Ben Murdoch | 3ef787d | 2012-04-12 10:51:47 +0100 | [diff] [blame] | 1 | /** |
| 2 | * Copyright 2012 the V8 project authors. All rights reserved. |
| 3 | * Copyright 2009 Oliver Hunt <http://nerget.com> |
| 4 | * |
| 5 | * Permission is hereby granted, free of charge, to any person |
| 6 | * obtaining a copy of this software and associated documentation |
| 7 | * files (the "Software"), to deal in the Software without |
| 8 | * restriction, including without limitation the rights to use, |
| 9 | * copy, modify, merge, publish, distribute, sublicense, and/or sell |
| 10 | * copies of the Software, and to permit persons to whom the |
| 11 | * Software is furnished to do so, subject to the following |
| 12 | * conditions: |
| 13 | * |
| 14 | * The above copyright notice and this permission notice shall be |
| 15 | * included in all copies or substantial portions of the Software. |
| 16 | * |
| 17 | * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, |
| 18 | * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES |
| 19 | * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND |
| 20 | * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT |
| 21 | * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, |
| 22 | * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| 23 | * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR |
| 24 | * OTHER DEALINGS IN THE SOFTWARE. |
| 25 | */ |
| 26 | |
| 27 | var NavierStokes = new BenchmarkSuite('NavierStokes', 1484000, |
| 28 | [new Benchmark('NavierStokes', |
| 29 | runNavierStokes, |
| 30 | setupNavierStokes, |
| 31 | tearDownNavierStokes)]); |
| 32 | |
| 33 | var solver = null; |
| 34 | |
| 35 | function runNavierStokes() |
| 36 | { |
| 37 | solver.update(); |
| 38 | } |
| 39 | |
| 40 | function setupNavierStokes() |
| 41 | { |
| 42 | solver = new FluidField(null); |
| 43 | solver.setResolution(128, 128); |
| 44 | solver.setIterations(20); |
| 45 | solver.setDisplayFunction(function(){}); |
| 46 | solver.setUICallback(prepareFrame); |
| 47 | solver.reset(); |
| 48 | } |
| 49 | |
| 50 | function tearDownNavierStokes() |
| 51 | { |
| 52 | solver = null; |
| 53 | } |
| 54 | |
| 55 | function addPoints(field) { |
| 56 | var n = 64; |
| 57 | for (var i = 1; i <= n; i++) { |
| 58 | field.setVelocity(i, i, n, n); |
| 59 | field.setDensity(i, i, 5); |
| 60 | field.setVelocity(i, n - i, -n, -n); |
| 61 | field.setDensity(i, n - i, 20); |
| 62 | field.setVelocity(128 - i, n + i, -n, -n); |
| 63 | field.setDensity(128 - i, n + i, 30); |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | var framesTillAddingPoints = 0; |
| 68 | var framesBetweenAddingPoints = 5; |
| 69 | |
| 70 | function prepareFrame(field) |
| 71 | { |
| 72 | if (framesTillAddingPoints == 0) { |
| 73 | addPoints(field); |
| 74 | framesTillAddingPoints = framesBetweenAddingPoints; |
| 75 | framesBetweenAddingPoints++; |
| 76 | } else { |
| 77 | framesTillAddingPoints--; |
| 78 | } |
| 79 | } |
| 80 | |
| 81 | // Code from Oliver Hunt (http://nerget.com/fluidSim/pressure.js) starts here. |
| 82 | function FluidField(canvas) { |
| 83 | function addFields(x, s, dt) |
| 84 | { |
| 85 | for (var i=0; i<size ; i++ ) x[i] += dt*s[i]; |
| 86 | } |
| 87 | |
| 88 | function set_bnd(b, x) |
| 89 | { |
| 90 | if (b===1) { |
| 91 | for (var i = 1; i <= width; i++) { |
| 92 | x[i] = x[i + rowSize]; |
| 93 | x[i + (height+1) *rowSize] = x[i + height * rowSize]; |
| 94 | } |
| 95 | |
| 96 | for (var j = 1; i <= height; i++) { |
| 97 | x[j * rowSize] = -x[1 + j * rowSize]; |
| 98 | x[(width + 1) + j * rowSize] = -x[width + j * rowSize]; |
| 99 | } |
| 100 | } else if (b === 2) { |
| 101 | for (var i = 1; i <= width; i++) { |
| 102 | x[i] = -x[i + rowSize]; |
| 103 | x[i + (height + 1) * rowSize] = -x[i + height * rowSize]; |
| 104 | } |
| 105 | |
| 106 | for (var j = 1; j <= height; j++) { |
| 107 | x[j * rowSize] = x[1 + j * rowSize]; |
| 108 | x[(width + 1) + j * rowSize] = x[width + j * rowSize]; |
| 109 | } |
| 110 | } else { |
| 111 | for (var i = 1; i <= width; i++) { |
| 112 | x[i] = x[i + rowSize]; |
| 113 | x[i + (height + 1) * rowSize] = x[i + height * rowSize]; |
| 114 | } |
| 115 | |
| 116 | for (var j = 1; j <= height; j++) { |
| 117 | x[j * rowSize] = x[1 + j * rowSize]; |
| 118 | x[(width + 1) + j * rowSize] = x[width + j * rowSize]; |
| 119 | } |
| 120 | } |
| 121 | var maxEdge = (height + 1) * rowSize; |
| 122 | x[0] = 0.5 * (x[1] + x[rowSize]); |
| 123 | x[maxEdge] = 0.5 * (x[1 + maxEdge] + x[height * rowSize]); |
| 124 | x[(width+1)] = 0.5 * (x[width] + x[(width + 1) + rowSize]); |
| 125 | x[(width+1)+maxEdge] = 0.5 * (x[width + maxEdge] + x[(width + 1) + height * rowSize]); |
| 126 | } |
| 127 | |
| 128 | function lin_solve(b, x, x0, a, c) |
| 129 | { |
| 130 | if (a === 0 && c === 1) { |
| 131 | for (var j=1 ; j<=height; j++) { |
| 132 | var currentRow = j * rowSize; |
| 133 | ++currentRow; |
| 134 | for (var i = 0; i < width; i++) { |
| 135 | x[currentRow] = x0[currentRow]; |
| 136 | ++currentRow; |
| 137 | } |
| 138 | } |
| 139 | set_bnd(b, x); |
| 140 | } else { |
| 141 | var invC = 1 / c; |
| 142 | for (var k=0 ; k<iterations; k++) { |
| 143 | for (var j=1 ; j<=height; j++) { |
| 144 | var lastRow = (j - 1) * rowSize; |
| 145 | var currentRow = j * rowSize; |
| 146 | var nextRow = (j + 1) * rowSize; |
| 147 | var lastX = x[currentRow]; |
| 148 | ++currentRow; |
| 149 | for (var i=1; i<=width; i++) |
| 150 | lastX = x[currentRow] = (x0[currentRow] + a*(lastX+x[++currentRow]+x[++lastRow]+x[++nextRow])) * invC; |
| 151 | } |
| 152 | set_bnd(b, x); |
| 153 | } |
| 154 | } |
| 155 | } |
| 156 | |
| 157 | function diffuse(b, x, x0, dt) |
| 158 | { |
| 159 | var a = 0; |
| 160 | lin_solve(b, x, x0, a, 1 + 4*a); |
| 161 | } |
| 162 | |
| 163 | function lin_solve2(x, x0, y, y0, a, c) |
| 164 | { |
| 165 | if (a === 0 && c === 1) { |
| 166 | for (var j=1 ; j <= height; j++) { |
| 167 | var currentRow = j * rowSize; |
| 168 | ++currentRow; |
| 169 | for (var i = 0; i < width; i++) { |
| 170 | x[currentRow] = x0[currentRow]; |
| 171 | y[currentRow] = y0[currentRow]; |
| 172 | ++currentRow; |
| 173 | } |
| 174 | } |
| 175 | set_bnd(1, x); |
| 176 | set_bnd(2, y); |
| 177 | } else { |
| 178 | var invC = 1/c; |
| 179 | for (var k=0 ; k<iterations; k++) { |
| 180 | for (var j=1 ; j <= height; j++) { |
| 181 | var lastRow = (j - 1) * rowSize; |
| 182 | var currentRow = j * rowSize; |
| 183 | var nextRow = (j + 1) * rowSize; |
| 184 | var lastX = x[currentRow]; |
| 185 | var lastY = y[currentRow]; |
| 186 | ++currentRow; |
| 187 | for (var i = 1; i <= width; i++) { |
| 188 | lastX = x[currentRow] = (x0[currentRow] + a * (lastX + x[currentRow] + x[lastRow] + x[nextRow])) * invC; |
| 189 | lastY = y[currentRow] = (y0[currentRow] + a * (lastY + y[++currentRow] + y[++lastRow] + y[++nextRow])) * invC; |
| 190 | } |
| 191 | } |
| 192 | set_bnd(1, x); |
| 193 | set_bnd(2, y); |
| 194 | } |
| 195 | } |
| 196 | } |
| 197 | |
| 198 | function diffuse2(x, x0, y, y0, dt) |
| 199 | { |
| 200 | var a = 0; |
| 201 | lin_solve2(x, x0, y, y0, a, 1 + 4 * a); |
| 202 | } |
| 203 | |
| 204 | function advect(b, d, d0, u, v, dt) |
| 205 | { |
| 206 | var Wdt0 = dt * width; |
| 207 | var Hdt0 = dt * height; |
| 208 | var Wp5 = width + 0.5; |
| 209 | var Hp5 = height + 0.5; |
| 210 | for (var j = 1; j<= height; j++) { |
| 211 | var pos = j * rowSize; |
| 212 | for (var i = 1; i <= width; i++) { |
| 213 | var x = i - Wdt0 * u[++pos]; |
| 214 | var y = j - Hdt0 * v[pos]; |
| 215 | if (x < 0.5) |
| 216 | x = 0.5; |
| 217 | else if (x > Wp5) |
| 218 | x = Wp5; |
| 219 | var i0 = x | 0; |
| 220 | var i1 = i0 + 1; |
| 221 | if (y < 0.5) |
| 222 | y = 0.5; |
| 223 | else if (y > Hp5) |
| 224 | y = Hp5; |
| 225 | var j0 = y | 0; |
| 226 | var j1 = j0 + 1; |
| 227 | var s1 = x - i0; |
| 228 | var s0 = 1 - s1; |
| 229 | var t1 = y - j0; |
| 230 | var t0 = 1 - t1; |
| 231 | var row1 = j0 * rowSize; |
| 232 | var row2 = j1 * rowSize; |
| 233 | d[pos] = s0 * (t0 * d0[i0 + row1] + t1 * d0[i0 + row2]) + s1 * (t0 * d0[i1 + row1] + t1 * d0[i1 + row2]); |
| 234 | } |
| 235 | } |
| 236 | set_bnd(b, d); |
| 237 | } |
| 238 | |
| 239 | function project(u, v, p, div) |
| 240 | { |
| 241 | var h = -0.5 / Math.sqrt(width * height); |
| 242 | for (var j = 1 ; j <= height; j++ ) { |
| 243 | var row = j * rowSize; |
| 244 | var previousRow = (j - 1) * rowSize; |
| 245 | var prevValue = row - 1; |
| 246 | var currentRow = row; |
| 247 | var nextValue = row + 1; |
| 248 | var nextRow = (j + 1) * rowSize; |
| 249 | for (var i = 1; i <= width; i++ ) { |
| 250 | div[++currentRow] = h * (u[++nextValue] - u[++prevValue] + v[++nextRow] - v[++previousRow]); |
| 251 | p[currentRow] = 0; |
| 252 | } |
| 253 | } |
| 254 | set_bnd(0, div); |
| 255 | set_bnd(0, p); |
| 256 | |
| 257 | lin_solve(0, p, div, 1, 4 ); |
| 258 | var wScale = 0.5 * width; |
| 259 | var hScale = 0.5 * height; |
| 260 | for (var j = 1; j<= height; j++ ) { |
| 261 | var prevPos = j * rowSize - 1; |
| 262 | var currentPos = j * rowSize; |
| 263 | var nextPos = j * rowSize + 1; |
| 264 | var prevRow = (j - 1) * rowSize; |
| 265 | var currentRow = j * rowSize; |
| 266 | var nextRow = (j + 1) * rowSize; |
| 267 | |
| 268 | for (var i = 1; i<= width; i++) { |
| 269 | u[++currentPos] -= wScale * (p[++nextPos] - p[++prevPos]); |
| 270 | v[currentPos] -= hScale * (p[++nextRow] - p[++prevRow]); |
| 271 | } |
| 272 | } |
| 273 | set_bnd(1, u); |
| 274 | set_bnd(2, v); |
| 275 | } |
| 276 | |
| 277 | function dens_step(x, x0, u, v, dt) |
| 278 | { |
| 279 | addFields(x, x0, dt); |
| 280 | diffuse(0, x0, x, dt ); |
| 281 | advect(0, x, x0, u, v, dt ); |
| 282 | } |
| 283 | |
| 284 | function vel_step(u, v, u0, v0, dt) |
| 285 | { |
| 286 | addFields(u, u0, dt ); |
| 287 | addFields(v, v0, dt ); |
| 288 | var temp = u0; u0 = u; u = temp; |
| 289 | var temp = v0; v0 = v; v = temp; |
| 290 | diffuse2(u,u0,v,v0, dt); |
| 291 | project(u, v, u0, v0); |
| 292 | var temp = u0; u0 = u; u = temp; |
| 293 | var temp = v0; v0 = v; v = temp; |
| 294 | advect(1, u, u0, u0, v0, dt); |
| 295 | advect(2, v, v0, u0, v0, dt); |
| 296 | project(u, v, u0, v0 ); |
| 297 | } |
| 298 | var uiCallback = function(d,u,v) {}; |
| 299 | |
| 300 | function Field(dens, u, v) { |
| 301 | // Just exposing the fields here rather than using accessors is a measurable win during display (maybe 5%) |
| 302 | // but makes the code ugly. |
| 303 | this.setDensity = function(x, y, d) { |
| 304 | dens[(x + 1) + (y + 1) * rowSize] = d; |
| 305 | } |
| 306 | this.getDensity = function(x, y) { |
| 307 | return dens[(x + 1) + (y + 1) * rowSize]; |
| 308 | } |
| 309 | this.setVelocity = function(x, y, xv, yv) { |
| 310 | u[(x + 1) + (y + 1) * rowSize] = xv; |
| 311 | v[(x + 1) + (y + 1) * rowSize] = yv; |
| 312 | } |
| 313 | this.getXVelocity = function(x, y) { |
| 314 | return u[(x + 1) + (y + 1) * rowSize]; |
| 315 | } |
| 316 | this.getYVelocity = function(x, y) { |
| 317 | return v[(x + 1) + (y + 1) * rowSize]; |
| 318 | } |
| 319 | this.width = function() { return width; } |
| 320 | this.height = function() { return height; } |
| 321 | } |
| 322 | function queryUI(d, u, v) |
| 323 | { |
| 324 | for (var i = 0; i < size; i++) |
| 325 | u[i] = v[i] = d[i] = 0.0; |
| 326 | uiCallback(new Field(d, u, v)); |
| 327 | } |
| 328 | |
| 329 | this.update = function () { |
| 330 | queryUI(dens_prev, u_prev, v_prev); |
| 331 | vel_step(u, v, u_prev, v_prev, dt); |
| 332 | dens_step(dens, dens_prev, u, v, dt); |
| 333 | displayFunc(new Field(dens, u, v)); |
| 334 | } |
| 335 | this.setDisplayFunction = function(func) { |
| 336 | displayFunc = func; |
| 337 | } |
| 338 | |
| 339 | this.iterations = function() { return iterations; } |
| 340 | this.setIterations = function(iters) { |
| 341 | if (iters > 0 && iters <= 100) |
| 342 | iterations = iters; |
| 343 | } |
| 344 | this.setUICallback = function(callback) { |
| 345 | uiCallback = callback; |
| 346 | } |
| 347 | var iterations = 10; |
| 348 | var visc = 0.5; |
| 349 | var dt = 0.1; |
| 350 | var dens; |
| 351 | var dens_prev; |
| 352 | var u; |
| 353 | var u_prev; |
| 354 | var v; |
| 355 | var v_prev; |
| 356 | var width; |
| 357 | var height; |
| 358 | var rowSize; |
| 359 | var size; |
| 360 | var displayFunc; |
| 361 | function reset() |
| 362 | { |
| 363 | rowSize = width + 2; |
| 364 | size = (width+2)*(height+2); |
| 365 | dens = new Array(size); |
| 366 | dens_prev = new Array(size); |
| 367 | u = new Array(size); |
| 368 | u_prev = new Array(size); |
| 369 | v = new Array(size); |
| 370 | v_prev = new Array(size); |
| 371 | for (var i = 0; i < size; i++) |
| 372 | dens_prev[i] = u_prev[i] = v_prev[i] = dens[i] = u[i] = v[i] = 0; |
| 373 | } |
| 374 | this.reset = reset; |
| 375 | this.setResolution = function (hRes, wRes) |
| 376 | { |
| 377 | var res = wRes * hRes; |
| 378 | if (res > 0 && res < 1000000 && (wRes != width || hRes != height)) { |
| 379 | width = wRes; |
| 380 | height = hRes; |
| 381 | reset(); |
| 382 | return true; |
| 383 | } |
| 384 | return false; |
| 385 | } |
| 386 | this.setResolution(64, 64); |
| 387 | } |