simulation.js

/**
 * @page Simulation
 * Organisation of all simulation code
 */


var simulationParams;    // simulation parametres
var simulation;          // simulation object
var display;             // display
var flag_running=true;

function mySimulation(params) {
    this.iter=0;
    this.time=0;  // history, actually
    this.dt=0;    // time step

    this.ge=0;    // geometry
    this.me=0;    // mechanics
    this.gr=0;    // growth
    this.di=0;    // display
}

/**
 * @function initSimulation
 */
function initSimulation(params) {
    var def=$.Deferred();

    flag_running=true;
    $("#startStop").html("Stop");
    var si=new mySimulation();
    var make;
    
    // create geometry
    switch(params.geometry) {
        case "block":
            make=makeBlock;
            break;
        case "ublock":
            make=makeUBlock;
            break;
        case "ring":
            make=makeRing;
            break;
        case "surface":
            make=makeSurface;
            break;
    }
    
    make(params)
    .then(function(ge) {
        si.ge=ge;

        // init mechanics
        si.me=initMechanics(si.ge,params);
        
        // init growth
        si.gr=initGrowth(params);
        switch(params.growth) {
            case "homogeneous":
                si.growthFunction=growHomogeneous;
                break;
            case "block border instantaneous":
                si.growthFunction=growBlockBorderInstantaneous;
                break;
            case "ring border instantaneous":
                si.growthFunction=growRingBorderInstantaneous;
                break;
            case "ring tangential instantaneous":
                si.growthFunction=growRingTangentialInstantaneous;
                break;
            case "surface homogeneous instantaneous":
                si.growthFunction=growSurfaceHomogeneousInstantaneous;
                break;
        }

        // compute time step for simulation
        si.dt=computeTimeStep(si.ge,si.me);

        if(params.T==0)
            si.growthFunction(si.ge,si.gr);
            
        // init hash array for collision detection
        if(si.ge.params["collision"])
            initHash(si.ge);

        /*
        $("#select").change(selectSimulation);
        $("#startStop").click(startStop);
        */

        def.resolve(si);
    });
    
    return def.promise();
}

/**
 * @function computeTimeStep
 */
function computeTimeStep(ge,me) {
    var a=0;    // average mesh spacing
    var n1,n2;
    var nt=ge.nt;
    var t=ge.t;
    var p=ge.p;
    var K=me.K;
    var rho=me.rho;
    var dt;
    
    for(i=0;i<nt;i++)
    for(j=0;j<4;j++) {
        n1=t[4*i+j];
        n2=t[4*i+(j+1)%4];
        a+=Math.sqrt(
            Math.pow(p[n1*3+0]-p[n2*3+0],2)+
            Math.pow(p[n1*3+1]-p[n2*3+1],2)+
            Math.pow(p[n1*3+2]-p[n2*3+2],2)
        );
    }
    a=a/nt/4;
    dt=0.2*0.1*Math.sqrt(rho*a*a/K);
    
    return dt;
}

/**
 * @function simulationStep
 * @description Simulation step. Request a new frame, call the render function, call the simulation functions and update model display.
 */
function simulationStep(si) {
    
    if(flag_running==false)
        return;
        
    // advance time
    si.time+=si.dt;
    si.iter+=1;

    var Ftet=0,Flin=0;

    // add elastic forces from tetrahedra
    Ftet=tetraElasticity(si.ge,si.me);
    
    // add elastic forces from linear elements
    if(si.ge.params["fibres"])// && si.ge.params.fibres==true)
        Flin=linElasticity(si.ge,si.me);
        
    // Collision detection
    if(si.ge.params["collision"]) {
        if(si.ge.params["surfaceOnly"]) {
            collision_surf_addConstraints(si.ge, si.iter);
            collision_surf_removeConstraints(si.ge, si.iter);
            collision_surf_enforceConstraints(si.ge, si.me, si.iter);
        } else
            collision_tetra(si.ge, si.iter);
    }

    //console.log("Ftet:",Ftet,"Flin:",Flin);
    
    move(si.ge,si.me,si.dt);
}

function pauseResume(di) {
    if(flag_running==true) {
        flag_running=false;
        $("#startStop").html("Continue");
    }
    else {
        flag_running=true;
    //    animate(param);
    //    param.growthFunc(param);
        $("#startStop").html("Stop");
    }
}