Problem Set: Sprites

This section contains a number of selected problems for the Sprites section.

It is recommended that you review the problems, and complete a few before moving on to the next section.

Problem #1: Duck, Duck, Goose

You’ve decided to make a game based off of “Duck, Duck, Goose”.

You notice that there is an image of a duck already included in the gallery, which is perfect for the game. Create two ||sprites:sprites|| using the ||sprites:sprites.duck.duck1|| image from the gallery.

There is still one thing missing, though: the “Goose.” Create a third ||sprites:sprite||, and use the image editor to draw the “Goose” for your game.

Problem #2: The Main Character

||sprites:Sprites|| allow for the representation of characters in games. The main character of a game will often be a ||sprites:Sprite|| that the player controls.

Create a ||sprites:sprite|| that uses an image of a character from the gallery. Make the character move around using the ||controller:controller||.

Problem #3: Quick Animation

Many of the ||sprites:sprites|| in the gallery form a sequence: slightly different images of the same character that can be used to ‘animate’ the sprite.

let duck: Sprite = sprites.create(sprites.duck.duck1, SpriteKind.Player);
for (let i = 0; i < 10; i++) {
    duck.setImage(sprites.duck.duck1);
    pause(150);
    duck.setImage(sprites.duck.duck2);
    pause(150);
}

||sprites:setImage|| can be used to change the image for a sprite that has already been made. The previous snippet shows an example of switching between two images for the ||sprites:sprite|| ||variables:duck||.

||loops:Pause|| is used after each ||sprites:setImage||, so that the images will be displayed on the screen for a little while before changing.

Fill out the animation with more calls to ||sprites:setImage|| and ||loops:pause|| in the ||loops:for|| loop. Add the following images to create an animation like the one below.

1. ||sprites:sprites.duck.duck3||
2. ||sprites:sprites.duck.duck4||
3. ||sprites:sprites.duck.duck5||
4. ||sprites:sprites.duck.duck6||

Problem #4: Picky Positioning

Review the code in the snippet below.

let hero: Sprite = sprites.create(sprites.castle.heroWalkFront1, SpriteKind.Player);

pause (1000);

if (hero.x < 40) {
    hero.say("That's not right!", 1000);
} else if (hero.x >= 50) {
    hero.say("That's too right!", 1000);
} else {
    hero.say("That is good!", 1000);
}

pause(2000);

if (hero.y < 100) {
    hero.say("Too high!", 1000);
}

if (hero.x >= 40) {
    hero.say("I don't want to be here.", 1000);
}

pause(2000);

if (hero.x >= 40 && hero.y > 100) {
    hero.say("Perfect!");
}

The ||variables:hero|| is a bit picky about where they want to be. Change the ||sprites:x|| and ||sprites:y|| position of the ||variables:hero|| after each ||loops:pause|| to make them only say “That is good!” and “Perfect!”