Game Lab Documentation

sprite.collide()

Category:Sprites

Makes the sprite stop when it runs into the target. If the target is moving, it will push the sprite with it. The target keeps moving as before.

Most games will involve sprites colliding with each other. There are four types of collisions available in Game Lab: bounce, bounceOff, collide and displace. These blocks will cause a certain type of interaction between the sprite and its target and must be used within the draw function.

Examples

var sprite1 = createSprite(75, 250, 50, 50);
sprite1.velocityX=2;
sprite1.velocityY=-1;
var sprite2 = createSprite(250, 250, 50, 50);
sprite2.velocityX=-1;
sprite2.velocityY=-0.5;
function draw() {
  background("white");
  sprite1.collide(sprite2);
  drawSprites();
}

Four Collisions

Demonstrate all four types of collisions.

// Demonstrate all four types of collisions.
var spriteDisplace1 = createSprite(75, 50, 50, 50);
spriteDisplace1.setAnimation("displace");
spriteDisplace1.scale=0.75;
spriteDisplace1.velocityX=2;
var spriteDisplace2 = createSprite(250, 50, 50, 50);
spriteDisplace2.setAnimation("displaceTarget");
spriteDisplace2.scale=0.75;
var spriteCollide1 = createSprite(75, 150, 50, 50);
spriteCollide1.setAnimation("collide");
spriteCollide1.scale=0.75;
spriteCollide1.velocityX=2;
var spriteCollide2 = createSprite(250, 150, 50, 50);
spriteCollide2.setAnimation("collideTarget");
spriteCollide2.scale=0.75;
var spriteBounce1 = createSprite(75, 250, 50, 50);
spriteBounce1.setAnimation("bounce");
spriteBounce1.scale=0.75;
spriteBounce1.velocityX=2;
var spriteBounce2 = createSprite(250, 250, 50, 50);
spriteBounce2.setAnimation("bounceTarget");
spriteBounce2.scale=0.75;
var spriteBounceOff1 = createSprite(75, 350, 50, 50);
spriteBounceOff1.setAnimation("bounceOff");
spriteBounceOff1.scale=0.75;
spriteBounceOff1.velocityX=2;
var spriteBounceOff2 = createSprite(250, 350, 50, 50);
spriteBounceOff2.setAnimation("bounceOffTarget");
spriteBounceOff2.scale=0.75;
function draw() {
  background("white");
  spriteDisplace1.displace(spriteDisplace2);
  spriteCollide1.collide(spriteCollide2);
  spriteBounce1.bounce(spriteBounce2);
  spriteBounceOff1.bounceOff(spriteBounceOff2);
  drawSprites();
}

Syntax

sprite.collide(target)

Parameters

Name	Type	Required?	Description
target	Sprite or Group		The name of the target sprite or target group you want to check for a collision.

Returns

Boolean true or false. Changes output in the display after the sprites touch and drawSprites() is called.

Tips

All four of the collisions are similar to including an "if (sprite.isTouching(target))" in the draw function, and then depending on the collision type, updating the sprite and target velocityX and velocityY properties.
Only one of the four types of collisions should be specified for each pair of sprites.
To fine tune your collision detection use setCollider to change the shape and size of the collider area and set debug to true for the sprites.
A sprite that is not visible can still collide with other sprites and user mouse interactions.
The collide collision will return true when the two sprites are touching.

Found a bug in the documentation? Let us know at support@code.org.