1 /* 2 * Copyright (C) 2007 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY 14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR 17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, 19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR 20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY 21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26 function createVector(x,y,z) { 27 return new Array(x,y,z); 28 } 29 30 function sqrLengthVector(self) { 31 return self[0] * self[0] + self[1] * self[1] + self[2] * self[2]; 32 } 33 34 function lengthVector(self) { 35 return Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]); 36 } 37 38 function addVector(self, v) { 39 self[0] += v[0]; 40 self[1] += v[1]; 41 self[2] += v[2]; 42 return self; 43 } 44 45 function subVector(self, v) { 46 self[0] -= v[0]; 47 self[1] -= v[1]; 48 self[2] -= v[2]; 49 return self; 50 } 51 52 function scaleVector(self, scale) { 53 self[0] *= scale; 54 self[1] *= scale; 55 self[2] *= scale; 56 return self; 57 } 58 59 function normaliseVector(self) { 60 var len = Math.sqrt(self[0] * self[0] + self[1] * self[1] + self[2] * self[2]); 61 self[0] /= len; 62 self[1] /= len; 63 self[2] /= len; 64 return self; 65 } 66 67 function add(v1, v2) { 68 return new Array(v1[0] + v2[0], v1[1] + v2[1], v1[2] + v2[2]); 69 } 70 71 function sub(v1, v2) { 72 return new Array(v1[0] - v2[0], v1[1] - v2[1], v1[2] - v2[2]); 73 } 74 75 function scalev(v1, v2) { 76 return new Array(v1[0] * v2[0], v1[1] * v2[1], v1[2] * v2[2]); 77 } 78 79 function dot(v1, v2) { 80 return v1[0] * v2[0] + v1[1] * v2[1] + v1[2] * v2[2]; 81 } 82 83 function scale(v, scale) { 84 return [v[0] * scale, v[1] * scale, v[2] * scale]; 85 } 86 87 function cross(v1, v2) { 88 return [v1[1] * v2[2] - v1[2] * v2[1], 89 v1[2] * v2[0] - v1[0] * v2[2], 90 v1[0] * v2[1] - v1[1] * v2[0]]; 91 92 } 93 94 function normalise(v) { 95 var len = lengthVector(v); 96 return [v[0] / len, v[1] / len, v[2] / len]; 97 } 98 99 function transformMatrix(self, v) { 100 var vals = self; 101 var x = vals[0] * v[0] + vals[1] * v[1] + vals[2] * v[2] + vals[3]; 102 var y = vals[4] * v[0] + vals[5] * v[1] + vals[6] * v[2] + vals[7]; 103 var z = vals[8] * v[0] + vals[9] * v[1] + vals[10] * v[2] + vals[11]; 104 return [x, y, z]; 105 } 106 107 function invertMatrix(self) { 108 var temp = new Array(16); 109 var tx = -self[3]; 110 var ty = -self[7]; 111 var tz = -self[11]; 112 for (h = 0; h < 3; h++) 113 for (v = 0; v < 3; v++) 114 temp[h + v * 4] = self[v + h * 4]; 115 for (i = 0; i < 11; i++) 116 self[i] = temp[i]; 117 self[3] = tx * self[0] + ty * self[1] + tz * self[2]; 118 self[7] = tx * self[4] + ty * self[5] + tz * self[6]; 119 self[11] = tx * self[8] + ty * self[9] + tz * self[10]; 120 return self; 121 } 122 123 124 // Triangle intersection using barycentric coord method 125 function Triangle(p1, p2, p3) { 126 var edge1 = sub(p3, p1); 127 var edge2 = sub(p2, p1); 128 var normal = cross(edge1, edge2); 129 if (Math.abs(normal[0]) > Math.abs(normal[1])) 130 if (Math.abs(normal[0]) > Math.abs(normal[2])) 131 this.axis = 0; 132 else 133 this.axis = 2; 134 else 135 if (Math.abs(normal[1]) > Math.abs(normal[2])) 136 this.axis = 1; 137 else 138 this.axis = 2; 139 var u = (this.axis + 1) % 3; 140 var v = (this.axis + 2) % 3; 141 var u1 = edge1[u]; 142 var v1 = edge1[v]; 143 144 var u2 = edge2[u]; 145 var v2 = edge2[v]; 146 this.normal = normalise(normal); 147 this.nu = normal[u] / normal[this.axis]; 148 this.nv = normal[v] / normal[this.axis]; 149 this.nd = dot(normal, p1) / normal[this.axis]; 150 var det = u1 * v2 - v1 * u2; 151 this.eu = p1[u]; 152 this.ev = p1[v]; 153 this.nu1 = u1 / det; 154 this.nv1 = -v1 / det; 155 this.nu2 = v2 / det; 156 this.nv2 = -u2 / det; 157 this.material = [0.7, 0.7, 0.7]; 158 } 159 160 Triangle.prototype.intersect = function(orig, dir, near, far) { 161 var u = (this.axis + 1) % 3; 162 var v = (this.axis + 2) % 3; 163 var d = dir[this.axis] + this.nu * dir[u] + this.nv * dir[v]; 164 var t = (this.nd - orig[this.axis] - this.nu * orig[u] - this.nv * orig[v]) / d; 165 if (t < near || t > far) 166 return null; 167 var Pu = orig[u] + t * dir[u] - this.eu; 168 var Pv = orig[v] + t * dir[v] - this.ev; 169 var a2 = Pv * this.nu1 + Pu * this.nv1; 170 if (a2 < 0) 171 return null; 172 var a3 = Pu * this.nu2 + Pv * this.nv2; 173 if (a3 < 0) 174 return null; 175 176 if ((a2 + a3) > 1) 177 return null; 178 return t; 179 } 180 181 function Scene(a_triangles) { 182 this.triangles = a_triangles; 183 this.lights = []; 184 this.ambient = [0,0,0]; 185 this.background = [0.8,0.8,1]; 186 } 187 var zero = new Array(0,0,0); 188 189 Scene.prototype.intersect = function(origin, dir, near, far) { 190 var closest = null; 191 for (i = 0; i < this.triangles.length; i++) { 192 var triangle = this.triangles[i]; 193 var d = triangle.intersect(origin, dir, near, far); 194 if (d == null || d > far || d < near) 195 continue; 196 far = d; 197 closest = triangle; 198 } 199 200 if (!closest) 201 return [this.background[0],this.background[1],this.background[2]]; 202 203 var normal = closest.normal; 204 var hit = add(origin, scale(dir, far)); 205 if (dot(dir, normal) > 0) 206 normal = [-normal[0], -normal[1], -normal[2]]; 207 208 var colour = null; 209 if (closest.shader) { 210 colour = closest.shader(closest, hit, dir); 211 } else { 212 colour = closest.material; 213 } 214 215 // do reflection 216 var reflected = null; 217 if (colour.reflection > 0.001) { 218 var reflection = addVector(scale(normal, -2*dot(dir, normal)), dir); 219 reflected = this.intersect(hit, reflection, 0.0001, 1000000); 220 if (colour.reflection >= 0.999999) 221 return reflected; 222 } 223 224 var l = [this.ambient[0], this.ambient[1], this.ambient[2]]; 225 for (var i = 0; i < this.lights.length; i++) { 226 var light = this.lights[i]; 227 var toLight = sub(light, hit); 228 var distance = lengthVector(toLight); 229 scaleVector(toLight, 1.0/distance); 230 distance -= 0.0001; 231 if (this.blocked(hit, toLight, distance)) 232 continue; 233 var nl = dot(normal, toLight); 234 if (nl > 0) 235 addVector(l, scale(light.colour, nl)); 236 } 237 l = scalev(l, colour); 238 if (reflected) { 239 l = addVector(scaleVector(l, 1 - colour.reflection), scaleVector(reflected, colour.reflection)); 240 } 241 return l; 242 } 243 244 Scene.prototype.blocked = function(O, D, far) { 245 var near = 0.0001; 246 var closest = null; 247 for (i = 0; i < this.triangles.length; i++) { 248 var triangle = this.triangles[i]; 249 var d = triangle.intersect(O, D, near, far); 250 if (d == null || d > far || d < near) 251 continue; 252 return true; 253 } 254 255 return false; 256 } 257 258 259 // this camera code is from notes i made ages ago, it is from *somewhere* -- i cannot remember where 260 // that somewhere is 261 function Camera(origin, lookat, up) { 262 var zaxis = normaliseVector(subVector(lookat, origin)); 263 var xaxis = normaliseVector(cross(up, zaxis)); 264 var yaxis = normaliseVector(cross(xaxis, subVector([0,0,0], zaxis))); 265 var m = new Array(16); 266 m[0] = xaxis[0]; m[1] = xaxis[1]; m[2] = xaxis[2]; 267 m[4] = yaxis[0]; m[5] = yaxis[1]; m[6] = yaxis[2]; 268 m[8] = zaxis[0]; m[9] = zaxis[1]; m[10] = zaxis[2]; 269 invertMatrix(m); 270 m[3] = 0; m[7] = 0; m[11] = 0; 271 this.origin = origin; 272 this.directions = new Array(4); 273 this.directions[0] = normalise([-0.7, 0.7, 1]); 274 this.directions[1] = normalise([ 0.7, 0.7, 1]); 275 this.directions[2] = normalise([ 0.7, -0.7, 1]); 276 this.directions[3] = normalise([-0.7, -0.7, 1]); 277 this.directions[0] = transformMatrix(m, this.directions[0]); 278 this.directions[1] = transformMatrix(m, this.directions[1]); 279 this.directions[2] = transformMatrix(m, this.directions[2]); 280 this.directions[3] = transformMatrix(m, this.directions[3]); 281 } 282 283 Camera.prototype.generateRayPair = function(y) { 284 rays = new Array(new Object(), new Object()); 285 rays[0].origin = this.origin; 286 rays[1].origin = this.origin; 287 rays[0].dir = addVector(scale(this.directions[0], y), scale(this.directions[3], 1 - y)); 288 rays[1].dir = addVector(scale(this.directions[1], y), scale(this.directions[2], 1 - y)); 289 return rays; 290 } 291 292 function renderRows(camera, scene, pixels, width, height, starty, stopy) { 293 for (var y = starty; y < stopy; y++) { 294 var rays = camera.generateRayPair(y / height); 295 for (var x = 0; x < width; x++) { 296 var xp = x / width; 297 var origin = addVector(scale(rays[0].origin, xp), scale(rays[1].origin, 1 - xp)); 298 var dir = normaliseVector(addVector(scale(rays[0].dir, xp), scale(rays[1].dir, 1 - xp))); 299 var l = scene.intersect(origin, dir); 300 pixels[y][x] = l; 301 } 302 } 303 } 304 305 Camera.prototype.render = function(scene, pixels, width, height) { 306 var cam = this; 307 var row = 0; 308 renderRows(cam, scene, pixels, width, height, 0, height); 309 } 310 311 312 313 function raytraceScene() 314 { 315 var startDate = new Date().getTime(); 316 var numTriangles = 2 * 6; 317 var triangles = new Array();//numTriangles); 318 var tfl = createVector(-10, 10, -10); 319 var tfr = createVector( 10, 10, -10); 320 var tbl = createVector(-10, 10, 10); 321 var tbr = createVector( 10, 10, 10); 322 var bfl = createVector(-10, -10, -10); 323 var bfr = createVector( 10, -10, -10); 324 var bbl = createVector(-10, -10, 10); 325 var bbr = createVector( 10, -10, 10); 326 327 // cube!!! 328 // front 329 var i = 0; 330 331 triangles[i++] = new Triangle(tfl, tfr, bfr); 332 triangles[i++] = new Triangle(tfl, bfr, bfl); 333 // back 334 triangles[i++] = new Triangle(tbl, tbr, bbr); 335 triangles[i++] = new Triangle(tbl, bbr, bbl); 336 // triangles[i-1].material = [0.7,0.2,0.2]; 337 // triangles[i-1].material.reflection = 0.8; 338 // left 339 triangles[i++] = new Triangle(tbl, tfl, bbl); 340 // triangles[i-1].reflection = 0.6; 341 triangles[i++] = new Triangle(tfl, bfl, bbl); 342 // triangles[i-1].reflection = 0.6; 343 // right 344 triangles[i++] = new Triangle(tbr, tfr, bbr); 345 triangles[i++] = new Triangle(tfr, bfr, bbr); 346 // top 347 triangles[i++] = new Triangle(tbl, tbr, tfr); 348 triangles[i++] = new Triangle(tbl, tfr, tfl); 349 // bottom 350 triangles[i++] = new Triangle(bbl, bbr, bfr); 351 triangles[i++] = new Triangle(bbl, bfr, bfl); 352 353 //Floor!!!! 354 var green = createVector(0.0, 0.4, 0.0); 355 var grey = createVector(0.4, 0.4, 0.4); 356 grey.reflection = 1.0; 357 var floorShader = function(tri, pos, view) { 358 var x = ((pos[0]/32) % 2 + 2) % 2; 359 var z = ((pos[2]/32 + 0.3) % 2 + 2) % 2; 360 if (x < 1 != z < 1) { 361 //in the real world we use the fresnel term... 362 // var angle = 1-dot(view, tri.normal); 363 // angle *= angle; 364 // angle *= angle; 365 // angle *= angle; 366 //grey.reflection = angle; 367 return grey; 368 } else 369 return green; 370 } 371 var ffl = createVector(-1000, -30, -1000); 372 var ffr = createVector( 1000, -30, -1000); 373 var fbl = createVector(-1000, -30, 1000); 374 var fbr = createVector( 1000, -30, 1000); 375 triangles[i++] = new Triangle(fbl, fbr, ffr); 376 triangles[i-1].shader = floorShader; 377 triangles[i++] = new Triangle(fbl, ffr, ffl); 378 triangles[i-1].shader = floorShader; 379 380 var _scene = new Scene(triangles); 381 _scene.lights[0] = createVector(20, 38, -22); 382 _scene.lights[0].colour = createVector(0.7, 0.3, 0.3); 383 _scene.lights[1] = createVector(-23, 40, 17); 384 _scene.lights[1].colour = createVector(0.7, 0.3, 0.3); 385 _scene.lights[2] = createVector(23, 20, 17); 386 _scene.lights[2].colour = createVector(0.7, 0.7, 0.7); 387 _scene.ambient = createVector(0.1, 0.1, 0.1); 388 // _scene.background = createVector(0.7, 0.7, 1.0); 389 390 var size = 30; 391 var pixels = new Array(); 392 for (var y = 0; y < size; y++) { 393 pixels[y] = new Array(); 394 for (var x = 0; x < size; x++) { 395 pixels[y][x] = 0; 396 } 397 } 398 399 var _camera = new Camera(createVector(-40, 40, 40), createVector(0, 0, 0), createVector(0, 1, 0)); 400 _camera.render(_scene, pixels, size, size); 401 402 return pixels; 403 } 404 405 function arrayToCanvasCommands(pixels) 406 { 407 var s = '<canvas id="renderCanvas" width="30px" height="30px"></canvas><scr' + 'ipt>\nvar pixels = ['; 408 var size = 30; 409 for (var y = 0; y < size; y++) { 410 s += "["; 411 for (var x = 0; x < size; x++) { 412 s += "[" + pixels[y][x] + "],"; 413 } 414 s+= "],"; 415 } 416 s += '];\n var canvas = document.getElementById("renderCanvas").getContext("2d");\n\ 417 \n\ 418 \n\ 419 var size = 30;\n\ 420 canvas.fillStyle = "red";\n\ 421 canvas.fillRect(0, 0, size, size);\n\ 422 canvas.scale(1, -1);\n\ 423 canvas.translate(0, -size);\n\ 424 \n\ 425 if (!canvas.setFillColor)\n\ 426 canvas.setFillColor = function(r, g, b, a) {\n\ 427 this.fillStyle = "rgb("+[Math.floor(r * 255), Math.floor(g * 255), Math.floor(b * 255)]+")";\n\ 428 }\n\ 429 \n\ 430 for (var y = 0; y < size; y++) {\n\ 431 for (var x = 0; x < size; x++) {\n\ 432 var l = pixels[y][x];\n\ 433 canvas.setFillColor(l[0], l[1], l[2], 1);\n\ 434 canvas.fillRect(x, y, 1, 1);\n\ 435 }\n\ 436 }</scr' + 'ipt>'; 437 438 return s; 439 } 440 441 testOutput = arrayToCanvasCommands(raytraceScene()); 442