collision dectection

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Taylor Ith

*/

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let player = Player();

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let ninjastar;

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let collisionRadius = 50;

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var time = 0;

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let gameState = 0;

// global variable to contain image data

//accessed by preload and draw

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let charIdleSprite, charWalkSprite, char2HealthSprite;

let ninjastar1move;

let startButton;

let titlescreen;

let backgroundImage;

let titlecard;

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let backgroundMusic;

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function preload() {

  charIdleSprite = loadImage("Sprite/character_Idle.gif");

  charWalkSprite = loadImage("Sprite/character_walk.gif");

  char2HealthSprite = loadImage("Sprite/sprite_2hp.gif");

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  ninjastar1move = loadImage("Sprite/NinjaStar2x0.gif");

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  backgroundMusic = loadSound("audio/8-Bit Ninja.mp3");

// https://opengameart.org/content/8-bit-ninja

  startButtomImage = loadImage("bg/startbutton.png");

  titlescreen = loadImage("bg/GameBG.png");

  backgroundImage = loadImage("bg/GameBG.png");

  titlecard = loadImage("bg/DodgeDojo.png");

}

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function setup() {

  createCanvas(480, 360);

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  imageMode(CENTER);

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  ninjastar = Ninjastar();

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  // backgroundMusic.play();

  backgroundMusic.loop(true);

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  startButton = Button(100, 300, startButton);

}

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function draw() {

  background(220);

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  if (gameState == 0) {

    startMenu();

  } else if (gameState == 1) {

    game();

  }

}

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function startMenu() {

  image(titlescreen, width / 2, height / 2);

  image(titlecard, width / 2, height / 3.5);

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  startButton.display();

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  if (startButton.clicked()) {

    gameState = 1;

  }

}

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function Button(x, y, img) {

  // x,y,img arguments are like

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  let w = 50;

  let h = 50;

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  let isClicked = false;

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  function display() {

    image(startButtomImage, x, y);

  }

  function clicked() {

    if (mouseIsPressed) {

      if (

        mouseX > x - w / 2 &&

        mouseX < x + w / 2 &&

        mouseY > y - h / 2 &&

        mouseY < y + h / 2

      ) {

        if (!isClicked) {

          isClicked = true;

          return true;

        }

      }

    } else if (isClicked) {

      isClicked = false;

    }

​

    return false;

  }

​

  return { display, clicked };

}

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function game() {

  image(backgroundImage, width / 2, height / 2);

  player.move();

  player.display();

​

  ninjastar.move();

  ninjastar.display();

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  let ninjacollide = detectCollision(player, ninjastar);

​

  if (ninjacollide) {

    player.hit();

    gameState = 0;

    time = 0;

    ninjastar.reset();

    // reset ninja star position

  }

​

  textSize(30); // time indicator

  image(charIdleSprite, 100, 20);

  text(floor(time / 60), 30, 30);

  time = time + 1;

  fill("red");

}

​

function Player() {

  let x = 200;

  let y = 200;

​

  let animationState = 0;

  // 1 = move

  // 0 = idle

  // 2 = 2hp

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  function move() {

    if (animationState != 2) {

      animationState = 0;

    }

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    if (keyIsDown(RIGHT_ARROW)) {

      x = x + 5;

      animationState = 1; //walk animation

    }

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    if (keyIsDown(LEFT_ARROW)) {

      x = x - 5;

      animationState = 1; //walk animation

    }

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    if (keyIsDown(UP_ARROW)) {

      y = y - 5;

      animationState = 1;

    }

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    if (keyIsDown(DOWN_ARROW)) {

      y = y + 5;

      animationState = 1;

    }

  }

​

  function display() {

    if (animationState == 0) {

      image(charIdleSprite, x, y);

    } else if (animationState == 1) {

      image(charWalkSprite, x, y);

    } else if (animationState == 2) {

      image(char2HealthSprite, x, y);

    }

  }

  function getPosition() {

    return { x, y };

  }

​

  function hit() {

    animationState = 2;

  }

​

  return { move, display, getPosition, hit };

}

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function coinFlip() {

  return random(-1, 1) > 0;

}

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function Ninjastar() {

  let x, y;

  let speedX, speedY;

  let defaultSpeed = 7;

  reset();

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  let animationState = 0;

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  function move() {

    x = x + speedX;

    y = y + speedY;

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    if (x > width || x < 0 || y > height || y < 0) {

      reset();

    }

  }

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  function reset() {

    x = random(0, 500);

    y = random(0, 500);

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    if (coinFlip()) {

      x = 0;

      if (coinFlip()) {

        x = width;

      }

    } else {

      y = 0;

      if (coinFlip()) {

        y = height;

      }

    }

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    let playerPosition = player.getPosition();

    let diffX = playerPosition.x - x;

    let diffY = playerPosition.y - y;

​

    if (abs(diffX) > abs(diffY)) {

      speedX = defaultSpeed * Math.sign(diffX);

      speedY = (diffY / diffX) * defaultSpeed * Math.sign(diffY);

    } else {

      speedX = (diffX / diffY) * defaultSpeed * Math.sign(diffX);

      speedY = defaultSpeed * Math.sign(diffY);

    }

​

    console.log(x, y, speedX, speedY);

  }

​

  function display() {

    if (animationState == 0) {

      image(ninjastar1move, x, y);

    }

  }

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  function getPosition() {

    return { x, y };

  }

​

  return { move, display, getPosition, reset };

}

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//compare the position of two objects

// return true if they are colliding

function detectCollision(objA, objB) {

  let aPosition = objA.getPosition();

  let bPosition = objB.getPosition();

​

  let d = dist(aPosition.x, aPosition.y, bPosition.x, bPosition.y);

  let isColliding = d < collisionRadius;

  return isColliding; // returns true or false

}

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function mousePressed() {}

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