I am using React/Redux and am storing animation data in JSON and trying to get it to display on a React page.
I am using setTimeout (for pauses) and setInterval (for animation movement). However, I seem to be having trouble understanding how to implement the animations correctly and think I'm going about things totally the wrong way.
JSON data:
"objects": [
{
"title": "puppy",
"image_set": [
{
"image": "images/puppy_sitting.png",
"startx": 520,
"starty": 28,
"pause": 1000
},
{
"image": "images/puppy_walking.png",
"startx": 520,
"starty": 28,
"endx": 1,
"endy": 1,
"time": 1000
},
{
"image": "images/puppy_crouching.png",
"startx": 1,
"starty": 1,
"endx": 500,
"endy": 400,
"time": 2000
}
]
},
{
"title": "scorpion",
"image_set": [
{
"image": "images/scorping_sleeping.png",
"startx": 100,
"starty": 400,
"pause": 5000
},
{
"image": "images/scorpion_walking.png",
"startx": 100,
"starty": 400,
"endx": 500,
"endy": 400,
"time": 7000
},
{
"image": "images/scorpion_walking.png",
"startx": 500,
"starty": 400,
"endx": 100,
"endy": 400,
"time": 2000
},
{
"image": "images/scorpion_walking.png",
"startx": 100,
"starty": 400,
"endx": 200,
"endy": 400,
"time": 7000
},
{
"image": "images/scorpion_walking.png",
"startx": 200,
"starty": 400,
"endx": 100,
"endy": 400,
"time": 1000
}
]
}
]
Each object can have several images related to them. The animations will continue to repeat non-stop. Each object should move concurrently with each of the other objects so that I can create a scene of various animals and objects moving around it.
Animation code:
I'm pretty sure I'm barking up the wrong tree here, but my code looks something like this:
// image_set is the list of images for a specific object
// object_num is the array index corresponding to the JSON objects array
// selected is the array index corresponding to which image in the image_set will be displayed
runAnimation(image_set, object_num, selected){
// Uses prevState so that we keep state immutable
this.setState(prevState => {
let images = [...prevState.images];
if (!images[object_num]){
images.push({image: null, x: 0, y: 0})
}
images[object_num].image = image_set[selected].image;
images[object_num].x = this.getFactoredX(image_set[selected].startx);
images[object_num].y = this.getFactoredY(image_set[selected].starty);
return {images: images};
})
if (image_set[selected].endx && image_set[selected].endy && image_set[selected].time){
let x = this.getFactoredX(image_set[selected].startx)
let y = this.getFactoredY(image_set[selected].starty)
let startx = x
let starty = y
let endx = this.getFactoredX(image_set[selected].endx)
let endy = this.getFactoredY(image_set[selected].endy)
let time = image_set[selected].time
let x_increment = (endx - x) / (time / 50)
let y_increment = (endy - y) / (time / 50)
let int = setInterval(function(){
x += x_increment
y += y_increment
if (x > endx || y > endy){
clearInterval(int)
}
this.setState(prevState => {
let images = [...prevState.images]
if (images[object_num]){
images[object_num].x = x
images[object_num].y = y
}
return {images: images};
})
}.bind(this),
50
)
}
if (image_set[selected].pause && image_set[selected].pause > 0){
selected++
if (selected == image_set.length){
selected = 0
}
setTimeout(function() {
this.runAnimation(image_set, object_num, selected)
}.bind(this),
image_set[selected].pause
)
}
else {
selected++
if (selected == image_set.length){
selected = 0
}
setTimeout(function() {
this.runAnimation(image_set, object_num, selected)
}.bind(this),
50
)
}
}
Redux and this.props.data
Redux brings in the data as props. So, I have a function called from my componentDidMount and componentWillReceiveProps functions that passes the original image set into the loadAnimationFunction.
My render()
In my render() function I have something like this:
if (this.state.images.length > 1){
animated = this.state.images.map((image, i) => {
let x_coord = image.x
let y_coord = image.y
return (
<div key={i} style={{transform: "scale(" + this.state.x_factor + ")", transformOrigin: "top left", position: "absolute", left: x_coord, top: y_coord}}>
<img src={`/api/get_image.php?image=${image.image}`} />
</div>
)
})
}
x_factor / y_factor
Throughout my code there is also reference to x and y factor. This is because the background that the animations appear in may be scaled smaller or larger. Therefore I also scale the position of the starting and ending x/y coordinates for each animation as well as scale the animated images themselves.
time and pause time
Time indicates the time in ms that the animation should take. Pause time indicates how long in ms to pause before moving to the next animation.
The problem
The code does not move the animations smoothly and they seem to jump around sporadically.
Also, when I click the mouse anywhere on the page it causes the animations to jump to another position. Why would clicking the mouse affect the animation?
One thing I've noticed is that if I have the console open for debugging purposes, this really slows down the animations.
What can I do to my code so that the animations work as expected?
You are trying to animate your element using a setInterval doing a setState of the coordinates and with an absolute position. All of these cannot achieve great performance.
First, setInterval should never be used for animations, and you should prefer requestAnimationFrame as it will allow 60fps animations since the animation will be run before the next repaint of the browser.
Second, doing a setState would re-render your whole component which could potentially have an impact on the rendering timing as I assume your component doesn't render only your images. You should try to avoid at maximum to re-render things that haven't changed, so try to isolate your images for the animations.
Lastly, when you position your element with left and top properties, but you should stick to that, positioning, and not animating as the browser would do the animation pixel by pixel and would not be able to create good performances. Instead, you should use CSS translate(), as it can do sub-pixel calculation and will work on the GPU instead, allowing you to achieve 60fps animations. There is a good article on that by Paul Irish.
That being said, you should probably use react-motion which would allow you a smooth animation:
import { Motion, spring } from 'react-motion'
<Motion defaultStyle={{ x: 0 }} style={{ x: spring(image.x), y: spring(image.y) }}>
{({ x, y }) => (
<div style={{
transform: `translate(${x}px, ${y}px)`
}}>
<img src={`/api/get_image.php?image=${image.image}`} />
</div>
)}
</Motion>
There is also the React Transition Group, Transition could move your elements using a translate animation like explained above. You should also go take a look at the react animations docs here.
Worth a try too, is React Pose, which is pretty easy to use and also performs quite well with a clean API. Here is the get started page for React.
Here is a quick demo using your concept with a sit/walking/running cycle. Notice how react-motion is the only one to handle the transition in between the frames without hardcoding the duration of the transition, which would go against a fluid UI, the state only handles going through the different steps.
Quoting the react-motion Readme:
For 95% of use-cases of animating components, we don't have to resort to using hard-coded easing curves and duration. Set up a stiffness and damping for your UI element, and let the magic of physics take care of the rest. This way, you don't have to worry about petty situations such as interrupted animation behavior. It also greatly simplifies the API.
If you are not satisfied with the default spring, you can change the dampling and stiffness parameters. There's an app which could help you get the one which satisfy you the most.
Source
React is not exactly meant to be used for animations. I'm not saying you can't animate react components, but it's not part of the problem domain react tries to solve. What it does do is provide you with a nice framework to have the several UI pieces interact with each other. I.e. when creating a game for instance, you'll use react and redux to create and manage the screens, buttons etc. however the game itself, would be separately contained and not use react.
Just a long-winded way to say that if you want to use animations react will not suffice, it's better to use something like greensock's animation library: https://greensock.com/
They provide a tutorial on how to use it in conjunction with react: https://greensock.com/react
Let css do the transitions. Use transform: translate instead of top and left.
The animations you have in your sample are very easy to express with css transition, transition-delay, and transform.
I would put my effort in converting the JSON to css (using a cssInJs solution that allows you to generate the classes on the fly) and apply those classes to the images.
something like this(working example with your JSON sample): https://stackblitz.com/edit/react-animate-json
const App = () =>
<div>
{objects.map(object =>
<Item item={object} />)
}
</div>
Item.js:
class Item extends React.Component {
state = { selected: 0, classNames: {} }
componentDidMount() {
this.nextImage();
this.generateClassNames();
}
generateClassNames = () => {
const stylesArray = this.props.item.image_set.flatMap((image, index) => {
const { startx, starty, endx = startx, endy = starty, time } = image;
return [{
[`image${index}_start`]: {
transform: `translate(${startx}px,${starty}px)`,
transition: `all ${time || 0}ms linear`
}
}, {
[`image${index}_end`]: { transform: `translate(${endx}px,${endy}px)` }
}]
});
const styles = stylesArray.reduce((res, style) => ({ ...res, ...style }), {})
const { classes: classNames } = jss.createStyleSheet(styles).attach();
this.setState({ classNames });
}
nextImage = async () => {
const { image_set } = this.props.item;
let currentImage = image_set[this.state.selected];
await wait(currentImage.pause);
await wait(currentImage.time);
this.setState(({ selected }) =>
({ selected: (selected + 1) % image_set.length }), this.nextImage)
}
render() {
const { selected, classNames } = this.state;
const startClassName = classNames[`image${selected}_start`];
const endClassName = classNames[`image${selected}_end`];
return <img
className={`${startClassName} ${endClassName}`}
src={this.props.item.image_set[selected].image}
/>
}
}
const wait = (ms) => new Promise(res => setTimeout(res, ms));
I believe that your fundamental problem lies in the way React/Redux handle state. React may batch multiple update requests together to make rendering more efficient. Without further diagnostic measures, my guess is that the state handling after setState will just respond too rigidly.
The solution would to update your animation outside the state system, either using a ready-made framework or simply by taking care of the animation yourself; get a reference to the element and update it instead of re-rendering the element every time the state is updated.
without going deep about animations in JS (there are already plently of valid answers here) you should consider how you render your images:
<div key={i} style={{transform: "scale(" + this.state.x_factor + ")", transformOrigin: "top left", position: "absolute", left: x_coord, top: y_coord}}>
<img src={`/api/get_image.php?image=${image.image}`} />
</div>
You should actually see a warning when compiling this (or was it in the docs?) because you use the loop index as the key. This should lead to an image object being rendered in different divs as more images are added/removed. This is especially critically if you have a css-transition effect on the div.
TLDR: use some identifier as the key instead of the variable i (may be generate one when you create the animation?)
Also if you have a css transition on the div, you should remove it, because together with the changes from setInterval the transition calculation won't be able to keep up with the changes.
Related
I am building a game with Pixi.js that features items that fall from the top of the canvas. So far I have been able to spawn the items and have them move down the canvas until they reach the end of the window and are then removed from the app and from the items array.
This seems to work correctly at first, however, after one item has reached the end of the canvas and is removed the newer items that were added later, seem to stop in place on the canvas.
How can I have a smooth continuous flow of items falling?
class Item {
constructor(color, radius, v) {
...
}
update() {
this.item.x = this.v.x;
this.item.y += this.v.y;
if (this.item.y >= (h) + this.radius) {
this.item.y = 0
this.remove()
}
}
remove() {
items.pop()
app.stage.removeChild(this.item);
}
}
function addItem() {
items.push(new Item(0x79a3b1, Math.random() * 10 + 10, {x: getRandomNumberBetween(0, w), y: 2 * getRandomNumberBetween(0.5, 1.5) }));
}
function gameLoop() {
items.forEach(c => {
c.update();
});
}
let spawnInterval = setInterval( () => {
addItem()
}, 2000);
setInterval(gameLoop, 1000/60);
My code demo can be found here: https://codepen.io/m1-interactive/pen/GRxMYVE
There are mainly two issues with your code.
One is related to how you remove the objects in your remove method. You use items.pop(), but that will always remove the last element of the array. By the time that one object reaches the bottom of the screen, there are newer elements in the array so you have to remove them by index:
remove() {
items.splice(items.indexOf(this), 1)
app.stage.removeChild(this.item);
}
Secondly, as you iterate through each item in your gameLoop, some objects might get removed from the array. That can result in skipping some elements. Read more about why this happens in this answer.
In your case, it can be easily fixed by cloning the array before splicing it:
items.slice().forEach(c => {
c.update();
});
i'm new to react native and i'm trying to do a moving arrow after a variable get a value, I thought about using a switch case and changing the style, but it seemed impossible to change the padding properties, how could i solve this?
Your question needs a lot of information to be answered thoroughly so I will assume you use hooks, I will try to guide you by giving you an example.
The whole principle is to place your arrow in an 'absolute' position and animate it with an animation. Then, all you need to do is to set the value of the variable 'arrowValue', example : setArrowValue(0.3). Your arrow will then places itself at 30% (according to your interpolation) from the left of your container.
Here is a code snippet to show you the right way :
import {StyleSheet, View, Animated} from "react-native";
export default function ArrowMover(props)
{
// This is the value you will set and your arrow will automatically be placed
const [arrowValue, setArrowValue] = React.useState(0); // From 0 to 1 for example
// This is your animation
// It is the value you have to change to make your arrow move
const [animation, setAnimation] = React.useState(new Animated.Value(0));
// This is an interpolation of your animation
// See this as a black box, it allows you to output value (and ranges of values)
// based on the value of your animation
const animateArrowPosition = animation.interpolate({
inputRange: [0, 1],
outputRange: ["0%", "100%"],
});
// This is where everthing happens automatically
React.useEffect(() =>
{
moveArrowTo(arrowValue);
}, [arrowValue]); // Anytime 'arrowValue' changes, execute the 'moveArrowTo' function
const moveArrowTo = (newArrowValue) =>
{
Animated.timing(animation, { toValue: newArrowValue, duration: 500, }).start(() =>
{
// Do something (or nothing) once the animation finished
});
};
return(
<View style={s.container}>
// Your animation interpolation will change along with 'animation' to follow your interpolation
// of the value
<Animated.View style={[s.arrow, {left:animateArrowPosition}]}> // Notice the 'Animated.View'
<View>
// Your arrow (icon, image, etc...)
</View>
</Animated.View>
</View>
);
}
let s = StyleSheet.create(
{
container:
{
// Your container style
},
arrow:
{
// Your arrow style
height:30,
aspectRatio:1,
position:'absolute',
// left:0 (no need for that, your animation is taking care of the 'left' property
},
}
I was testing my websocket implementation by sending the mouse positions of my connected clients and rendering them with a red <div> box. When I added the "visualizer" to the connected clients the framerate was cut in half for each new client that connected.
I am not sure how to optimize something like this, I've tried minimizing the amount of looping (which helped a bit, but after some time it became as slow as my first approach).
The pointer is updated (debounced to) 60 times a second, what would I need to do to let that pointer update 60 times per second for at least four clients ?
I would like to keep those pointers, even though they are not part of the main application. React is probably not meant for this kind of thing, the question then is what should I have used instead ?
First Aproach
const MousePointer = ({ GameLobby }) => {
console.log(GameLobby);
if (!GameLobby) return null;
return Object.values(GameLobby).map((data, i) => {
const pos = data.currentMousePosition ? data.currentMousePosition : [0, 0];
const backgroundColor = 'red';
return (
<div
key={i}
css={{
backgroundColor,
height: '15px',
width: '15px',
boxSizing: 'border-box',
position: 'absolute',
left: pos[0],
top: pos[1],
}}></div>
);
});
};
One less loop
const MousePointer = ({ GameLobby }) => {
if (!GameLobby) return null;
const {
[Object.keys(GameLobby)[0]]: {
backgroundColor = 'red',
currentMousePosition: pos = [0, 0],
},
} = GameLobby;
return (
<div
key={1}
css={{
backgroundColor,
height: '15px',
width: '15px',
boxSizing: 'border-box',
position: 'absolute',
left: pos[0],
top: pos[1],
}}></div>
);
};
Yeah, rerendering at that rate will cause performance problems. You should try attaching a callback ref to the div and updating only the properties that need to change using setInterval.
In order to check the most updated version of GameLobby without rerendering, you will have to refer it some other way (it can't be a prop). One very easy (and extremely questionable) way to do this is by sticking it on the window object or creating another global. I have also seen people add variables as instance properties of their components.
You might also just choose to handle the cursor ghosts outside of your React tree, right when you receive the GameLobby object. Probably easy enough to just append absolutely positioned divs directly to the DOM.
Note that these patterns shouldn't be generalized for other things you build in React, I would categorize them as "dirty tricks" that you need in rare situations (usually related to animation).
In my Phaser3 game there is a global gameTick variable that is incremented every update. I am using this to spawn in enemies in my game every 100th update.
Here is a simplifed example of what is going on in my scene class:
update () {
global.gameTick++;
if (global.gameTick % 100 === 0) {
this.spawnAlien();
}
}
This works fine but as soon as a user plays the game on a monitor with a refresh rate >60hz the update timing breaks and causes the aliens to spawn more frequently.
I have checked this.physics.world.fps and it is 60. I can also modify this.physics.world.timescale but then I would have to do a giant switch statement for every refresh rate.
Either I am missing an obvious solution or my global.gameTick method is not an effective way to accomplish this task.
This is what I have in my config so far
let config = {
type: Phaser.AUTO,
backgroundColor: "#000",
scale: {
parent: "game",
mode: Phaser.Scale.FIT,
width: 1900,
height: 600,
},
physics: {
default: "arcade",
arcade: {
debug: true,
fps: 60 // doesn't fix update frequency
},
fps: { // not sure if this is even doing anything
max: 60,
min: 20,
target: 60,
}
},
pixelArt: true,
};
You can also set the following property in your game's config object:
fps: {
target: 24,
forceSetTimeOut: true
},
Source: https://phaser.discourse.group/t/how-to-limit-fps-with-phaser-3/275/14?u=saricden
To limit the update rate, use the following method.
// The time and delta variables are passed to `update()` by Phaser
update(time, delta) {
this.frameTime += delta
if (this.frameTime > 16.5) {
this.frameTime = 0;
g.gameTick++;
// Code that relies on a consistent 60hz update
}
}
This accumulates the miiliseconds between the last frame and the current frame. It only runs the update() code if there has been 16.5ms of delay.
The example above works for 60fps, but if you want to limit the FPS to a different value use the formula: delay = 1000/fps.
I'm working on a project and I need to add 3d sounds effects, like the sound is continually moving around the listener effects. Is it possible to achieve that with howlerjs i see that with howler i'm able to play a sound from specific coordinates/orientation but how to achieve surrounding/ambisonics sounds ?
Or another library in JavaScript to achieve that?
Thanks for your help.
Half a year late, but yeah that's entirely possible in howler.js, haven't used it myself but judging from the docs you can just update the position. there's some more libraries that do it that I've found, check here how 3dage does exactly what you want:
https://codepen.io/naugtur/pen/QgmvOB?editors=1010
var world = IIIdage.World({
tickInterval: 200
})
var annoyingFly = IIIdage.Thing({
is: ['fly'],
sounds: {
'buzzing constantly': {
sound: 'buzz',
times: Infinity
}
},
reacts: [
{
// to: world.random.veryOften(),
to: world.time.once(),
with: 'buzzing constantly'
}
]
})
// scene should create and expose a default world or accept one
var scene = IIIdage.Scene({
title: 'Annoying fly',
library: {
sounds: {
'buzz': {
src: ['https://webaudiogaming.github.io/3dage/fly.mp3']
}
}
},
world: world,
things: [ // scene iterates all things and spawns them into the world. same can be done manually later on.
annoyingFly({
pos: [-1, -15, 0],
dir: [1, 0, 0],
v: 1
})
]
}).load().run()
setTimeout(function () {
scene.dev.trace(IIIdage.dev.preview.dom())
}, 500)
setInterval(function rotateVector() {
var angleRad = 0.15
var d=scene.things[0].attributes.dir
var x=d[0], y=d[1]
var cosAngle = Math.cos(angleRad), sinAngle = Math.sin(angleRad)
scene.things[0].attributes.dir = [x * cosAngle - y * sinAngle, y * cosAngle + x * sinAngle, 0]
}, 500)
window.scene = scene
There's still some others that do similar stuff:
https://www.npmjs.com/package/songbird-audio
https://www.npmjs.com/package/ambisonics
Hope this pushes you in the right direction if you still want help with it.