/*
* 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 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 = '\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\
}';
return s;
}
testOutput = arrayToCanvasCommands(raytraceScene());
expected = '';
assertEq(testOutput, expected)