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<html>
<head>
<title>ExplorerCanvas Example 1</title>
<!--[if IE]><script type="text/javascript" src="../excanvas.js"></script><![endif]-->
<script type="text/javascript">
/* -------------------------------------------------------------------- */
var canvas, ctx;
var canvasWidth, halfCanvasWidth;
var canvasHeight, halfCanvasHeight;
var space; // 3D Engine
var scene; // 3D Scene
/* -------------------------------------------------------------------- */
/**
* Space is a simple 3D system.
*
* Y+ = up
* Z+ = into screen
* X+ = right
*/
function Space() {
this.m = this.createMatrixIdentity();
this.mStack = [];
}
Space.prototype.createMatrixIdentity = function() {
return [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]
];
}
/**
* Multiplies two 4x4 matricies together.
*/
Space.prototype.matrixMultiply = function(m1, m2) {
var result = this.createMatrixIdentity();
var width = m1[0].length;
var height = m1.length;
if (width != m2.length) {
// error
}
for (var x = 0; x < width; x++) {
for (var y = 0; y < height; y++) {
var sum = 0;
for (var z = 0; z < width; z++) {
sum += m1[y][z] * m2[z][x];
}
result[y][x] = sum;
}
}
return result;
}
/**
* Transforms a coordinate using the current transformation
* matrix, then flattens it using the projection matrix.
*/
Space.prototype.flatten = function(point) {
var p = [[point.x, point.y, point.z, 1]];
var pm = this.matrixMultiply(p, this.m);
point.tx = pm[0][0];
point.ty = pm[0][1];
point.tz = pm[0][2];
// lazy projection
point.fx = halfCanvasWidth + (canvasWidth * point.tx / point.tz);
point.fy = halfCanvasHeight -(canvasWidth * point.ty / point.tz);
}
/**
* Translate (move) the current transformation matrix
*/
Space.prototype.translate = function(x, y, z) {
var m = [
[1, 0, 0, 0],
[0, 1, 0, 0],
[0, 0, 1, 0],
[x, y, z, 1]
];
this.m = this.matrixMultiply(m, this.m);
}
/**
* Rotate the current transformation matrix. Rotations are
* world-oriented, and occur in y,x,z order.
*/
Space.prototype.rotate = function(x, y, z) {
if (y) {
var cosY = Math.cos(y);
var sinY = Math.sin(y);
var rotY = [
[cosY, 0, sinY, 0],
[0, 1, 0, 0],
[-sinY, 0, cosY, 0],
[0, 0, 0, 1]
];
this.m = this.matrixMultiply(this.m, rotY);
}
if (x) {
var cosX = Math.cos(x);
var sinX = Math.sin(x);
var rotX = [
[1, 0, 0, 0],
[0, cosX, -sinX, 0],
[0, sinX, cosX,0],
[0, 0, 0, 1]
];
this.m = this.matrixMultiply(this.m, rotX);
}
if (z) {
var cosZ = Math.cos(z);
var sinZ = Math.sin(z);
var rotZ = [
[cosZ, -sinZ, 0, 0],
[sinZ, cosZ, 0, 0],
[0, 0, 1, 0],
[0, 0, 0, 1]
];
this.m = this.matrixMultiply(this.m, rotZ);
}
}
/**
* Pushes the current transformation onto the stack
*/
Space.prototype.push = function() {
this.mStack.push(this.m);
this.m = [
[this.m[0][0], this.m[0][1], this.m[0][2], this.m[0][3]],
[this.m[1][0], this.m[1][1], this.m[1][2], this.m[1][3]],
[this.m[2][0], this.m[2][1], this.m[2][2], this.m[2][3]],
[this.m[3][0], this.m[3][1], this.m[3][2], this.m[3][3]]
];
}
/**
* Pops the end off the transformation stack
*/
Space.prototype.pop = function() {
this.m = this.mStack.pop();
}
/* -------------------------------------------------------------------- */
/**
* A 3d coordinate
*/
function Point(x, y, z) {
this.x = x;
this.y = y;
this.z = z;
// Relative to camera coordinates
this.tx;
this.ty;
this.tz;
// Flattened coordinates
this.fx;
this.fy;
}
/**
* A Shape is made up of polygons
*/
function Shape() {
this.points = [];
this.polygons = [];
}
/**
* Draws the shape
*/
Shape.prototype.draw = function(drawlist) {
for (var i = 0; i< this.points.length; i++) {
space.flatten(this.points[i]);
}
for (var i = 0; i< this.polygons.length; i++) {
var poly = this.polygons[i]; // convenience
space.flatten(poly.origin);
// lazy backface culling
if (poly.normal && this.backface) {
space.flatten(poly.normal);
var originDist = Math.pow(poly.origin.tx, 2)
+ Math.pow(poly.origin.ty, 2)
+ Math.pow(poly.origin.tz, 2);
var normalDist = Math.pow(poly.normal.tx, 2)
+ Math.pow(poly.normal.ty, 2)
+ Math.pow(poly.normal.tz, 2);
if(originDist > normalDist) {
drawlist.push(poly);
}
} else {
drawlist.push(poly);
}
}
}
/**
* A polygon is a connection of points in the shape object. You
* should probably try to make them coplanar.
*/
function Polygon(points, normal, backface, type, color) {
this.points = points;
this.origin = new Point(0, 0, 0);
for(var i = 0; i < this.points.length; i++) {
this.origin.x += this.points[i].x;
this.origin.y += this.points[i].y;
this.origin.z += this.points[i].z;
}
this.origin.x /= this.points.length;
this.origin.y /= this.points.length;
this.origin.z /= this.points.length;
if (normal) {
this.normal = new Point(this.origin.x + normal.x,
this.origin.y + normal.y,
this.origin.z + normal.z);
} else {
this.normal = null;
}
this.backface = backface;
this.type = type;
this.color = color;
}
Polygon.SOLID = 0;
Polygon.WIRE = 1;
/**
* Draws the polygon. Assumes that the points have already been
* flattened.
*/
Polygon.prototype.draw = function() {
ctx.beginPath();
ctx.moveTo(this.points[0].fx, this.points[0].fy);
for(var i = 0; i < this.points.length; i++) {
ctx.lineTo(this.points[i].fx, this.points[i].fy);
}
ctx.closePath();
var color = this.color;
/*
// Do lighting here
lightvector = Math.abs(this.normal.x + this.normal.y);
if(lightvector > 1) {
lightvector = 1;
}
color[0] = (color[0] * lightvector).toString();
color[1] = (color[1] * lightvector).toString();
color[2] = (color[2] * lightvector).toString();
*/
if (color.length > 3) {
var style = ["rgba(",
color[0], ",",
color[1], ",",
color[2], ",",
color[3], ")"].join("");
} else {
var style = ["rgb(",
color[0], ",",
color[1], ",",
color[2], ")"].join("");
}
if (this.type == Polygon.SOLID) {
ctx.fillStyle = style;
ctx.fill();
} else if (this.type == Polygon.WIRE) {
ctx.strokeStyle = style;
ctx.stroke();
}
}
/* -------------------------------------------------------------------- */
/**
* Scene describes the 3D environment
*/
function Scene() {
this.shapes = {};
this.camera = new Point(0, 0, 0);
this.cameraTarget = new Point(0, 0, 0);
this.cameraRotation = 0;
this.drawlist = [];
}
/**
* Dr
excanvas_r3.zip
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2018-07-30
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收藏 98KB ZIP 举报 
excanvas_r3.zip （44个子文件） 
testcases 
arc.html 883B stroke-scale-rotate.html 1KB quadraticcurve.html 1KB .svn tmp props prop-base text-base props 
all-wcprops 1KB entries 2KB prop-base overflow.html.svn-base 67B text-base arc.html.svn-base 883B gradient2.html.svn-base 874B saverestorepath.html.svn-base 858B gradient.html.svn-base 810B linewidth.html.svn-base 887B overflow.html.svn-base 651B resizing.html.svn-base 2KB stroke-scale-rotate.html.svn-base 1KB clearpath.html.svn-base 942B quadraticcurve.html.svn-base 1KB drawimage.html.svn-base 574B stroke-should-not-close-path.html.svn-base 629B format 2B stroke-should-not-close-path.html 629B clearpath.html 942B linewidth.html 887B drawimage.html 574B gradient2.html 874B saverestorepath.html 858B overflow.html 687B gradient.html 810B resizing.html 2KB AUTHORS 205B COPYING 11KB excanvas.compiled.js 11KB examples example2.html 12KB .svn tmp props prop-base text-base props all-wcprops 468B entries 857B prop-base ff.jpg.svn-base 53B text-base example3.html.svn-base 7KB example1.html.svn-base 2KB ff.jpg.svn-base 25KB example2.html.svn-base 12KB format 2B example3.html 7KB
ff.jpg 25KB example1.html 2KB excanvas.js 26KB资源评论
wode02392019-05-23可以用，兼容了
jacksondq2019-01-21可以用，兼容了
