Unit 3.22 Game Sprites are getting stuck on the platforms. Why is it doing that?

CS Discoveries
1

// Variables

var score = 0;

var lives = 3;

// Create Sprites

var platform1 = createSprite(randomNumber(80, 310), 50);

platform1.setAnimation(“platform”);

platform1.velocityY = 1;

platform1.scale = 0.4;

var platform2 = createSprite(randomNumber(80, 310), 250);

platform2.setAnimation(“platform”);

platform2.velocityY = 1;

platform2.scale = 0.4;

var star1 = createSprite(randomNumber(50, 350), randomNumber(-40, -60));

star1.setAnimation(“star”);

star1.velocityY = 2.5;

star1.scale = 0.5;

star1.setCollider(“circle”);

var star2 = createSprite(randomNumber(50, 350), randomNumber(-30, -60));

star2.setAnimation(“star”);

star2.velocityY = 2.5;

star2.scale = 0.5;

star2.setCollider(“circle”);

var alien = createSprite(200, -30);

alien.setAnimation(“alien”);

var rock1 = createSprite(randomNumber(50, 350), -250);

rock1.setAnimation(“rock”);

rock1.velocityY = 1.5;

rock1.rotationSpeed = -6;

rock1.setCollider(“circle”);

var rock2 = createSprite(randomNumber(50, 350), -250);

rock2.setAnimation(“rock”);

rock2.velocityY = 1.5;

rock2.rotationSpeed = 6;

rock2.setCollider(“circle”);

function draw() {

// draw the background

background1();

// update the sprites

if (score > 20) {

background2();

showScore();

} else {

background1();

showScore();

}

loopPlatforms();

loopItems();

playerFall();

controlPlayer();

playerLands();

collectItems();

alienReset();

showLives();

rockReset();

if (lives < 1) {

background3();

}

if (rock1.isTouching(alien)) {

alien.x = 200;

alien.y = -30;

lives = lives-1;

}

if (rock2.isTouching(alien)) {

alien.x = 200;

alien.y = -30;

lives = lives-1;

}

if (rock1.isTouching(rock2)) {

rockReset();

}

if (platform1.isTouching(platform2)) {

platform1.x = randomNumber(80, 310);

platform1.y = -350;

platform2.x = randomNumber(80, 310);

platform2.y = -350;

}

if (star1.isTouching(star2)) {

star1.x = randomNumber(50, 350);

star1.y = randomNumber(-30,-60);

star2.x = randomNumber(50, 350);

star2.y = randomNumber(-30,-60);

}

drawSprites();

}

// Functions

function background1() {

background(“darkBlue”);

noStroke();

fill(“yellow”);

ellipse(randomNumber(0, 400), randomNumber(0, 400), 3, 3);

ellipse(randomNumber(0, 400), randomNumber(0, 400), 3, 3);

ellipse(340, 50, 60, 60);

fill(“darkBlue”);

ellipse(320, 30, 60, 60);

}

function background2() {

background(“purple”);

stroke(“darkGreen”);

fill(“green”);

rect(randomNumber(0, 400), randomNumber(0, 400), 30, 30);

rect(randomNumber(0, 400), randomNumber(0, 400), 30, 30);

}

function showScore() {

fill(“white”);

textSize(20);

text("Score: ",10, 10, 80, 20);

text(score, 75, 30);

}

function showLives() {

fill(“white”);

textSize(20);

text("Lives: ", 10, 37, 80, 20);

text(lives, 70, 57);

}

function loopPlatforms() {

if (platform1.y>450) {

platform1.y = -10;

platform1.x = randomNumber(80, 310);

}

if (platform2.y>450) {

platform2.y = -10;

platform2.x = randomNumber(80, 310);

}

}

function loopItems() {

if (star1.y > 410) {

star1.y = randomNumber(-30, -60);

star1.x = randomNumber(50, 350);

}

if (star2.y > 410) {

star2.y = randomNumber(-30, -60);

star2.x = randomNumber(50, 350);

}

}

function playerFall() {

alien.velocityY = alien.velocityY+0.5;

}

function controlPlayer() {

if (keyDown(“left”)) {

alien.x = alien.x-3;

alien.setAnimation("alienleft");

}

if (keyDown(“right”)) {

alien.setAnimation("alien");

alien.x = alien.x+3;

}

if (keyDown(“up”)) {

alien.velocityY = alien.velocityY=-5;

}

}

function playerLands() {

alien.collide(platform1);

alien.collide(platform2);

}

function collectItems() {

if (alien.isTouching(star1)) {

score = score+1;

star1.y = randomNumber(-30, -60);

star1.x = randomNumber(50, 350);

}

if (alien.isTouching(star2)) {

score = score+1;

star2.y = randomNumber(-30, -60);

star2.x = randomNumber(50, 350);

}

}

function alienReset() {

if (alien.y > 410) {

alien.x = 200;

alien.y = -40;

lives = lives-1;

}

}

function background3() {

background(“red”);

fill(“blue”);

text(“Game Over”, 150, 210, 400, 400);

textSize(300);

}

function rockReset() {

if (rock1.y > 410) {

rock1.x = randomNumber(50, 350);

rock1.y = -250;

}

if (rock2.y > 410) {

rock2.x = randomNumber(50, 350);

rock2.y = -250;

}

}

2

Hi,
Thanks for sharing your code. Could you also use the Share button to get a link to the project? This will make it easier for folks to poke around and try your project. With just the code, someone would still need to create or find all of your sprites’ animations.
Mike

3

here is the link

Thank you for looking.

4

I think the issue is the order in which you are calling your functions in lines 52 and 53.

You have

controlPlayer();
playerLands();

The controlPlayer is trying to move the character but then the playerLands sticks the character to the platform.
If you switch the order of these two, it seems like it works.

playerLands();
controlPlayer();

So now it is collide if we are touching but then move the character if we are pushing the up arrow as opposed to move the character but if we are still touching then stick to the platform. This allows the character to move all of the time.

Its awesome that you have made a bunch of functions because it makes it easy to switch things around! The power of the function!

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