83     function addFields(x, s, dt)  argument
85         for (var i=0; i<size ; i++ ) x[i] += dt*s[i];
157     function diffuse(b, x, x0, dt)  argument
198     function diffuse2(x, x0, y, y0, dt)  argument
204     function advect(b, d, d0, u, v, dt)  argument
206         var Wdt0 = dt * width;
207         var Hdt0 = dt * height;
277     function dens_step(x, x0, u, v, dt)  argument
279         addFields(x, x0, dt);
280         diffuse(0, x0, x, dt );
281         advect(0, x, x0, u, v, dt );
284     function vel_step(u, v, u0, v0, dt)  argument
286         addFields(u, u0, dt );
287         addFields(v, v0, dt );
290         diffuse2(u,u0,v,v0, dt);
294         advect(1, u, u0, u0, v0, dt);
295         advect(2, v, v0, u0, v0, dt);
331         vel_step(u, v, u_prev, v_prev, dt);
332         dens_step(dens, dens_prev, u, v, dt);
349     var dt = 0.1;