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/*↩
* Copyright (C) 2007 Apple Inc. All rights reserved.↩
*↩
* Redistribution and use in source and binary forms, with or without↩
* modification, are permitted provided that the following conditions↩
* are met:↩
* 1. Redistributions of source code must retain the above copyright↩
* notice, this list of conditions and the following disclaimer.↩
* 2. Redistributions in binary form must reproduce the above copyright↩
* notice, this list of conditions and the following disclaimer in the↩
* documentation and/or other materials provided with the distribution.↩
*↩
* THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY↩
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE↩
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR↩
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR↩
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,↩
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,↩
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR↩
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY↩
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT↩
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE↩
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. ↩
*/↩
↩
function createVector(x,y,z) {↩
return new Array(x,y,z);↩
}↩
↩
function sqrLengthVector(self) {↩
return self[0] * self[0] + self[1] * self[1] + self[2] * self[2];↩
}↩
↩
function lengthVector(self) {↩
return Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]);↩
}↩
↩
function addVector(self, v) {↩
self[0] += v[0];↩
self[1] += v[1];↩
self[2] += v[2];↩
return self;↩
}↩
↩
function subVector(self, v) {↩
self[0] -= v[0];↩
self[1] -= v[1];↩
self[2] -= v[2];↩
return self;↩
}↩
↩
function scaleVector(self, scale) {↩
self[0] *= scale;↩
self[1] *= scale;↩
self[2] *= scale;↩
return self;↩
}↩
↩
function normaliseVector(self) {↩
var len = Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]);↩
self[0] /= len;↩
self[1] /= len;↩
self[2] /= len;↩
return self;↩
}↩
↩
function add(v1, v2) {↩
return new Array(v1[0] + v2[0], v1[1] + v2[1], v1[2] + v2[2]);↩
}↩
↩
function sub(v1, v2) {↩
return new Array(v1[0] - v2[0], v1[1] - v2[1], v1[2] - v2[2]);↩
}↩
↩
function scalev(v1, v2) {↩
return new Array(v1[0] * v2[0], v1[1] * v2[1], v1[2] * v2[2]);↩
}↩
↩
function dot(v1, v2) {↩
return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2];↩
}↩
↩
function scale(v, scale) {↩
return [v[0] * scale, v[1] * scale, v[2] * scale];↩
}↩
↩
function cross(v1, v2) {↩
return [v1[1] * v2[2] - v1[2] * v2[1], ↩
v1[2] * v2[0] - v1[0] * v2[2],↩
v1[0] * v2[1] - v1[1] * v2[0]];↩
↩
}↩
↩
function normalise(v) {↩
var len = lengthVector(v);↩
return [v[0] / len, v[1] / len, v[2] / len];↩
}↩
↩
function transformMatrix(self, v) {↩
var vals = self;↩
var x = vals[0] * v[0] + vals[1] * v[1] + vals[2] * v[2] + vals[3];↩
var y = vals[4] * v[0] + vals[5] * v[1] + vals[6] * v[2] + vals[7];↩
var z = vals[8] * v[0] + vals[9] * v[1] + vals[10] * v[2] + vals[11];↩
return [x, y, z];↩
}↩
↩
function invertMatrix(self) {↩
var temp = new Array(16);↩
var tx = -self[3];↩
var ty = -self[7];↩
var tz = -self[11];↩
for (h = 0; h < 3; h++) ↩
for (v = 0; v < 3; v++) ↩
temp[h + v * 4] = self[v + h * 4];↩
for (i = 0; i < 11; i++)↩
self[i] = temp[i];↩
self[3] = tx * self[0] + ty * self[1] + tz * self[2];↩
self[7] = tx * self[4] + ty * self[5] + tz * self[6];↩
self[11] = tx * self[8] + ty * self[9] + tz * self[10];↩
return self;↩
}↩
↩
↩
// Triangle intersection using barycentric coord method↩
function Triangle(p1, p2, p3) {↩
var edge1 = sub(p3, p1);↩
var edge2 = sub(p2, p1);↩
var normal = cross(edge1, edge2);↩
if (Math.abs(normal[0]) > Math.abs(normal[1]))↩
if (Math.abs(normal[0]) > Math.abs(normal[2]))↩
this.axis = 0; ↩
else ↩
this.axis = 2;↩
else↩
if (Math.abs(normal[1]) > Math.abs(normal[2])) ↩
this.axis = 1;↩
else ↩
this.axis = 2;↩
var u = (this.axis + 1) % 3;↩
var v = (this.axis + 2) % 3;↩
var u1 = edge1[u];↩
var v1 = edge1[v];↩
↩
var u2 = edge2[u];↩
var v2 = edge2[v];↩
this.normal = normalise(normal);↩
this.nu = normal[u] / normal[this.axis];↩
this.nv = normal[v] / normal[this.axis];↩
this.nd = dot(normal, p1) / normal[this.axis];↩
var det = u1 * v2 - v1 * u2;↩
this.eu = p1[u];↩
this.ev = p1[v]; ↩
this.nu1 = u1 / det;↩
this.nv1 = -v1 / det;↩
this.nu2 = v2 / det;↩
this.nv2 = -u2 / det; ↩
this.material = [0.7, 0.7, 0.7];↩
}↩
↩
Triangle.prototype.intersect = function(orig, dir, near, far) {↩
var u = (this.axis + 1) % 3;↩
var v = (this.axis + 2) % 3;↩
var d = dir[this.axis] + this.nu * dir[u] + this.nv * dir[v];↩
var t = (this.nd - orig[this.axis] - this.nu * orig[u] - this.nv * orig[v]) / d;↩
if (t < near || t > far)↩
return null;↩
var Pu = orig[u] + t * dir[u] - this.eu;↩
var Pv = orig[v] + t * dir[v] - this.ev;↩
var a2 = Pv * this.nu1 + Pu * this.nv1;↩
if (a2 < 0) ↩
return null;↩
var a3 = Pu * this.nu2 + Pv * this.nv2;↩
if (a3 < 0) ↩
return null;↩
↩
if ((a2 + a3) > 1) ↩
return null;↩
return t;↩
}↩
↩
function Scene(a_triangles) {↩
this.triangles = a_triangles;↩
this.lights = [];↩
this.ambient = [0,0,0];↩
this.background = [0.8,0.8,1];↩
}↩
var zero = new Array(0,0,0);↩
↩
Scene.prototype.intersect = function(origin, dir, near, far) {↩
var closest = null;↩
for (i = 0; i < this.triangles.length; i++) {↩
var triangle = this.triangles[i]; ↩
var d = triangle.intersect(origin, dir, near, far);↩
if (d == null || d > far || d < near)↩
continue;↩
far = d;↩
closest = triangle;↩
}↩
↩
if (!closest)↩
return [this.background[0],this.background[1],this.background[2]];↩
↩
var normal = closest.normal;↩
var hit = add(origin, scale(dir, far)); ↩
if (dot(dir, normal) > 0)↩
normal = [-normal[0], -normal[1], -normal[2]];↩
↩
var colour = null;↩
if (closest.shader) {↩
colour = closest.shader(closest, hit, dir);↩
} else {↩
colour = closest.material;↩
}↩
↩
// do reflection↩
var reflected = null;↩
if (colour.reflection > 0.001) {↩
var reflection = addVector(scale(normal, -2*dot(dir, normal)), dir);↩
reflected = this.intersect(hit, reflection, 0.0001, 1000000);↩
if (colour.reflection >= 0.999999)↩
return reflected;↩
}↩
↩
var l = [this.ambient[0], this.ambient[1], this.ambient[2]];↩
for (var i = 0; i < this.lights.length; i++) {↩
var light = this.lights[i];↩
var toLight = sub(light, hit);↩
var distance = lengthVector(toLight);↩
scaleVector(toLight, 1.0/distance);↩
distance -= 0.0001;↩
if (this.blocked(hit, toLight, distance))↩
continue;↩
var nl = dot(normal, toLight);↩
if (nl > 0)↩
addVector(l, scale(light.colour, nl));↩
}↩
l = scalev(l, colour);↩
if (reflected) {↩
l = addVector(scaleVector(l, 1 - colour.reflection), scaleVector(reflected, colour.reflection));↩
}↩
return l;↩
}↩
↩
Scene.prototype.blocked = function(O, D, far) {↩
var near = 0.0001;↩
var closest = null;↩
for (i = 0; i < this.triangles.length; i++) {↩
var triangle = this.triangles[i]; ↩
var d = triangle.intersect(O, D, near, far);↩
if (d == null || d > far || d < near)↩
continue;↩
return true;↩
}↩
↩
return false;↩
}↩
↩
↩
// this camera code is from notes i made ages ago, it is from *somewhere* -- i cannot remember where↩
// that somewhere is↩
function Camera(origin, lookat, up) {↩
var zaxis = normaliseVector(subVector(lookat, origin));↩
var xaxis = normaliseVector(cross(up, zaxis));↩
var yaxis = normaliseVector(cross(xaxis, subVector([0,0,0], zaxis)));↩
var m = new Array(16);↩
m[0] = xaxis[0]; m[1] = xaxis[1]; m[2] = xaxis[2];↩
m[4] = yaxis[0]; m[5] = yaxis[1]; m[6] = yaxis[2];↩
m[8] = zaxis[0]; m[9] = zaxis[1]; m[10] = zaxis[2];↩
invertMatrix(m);↩
m[3] = 0; m[7] = 0; m[11] = 0;↩
this.origin = origin;↩
this.directions = new Array(4);↩
this.directions[0] = normalise([-0.7, 0.7, 1]);↩
this.directions[1] = normalise([ 0.7, 0.7, 1]);↩
this.directions[2] = normalise([ 0.7, -0.7, 1]);↩
this.directions[3] = normalise([-0.7, -0.7, 1]);↩
this.directions[0] = transformMatrix(m, this.directions[0]);↩
this.directions[1] = transformMatrix(m, this.directions[1]);↩
this.directions[2] = transformMatrix(m, this.directions[2]);↩
this.directions[3] = transformMatrix(m, this.directions[3]);↩
}↩
↩
Camera.prototype.generateRayPair = function(y) {↩
rays = new Array(new Object(), new Object());↩
rays[0].origin = this.origin;↩
rays[1].origin = this.origin;↩
rays[0].dir = addVector(scale(this.directions[0], y), scale(this.directions[3], 1 - y));↩
rays[1].dir = addVector(scale(this.directions[1], y), scale(this.directions[2], 1 - y));↩
return rays;↩
}↩
↩
function renderRows(camera, scene, pixels, width, height, starty, stopy) {↩
for (var y = starty; y < stopy; y++) {↩
var rays = camera.generateRayPair(y / height);↩
for (var x = 0; x < width; x++) {↩
var xp = x / width;↩
var origin = addVector(scale(rays[0].origin, xp), scale(rays[1].origin, 1 - xp));↩
var dir = normaliseVector(addVector(scale(rays[0].dir, xp), scale(rays[1].dir, 1 - xp)));↩
var l = scene.intersect(origin, dir);↩
pixels[y][x] = l;↩
}↩
}↩
}↩
↩
Camera.prototype.render = function(scene, pixels, width, height) {↩
var cam = this;↩
var row = 0;↩
renderRows(cam, scene, pixels, width, height, 0, height);↩
}↩
↩
↩
↩
function raytraceScene()↩
{↩
var startDate = new Date().getTime();↩
var numTriangles = 2 * 6;↩
var triangles = new Array();//numTriangles);↩
var tfl = createVector(-10, 10, -10);↩
var tfr = createVector( 10, 10, -10);↩
var tbl = createVector(-10, 10, 10);↩
var tbr = createVector( 10, 10, 10);↩
var bfl = createVector(-10, -10, -10);↩
var bfr = createVector( 10, -10, -10);↩
var bbl = createVector(-10, -10, 10);↩
var bbr = createVector( 10, -10, 10);↩
↩
// cube!!!↩
// front↩
var i = 0;↩
↩
triangles[i++] = new Triangle(tfl, tfr, bfr);↩
triangles[i++] = new Triangle(tfl, bfr, bfl);↩
// back↩
triangles[i++] = new Triangle(tbl, tbr, bbr);↩
triangles[i++] = new Triangle(tbl, bbr, bbl);↩
// triangles[i-1].material = [0.7,0.2,0.2];↩
// triangles[i-1].material.reflection = 0.8;↩
// left↩
triangles[i++] = new Triangle(tbl, tfl, bbl);↩
// triangles[i-1].reflection = 0.6;↩
triangles[i++] = new Triangle(tfl, bfl, bbl);↩
// triangles[i-1].reflection = 0.6;↩
// right↩
triangles[i++] = new Triangle(tbr, tfr, bbr);↩
triangles[i++] = new Triangle(tfr, bfr, bbr);↩
// top↩
triangles[i++] = new Triangle(tbl, tbr, tfr);↩
triangles[i++] = new Triangle(tbl, tfr, tfl);↩
// bottom↩
triangles[i++] = new Triangle(bbl, bbr, bfr);↩
triangles[i++] = new Triangle(bbl, bfr, bfl);↩
↩
//Floor!!!!↩
var green = createVector(0.0, 0.4, 0.0);↩
var grey = createVector(0.4, 0.4, 0.4);↩
grey.reflection = 1.0;↩
var floorShader = function(tri, pos, view) {↩
var x = ((pos[0]/32) % 2 + 2) % 2;↩
var z = ((pos[2]/32 + 0.3) % 2 + 2) % 2;↩
if (x < 1 != z < 1) {↩
//in the real world we use the fresnel term...↩
// var angle = 1-dot(view, tri.normal);↩
// angle *= angle;↩
// angle *= angle;↩
// angle *= angle;↩
//grey.reflection = angle;↩
return grey;↩
} else ↩
return green;↩
}↩
var ffl = createVector(-1000, -30, -1000);↩
var ffr = createVector( 1000, -30, -1000);↩
var fbl = createVector(-1000, -30, 1000);↩
var fbr = createVector( 1000, -30, 1000);↩
triangles[i++] = new Triangle(fbl, fbr, ffr);↩
triangles[i-1].shader = floorShader;↩
triangles[i++] = new Triangle(fbl, ffr, ffl);↩
triangles[i-1].shader = floorShader;↩
↩
var _scene = new Scene(triangles);↩
_scene.lights[0] = createVector(20, 38, -22);↩
_scene.lights[0].colour = createVector(0.7, 0.3, 0.3);↩
_scene.lights[1] = createVector(-23, 40, 17);↩
_scene.lights[1].colour = createVector(0.7, 0.3, 0.3);↩
_scene.lights[2] = createVector(23, 20, 17);↩
_scene.lights[2].colour = createVector(0.7, 0.7, 0.7);↩
_scene.ambient = createVector(0.1, 0.1, 0.1);↩
// _scene.background = createVector(0.7, 0.7, 1.0);↩
↩
var size = 30;↩
var pixels = new Array();↩
for (var y = 0; y < size; y++) {↩
pixels[y] = new Array();↩
for (var x = 0; x < size; x++) {↩
pixels[y][x] = 0;↩
}↩
}↩
↩
var _camera = new Camera(createVector(-40, 40, 40), createVector(0, 0, 0), createVector(0, 1, 0));↩
_camera.render(_scene, pixels, size, size);↩
↩
return pixels;↩
}↩
↩
function arrayToCanvasCommands(pixels)↩
{↩
var s = '<canvas id="renderCanvas" width="30px" height="30px"></canvas><scr' + 'ipt>\nvar pixels = [';↩
var size = 30;↩
for (var y = 0; y < size; y++) {↩
s += "[";↩
for (var x = 0; x < size; x++) {↩
s += "[" + pixels[y][x] + "],";↩
}↩
s+= "],";↩
}↩
s += '];\n var canvas = document.getElementById("renderCanvas").getContext("2d");\n\↩
\n\↩
\n\↩
var size = 30;\n\↩
canvas.fillStyle = "red";\n\↩
canvas.fillRect(0, 0, size, size);\n\↩
canvas.scale(1, -1);\n\↩
canvas.translate(0, -size);\n\↩
\n\↩
if (!canvas.setFillColor)\n\↩
canvas.setFillColor = function(r, g, b, a) {\n\↩
this.fillStyle = "rgb("+[Math.floor(r * 255), Math.floor(g * 255), Math.floor(b * 255)]+")";\n\↩
}\n\↩
\n\↩
for (var y = 0; y < size; y++) {\n\↩
for (var x = 0; x < size; x++) {\n\↩
var l = pixels[y][x];\n\↩
canvas.setFillColor(l[0], l[1], l[2], 1);\n\↩
canvas.fillRect(x, y, 1, 1);\n\↩
}\n\↩
}</scr' + 'ipt>';↩
↩
return s;↩
}↩
↩
testOutput = arrayToCanvasCommands(raytraceScene());↩