How to load animations
An animation is a series of images that are displayed one after the other at a fast enough rate to give the appearance of motion.
The loadAni function has three different modes: sequence, list, and sprite sheet.
In this code example, the cloud breathing animation is loaded using a numbered sequence of images given the path to the first image and the index of the last image in the sequence.
The animation function is similar to the p5.js image function. Use it in
the p5.js draw function to display an animation at a position.
In this code example the loadAnimation function is given a list of images.
The ani.frameDelay property defines how many frames an image in the animation is
displayed before the next image is displayed. The default is 4. Higher values make the animation
play slower. A frame delay of 1 would make the animation play as fast as possible.
Try it! Try changing the frameDelay in this mini-example.
This code example loads an animation from a sprite sheet, which is a single image that contains all the frames of an animation. Take a look at the sprite sheet in this sketch which is displayed just so you can see what one looks like.
In sprite sheet mode, an atlas object can be used to specify the size of each frame and how many frames of animation there are.
If you really need to use an animation when your program starts, you should load it in the p5.js preload function instead of setup.
Animating
p5play gives you total control over your animations.
Try using your keyboard to test out some of the different ways to control animations!
Sprites with Animations
The sprite.addAni function can add an animation to a sprite. It can also load the
animation, just like loadAni. As an optional first input parameter, you can provide
a name for the animation.
Try pressing the left mouse button. When
sprite.debug property is set to true you can
see the sprite's physics body collider.
Control a Sprite's Animation
Use the sprite.changeAni function to change a sprite's animation, this function
accepts an animation object or the name of a previously loaded animation.
sprite.ani stores the sprite's current animation, which enables access to its
properties and functions like play and stop.
The sprite.mirror vector can be used to flip the sprite
horizontally or vertically.
Try pressing left and right to make the ghost move.
Try pressing the space bar to stop the animation.
Groups with Animations
If an animation is added to a group, new group sprites will receive a copy of that animation.
Note that in this mini-example if you put splats too close together they'll move apart until their colliders are no longer overlapping. The size of the collider is taken from the size of the animation.
Try clicking the mouse to add new splats!
Sprite Sheets with Multiple Animations
To load multiple animations from the same sprite sheet image, first set the
spriteSheet property of the sprite or group.
Next, use the addAnimations / addAnis function. They accept an object
that uses animation names as keys and sprite sheet atlases as values.
Using an atlas object is way easier than manually specifying the coordinates of every frame!
Atlas objects can have the following properties:
x, y, pos, w/width,
h/height, size/frameSize, row,
col, frames/frameCount,
delay/frameDelay, and rotation.
In the "hero" example the size of the hero sprite is set to 32x32 pixels in the
Sprite constructor. That size is used as a multiplier to the row value given.
The ani.offset property is used to adjust the position of an animation relative to
the sprite's position.
Click this link to see the full questKid sprite sheet used in the example.
If you'd like to truly appreciate p5play, compare the example code to this Phaser demo. Ha!
I recommend making every frame in an animation the same size and putting them in order from left to right. If not you'll need to manually specify the position of each frame, which can be done using an array of coordinates instead of an atlas object.
anis
Every sprite and group has an animations / anis object that stores its
animations. The keys are animation names and values are animation objects. It works like groups
do, utilizing soft and dynamic inheritance.
When sprite.pixelPerfect is set to true, the sprite will be drawn at integer
coordinates, while retaining the precise position of its collider. This is useful for pixel art
games!
Animation Sequencing
sprite.changeAni can accept an animation object, animation name, or array of animation
names that will be played in sequence.
By default if looping is enabled, the last animation in the sequence will be looped. To loop the
entire sequence, use '**' as the last animation name. If instead you want the sequence
to stop at the end, use ';;' as the last animation name.
This example shows how the hero character can be moved around the screen using WASD or the arrow keys!
Advanced Animation Sequencing
sprite.changeAni is an async function, you can use it to wait for animations to finish
playing. It's particularly useful for scripted animation sequences for NPCs. It could also be used
when the player character is idling (not moving), they could sit down and eventually fall asleep.
Code example coming soon!