Creating An HTML5 3D Cube Slideshow
Today’s tutorial I’ll be featuring is from Andrew of Script Tutorials. It’s an animated 3D Cube slideshow which makes the cube rotates continuously.
Below are the codes to follow:
HTML
Index.html
<!DOCTYPE html> <html lang="en" > <head> <meta charset="utf-8" /> <title>HTML5 3D Cube Slideshow | Script Tutorials</title> <link href="css/main.css" rel="stylesheet" type="text/css" /> <script src="js/script.js"></script> </head> <body> <header> <h2>HTML5 3D Cube Slideshow</h2> <a href="http://www.script-tutorials.com/html5-3d-cube-slideshow/">Back to original tutorial on <span>Script Tutorials</span></a> </header> <canvas id="slideshow" width="1280" height="800"></canvas> </body> </html>
CSS
The CSS file is available on the package and you can download it HERE.
JavaScript
Js/script.js
var canvas, ctx;
var aImages = [];
var points = [];
var triangles = [];
var textureWidth, textureHeight;
var lev = 3;
var angle = 0;
// scene vertices
var vertices = [
new Point3D(-2,-1,2),
new Point3D(2,-1,2),
new Point3D(2,1,2),
new Point3D(-2,1,2),
new Point3D(-2,-1,-2),
new Point3D(2,-1,-2),
new Point3D(2,1,-2),
new Point3D(-2,1,-2)
];
// scene faces (6 faces)
var faces = [[0,1,2,3],[1,5,6,2],[5,4,7,6],[4,0,3,7],[0,4,5,1],[3,2,6,7]];
function Point3D(x,y,z) {
this.x = x;
this.y = y;
this.z = z;
this.rotateX = function(angle) {
var rad, cosa, sina, y, z
rad = angle * Math.PI / 180
cosa = Math.cos(rad)
sina = Math.sin(rad)
y = this.y * cosa - this.z * sina
z = this.y * sina + this.z * cosa
return new Point3D(this.x, y, z)
}
this.rotateY = function(angle) {
var rad, cosa, sina, x, z
rad = angle * Math.PI / 180
cosa = Math.cos(rad)
sina = Math.sin(rad)
z = this.z * cosa - this.x * sina
x = this.z * sina + this.x * cosa
return new Point3D(x,this.y, z)
}
this.rotateZ = function(angle) {
var rad, cosa, sina, x, y
rad = angle * Math.PI / 180
cosa = Math.cos(rad)
sina = Math.sin(rad)
x = this.x * cosa - this.y * sina
y = this.x * sina + this.y * cosa
return new Point3D(x, y, this.z)
}
this.projection = function(viewWidth, viewHeight, fov, viewDistance) {
var factor, x, y
factor = fov / (viewDistance + this.z)
x = this.x * factor + viewWidth / 2
y = this.y * factor + viewHeight / 2
return new Point3D(x, y, this.z)
}
}
// array of photos
var aImgs = [
'images/pic1.jpg',
'images/pic2.jpg',
'images/pic3.jpg',
'images/pic4.jpg'
];
for (var i = 0; i < aImgs.length; i++) {
var oImg = new Image();
oImg.src = aImgs[i];
aImages.push(oImg);
oImg.onload = function () {
textureWidth = oImg.width;
textureHeight = oImg.height;
}
}
window.onload = function(){
// creating canvas objects
canvas = document.getElementById('slideshow');
ctx = canvas.getContext('2d');
// prepare points
for (var i = 0; i <= lev; i++) {
for (var j = 0; j <= lev; j++) {
var tx = (i * (textureWidth / lev));
var ty = (j * (textureHeight / lev));
points.push({
tx: tx,
ty: ty,
nx: tx / textureWidth,
ny: ty / textureHeight,
ox: i,
oy: j
});
}
}
// prepare triangles ----
var levT = lev + 1;
for (var i = 0; i < lev; i++) {
for (var j = 0; j < lev; j++) {
triangles.push({
p0: points[j + i * levT],
p1: points[j + i * levT + 1],
p2: points[j + (i + 1) * levT],
up: true
});
triangles.push({
p0: points[j + (i + 1) * levT + 1],
p1: points[j + (i + 1) * levT],
p2: points[j + i * levT + 1],
up: false
});
}
}
drawScene();
};
function drawScene() {
// clear context
ctx.clearRect(0, 0, ctx.canvas.width, ctx.canvas.height);
// rotate scene
var t = new Array();
for (var iv = 0; iv < vertices.length; iv++) {
var v = vertices[iv];
var r = v.rotateY(angle);
//var r = v.rotateX(angle).rotateY(angle);
var prj = r.projection(ctx.canvas.width, ctx.canvas.height, 1000, 3);
t.push(prj)
}
var avg_z = new Array();
for (var i = 0; i < faces.length; i++) {
var f = faces[i];
avg_z[i] = {"ind":i, "z":(t[f[0]].z + t[f[1]].z + t[f[2]].z + t[f[3]].z) / 4.0};
}
// get around through all faces
for (var i = 0; i < faces.length; i++) {
var f = faces[avg_z[i].ind];
if (t[f[3]].z+t[f[2]].z+t[f[1]].z+t[f[0]].z > -3) {
ctx.save();
// draw surfaces
ctx.fillStyle = "rgb(160,180,160)";
ctx.beginPath();
ctx.moveTo(t[f[0]].x,t[f[0]].y);
ctx.lineTo(t[f[1]].x,t[f[1]].y);
ctx.lineTo(t[f[2]].x,t[f[2]].y);
ctx.lineTo(t[f[3]].x,t[f[3]].y);
ctx.closePath();
ctx.fill();
// draw stretched images
if (i < 4) {
var ip = points.length;
while (--ip > -1) {
var p = points[ip];
var mx = t[f[0]].x + p.ny * (t[f[3]].x - t[f[0]].x);
var my = t[f[0]].y + p.ny * (t[f[3]].y - t[f[0]].y);
p.px = (mx + p.nx * (t[f[1]].x + p.ny * (t[f[2]].x - t[f[1]].x) - mx)) + p.ox;
p.py = (my + p.nx * (t[f[1]].y + p.ny * (t[f[2]].y - t[f[1]].y) - my)) + p.oy;
}
var n = triangles.length;
while (--n > -1) {
var tri = triangles[n];
var p0 = tri.p0;
var p1 = tri.p1;
var p2 = tri.p2;
var xc = (p0.px + p1.px + p2.px) / 3;
var yc = (p0.py + p1.py + p2.py) / 3;
ctx.save();
ctx.beginPath();
ctx.moveTo((1.05 * p0.px - xc * 0.05), (1.05 * p0.py - yc * 0.05));
ctx.lineTo((1.05 * p1.px - xc * 0.05), (1.05 * p1.py - yc * 0.05));
ctx.lineTo((1.05 * p2.px - xc * 0.05), (1.05 * p2.py - yc * 0.05));
ctx.closePath();
ctx.clip();
// transformation
var d = p0.tx * (p2.ty - p1.ty) - p1.tx * p2.ty + p2.tx * p1.ty + (p1.tx - p2.tx) * p0.ty;
ctx.transform(
-(p0.ty * (p2.px - p1.px) - p1.ty * p2.px + p2.ty * p1.px + (p1.ty - p2.ty) * p0.px) / d, // m11
(p1.ty * p2.py + p0.ty * (p1.py - p2.py) - p2.ty * p1.py + (p2.ty - p1.ty) * p0.py) / d, // m12
(p0.tx * (p2.px - p1.px) - p1.tx * p2.px + p2.tx * p1.px + (p1.tx - p2.tx) * p0.px) / d, // m21
-(p1.tx * p2.py + p0.tx * (p1.py - p2.py) - p2.tx * p1.py + (p2.tx - p1.tx) * p0.py) / d, // m22
(p0.tx * (p2.ty * p1.px - p1.ty * p2.px) + p0.ty * (p1.tx * p2.px - p2.tx * p1.px) + (p2.tx * p1.ty - p1.tx * p2.ty) * p0.px) / d, // dx
(p0.tx * (p2.ty * p1.py - p1.ty * p2.py) + p0.ty * (p1.tx * p2.py - p2.tx * p1.py) + (p2.tx * p1.ty - p1.tx * p2.ty) * p0.py) / d // dy
);
ctx.drawImage(aImages[i], 0, 0);
ctx.restore();
}
}
}
}
// shift angle and redraw scene
angle += 0.3;
setTimeout(drawScene, 40);
}
Check out Andrew’s cool demo.
To know more about this awesome feature, click on the image.
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