Make Magic object, and /magic page

This commit is contained in:
Tyler Hallada 2014-12-20 18:18:08 -05:00
parent 3c16648f09
commit 5dff1b2fd7
5 changed files with 296 additions and 256 deletions

9
_data/magic.yml Normal file
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@ -0,0 +1,9 @@
counting: false
waitTime: 20
step: 0.4
prune_to: 15
maxDuration: 600
minDuration: 50
splineLength: 15
maxAngleChange: 180
minAngleChange: 90

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@ -30,8 +30,8 @@
<link rel="shortcut icon" href="/favicon.png" />
<!-- Scripts -->
<script src="js/AnimationFrame.min.js"></script>
<script async src="js/magic.js"></script>
<script src="/js/AnimationFrame.min.js"></script>
<script async src="/js/magic.js"></script>
<!-- Google Analytics -->
<script>

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@ -3,6 +3,11 @@ layout: home
title: Tyler Hallada
---
<script>
window.onload = function () {
new Magic().draw();
}
</script>
<div id="home">
<div class="card profile-card">
<div class="row clearfix">

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@ -1,29 +1,46 @@
window.onload = function () {
var Magic = function (options) {
options = options || {}
// Array to hold all active spells being drawn
var spells = [];
this.spells = [];
// When on, wait a certain amount of time before casting (for initial
// load-up)
var counting = true;
this.counting = options.counting || true;
// The amount of time to wait (in number of animate() calls)
var waitTime = 20;
this.waitTime = options.waitTime || 20;
// How fast to draw the spells
var step = 0.2;
this.step = options.step || 0.2;
// Limit of branches per spell at any time
var prune_to = 20;
this.prune_to = options.prune_to || 20;
// Max duration possible (in steps) of a spell
this.maxDuration = options.maxDuration || 600;
// Min duration possible (in steps) of a spell
this.minDuration = options.minDuration || 50;
// Max angle deviation during branch split
this.maxAngleChange = options.maxAngleChange || 180;
// Min angle deviation during branch split
this.minAngleChange = options.minAngleChange || 90;
// Average length of new spline (branch)
this.splineLength = options.splineLength || 15;
// Save this query here now that the page is loaded
var canvas = document.getElementById("magic");
this.canvas = document.getElementById("magic");
}
/* Get the height and width of full document. To avoid browser
* incompatibility issues, choose the maximum of all height/width values.
*
* Method from http://stackoverflow.com/a/1147768 */
function getDocumentDimensions() {
Magic.prototype.getDocumentDimensions = function () {
var body = document.body,
html = document.documentElement;
@ -40,7 +57,7 @@ window.onload = function () {
/* Specifies what will be added to the red, green, and blue values of the
* color at each interval. */
function pickGradient() {
Magic.prototype.pickGradient = function () {
var directions = [-1, 0, 1];
var magnitudes = [1, 2, 3];
@ -60,7 +77,7 @@ window.onload = function () {
Unused for now. It turns out that changing the canvas stroke color is a
costly operation and slows things down a lot. */
function nextColor(color, gradient) {
Magic.prototype.nextColor = function(color, gradient) {
var values = ["r", "g", "b"];
// Check if color at end of range and reverse gradient direction if so
@ -82,13 +99,13 @@ window.onload = function () {
}
/* Choose a random RGB color to begin the color gradient with */
function pickRandomColor() {
Magic.prototype.pickRandomColor = function() {
return {"r": Math.floor(Math.random() * (255 + 1)),
"g": Math.floor(Math.random() * (255 + 1)),
"b": Math.floor(Math.random() * (255 + 1))};
}
function drawSplineSegment(branch, context) {
Magic.prototype.drawSplineSegment = function(branch, context) {
var ax = (-branch.points[0].x + 3*branch.points[1].x - 3*branch.points[2].x + branch.points[3].x) / 6;
var ay = (-branch.points[0].y + 3*branch.points[1].y - 3*branch.points[2].y + branch.points[3].y) / 6;
var bx = (branch.points[0].x - 2*branch.points[1].x + branch.points[2].x) / 2;
@ -102,22 +119,22 @@ window.onload = function () {
ay*Math.pow(branch.t, 3) + by*Math.pow(branch.t, 2) + cy*branch.t + dy
);
context.lineTo(
ax*Math.pow(branch.t+step, 3) + bx*Math.pow(branch.t+step, 2) + cx*(branch.t+step) + dx,
ay*Math.pow(branch.t+step, 3) + by*Math.pow(branch.t+step, 2) + cy*(branch.t+step) + dy
ax*Math.pow(branch.t+this.step, 3) + bx*Math.pow(branch.t+this.step, 2) + cx*(branch.t+this.step) + dx,
ay*Math.pow(branch.t+this.step, 3) + by*Math.pow(branch.t+this.step, 2) + cy*(branch.t+this.step) + dy
);
branch.t += step;
branch.t += this.step;
}
function splitBranch(branch) {
Magic.prototype.splitBranch = function(branch) {
var newBranches = [];
// Replace with 2 new branches
for (var k = 0; k < 2; k++) {
// Generate random deviation from previous angle
var angle = branch.angle - (Math.random() * 180 - 90);
var angle = branch.angle - (Math.random() * this.maxAngleChange - this.minAngleChange);
// Generate random length
var length = Math.random() * 15 + 4;
var length = Math.random() * this.splineLength + 4;
// Calculate new point
var x2 = branch.points[3].x + Math.sin(Math.PI * angle / 180) * length;
@ -139,37 +156,37 @@ window.onload = function () {
return newBranches;
}
function cast(x, y, angle, chain) {
Magic.prototype.cast = function(x, y, angle, chain) {
// Find random position if not defined
if (x === undefined) {
x = Math.floor(Math.random() * (canvas.width + 1));
x = Math.floor(Math.random() * (this.canvas.width + 1));
}
if (y === undefined) {
y = Math.floor(Math.random() * (canvas.height + 1));
y = Math.floor(Math.random() * (this.canvas.height + 1));
}
if (angle === undefined) {
angle = Math.random() * 360;
}
var color = pickRandomColor();
var color = this.pickRandomColor();
var colorString = "rgb(" + color.r + "," + color.g + "," + color.b + ")";
// Create new spell (branch)
spells.push({
this.spells.push({
branches:new Array({
points:new Array({x:x, y:y}, {x:x, y:y}, {x:x, y:y}, {x:x, y:y}),
angle:angle,
t:0,
}),
color:colorString,
duration:Math.floor(Math.random() * (600 - 50 + 1)) + 50,
duration:Math.floor(Math.random() * (this.maxDuration - this.minDuration + 1)) + 50,
chain:chain,
});
}
/* Most of this funtion is provided by Maissan Inc. in their tutorial:
http://www.maissan.net/articles/simulating-vines */
function drawSpells(context, sort, prune, chain) {
Magic.prototype.drawSpells = function(context, sort, prune, chain) {
var AnimationFrame = window.AnimationFrame;
AnimationFrame.shim();
var animationFrame = new AnimationFrame(30),
@ -178,51 +195,52 @@ window.onload = function () {
gradient;
context.lineWidth = 0.5;
var self = this;
function animate(time) {
// resize canvas if document size changed
dimensions = getDocumentDimensions();
if ((dimensions.height !== canvas.height) ||
(dimensions.width !== canvas.width)) {
canvas.height = dimensions.height;
canvas.width = dimensions.width;
dimensions = self.getDocumentDimensions();
if ((dimensions.height !== self.canvas.height) ||
(dimensions.width !== self.canvas.width)) {
self.canvas.height = dimensions.height;
self.canvas.width = dimensions.width;
}
// if enough time has passed, cast another spell to draw
if (timeCounter >= waitTime && counting) {
cast(undefined, undefined, undefined, chain); // start position
counting = false;
if (timeCounter >= self.waitTime && self.counting) {
self.cast(undefined, undefined, undefined, chain); // start position
self.counting = false;
}
// Draw branches
for (var i in spells) {
for (var i in self.spells) {
context.beginPath();
context.strokeStyle = spells[i].color;
context.strokeStyle = self.spells[i].color;
if (spells[i].duration > 0) {
for (var j in spells[i].branches) {
drawSplineSegment(spells[i].branches[j], context);
if (self.spells[i].duration > 0) {
for (var j in self.spells[i].branches) {
self.drawSplineSegment(self.spells[i].branches[j], context);
// When finished drawing splines, create a new set of branches
if (spells[i].branches[j].t >= 1) {
if (self.spells[i].branches[j].t >= 1) {
var newBranches = splitBranch(spells[i].branches[j]);
var newBranches = self.splitBranch(self.spells[i].branches[j]);
// Replace old branch with two new branches
spells[i].branches.splice(j, 1);
spells[i].branches = spells[i].branches.concat(newBranches);
self.spells[i].branches.splice(j, 1);
self.spells[i].branches = self.spells[i].branches.concat(newBranches);
}
}
// If over 10 branches, prune the branches
if (prune) {
if (sort) {
while (spells[i].branches.length > prune_to) {
spells[i].branches.pop();
while (self.spells[i].branches.length > self.prune_to) {
self.spells[i].branches.pop();
}
} else {
while (spells[i].branches.length > prune_to) {
spells[i].branches.splice(
Math.floor(Math.random() * spells[i].branches.length),
while (self.spells[i].branches.length > self.prune_to) {
self.spells[i].branches.splice(
Math.floor(Math.random() * self.spells[i].branches.length),
1);
}
}
@ -230,18 +248,18 @@ window.onload = function () {
context.stroke();
context.closePath();
spells[i].duration--;
self.spells[i].duration--;
} else {
// cast a new spell at random position
if (spells[i].chain) {
cast(undefined, undefined, undefined, true);
if (self.spells[i].chain) {
self.cast(undefined, undefined, undefined, true);
}
spells.splice(i, 1); // spell is done now
self.spells.splice(i, 1); // spell is done now
}
}
if (counting) {
if (self.counting) {
timeCounter++;
}
frameId = animationFrame.request(animate);
@ -252,31 +270,29 @@ window.onload = function () {
return frameId;
}
function canvasClickHandler(event) {
Magic.prototype.canvasClickHandler = function(event) {
var x = event.pageX;
var y = event.pageY;
cast(x, y, undefined, false);
this.cast(x, y, undefined, false);
}
function draw() {
Magic.prototype.draw = function() {
var interval_time = 2000;
// Initialize canvas
var dimensions = getDocumentDimensions();
canvas.height = dimensions.height;
canvas.width = dimensions.width;
var dimensions = this.getDocumentDimensions();
this.canvas.height = dimensions.height;
this.canvas.width = dimensions.width;
// Check for canvas support, bind click event, and get context
if (canvas.getContext){
canvas.addEventListener("click", canvasClickHandler);
if (this.canvas.getContext){
var self = this;
this.canvas.addEventListener("click", function () { self.canvasClickHandler.apply(self, arguments); });
var context = canvas.getContext("2d");
var context = this.canvas.getContext("2d");
// Cast magic spells
var frameId = drawSpells(context, false, true, true);
var frameId = this.drawSpells(context, false, true, true);
}
}
draw();
};

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magic/index.html Normal file
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@ -0,0 +1,10 @@
---
layout: home
title: Tyler Hallada
---
<script>
window.onload = function () {
new Magic({{ site.data.magic | jsonify }}).draw();
}
</script>