/*

* FR_layout.cpp

* topicNet

*

* Created by basak alper on 5/31/10.

* Copyright 2010 ucsb. All rights reserved.

*

*/

#include "FR_Layout.h"

//typedef space::Vec3d vec3d;

FR_Layout :: FR_Layout()

{

}

FR_Layout ::FR_Layout(int itr, double ar, double temp )

:numiter(itr), area(ar), temparature(temp)

{

}

FR_Layout :: ~FR_Layout()

{

}

void FR_Layout :: calculateK(Graph * gr){

printf("FRLayout: calculate constants, graph area: %f \n", area);

K = sqrt(AREA/gr->getNumNodes());

Ksqr = K*K; //multiply by a scalar to get more repulsive force

printf("graph constants K: %f, Ksqr: %f \n", K, Ksqr);

}

void FR_Layout :: layout(Graph * thegraph, Grid * thegrid){

//area := W * L; { W and L are the width and length of the frame }

//G := (V, E); { the vertices are assigned random initial positions }

calculateK(thegraph);

for(int it=0; it<numiter; it++){

// calculate repulsive forces

calculateRepulsiveForces(thegraph, thegrid);

// calculate attractive forces

calculateAttractiveForces(thegraph);

// limit the maximum displacement to the temperature t

// and then prevent from being displaced outside frame

for(int vind=0; vind<thegraph->getNumNodes(); vind++){

GraphNode * v = thegraph->getGraphNode(vind);

vec3d dis = v->getDisp();

double dismag = vec3d::mag(dis);

vec3d::normalize(dis);

vec3d scaled = dis * min ( dismag, temparature );

vec3d newpos = v->getPos() + scaled;

double dms = thegrid->getdim();

newpos.x = min(dms, newpos.x);

newpos.y = min(dms, newpos.y);

//newpos.z = min(dms, newpos.z);

newpos.x = max(0.0, newpos.x);

newpos.y = max(0.0, newpos.y);

//newpos.z = max(0.0, newpos.z);

v->setPos(newpos);

}

thegrid->cleargrid();

thegrid->addGraph(thegraph);

// reduce the temperature as the layout approaches a better configuration

temparature = temparature * 0.9;

}//iterations end

}

void FR_Layout :: step(bool threed, double temp, Graph * thegraph, Grid * thegrid){

calculateRepulsiveForces(thegraph, thegrid);

//calculateRepulsiveForcesWithoutGrid(thegraph);

// calculate attractive forces

calculateAttractiveForces(thegraph);

// limit the maximum displacement to the temperature t

// and then prevent from being displaced outside frame

for(int vind=0; vind<thegraph->getNumNodes(); vind++){

GraphNode * v = thegraph->getGraphNode(vind);

vec3d dis = v->getDisp();

double dismag = vec3d::mag(dis);

vec3d::normalize(dis);

vec3d scaled = dis * min ( dismag, temp );

vec3d newpos = v->getPos() + scaled;

double dms = thegrid->getdim();

newpos.x = min(dms, newpos.x);

newpos.y = min(dms, newpos.y);

newpos.x = max(0.0, newpos.x);

newpos.y = max(0.0, newpos.y);

if(threed){

newpos.z = min(dms, newpos.z);

newpos.z = max(0.0, newpos.z);

}

else {

newpos.z = 0.0;

}

v->setPos(newpos);

}

thegrid->cleargrid();

thegrid->addGraph(thegraph);

}

void FR_Layout :: calculateRepulsiveForces(Graph * thegraph, Grid * thegrid){

for(int gni=0; gni<thegraph->getNumNodes(); gni++){

// each vertex has two vectors: .pos and .disp

GraphNode * v = thegraph->getGraphNode(gni);

v->resetDisp();

int i, j, k;

bool foundgridindex = thegrid->getgridindex(v->getPos(), i, j, k);

if (foundgridindex) {

//find neighboring grid nodes

int bx = i; int by = j; int bz = k;

int ex = i; int ey = j; int ez = k;

if (i>0) bx -= 1;

if (j>0) by -= 1;

if (k>0) bz -= 1;

int last = thegrid->getgridsize() - 1;

if (i < last) ex += 1;

if (j < last) ey += 1;

if (k < last) ez += 1;

//need to do the search in all adjacent grid nodes

for (int xind=bx; xind<=ex; xind++) {

for (int yind=by; yind<=ey; yind++) {

for (int zind=bz; zind<=ez; zind++) {

GridNode * gnod = thegrid->getgridnode(xind, yind, zind);

for (int s=0; s < (int)gnod->graph_nodes.size(); s++) {

GraphNode * u = gnod->graph_nodes.at(s);

if (v != u) {

// D is short hand for the difference

// vector between the positions of the two vertices

vec3d dist = v->getPos() - u->getPos();

float distmag = vec3d::mag(dist);

vec3d::normalize(dist);

if (distmag == 0.0) {

distmag = 0.0001;

}

vec3d repforce = dist * fr(distmag);

v->accumDisp(repforce);

}

}

}

}

}

}

}

}

void FR_Layout :: calculateRepulsiveForcesWithoutGrid(Graph * thegraph){

for(int gni=0; gni<thegraph->getNumNodes(); gni++){

// each vertex has two vectors: .pos and .disp

GraphNode * v = thegraph->getGraphNode(gni);

v->resetDisp();

for(int cmpnd=0; cmpnd<thegraph->getNumNodes(); cmpnd++){

GraphNode * u = thegraph->getGraphNode(cmpnd);

if (v != u) {

// D is short hand for the difference

// vector between the positions of the two vertices

vec3d dist = v->getPos() - u->getPos();

float distmag = vec3d::mag(dist);

vec3d::normalize(dist);

vec3d repforce = dist * fr(distmag);

v->accumDisp(repforce);

}

}

}

}

void FR_Layout :: calculateAttractiveForces(Graph * thegraph){

for(int eind=0; eind<thegraph->getNumEdges(); eind++){

// each edge is an ordered pair of vertices .v and .u

GraphEdge * e = thegraph->getGraphEdge(eind);

GraphNode * vv = e->get_from();

GraphNode * uu = e->get_to();

vec3d D = vv->getPos() - uu->getPos();

double dismag = vec3d::mag(D);

vec3d::normalize(D);

vec3d scaled = D * fa(dismag);

vec3d invscaled = scaled * -1.0;

vv->accumDisp(invscaled);

uu->accumDisp(scaled);

}

}