

        shot.y - shot.length < alien.y + alien.alienHeight / 2 &&

        !shot.hit && alien.alive

      ) {

        alien.alive = false;

        shot.hit = true;

        score += alien.points; // increases score when an alien is shot

      }

    }

  }

}

​

// returns true if all aliens have been shot

function allAliensKilled() {

  let bool = true;

  for (let alien of aliens) {

    if (alien.alive) {

      bool = false;

    }

  }

  return bool;

}

​

// resets alaien positions and incriments speed

function resetAliens() {

  createAllAliens();

  redAlienUFOThing.x = 0 - redAlienUFOThing.shipWidth; // hides any current red alien off screen if game is reset

  if (speed > 2) {

    speed -= 2;

  }

  chanceOfFiringLaser += 10;

​

}

​

function fireLaser() {

  // only fires laser if random number from 0 to 100 is less than the current 'chance of firing laser) global varialbe

  if (random(100) < chanceOfFiringLaser) {

    let i = floor(random(aliens.length));

    if (aliens[i].alive) {

      let l = new Laser(aliens[i].x, aliens[i].y + (aliens[i].alienHeight / 2), laserSpeed, white);

      lasers.push(l);

    }

  }

}

​

// draws all lasers

function drawAllLasers() {

  for (let laser of lasers) {

    laser.draw();

  }

}

​

// moves all active lasers

function moveAllLasers() {

  for (let laser of lasers) {

    laser.move();

  }

}

​

// draws score to screen

function drawScore() {

  noStroke();

  fill(255);

  textSize(14);

  textAlign(LEFT);

  text('LIVES: ', width - 175, 28);

  text('SCORE:', 25, 28);

  // makes score red if it has surpased the previous high score

  if (highScore > 0 && score > highScore) {

    fill(red);

  }

  text(score, 85, 28);

}

​

// checks if player was hit

function hitPlayer() {

  for (let laser of lasers) {

    let leftEdgeOfLaser = laser.x - 2;

    let rightEdgeOfLaser = laser.x + 2;

    let frontOfLaser = laser.y + 8;

    let backOfLaser = laser.y;

    let leftEdgeOfShip = player.x - (player.shipWidth / 2);

    let rightEdgeOfShip = player.x + (player.shipWidth / 2);

    let frontOfShip = player.y - (player.shipHeight / 2);

    let backOfShip = player.y + (player.shipHeight / 2);

​

    // below shapes used for figuring out and debigging of laser/ship overlap detection 

    //     noFill();

    //     stroke(255, 0, 0);

    //     strokeWeight(1);

    //     beginShape();

    //     vertex(leftEdgeOfLaser, backOfLaser);

    //     vertex(leftEdgeOfLaser, frontOfLaser);

    //     vertex(rightEdgeOfLaser, frontOfLaser);

    //     vertex(rightEdgeOfLaser, backOfLaser);

    //     endShape(CLOSE);

​

    //     beginShape();

    //     vertex(leftEdgeOfShip, backOfShip);

    //     vertex(leftEdgeOfShip, frontOfShip);

    //     vertex(rightEdgeOfShip, frontOfShip);

    //     vertex(rightEdgeOfShip, backOfShip);

    //     endShape(CLOSE);

​

    // if the player has been shot...

    if (rightEdgeOfLaser > leftEdgeOfShip &&

      leftEdgeOfLaser < rightEdgeOfShip &&

      frontOfLaser > frontOfShip &&

      backOfLaser < backOfShip &&

      !laser.used) {

      print('player hit!!!');

      laser.used = true; // that laser is now used and can't hit player again, or be drawn

      if (player.lives > 0) {

        lifeLost();

      }

      if (player.lives == 0) {

        gameOver();

      }

    }

  }

}

​

// functio level up

function levelUp() {}

​

// function life lost

function lifeLost() {

  pauseTime = frameCount;

  print('life lost!');

  player.color = red;

  pauseMode = true;

}

​

// animates a new life

function animateNewLife() {

  print('animating new life');

  //  makes the player blink for 30 frames

  if ((frameCount - pauseTime > 5 && frameCount - pauseTime < 10) ||

    (frameCount - pauseTime > 15 && frameCount - pauseTime < 20) ||

    (frameCount - pauseTime > 25 && frameCount - pauseTime < 30)

  ) {

    noStroke();

    fill(bgColor);

    rectMode(CENTER);

    // draws background colored rectangle over player to make it appear as if it's blinking

    rect(player.x, player.y - 4,

      player.shipWidth + 2, player.shipHeight + 8);

  }

  // after 30 frames, resets player with new life

  if (frameCount - pauseTime > 30) {

    player.color = green;

    player.x = width / 2;

    pauseMode = false;

    player.lives -= 1;

    // clears all current lasers

    // or else player could get hit with laser as soon as they respawn with their new life in the center, which is unfair

    for (let laser of lasers) {

      laser.used = true;

    }

    // clears all current shots too

    for (let shot of shots) {

      shot.hit = true;

    }

  }

}

​

// clears all current lasers

function clearAllLasers() {}

​

// function game over

function gameOver() {

  gameOverBool = true;

  background(0, 125);

  print('game over!');

  textSize(60);

  stroke(0);

  fill(255);

  textAlign(CENTER);

  text('GAME OVER', width / 2, height / 2);

  textSize(20);

  text('Score: ' + score, width / 2, height / 2 + 50);

  if (score > highScore) {

    fill(red);

    text('NEW HIGH SCORE!!!', width / 2, height / 2 + 75);

    fill(255);

  }

  text("Press 'ENTER' to play again!", width / 2, height / 2 + 125);

  noLoop();

}

​

// resets game

function reset() {

  highScore = score;

  score = 0;

  player = new MyShip();

  createAllAliens();

  for (let laser of lasers) {

    laser.used = true;

  }

  // clears all current shots too

  for (let shot of shots) {

    shot.hit = true;

  }

  loop();

}

​

// create red alien

function createRedAlien() {

  redAlienUFOThing = new RedAlien();

  isThereARedAlien = true;

  print('red alien created!');

}

​

// moves red alien only if one exists

function moveRedAlien() {

  if (isThereARedAlien) {

    redAlienUFOThing.move();

  }

}

​

// draws red alien only if one exists

function drawRedAlien() {

  if (isThereARedAlien) {

    redAlienUFOThing.draw();

  }

}

​

function hitRedAlien() {

  if (isThereARedAlien) {

    for (let shot of shots) {

      if (shot.x > redAlienUFOThing.x - redAlienUFOThing.alienWidth / 2 &&

        shot.x < redAlienUFOThing.x + redAlienUFOThing.alienWidth / 2 &&

        shot.y - shot.length > redAlienUFOThing.y - redAlienUFOThing.alienHeight / 2 &&

        shot.y - shot.length < redAlienUFOThing.y + redAlienUFOThing.alienHeight / 2 &&

        !shot.hit && redAlienUFOThing.alive

      ) {

        redAlienUFOThing.alive = false;

        shot.hit = true;

        score += redAlienUFOThing.points; // increases score when an alien is shot

      }

    }

  }

}

​

function moveRedLaser() {

  if (isThereARedAlien) {

    if (redAlienUFOThing.redLaserFired) {

      redLaser.move();

    }

  }

}