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I've been trying to add a (code pen) animation on my website and I'm honestly not sure what I'm missing on this one. I have tried running it in jsfiddle as well and it tells me that delaunay is not defined. https://codepen.io/hduffin1/pen/QOMZJg I'm not too sure what I'm doing wrong since the code works inside of code pen and I have been able to replicate other ones that I've tried using from code pen but for whatever reason, I can't seem to get this one to work.
Html
<canvas id="stars" width="300" height="300"></canvas>
CSS
html,
body {
margin: 0;
padding: 0;
}
body {
background-color: #31102f; //#280B29
background: radial-gradient(
ellipse at center,
rgba(49, 16, 47, 1) 0%,
rgba(40, 11, 41, 1) 100%
);
}
#stars {
display: block;
position: relative;
width: 100%;
height: 16rem;
height: 100vh;
z-index: 1;
}
JS
/**
* Stars
* Inspired by Steve Courtney's poster art for Celsius GS's Drifter - http://celsiusgs.com/drifter/posters.php
* by Cory Hughart - http://coryhughart.com
*/
// Settings
var particleCount = 40,
flareCount = 10,
motion = 0.05,
tilt = 0.05,
color = '#FFEED4',
particleSizeBase = 1,
particleSizeMultiplier = 0.5,
flareSizeBase = 100,
flareSizeMultiplier = 100,
lineWidth = 1,
linkChance = 75, // chance per frame of link, higher = smaller chance
linkLengthMin = 5, // min linked vertices
linkLengthMax = 7, // max linked vertices
linkOpacity = 0.25; // number between 0 & 1
linkFade = 90, // link fade-out frames
linkSpeed = 1, // distance a link travels in 1 frame
glareAngle = -60,
glareOpacityMultiplier = 0.05,
renderParticles = true,
renderParticleGlare = true,
renderFlares = true,
renderLinks = true,
renderMesh = false,
flicker = true,
flickerSmoothing = 15, // higher = smoother flicker
blurSize = 0,
orbitTilt = true,
randomMotion = true,
noiseLength = 1000,
noiseStrength = 1;
var canvas = document.getElementById('stars'),
//orbits = document.getElementById('orbits'),
context = canvas.getContext('2d'),
mouse = { x: 0, y: 0 },
m = {},
r = 0,
c = 1000, // multiplier for delaunay points, since floats too small can mess up the algorithm
n = 0,
nAngle = (Math.PI * 2) / noiseLength,
nRad = 100,
nScale = 0.5,
nPos = {x: 0, y: 0},
points = [],
vertices = [],
triangles = [],
links = [],
particles = [],
flares = [];
function init() {
var i, j, k;
// requestAnimFrame polyfill
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
// Fade in background
/*
var background = document.getElementById('background'),
bgImg = new Image(),
bgURL = '/img/background.jpg';
bgImg.onload = function() {
//console.log('background loaded');
background.style.backgroundImage = 'url("'+bgURL+'")';
background.className += ' loaded';
}
bgImg.src = bgURL;
*/
// Size canvas
resize();
mouse.x = canvas.clientWidth / 2;
mouse.y = canvas.clientHeight / 2;
// Create particle positions
for (i = 0; i < particleCount; i++) {
var p = new Particle();
particles.push(p);
points.push([p.x*c, p.y*c]);
}
//console.log(JSON.stringify(points));
// Delaunay triangulation
//var Delaunay = require('delaunay-fast');
vertices = Delaunay.triangulate(points);
//console.log(JSON.stringify(vertices));
// Create an array of "triangles" (groups of 3 indices)
var tri = [];
for (i = 0; i < vertices.length; i++) {
if (tri.length == 3) {
triangles.push(tri);
tri = [];
}
tri.push(vertices[i]);
}
//console.log(JSON.stringify(triangles));
// Tell all the particles who their neighbors are
for (i = 0; i < particles.length; i++) {
// Loop through all tirangles
for (j = 0; j < triangles.length; j++) {
// Check if this particle's index is in this triangle
k = triangles[j].indexOf(i);
// If it is, add its neighbors to the particles contacts list
if (k !== -1) {
triangles[j].forEach(function(value, index, array) {
if (value !== i && particles[i].neighbors.indexOf(value) == -1) {
particles[i].neighbors.push(value);
}
});
}
}
}
//console.log(JSON.stringify(particles));
if (renderFlares) {
// Create flare positions
for (i = 0; i < flareCount; i++) {
flares.push(new Flare());
}
}
// Motion mode
//if (Modernizr && Modernizr.deviceorientation) {
if ('ontouchstart' in document.documentElement && window.DeviceOrientationEvent) {
console.log('Using device orientation');
window.addEventListener('deviceorientation', function(e) {
mouse.x = (canvas.clientWidth / 2) - ((e.gamma / 90) * (canvas.clientWidth / 2) * 2);
mouse.y = (canvas.clientHeight / 2) - ((e.beta / 90) * (canvas.clientHeight / 2) * 2);
//console.log('Center: x:'+(canvas.clientWidth/2)+' y:'+(canvas.clientHeight/2));
//console.log('Orientation: x:'+mouse.x+' ('+e.gamma+') y:'+mouse.y+' ('+e.beta+')');
}, true);
}
else {
// Mouse move listener
console.log('Using mouse movement');
document.body.addEventListener('mousemove', function(e) {
//console.log('moved');
mouse.x = e.clientX;
mouse.y = e.clientY;
});
}
// Random motion
if (randomMotion) {
//var SimplexNoise = require('simplex-noise');
//var simplex = new SimplexNoise();
}
// Animation loop
(function animloop(){
requestAnimFrame(animloop);
resize();
render();
})();
}
function render() {
if (randomMotion) {
n++;
if (n >= noiseLength) {
n = 0;
}
nPos = noisePoint(n);
//console.log('NOISE x:'+nPos.x+' y:'+nPos.y);
}
// Clear
context.clearRect(0, 0, canvas.width, canvas.height);
if (blurSize > 0) {
context.shadowBlur = blurSize;
context.shadowColor = color;
}
if (renderParticles) {
// Render particles
for (var i = 0; i < particleCount; i++) {
particles[i].render();
}
}
if (renderMesh) {
// Render all lines
context.beginPath();
for (var v = 0; v < vertices.length-1; v++) {
// Splits the array into triplets
if ((v + 1) % 3 === 0) { continue; }
var p1 = particles[vertices[v]],
p2 = particles[vertices[v+1]];
//console.log('Line: '+p1.x+','+p1.y+'->'+p2.x+','+p2.y);
var pos1 = position(p1.x, p1.y, p1.z),
pos2 = position(p2.x, p2.y, p2.z);
context.moveTo(pos1.x, pos1.y);
context.lineTo(pos2.x, pos2.y);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
}
if (renderLinks) {
// Possibly start a new link
if (random(0, linkChance) == linkChance) {
var length = random(linkLengthMin, linkLengthMax);
var start = random(0, particles.length-1);
startLink(start, length);
}
// Render existing links
// Iterate in reverse so that removing items doesn't affect the loop
for (var l = links.length-1; l >= 0; l--) {
if (links[l] && !links[l].finished) {
links[l].render();
}
else {
delete links[l];
}
}
}
if (renderFlares) {
// Render flares
for (var j = 0; j < flareCount; j++) {
flares[j].render();
}
}
/*
if (orbitTilt) {
var tiltX = -(((canvas.clientWidth / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * tilt),
tiltY = (((canvas.clientHeight / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * tilt);
orbits.style.transform = 'rotateY('+tiltX+'deg) rotateX('+tiltY+'deg)';
}
*/
}
function resize() {
canvas.width = window.innerWidth * (window.devicePixelRatio || 1);
canvas.height = canvas.width * (canvas.clientHeight / canvas.clientWidth);
}
function startLink(vertex, length) {
//console.log('LINK from '+vertex+' (length '+length+')');
links.push(new Link(vertex, length));
}
// Particle class
var Particle = function() {
this.x = random(-0.1, 1.1, true);
this.y = random(-0.1, 1.1, true);
this.z = random(0,4);
this.color = color;
this.opacity = random(0.1,1,true);
this.flicker = 0;
this.neighbors = []; // placeholder for neighbors
};
Particle.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * particleSizeMultiplier) + particleSizeBase) * (sizeRatio() / 1000),
o = this.opacity;
if (flicker) {
var newVal = random(-0.5, 0.5, true);
this.flicker += (newVal - this.flicker) / flickerSmoothing;
if (this.flicker > 0.5) this.flicker = 0.5;
if (this.flicker < -0.5) this.flicker = -0.5;
o += this.flicker;
if (o > 1) o = 1;
if (o < 0) o = 0;
}
context.fillStyle = this.color;
context.globalAlpha = o;
context.beginPath();
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fill();
context.closePath();
if (renderParticleGlare) {
context.globalAlpha = o * glareOpacityMultiplier;
/*
context.ellipse(pos.x, pos.y, r * 30, r, 90 * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
*/
context.ellipse(pos.x, pos.y, r * 100, r, (glareAngle - ((nPos.x - 0.5) * noiseStrength * motion)) * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
}
context.globalAlpha = 1;
};
// Flare class
var Flare = function() {
this.x = random(-0.25, 1.25, true);
this.y = random(-0.25, 1.25, true);
this.z = random(0,2);
this.color = color;
this.opacity = random(0.001, 0.01, true);
};
Flare.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * flareSizeMultiplier) + flareSizeBase) * (sizeRatio() / 1000);
// Feathered circles
/*
var grad = context.createRadialGradient(x+r,y+r,0,x+r,y+r,r);
grad.addColorStop(0, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(0.8, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(1, 'rgba(255,255,255,0)');
context.fillStyle = grad;
context.beginPath();
context.fillRect(x, y, r*2, r*2);
context.closePath();
*/
context.beginPath();
context.globalAlpha = this.opacity;
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fillStyle = this.color;
context.fill();
context.closePath();
context.globalAlpha = 1;
};
// Link class
var Link = function(startVertex, numPoints) {
this.length = numPoints;
this.verts = [startVertex];
this.stage = 0;
this.linked = [startVertex];
this.distances = [];
this.traveled = 0;
this.fade = 0;
this.finished = false;
};
Link.prototype.render = function() {
// Stages:
// 0. Vertex collection
// 1. Render line reaching from vertex to vertex
// 2. Fade out
// 3. Finished (delete me)
var i, p, pos, points;
switch (this.stage) {
// VERTEX COLLECTION STAGE
case 0:
// Grab the last member of the link
var last = particles[this.verts[this.verts.length-1]];
//console.log(JSON.stringify(last));
if (last && last.neighbors && last.neighbors.length > 0) {
// Grab a random neighbor
var neighbor = last.neighbors[random(0, last.neighbors.length-1)];
// If we haven't seen that particle before, add it to the link
if (this.verts.indexOf(neighbor) == -1) {
this.verts.push(neighbor);
}
// If we have seen that article before, we'll just wait for the next frame
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (0)');
this.stage = 3;
this.finished = true;
}
if (this.verts.length >= this.length) {
// Calculate all distances at once
for (i = 0; i < this.verts.length-1; i++) {
var p1 = particles[this.verts[i]],
p2 = particles[this.verts[i+1]],
dx = p1.x - p2.x,
dy = p1.y - p2.y,
dist = Math.sqrt(dx*dx + dy*dy);
this.distances.push(dist);
}
//console.log('Distances: '+JSON.stringify(this.distances));
//console.log('verts: '+this.verts.length+' distances: '+this.distances.length);
//console.log(this.verts[0]+' moving to stage 1');
this.stage = 1;
}
break;
// RENDER LINE ANIMATION STAGE
case 1:
if (this.distances.length > 0) {
points = [];
//var a = 1;
// Gather all points already linked
for (i = 0; i < this.linked.length; i++) {
p = particles[this.linked[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
var linkSpeedRel = linkSpeed * 0.00001 * canvas.width;
this.traveled += linkSpeedRel;
var d = this.distances[this.linked.length-1];
// Calculate last point based on linkSpeed and distance travelled to next point
if (this.traveled >= d) {
this.traveled = 0;
// We've reached the next point, add coordinates to array
//console.log(this.verts[0]+' reached vertex '+(this.linked.length+1)+' of '+this.verts.length);
this.linked.push(this.verts[this.linked.length]);
p = particles[this.linked[this.linked.length-1]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
if (this.linked.length >= this.verts.length) {
//console.log(this.verts[0]+' moving to stage 2 (1)');
this.stage = 2;
}
}
else {
// We're still travelling to the next point, get coordinates at travel distance
// http://math.stackexchange.com/a/85582
var a = particles[this.linked[this.linked.length-1]],
b = particles[this.verts[this.linked.length]],
t = d - this.traveled,
x = ((this.traveled * b.x) + (t * a.x)) / d,
y = ((this.traveled * b.y) + (t * a.y)) / d,
z = ((this.traveled * b.z) + (t * a.z)) / d;
pos = position(x, y, z);
//console.log(this.verts[0]+' traveling to vertex '+(this.linked.length+1)+' of '+this.verts.length+' ('+this.traveled+' of '+this.distances[this.linked.length]+')');
points.push([pos.x, pos.y]);
}
this.drawLine(points);
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (1)');
this.stage = 3;
this.finished = true;
}
break;
// FADE OUT STAGE
case 2:
if (this.verts.length > 1) {
if (this.fade < linkFade) {
this.fade++;
// Render full link between all vertices and fade over time
points = [];
var alpha = (1 - (this.fade / linkFade)) * linkOpacity;
for (i = 0; i < this.verts.length; i++) {
p = particles[this.verts[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
this.drawLine(points, alpha);
}
else {
//console.log(this.verts[0]+' moving to stage 3 (2a)');
this.stage = 3;
this.finished = true;
}
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (2b)');
this.stage = 3;
this.finished = true;
}
break;
// FINISHED STAGE
case 3:
default:
this.finished = true;
break;
}
};
Link.prototype.drawLine = function(points, alpha) {
if (typeof alpha !== 'number') alpha = linkOpacity;
if (points.length > 1 && alpha > 0) {
//console.log(this.verts[0]+': Drawing line '+alpha);
context.globalAlpha = alpha;
context.beginPath();
for (var i = 0; i < points.length-1; i++) {
context.moveTo(points[i][0], points[i][1]);
context.lineTo(points[i+1][0], points[i+1][1]);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
context.globalAlpha = 1;
}
};
// Utils
function noisePoint(i) {
var a = nAngle * i,
cosA = Math.cos(a),
sinA = Math.sin(a),
//value = simplex.noise2D(nScale * cosA + nScale, nScale * sinA + nScale),
//rad = nRad + value;
rad = nRad;
return {
x: rad * cosA,
y: rad * sinA
};
}
function position(x, y, z) {
return {
x: (x * canvas.width) + ((((canvas.width / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * z) * motion),
y: (y * canvas.height) + ((((canvas.height / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * z) * motion)
};
}
function sizeRatio() {
return canvas.width >= canvas.height ? canvas.width : canvas.height;
}
function random(min, max, float) {
return float ?
Math.random() * (max - min) + min :
Math.floor(Math.random() * (max - min + 1)) + min;
}
// init
if (canvas) init();
When I entered 'https://codepen.io/hduffin1/pen/QOMZJg', 'delaunay.js' is included in the setting.
Add the following script and it should work.
<script src="https://rawgit.com/ironwallaby/delaunay/master/delaunay.js"></script>
/**
* Stars
* Inspired by Steve Courtney's poster art for Celsius GS's Drifter - http://celsiusgs.com/drifter/posters.php
* by Cory Hughart - http://coryhughart.com
*/
// Settings
var particleCount = 40,
flareCount = 10,
motion = 0.05,
tilt = 0.05,
color = '#FFEED4',
particleSizeBase = 1,
particleSizeMultiplier = 0.5,
flareSizeBase = 100,
flareSizeMultiplier = 100,
lineWidth = 1,
linkChance = 75, // chance per frame of link, higher = smaller chance
linkLengthMin = 5, // min linked vertices
linkLengthMax = 7, // max linked vertices
linkOpacity = 0.25; // number between 0 & 1
linkFade = 90, // link fade-out frames
linkSpeed = 1, // distance a link travels in 1 frame
glareAngle = -60,
glareOpacityMultiplier = 0.05,
renderParticles = true,
renderParticleGlare = true,
renderFlares = true,
renderLinks = true,
renderMesh = false,
flicker = true,
flickerSmoothing = 15, // higher = smoother flicker
blurSize = 0,
orbitTilt = true,
randomMotion = true,
noiseLength = 1000,
noiseStrength = 1;
var canvas = document.getElementById('stars'),
//orbits = document.getElementById('orbits'),
context = canvas.getContext('2d'),
mouse = { x: 0, y: 0 },
m = {},
r = 0,
c = 1000, // multiplier for delaunay points, since floats too small can mess up the algorithm
n = 0,
nAngle = (Math.PI * 2) / noiseLength,
nRad = 100,
nScale = 0.5,
nPos = {x: 0, y: 0},
points = [],
vertices = [],
triangles = [],
links = [],
particles = [],
flares = [];
function init() {
var i, j, k;
// requestAnimFrame polyfill
window.requestAnimFrame = (function(){
return window.requestAnimationFrame ||
window.webkitRequestAnimationFrame ||
window.mozRequestAnimationFrame ||
function( callback ){
window.setTimeout(callback, 1000 / 60);
};
})();
// Fade in background
/*
var background = document.getElementById('background'),
bgImg = new Image(),
bgURL = '/img/background.jpg';
bgImg.onload = function() {
//console.log('background loaded');
background.style.backgroundImage = 'url("'+bgURL+'")';
background.className += ' loaded';
}
bgImg.src = bgURL;
*/
// Size canvas
resize();
mouse.x = canvas.clientWidth / 2;
mouse.y = canvas.clientHeight / 2;
// Create particle positions
for (i = 0; i < particleCount; i++) {
var p = new Particle();
particles.push(p);
points.push([p.x*c, p.y*c]);
}
//console.log(JSON.stringify(points));
// Delaunay triangulation
//var Delaunay = require('delaunay-fast');
vertices = Delaunay.triangulate(points);
//console.log(JSON.stringify(vertices));
// Create an array of "triangles" (groups of 3 indices)
var tri = [];
for (i = 0; i < vertices.length; i++) {
if (tri.length == 3) {
triangles.push(tri);
tri = [];
}
tri.push(vertices[i]);
}
//console.log(JSON.stringify(triangles));
// Tell all the particles who their neighbors are
for (i = 0; i < particles.length; i++) {
// Loop through all tirangles
for (j = 0; j < triangles.length; j++) {
// Check if this particle's index is in this triangle
k = triangles[j].indexOf(i);
// If it is, add its neighbors to the particles contacts list
if (k !== -1) {
triangles[j].forEach(function(value, index, array) {
if (value !== i && particles[i].neighbors.indexOf(value) == -1) {
particles[i].neighbors.push(value);
}
});
}
}
}
//console.log(JSON.stringify(particles));
if (renderFlares) {
// Create flare positions
for (i = 0; i < flareCount; i++) {
flares.push(new Flare());
}
}
// Motion mode
//if (Modernizr && Modernizr.deviceorientation) {
if ('ontouchstart' in document.documentElement && window.DeviceOrientationEvent) {
console.log('Using device orientation');
window.addEventListener('deviceorientation', function(e) {
mouse.x = (canvas.clientWidth / 2) - ((e.gamma / 90) * (canvas.clientWidth / 2) * 2);
mouse.y = (canvas.clientHeight / 2) - ((e.beta / 90) * (canvas.clientHeight / 2) * 2);
//console.log('Center: x:'+(canvas.clientWidth/2)+' y:'+(canvas.clientHeight/2));
//console.log('Orientation: x:'+mouse.x+' ('+e.gamma+') y:'+mouse.y+' ('+e.beta+')');
}, true);
}
else {
// Mouse move listener
console.log('Using mouse movement');
document.body.addEventListener('mousemove', function(e) {
//console.log('moved');
mouse.x = e.clientX;
mouse.y = e.clientY;
});
}
// Random motion
if (randomMotion) {
//var SimplexNoise = require('simplex-noise');
//var simplex = new SimplexNoise();
}
// Animation loop
(function animloop(){
requestAnimFrame(animloop);
resize();
render();
})();
}
function render() {
if (randomMotion) {
n++;
if (n >= noiseLength) {
n = 0;
}
nPos = noisePoint(n);
//console.log('NOISE x:'+nPos.x+' y:'+nPos.y);
}
// Clear
context.clearRect(0, 0, canvas.width, canvas.height);
if (blurSize > 0) {
context.shadowBlur = blurSize;
context.shadowColor = color;
}
if (renderParticles) {
// Render particles
for (var i = 0; i < particleCount; i++) {
particles[i].render();
}
}
if (renderMesh) {
// Render all lines
context.beginPath();
for (var v = 0; v < vertices.length-1; v++) {
// Splits the array into triplets
if ((v + 1) % 3 === 0) { continue; }
var p1 = particles[vertices[v]],
p2 = particles[vertices[v+1]];
//console.log('Line: '+p1.x+','+p1.y+'->'+p2.x+','+p2.y);
var pos1 = position(p1.x, p1.y, p1.z),
pos2 = position(p2.x, p2.y, p2.z);
context.moveTo(pos1.x, pos1.y);
context.lineTo(pos2.x, pos2.y);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
}
if (renderLinks) {
// Possibly start a new link
if (random(0, linkChance) == linkChance) {
var length = random(linkLengthMin, linkLengthMax);
var start = random(0, particles.length-1);
startLink(start, length);
}
// Render existing links
// Iterate in reverse so that removing items doesn't affect the loop
for (var l = links.length-1; l >= 0; l--) {
if (links[l] && !links[l].finished) {
links[l].render();
}
else {
delete links[l];
}
}
}
if (renderFlares) {
// Render flares
for (var j = 0; j < flareCount; j++) {
flares[j].render();
}
}
/*
if (orbitTilt) {
var tiltX = -(((canvas.clientWidth / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * tilt),
tiltY = (((canvas.clientHeight / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * tilt);
orbits.style.transform = 'rotateY('+tiltX+'deg) rotateX('+tiltY+'deg)';
}
*/
}
function resize() {
canvas.width = window.innerWidth * (window.devicePixelRatio || 1);
canvas.height = canvas.width * (canvas.clientHeight / canvas.clientWidth);
}
function startLink(vertex, length) {
//console.log('LINK from '+vertex+' (length '+length+')');
links.push(new Link(vertex, length));
}
// Particle class
var Particle = function() {
this.x = random(-0.1, 1.1, true);
this.y = random(-0.1, 1.1, true);
this.z = random(0,4);
this.color = color;
this.opacity = random(0.1,1,true);
this.flicker = 0;
this.neighbors = []; // placeholder for neighbors
};
Particle.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * particleSizeMultiplier) + particleSizeBase) * (sizeRatio() / 1000),
o = this.opacity;
if (flicker) {
var newVal = random(-0.5, 0.5, true);
this.flicker += (newVal - this.flicker) / flickerSmoothing;
if (this.flicker > 0.5) this.flicker = 0.5;
if (this.flicker < -0.5) this.flicker = -0.5;
o += this.flicker;
if (o > 1) o = 1;
if (o < 0) o = 0;
}
context.fillStyle = this.color;
context.globalAlpha = o;
context.beginPath();
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fill();
context.closePath();
if (renderParticleGlare) {
context.globalAlpha = o * glareOpacityMultiplier;
/*
context.ellipse(pos.x, pos.y, r * 30, r, 90 * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
*/
context.ellipse(pos.x, pos.y, r * 100, r, (glareAngle - ((nPos.x - 0.5) * noiseStrength * motion)) * (Math.PI / 180), 0, 2 * Math.PI, false);
context.fill();
context.closePath();
}
context.globalAlpha = 1;
};
// Flare class
var Flare = function() {
this.x = random(-0.25, 1.25, true);
this.y = random(-0.25, 1.25, true);
this.z = random(0,2);
this.color = color;
this.opacity = random(0.001, 0.01, true);
};
Flare.prototype.render = function() {
var pos = position(this.x, this.y, this.z),
r = ((this.z * flareSizeMultiplier) + flareSizeBase) * (sizeRatio() / 1000);
// Feathered circles
/*
var grad = context.createRadialGradient(x+r,y+r,0,x+r,y+r,r);
grad.addColorStop(0, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(0.8, 'rgba(255,255,255,'+f.o+')');
grad.addColorStop(1, 'rgba(255,255,255,0)');
context.fillStyle = grad;
context.beginPath();
context.fillRect(x, y, r*2, r*2);
context.closePath();
*/
context.beginPath();
context.globalAlpha = this.opacity;
context.arc(pos.x, pos.y, r, 0, 2 * Math.PI, false);
context.fillStyle = this.color;
context.fill();
context.closePath();
context.globalAlpha = 1;
};
// Link class
var Link = function(startVertex, numPoints) {
this.length = numPoints;
this.verts = [startVertex];
this.stage = 0;
this.linked = [startVertex];
this.distances = [];
this.traveled = 0;
this.fade = 0;
this.finished = false;
};
Link.prototype.render = function() {
// Stages:
// 0. Vertex collection
// 1. Render line reaching from vertex to vertex
// 2. Fade out
// 3. Finished (delete me)
var i, p, pos, points;
switch (this.stage) {
// VERTEX COLLECTION STAGE
case 0:
// Grab the last member of the link
var last = particles[this.verts[this.verts.length-1]];
//console.log(JSON.stringify(last));
if (last && last.neighbors && last.neighbors.length > 0) {
// Grab a random neighbor
var neighbor = last.neighbors[random(0, last.neighbors.length-1)];
// If we haven't seen that particle before, add it to the link
if (this.verts.indexOf(neighbor) == -1) {
this.verts.push(neighbor);
}
// If we have seen that particle before, we'll just wait for the next frame
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (0)');
this.stage = 3;
this.finished = true;
}
if (this.verts.length >= this.length) {
// Calculate all distances at once
for (i = 0; i < this.verts.length-1; i++) {
var p1 = particles[this.verts[i]],
p2 = particles[this.verts[i+1]],
dx = p1.x - p2.x,
dy = p1.y - p2.y,
dist = Math.sqrt(dx*dx + dy*dy);
this.distances.push(dist);
}
//console.log('Distances: '+JSON.stringify(this.distances));
//console.log('verts: '+this.verts.length+' distances: '+this.distances.length);
//console.log(this.verts[0]+' moving to stage 1');
this.stage = 1;
}
break;
// RENDER LINE ANIMATION STAGE
case 1:
if (this.distances.length > 0) {
points = [];
//var a = 1;
// Gather all points already linked
for (i = 0; i < this.linked.length; i++) {
p = particles[this.linked[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
var linkSpeedRel = linkSpeed * 0.00001 * canvas.width;
this.traveled += linkSpeedRel;
var d = this.distances[this.linked.length-1];
// Calculate last point based on linkSpeed and distance travelled to next point
if (this.traveled >= d) {
this.traveled = 0;
// We've reached the next point, add coordinates to array
//console.log(this.verts[0]+' reached vertex '+(this.linked.length+1)+' of '+this.verts.length);
this.linked.push(this.verts[this.linked.length]);
p = particles[this.linked[this.linked.length-1]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
if (this.linked.length >= this.verts.length) {
//console.log(this.verts[0]+' moving to stage 2 (1)');
this.stage = 2;
}
}
else {
// We're still travelling to the next point, get coordinates at travel distance
// http://math.stackexchange.com/a/85582
var a = particles[this.linked[this.linked.length-1]],
b = particles[this.verts[this.linked.length]],
t = d - this.traveled,
x = ((this.traveled * b.x) + (t * a.x)) / d,
y = ((this.traveled * b.y) + (t * a.y)) / d,
z = ((this.traveled * b.z) + (t * a.z)) / d;
pos = position(x, y, z);
//console.log(this.verts[0]+' traveling to vertex '+(this.linked.length+1)+' of '+this.verts.length+' ('+this.traveled+' of '+this.distances[this.linked.length]+')');
points.push([pos.x, pos.y]);
}
this.drawLine(points);
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (1)');
this.stage = 3;
this.finished = true;
}
break;
// FADE OUT STAGE
case 2:
if (this.verts.length > 1) {
if (this.fade < linkFade) {
this.fade++;
// Render full link between all vertices and fade over time
points = [];
var alpha = (1 - (this.fade / linkFade)) * linkOpacity;
for (i = 0; i < this.verts.length; i++) {
p = particles[this.verts[i]];
pos = position(p.x, p.y, p.z);
points.push([pos.x, pos.y]);
}
this.drawLine(points, alpha);
}
else {
//console.log(this.verts[0]+' moving to stage 3 (2a)');
this.stage = 3;
this.finished = true;
}
}
else {
//console.log(this.verts[0]+' prematurely moving to stage 3 (2b)');
this.stage = 3;
this.finished = true;
}
break;
// FINISHED STAGE
case 3:
default:
this.finished = true;
break;
}
};
Link.prototype.drawLine = function(points, alpha) {
if (typeof alpha !== 'number') alpha = linkOpacity;
if (points.length > 1 && alpha > 0) {
//console.log(this.verts[0]+': Drawing line '+alpha);
context.globalAlpha = alpha;
context.beginPath();
for (var i = 0; i < points.length-1; i++) {
context.moveTo(points[i][0], points[i][1]);
context.lineTo(points[i+1][0], points[i+1][1]);
}
context.strokeStyle = color;
context.lineWidth = lineWidth;
context.stroke();
context.closePath();
context.globalAlpha = 1;
}
};
// Utils
function noisePoint(i) {
var a = nAngle * i,
cosA = Math.cos(a),
sinA = Math.sin(a),
//value = simplex.noise2D(nScale * cosA + nScale, nScale * sinA + nScale),
//rad = nRad + value;
rad = nRad;
return {
x: rad * cosA,
y: rad * sinA
};
}
function position(x, y, z) {
return {
x: (x * canvas.width) + ((((canvas.width / 2) - mouse.x + ((nPos.x - 0.5) * noiseStrength)) * z) * motion),
y: (y * canvas.height) + ((((canvas.height / 2) - mouse.y + ((nPos.y - 0.5) * noiseStrength)) * z) * motion)
};
}
function sizeRatio() {
return canvas.width >= canvas.height ? canvas.width : canvas.height;
}
function random(min, max, float) {
return float ?
Math.random() * (max - min) + min :
Math.floor(Math.random() * (max - min + 1)) + min;
}
// init
if (canvas) init();
html,
body {
margin: 0;
padding: 0;
}
body {
background-color: #31102F;
background: radial-gradient(ellipse at center, #31102f 0%, #280b29 100%);
}
#stars {
display: block;
position: relative;
width: 100%;
height: 16rem;
height: 100vh;
z-index: 1;
}
<script src="https://rawgit.com/ironwallaby/delaunay/master/delaunay.js"></script>
<canvas id="stars" width="300" height="300"></canvas>
I have implemented a recursive maze generation algorithm in Javascript, and am rendering using HTML canvas.
The problem I have, is that I am unable to render to the canvas while the recursive function is in progress. The render only appears after recursive calls have finished.
Here is my (rough) functioning recursive function :
function start(canvas_context)
{
//do some stuff here...
render(canvas_context);
if()...{
start(canvas_context);
}
else if(...)
{
if(...)
{
start(canvas_context);
}
}
}
Here is my rendering function:
function render(canvas_context)
{
canvas_context.fillStyle = 'black';
canvas_context.fillRect(0,0,canvas.width, canvas.height);
for(..)
{
for(...)
{
canvas_context.strokeStyle = 'red';
canvas_context.beginPath();
canvas_context.moveTo(start.x, start.y);
canvas_context.lineTo(end.x,end.y);
canvas_context.stroke();
}
}
}
Here are the full functions if they are needed:
function start(canvas_context)
{
//Vector2.print(game_config["current_grid_pos"]);
var current_block = game_config["grid_space"][game_config["current_grid_pos"].y][game_config["current_grid_pos"].x];
var random_neighbor_grid_pos = random_neighbor(current_block);
//render(canvas_context);
if(random_neighbor_grid_pos.x != -1 && random_neighbor_grid_pos.y != -1)
{
var next_block = game_config["grid_space"][random_neighbor_grid_pos.y][random_neighbor_grid_pos.x];
next_block.visited = true;
game_config["visited_stack"].push(random_neighbor_grid_pos);
remove_walls(current_block, next_block);
game_config["current_grid_pos"] = random_neighbor_grid_pos;
start(canvas_context);
}
else if (game_config["visited_stack"].length > 0)
{
current_block.visited = true;
game_config["visited_stack"].pop();
if(game_config["visited_stack"].length != 0)
{
game_config["current_grid_pos"] = game_config["visited_stack"][game_config["visited_stack"].length - 1];
start(canvas_context);
}
}
}
function render(canvas_context)
{
//Initialise the canvas background.
canvas_context.fillStyle = 'black';
canvas_context.fillRect(0,0,canvas.width, canvas.height);
for(var y = 0; y < game_config["grid_space"].length; y++)
{
for(var x = 0; x < game_config["grid_space"][0].length; x++)
{
var block = game_config["grid_space"][y][x];
var walls = block.get_walls();
for(var key in walls)
{
var wall = walls[key];
render_line(canvas_context, wall.start, wall.end);
}
}
}
}
function render_line(canvas_context, start, end)
{
canvas_context.strokeStyle = 'red';
canvas_context.beginPath();
canvas_context.moveTo(start.x, start.y);
canvas_context.lineTo(end.x,end.y);
canvas_context.stroke();
}
Is it even possible to render during recursive calls with HTML canvas?
I think you can do it without a recursion but I show both ways:
const cellsise = 10;
class block {
constructor (x, y){
this.x = x;
this. y = y;
this.delta = {x: x * cellsise , y: y * cellsise};
this.walls = {
left: {
start: {
x: 0 + this.delta.x,
y: 0 + this.delta.y
},
end: {
x: 0 + this.delta.x,
y: cellsise + this.delta.y
}
},
top: {
start: {
x: 0 + this.delta.x,
y: 0 + this.delta.y
},
end: {
x: cellsise + this.delta.x,
y: 0 + this.delta.y
}
},
right: {
start: {
x: cellsise + this.delta.x,
y: 0 + this.delta.y
},
end: {
x: cellsise + this.delta.x,
y: cellsise + this.delta.y
}
},
bottom: {
start: {
x: 0 + this.delta.x,
y: cellsise + this.delta.y
},
end: {
x: cellsise + this.delta.x,
y: cellsise + this.delta.y
}
}
};
}
get_walls(){
return this.walls;
}
}
const game_config = {
grid_space:[],
height: 10,
width: 10,
}
function generateGridSpace() {
game_config.grid_space=[];
for(y = 0 ; y < game_config.height; ++y){
game_config.grid_space.push([]);
for(x = 0 ; x < game_config.width; ++x){
game_config.grid_space[y].push(new block(x, y))
}
}
}
function remove_walls(current_block){
let left = Math.random() > 0.5;
let top = !left //Math.random() > 0.5;
let right = Math.random() > 0.5;
let bottom = !right //false// Math.random() > 0.5;
if (left && current_block.x - 1 > 0) {
delete current_block.walls.left;
delete game_config.grid_space[current_block.x-1][current_block.y].walls.right
}
if (top && current_block.y - 1 > 0) {
delete current_block.walls.top;
delete game_config.grid_space[current_block.x][current_block.y-1].walls.bottom;
}
if (right && current_block.x+1 < game_config.width -1) {
delete current_block.walls.right;
delete game_config.grid_space[current_block.x + 1][current_block.y].walls.left;
}
if (bottom && current_block.y+1 < game_config.height -1) {
delete current_block.walls.bottom;
delete game_config.grid_space[current_block.x][current_block.y + 1].walls.top;
}
}
function start_with_recursion(canvas_context, mix=null) {
if (!mix) {
mix = game_config.grid_space.reduce((acc, e) => [...acc,...e], [])
.sort(() => Math.random() - 0.5)
} else if (mix.length === 0) {
return;
}
const block = mix.pop();
const i = game_config.width * game_config.height - mix.length
setTimeout(() => {
remove_walls(block);
render_block(canvas_context, block);
}, i * 50)
start_with_recursion(canvas_context, mix)
}
function start_without_recursion(canvas_context) {
const mix = game_config.grid_space.reduce((acc, e) => [...acc,...e], [])
.sort(() => Math.random() - 0.5)
for(let i = 0; i < mix.length; ++i){
setTimeout(() => {
remove_walls(mix[i]);
render_block(canvas_context, mix[i]);
}, i * 50)
}
}
function render_block(canvas_context, block) {
var walls = block.get_walls();
for(var key in walls)
{
var wall = walls[key];
render_line(canvas_context, wall.start, wall.end);
}
}
function render_line(canvas_context, start, end) {
canvas_context.strokeStyle = 'red';
canvas_context.beginPath();
canvas_context.moveTo(
5 + start.x + .5,
5 + start.y + .5
);
canvas_context.lineTo(
5 + end.x + .5,
5 + end.y + .5
);
canvas_context.stroke();
}
canvas = document.querySelector('canvas');
canvas.height = game_config.height * cellsise + 5 * 2;
canvas.width = game_config.width * cellsise + 5 * 2;
ctx = canvas.getContext('2d');
ctx.fillStyle = 'black';
ctx.fillRect(0,0,canvas.width, canvas.height);
// ctx.lineWidth = 2;
generateGridSpace();
// start_without_recursion(ctx);
start_with_recursion(ctx);
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title></title>
</head>
<body>
<canvas></canvas>
</body>
</html>
also for get a random neighbor:
function random_neighbor(current_block) {
const {height, width} = game_config;
const neighbors = [
{x: current_block.x, y: current_block.y - 1}, // from top
{x: current_block.x - 1, y: current_block.y}, // from left
{x: current_block.x + 1, y: current_block.y}, // from right
{x: current_block.x, y: current_block.y + 1}, // from bottom
].filter(e => e.x >= 0 && e.x < width && e.y >= 0 && e.y < height)
const rnd = neighbors[Math.floor(Math.random() * neighbors.length)]
return rnd; // {x, y}
}
You also need to take into account that the drawn wall can be removed later, which will not correspond to reality. Therefore, it is better to render (even with a delay) after the maze is fully generated.
Suggest converting your recursive function into an iterator function, and then introducing a second function that makes use of setInterval to iteratively draw your maze, and once complete, then performs a clearInterval.
Here's a quick sample that I whipped up exemplifying the concept, which simply draws increasingly larger rectangles on the canvas every 50ms, with the iterator function returning the size of the next rectangle to be drawn. In your case, you'll likely want to yield an object defining the portion of the maze to be drawn...
var ctx = document.getElementById('canvas').getContext('2d');
function* recurse( n, max ) {
yield n;
if ( n < max ) {
yield* recurse( n + 1, max );
}
}
function drawRectangles() {
function drawIteratively() {
let nd = iterator.next();
if ( nd.done ) {
clearInterval( interval );
} else {
ctx.lineWidth = 1;
ctx.strokeStyle = '#FF0000';
ctx.beginPath();
ctx.rect( nd.value, nd.value, nd.value * 2, nd.value * 2 );
ctx.stroke();
}
}
let iterator = recurse( 25, 100 );
let interval = setInterval( drawIteratively, 50 );
}
drawRectangles();
<canvas id='canvas' width="300" height="300"></canvas>
Note that the iterator function is a very basic recursive function, but recursive nonetheless, showing the critical syntax involved in a recursive iterator function...
I want to modify the platformer game that I find in codepen.
http://codepen.io/loktar00/pen/JEdqD
the original is like the below image.
I want to change it to be:
I want to zoom in the viewport to player and making a camera-like view where I could scroll a level within a canvas element.
Like this game http://www.html5quintus.com/quintus/examples/platformer_full/
The viewport and camera is tracking the player.
This is my code:
(function () {
var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
window.requestAnimationFrame = requestAnimationFrame;
})();
var canvas = document.getElementById("canvas"),
ctx = canvas.getContext("2d"),
width = 100,
height = 100,
player = {
x: width / 2,
y: height - 15,
width: 5,
height: 5,
speed: 3,
velX: 0,
velY: 0,
jumping: false,
grounded: false
},
keys = [],
friction = 0.8,
gravity = 0.3;
var boxes = [];
// player's position
var playerX = 20;
var playerY = 20;
// how far offset the canvas is
var offsetX = 0;
var offsetY = 0;
// dimensions
boxes.push({
x: 0,
y: 0,
width: 10,
height: height
});
boxes.push({
x: 0,
y: height - 2,
width: width,
height: 50
});
boxes.push({
x: width - 10,
y: 0,
width: 50,
height: height
});
boxes.push({
x: 120,
y: 10,
width: 80,
height: 80
});
boxes.push({
x: 170,
y: 50,
width: 80,
height: 80
});
boxes.push({
x: 220,
y: 100,
width: 80,
height: 80
});
boxes.push({
x: 270,
y: 150,
width: 40,
height: 40
});
canvas.width = width;
canvas.height = height;
function update() {
// check keys
if (keys[38] || keys[32] || keys[87]) {
// up arrow or space
if (!player.jumping && player.grounded) {
player.jumping = true;
player.grounded = false;
player.velY = -player.speed * 2;
}
}
if (keys[39] || keys[68]) {
// right arrow
if (player.velX < player.speed) {
player.velX++;
offsetX--;
}
}
if (keys[37] || keys[65]) {
// left arrow
if (player.velX > -player.speed) {
player.velX--;
offsetX++;
}
}
player.velX *= friction;
player.velY += gravity;
ctx.clearRect(0, 0, width, height);
ctx.fillStyle = "black";
ctx.beginPath();
player.grounded = false;
for (var i = 0; i < boxes.length; i++) {
ctx.rect(boxes[i].x, boxes[i].y, boxes[i].width, boxes[i].height);
var dir = colCheck(player, boxes[i]);
if (dir === "l" || dir === "r") {
player.velX = 0;
player.jumping = false;
} else if (dir === "b") {
player.grounded = true;
player.jumping = false;
} else if (dir === "t") {
player.velY *= -1;
}
}
if(player.grounded){
player.velY = 0;
}
player.x += player.velX;
player.y += player.velY;
ctx.save();
ctx.translate(offsetX, offsetY);
// clear the viewport
ctx.clearRect(-offsetX, -offsetY, 100,100);
ctx.fill();
ctx.fillStyle = "red";
ctx.fillRect(player.x, player.y, player.width, player.height);
ctx.fillRect(playerX-offsetX, playerY-offsetY, 8, 8);
// draw the other stuff
var l = boxes.length;
for (var i = 0; i < l; i++) {
// we should really only draw the things that intersect the viewport!
// but I am lazy so we are drawing everything here
var x = boxes[i][0];
var y = boxes[i][1];
ctx.fillStyle = 'lightblue';
ctx.fillRect(x, y, 8, 8);
ctx.fillStyle = 'black';
ctx.fillText(x + ', ' + y, x, y) // just to show where we are drawing these things
}
ctx.restore();
requestAnimationFrame(update);
}
function colCheck(shapeA, shapeB) {
// get the vectors to check against
var vX = (shapeA.x + (shapeA.width / 2)) - (shapeB.x + (shapeB.width / 2)),
vY = (shapeA.y + (shapeA.height / 2)) - (shapeB.y + (shapeB.height / 2)),
// add the half widths and half heights of the objects
hWidths = (shapeA.width / 2) + (shapeB.width / 2),
hHeights = (shapeA.height / 2) + (shapeB.height / 2),
colDir = null;
// if the x and y vector are less than the half width or half height, they we must be inside the object, causing a collision
if (Math.abs(vX) < hWidths && Math.abs(vY) < hHeights) {
// figures out on which side we are colliding (top, bottom, left, or right)
var oX = hWidths - Math.abs(vX),
oY = hHeights - Math.abs(vY);
if (oX >= oY) {
if (vY > 0) {
colDir = "t";
shapeA.y += oY;
} else {
colDir = "b";
shapeA.y -= oY;
}
} else {
if (vX > 0) {
colDir = "l";
shapeA.x += oX;
} else {
colDir = "r";
shapeA.x -= oX;
}
}
}
return colDir;
}
document.body.addEventListener("keydown", function (e) {
keys[e.keyCode] = true;
});
document.body.addEventListener("keyup", function (e) {
keys[e.keyCode] = false;
});
window.addEventListener("load", function () {
update();
});
<h3>A, D or Arrow keys to move, W or space to jump</h3>
<canvas id="canvas"></canvas>
But this does not work.
You can use the same code that you had in the codepen, but add a couple lines in the load event, before the first update().
Let's say something like:
window.addEventListener("load", function () {
ctx.scale(2,2);
ctx.translate(-100,-100);
update();
});
This will zoom by two times and center on new coordinates, BUT keep in mind that you have to do it yourself if you want to re-center when the player is going out of the view.
As a partial way of doing this, you can check if the player moved and translate the canvas using the opposite values of player.velX and player.velY. Something like:
var playerMoved = false;
if (keys[38] || keys[32] || keys[87]) {
playerMoved = true;
//...Other stuff
}
if (keys[39] || keys[68]) {
playerMoved = true;
//...Other stuff
}
if (keys[37] || keys[65]) {
playerMoved = true;
//...Other stuff
}
if (playerMoved) {
// You still need to check quite a few things, like
// the player being out of bounds, the view not translating
// when x less than or bigger then a specific value, and so on
ctx.translate(-player.velX, -player.velY);
}
This is not a complete solution because that would require quite some code, but it should get you started.
I have made a program that is supposed to make several balls move along a path. So far, I have only been able to make one ball successfully traverse the course because whenever I add another ball (from the array of balls) it begins to flicker and spasmodically disappears. I would appreciate any assistance in solving this problem.
JS bin
<!DOCTYPE html>
<html>
<head>
<style>
* {
padding: 0;
margin: 0;
}
canvas {
background: #eee;
display: block;
margin: 0 auto;
}
</style>
</head>
<body>
<canvas id="Circuit" width="500" height="320"></canvas>
<script>
var dad = [];
var canvas = document.getElementById("Circuit");
var ctx = canvas.getContext("2d");
var bool = false;
var dx1 = 2;
var dx2 = -2;
var dy1 = 0;
var dy2 = 2;
var memes = [{
x: 0,
y: 100,
}, {
x: 0,
y: 100,
}, {
x: 0,
y: 100,
}, {
x: 0,
y: 100,
}];
function drawCircle(index) {
ctx.beginPath();
ctx.arc(memes[index].x, memes[index].y, 10, 0, Math.PI * 2);
ctx.fillStyle = "#0095DD";
ctx.fill();
ctx.closePath();
}
function draw(index) {
if (index == 0) {
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
if (memes[index].x < 490 && memes[index].y < 291 && !bool) {
drawCircle(index);
memes[index].x += dx1;
memes[index].y += dy1;
}
else if (memes[index].x == 490) {
drawCircle(index);
memes[index].x += 1;
}
else if (memes[index].x > 490 && memes[index].y < 291) {
drawCircle(index);
memes[index].y += dy2;
}
else if (memes[index].y == 291) {
drawCircle(index);
memes[index].y += 1;
}
else if (memes[index].y > 291 && memes[index].x > 2) {
drawCircle(index);
bool = true;
memes[index].x -= 2;
}
else if (memes[index].x == 2 && memes[index].y > 291) {
drawCircle(index);
memes[index].x -= 1;
}
else if (memes[index].x < 2) {
drawCircle(index);
memes[index].y -= dy2;
if (memes[index].y < 100) {
clearInterval(dad[index]);
ctx.clearRect(0, 0, canvas.width, canvas.height);
}
}
ctx.strokeStyle = "red";
ctx.strokeRect(2, 101, 490, 190);
ctx.strokeStyle = "blue";
ctx.strokeRect(2, 82, 40, 40);
}
setTimeout(function() {
setTimeout(function() {
dad[1] = setInterval(function() {
draw(1);
}, 20);
}, 1000);
dad[0] = setInterval(function() {
draw(0);
}, 20);
}, 1000);
</script>
</body>
</html>
The flicker happens when the second ball tries to render the frame. You have two sprites (animating things) clearing and drawing the frame. You also have multiple timers and when animating you usually want a nextFrame function that handles movement of the sprites and drawing the frame.
The sprites array is a list of things that need to be moved and drawn. I added some properties to the meme sprites so you can see that their state needs to be internal like with the "bool" value. Without that you end up effecting the other balls. You'll need to figure out how to remove sprites when they're no longer in play.
var dad = [];
var canvas = document.getElementById("Circuit");
var ctx = canvas.getContext("2d");
var bool = false;
var dx1 = 2;
var dx2 = -2;
var dy1 = 0;
var dy2 = 2;
var memes = [{
x: 0,
y: 100,
color: "#0095DD",
draw: drawMeme,
move: moveMeme,
vx: 1.2,
vy: 1.5,
}, {
x: 0,
y: 100,
vx: 1.5,
vy: 1,
color: "#DD9500",
draw: drawMeme,
move: moveMeme
}, {
x: 0,
y: 100,
vx: 2,
vy: 1,
color: "#FF0000",
draw: drawMeme,
move: moveMeme
}, {
x: 0,
y: 100,
vx: 3,
vy: 2,
color: "#009999",
draw: drawMeme,
move: moveMeme
}];
function drawMeme(meme) {
ctx.beginPath();
ctx.arc(meme.x, meme.y, 10, 0, Math.PI * 2);
ctx.fillStyle = meme.color;
ctx.fill();
ctx.closePath();
}
var sprites = [];
function nextFrame () {
ctx.clearRect(0, 0, canvas.width, canvas.height);
var len = sprites.length;
for (var i = 0; i < len; i++) {
var sprite = sprites[i];
sprite.move(sprite);
sprite.draw(sprite);
}
ctx.strokeStyle = "red";
ctx.strokeRect(2, 101, 490, 190);
ctx.strokeStyle = "blue";
ctx.strokeRect(2, 82, 40, 40);
requestAnimationFrame(nextFrame);
}
function moveMeme(meme) {
if (meme.x < 490 && meme.y < 291 && !meme.bool) {
meme.x += dx1 * meme.vx;
meme.y += dy1 * meme.vy;
}
else if (meme.x == 490) {
meme.x += 1 * meme.vx;
}
else if (meme.x > 490 && meme.y < 291) {
meme.y += dy2 * meme.vy;
}
else if (meme.y == 291) {
meme.y += 1 * meme.vy;
}
else if (meme.y > 291 && meme.x > 2) {
meme.bool = true;
meme.x -= 2 * meme.vx;
}
else if (meme.x == 2 && meme.y > 291) {
meme.x -= 1 * meme.vx;
}
else if (meme.x < 2) {
meme.y -= dy2 * meme.vy;
if (meme.y < 100) {
// stop drawing this sprite
meme.draw = function(){};
meme.delete = 1; // for a cleanup function
}
}
}
nextFrame();
function startMeme(index) {
var meme = memes[index];
sprites.push(meme);
}
setTimeout(function() {
setTimeout(function() {
startMeme(1);
}, 1000);
startMeme(0);
startMeme(2);
startMeme(3);
}, 1000);
<canvas id="Circuit" width="500" height="320"></canvas>
I recently made a JS Pong game. It works well, but the ball rarely gets stuck at the bottom or top. It looks like it is halfway through the wall and constantly bouncing. Video of the issue happening. You can try the game here. I do not know why this issue is happening because the logic seems right and works 90% of the time correctly. Here are the main two functions of my program:
function moveAll() {
if (showingWinScreen) {
return;
}
computerMovement();
ballX += ballSpeedX;
ballY += ballSpeedY;
if (ballY <= 10) {
ballSpeedY = -ballSpeedY;
} else if (ballY >= HEIGHT - 10) {
ballSpeedY = -ballSpeedY;
}
if (ballX >= WIDTH - 10) {
if ((ballY > paddleY) && (ballY < paddleY + 100)) {
ballSpeedX = -ballSpeedX;
var deltaY = ballY - paddleY - 50;
ballSpeedY = deltaY / 5;
} else {
player1Score++;
ballReset();
}
} else if (ballX <= 10) {
if ((ballY > mouseY - 50) && (ballY < mouseY + 50)) {
ballSpeedX = -ballSpeedX;
deltaY = ballY - mouseY;
ballSpeedY = deltaY / 6;
} else {
player2Score++;
ballReset();
}
}
}
function drawAll() {
if (showingWinScreen) {
colorRect(0, 0, WIDTH, HEIGHT, "black");
canvas.fillStyle = "yellow";
canvas.fillText("Click to continue!", 300, 300);
if (player1Score == WINNING_SCORE) {
canvas.fillText("You won!", 360, 500);
} else if (player2Score == WINNING_SCORE) {
canvas.fillText("The computer beat you!", 280, 500);
}
return;
}
colorRect(0, 0, WIDTH, HEIGHT, "black");
drawNet();
makeCircle(ballX, ballY, 10, 0, Math.PI * 2, "red");
colorRect(790, paddleY, 10, 100, "cyan");
colorRect(0, mouseY - 50, 10, 100, "yellow");
canvas.fillStyle = "white";
canvas.fillText(player1Score + " " + player2Score, 360, 100);
}
Thank you for your help!
I think there's only one case in which this could happen: when, in a colliding frame, you decrease the speed.
When the speed remains the same, no matter what, your ball will always bounce back to the previous' frames position:
var cvs = document.querySelector("canvas");
var ctx = cvs.getContext("2d");
var balls = [
Ball(50, 50, 0, 5, 5, "red"),
Ball(100, 50, 0, 5, 10, "blue"),
Ball(150, 50, 0, 5, 15, "green"),
Ball(200, 50, 0, 5, 20, "yellow")
];
var next = () => {
updateFrame(balls);
drawFrame(balls);
}
var loop = () => {
requestAnimationFrame(() => {
next();
loop();
});
}
next();
function Ball(x, y, vx, vy, r, color) {
return {
x: x,
y: y,
vx: vx,
vy: vy,
r: r,
color: color
}
};
function updateBall(b) {
b.x += b.vx;
b.y += b.vy;
if (b.y <= b.r ||
b.y >= cvs.height - b.r) {
b.vy *= -1;
}
};
function drawBall(b) {
ctx.beginPath();
ctx.fillStyle = b.color;
ctx.arc(b.x, b.y, b.r, 0, 2 * Math.PI, false);
ctx.fill();
}
function updateFrame(balls) {
balls.forEach(updateBall);
}
function drawFrame(balls) {
ctx.clearRect(0, 0, cvs.width, cvs.height);
balls.forEach(drawBall);
};
<canvas width="300" height="150" style="background: #454545"></canvas>
<button onclick="next()">next</button>
<button onclick="loop()">run</button>
But when the speed changes, things get stuck:
var cvs = document.querySelector("canvas");
var ctx = cvs.getContext("2d");
var balls = [
Ball(50, 50, 0, 10, 5, "red"),
Ball(100, 50, 0, 10, 10, "blue"),
Ball(150, 50, 0, 10, 15, "green"),
Ball(200, 50, 0, 10, 20, "yellow")
];
var next = () => {
updateFrame(balls);
drawFrame(balls);
}
var loop = () => {
requestAnimationFrame(() => {
next();
loop();
});
}
next();
function Ball(x, y, vx, vy, r, color) {
return {
x: x,
y: y,
vx: vx,
vy: vy,
r: r,
color: color
}
};
function updateBall(b) {
b.x += b.vx;
b.y += b.vy;
if (b.y <= b.r ||
b.y >= cvs.height - b.r) {
b.vy *= -0.5;
}
};
function drawBall(b) {
ctx.beginPath();
ctx.fillStyle = b.color;
ctx.arc(b.x, b.y, b.r, 0, 2 * Math.PI, false);
ctx.fill();
}
function updateFrame(balls) {
balls.forEach(updateBall);
}
function drawFrame(balls) {
ctx.clearRect(0, 0, cvs.width, cvs.height);
balls.forEach(drawBall);
};
<canvas width="300" height="150" style="background: #454545"></canvas>
<button onclick="next()">next</button>
<button onclick="loop()">run</button>
In your case, I'm thinking this can only happen when there's a paddle collision AND a wall collision simultaneously.
A quick-to-implement solution would be to check if the new position is valid before translating the ball position. If you don't want the precise location, you can place the ball at the point of collision. Note that this will produce a slightly off frame.
E.g.:
var newY = ballY + ballSpeedY;
// Top wall
if(newY <= 10) {
ballY = 10;
ballSpeedY = -ballSpeedY;
}
// Bottom wall
else if(newY >= HEIGHT-10){
ballY = HEIGHT - 10;
ballSpeedY = -ballSpeedY;
}
// No collision
else {
ballY = newY;
}
Update: a more detailed description of what can happen
Let's say your ball collides with the top border of your canvas and with your paddle in the same frame.
First, you move the ball to the colliding position: ballY += ballSpeedY; Say your ballY is 4, and your ballSpeedY is -5, you'll position the ball to -1, inside the wall.
If this were to be the only collision, you should be okay. You flip the speed (ballSpeedY = -ballSpeedY), so in the next frame, your ball should be back at -1 + 5 = 4, so ballY will be 4 again, and your ball will move towards 4 + 5 = 9 in the next frame.
Now a problem arises, when in the -1 positioned frame, you collide with the paddle as well! When the paddle hits the ball, you modify the ballspeed: ballSpeedY = deltaY / 5;. If this turns out to be < 1, your ball won't be able to exit the wall in the next frame. Instead of -1 + 5 = 4, your ball will, for example, move to: -1 + 0.5 = -0.5.
Now, your ball won't be able to get back in to play, since the next frame will, again, calculate a collision and flip the speed. This results in the bouncy, trembling effect you see when the ball gets stuck.
A naive but pretty decent solution, is to only update the position of the ball to a valid position. I.e.: never to a colliding coordinate.
var animate = window.requestAnimationFrame || window.webkitRequestAnimationFrame || window.mozRequestAnimationFrame || function (callback) {
window.setTimeout(callback, 1000 / 60)
};
var canvas = document.createElement("canvas");
var width = 400;
var height = 600;
canvas.width = width;
canvas.height = height;
var context = canvas.getContext('2d');
var player = new Player();
var computer = new Computer();
var ball = new Ball(200, 300);
var keysDown = {};
var render = function () {
context.fillStyle = "#FF00FF";
context.fillRect(0, 0, width, height);
player.render();
computer.render();
ball.render();
};
var update = function () {
player.update();
computer.update(ball);
ball.update(player.paddle, computer.paddle);
};
var step = function () {
update();
render();
animate(step);
};
function Paddle(x, y, width, height) {
this.x = x;
this.y = y;
this.width = width;
this.height = height;
this.x_speed = 0;
this.y_speed = 0;
}
Paddle.prototype.render = function () {
context.fillStyle = "#0000FF";
context.fillRect(this.x, this.y, this.width, this.height);
};
Paddle.prototype.move = function (x, y) {
this.x += x;
this.y += y;
this.x_speed = x;
this.y_speed = y;
if (this.x < 0) {
this.x = 0;
this.x_speed = 0;
} else if (this.x + this.width > 400) {
this.x = 400 - this.width;
this.x_speed = 0;
}
};
function Computer() {
this.paddle = new Paddle(175, 10, 50, 10);
}
Computer.prototype.render = function () {
this.paddle.render();
};
Computer.prototype.update = function (ball) {
var x_pos = ball.x;
var diff = -((this.paddle.x + (this.paddle.width / 2)) - x_pos);
if (diff < 0 && diff < -4) {
diff = -5;
} else if (diff > 0 && diff > 4) {
diff = 5;
}
this.paddle.move(diff, 0);
if (this.paddle.x < 0) {
this.paddle.x = 0;
} else if (this.paddle.x + this.paddle.width > 400) {
this.paddle.x = 400 - this.paddle.width;
}
};
function Player() {
this.paddle = new Paddle(175, 580, 50, 10);
}
Player.prototype.render = function () {
this.paddle.render();
};
Player.prototype.update = function () {
for (var key in keysDown) {
var value = Number(key);
if (value == 37) {
this.paddle.move(-4, 0);
} else if (value == 39) {
this.paddle.move(4, 0);
} else {
this.paddle.move(0, 0);
}
}
};
function Ball(x, y) {
this.x = x;
this.y = y;
this.x_speed = 0;
this.y_speed = 3;
}
Ball.prototype.render = function () {
context.beginPath();
context.arc(this.x, this.y, 5, 2 * Math.PI, false);
context.fillStyle = "#000000";
context.fill();
};
Ball.prototype.update = function (paddle1, paddle2) {
this.x += this.x_speed;
this.y += this.y_speed;
var top_x = this.x - 5;
var top_y = this.y - 5;
var bottom_x = this.x + 5;
var bottom_y = this.y + 5;
if (this.x - 5 < 0) {
this.x = 5;
this.x_speed = -this.x_speed;
} else if (this.x + 5 > 400) {
this.x = 395;
this.x_speed = -this.x_speed;
}
if (this.y < 0 || this.y > 600) {
this.x_speed = 0;
this.y_speed = 3;
this.x = 200;
this.y = 300;
}
if (top_y > 300) {
if (top_y < (paddle1.y + paddle1.height) && bottom_y > paddle1.y && top_x < (paddle1.x + paddle1.width) && bottom_x > paddle1.x) {
this.y_speed = -3;
this.x_speed += (paddle1.x_speed / 2);
this.y += this.y_speed;
}
} else {
if (top_y < (paddle2.y + paddle2.height) && bottom_y > paddle2.y && top_x < (paddle2.x + paddle2.width) && bottom_x > paddle2.x) {
this.y_speed = 3;
this.x_speed += (paddle2.x_speed / 2);
this.y += this.y_speed;
}
}
};
document.body.appendChild(canvas);
animate(step);
window.addEventListener("keydown", function (event) {
keysDown[event.keyCode] = true;
});
window.addEventListener("keyup", function (event) {
delete keysDown[event.keyCode];
});
http://jsfiddle.net/kHJr6/2/