createEdgeSprites()

Creates four sprites just off each edge of the screen ("topEdge", "bottomEdge", "leftEdge", "rightEdge") and a group called "edges" containing the four sprites.

createEdgeSprites is a helper command for games where you want to prevent sprites from going off the screen.

Examples

                            // Stay cool! Keep all the bad vibes from getting you down.
// Uses createGroup to make a bunch of bouncing baddies, 
// createEdgeSprites to make sure the baddies don't just fly off.

var cool = createSprite(200, 325);
cool.setAnimation("cool");
createEdgeSprites();
var group = createGroup();

for (var i = 0; i < 20; i++) {
  var sprite = createSprite(randomNumber(0, 400), randomNumber(0, 100), 10, 10);
  sprite.velocityY=randomNumber(5, 10);
  sprite.velocityX=randomNumber(-5, 5);
  sprite.bounciness = 1
  group.add(sprite);
}

group.setAnimationEach("mean");

function draw() {
  background("white");
  drawSprites();
  cool.x = World.mouseX;
  group.bounceOff(cool);
  group.bounceOff(topEdge);
  group.bounceOff(leftEdge);
  group.bounceOff(rightEdge);  
}

                        

createEdgeSprites();
var sprite = createSprite(200, 200);
sprite.setVelocity(randomNumber(-5, 5), randomNumber(-5, 5));
function draw() {
  background("white");
  drawSprites();
  sprite.bounceOff(edges);
}

Walls Closing In

Make the walls slowly close in using the edge sprite names topEdge, bottomEdge, leftEdge and rightEdge.

// Make the walls slowly close in using the edge sprite names topEdge, bottomEdge, leftEdge and rightEdge.
createEdgeSprites();
var sprite = createSprite(200, 200);
sprite.setVelocity(randomNumber(-5, 5), randomNumber(-5, 5));
function draw() {
  background("white");
  drawSprites();
  topEdge.y=topEdge.y+1;
  bottomEdge.y=bottomEdge.y-1;
  leftEdge.x=leftEdge.x+1;
  rightEdge.x=rightEdge.x-1;
  sprite.bounceOff(edges);
}

Syntax

createEdgeSprites()

Returns

No return value. Creates four sprites just outside the edges of the screen.

Tips

• Use the group "edges" to manage all four edge sprite interactions with other sprites.
• Change the image displayed for an edge sprite from the default rectangle using the setAnimation command. All images must be first loaded and given a label using the Animation tab above the display window in Game Lab.
• Edge sprites all have the same properties and you use the dot notation (combining the name of the edge sprite, followed by a dot, with the label of the property) to both access and update the property for that edge sprite.
• If you attempt to set an edge sprite property to an incorrect value the property reverts to its default value.

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