adjust.c

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/*************************************************************************
 * Copyright (c) 2011 AT&T Intellectual Property 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * https://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors: Details at https://graphviz.org
 *************************************************************************/
 
/* adjust.c
 * Routines for repositioning nodes after initial layout in
 * order to reduce/remove node overlaps.
 */
 
#include <assert.h>
#include <neatogen/neato.h>
#include <common/utils.h>
#include <float.h>
#include <math.h>
#include <neatogen/voronoi.h>
#include <neatogen/info.h>
#include <neatogen/edges.h>
#include <neatogen/site.h>
#include <neatogen/digcola.h>
#if defined(HAVE_GTS) && defined(SFDP)
#include <neatogen/overlap.h>
#endif
#include <stdbool.h>
#ifdef IPSEPCOLA
#include <vpsc/csolve_VPSC.h>
#include <neatogen/quad_prog_vpsc.h>
#endif
#include <stddef.h>
#include <util/agxbuf.h>
#include <util/alloc.h>
#include <util/debug.h>
#include <util/gv_ctype.h>
#include <util/startswith.h>
#include <util/strcasecmp.h>
 
#define SEPFACT         0.8 // default esep/sep
 
static const double incr = 0.05;        /* Increase bounding box by adding
                                 * incr * dimension around box.
                                 */
 
typedef struct {
  Site **sites; 
  Site **endSite; 
  Point nw, ne, sw, se; 
  Site **nextSite;
} state_t;
 
static void setBoundBox(state_t *st, Point *ll, Point *ur) {
    pxmin = ll->x;
    pxmax = ur->x;
    pymin = ll->y;
    pymax = ur->y;
    st->nw.x = st->sw.x = pxmin;
    st->ne.x = st->se.x = pxmax;
    st->nw.y = st->ne.y = pymax;
    st->sw.y = st->se.y = pymin;
}
 
static void freeNodes(void)
{
    for (size_t i = 0; i < nsites; i++) {
        breakPoly(&nodeInfo[i].poly);
    }
    if (nodeInfo != NULL) {
        free(nodeInfo->verts); // Free vertices
    }
    free(nodeInfo);
}
 
/*   Compute extremes of graph, then set up bounding box.
 *   If user supplied a bounding box, use that;
 *   else if "window" is a graph attribute, use that; 
 *   otherwise, define bounding box as a percentage expansion of
 *   graph extremes.
 *   In the first two cases, check that graph fits in bounding box.
 */
static void chkBoundBox(state_t *st, Agraph_t *graph) {
    Point ll, ur;
 
    double x_min = DBL_MAX;
    double y_min = DBL_MAX;
    double x_max = -DBL_MAX;
    double y_max = -DBL_MAX;
    assert(nsites > 0);
    for (size_t i = 0; i < nsites; ++i) {
        Info_t *ip = &nodeInfo[i];
        Poly *pp = &ip->poly;
        double x = ip->site.coord.x;
        double y = ip->site.coord.y;
        x_min = fmin(x_min, pp->origin.x + x);
        y_min = fmin(y_min, pp->origin.y + y);
        x_max = fmax(x_max, pp->corner.x + x);
        y_max = fmax(y_max, pp->corner.y + y);
    }
 
    // create initial bounding box by adding margin × dimension around box
    // enclosing nodes
    char *marg = agget(graph, "voro_margin");
    const double margin = (marg && *marg != '\0') ? atof(marg) : 0.05;
    double ydelta = margin * (y_max - y_min);
    double xdelta = margin * (x_max - x_min);
    ll.x = x_min - xdelta;
    ll.y = y_min - ydelta;
    ur.x = x_max + xdelta;
    ur.y = y_max + ydelta;
 
    setBoundBox(st, &ll, &ur);
}
 
static int makeInfo(Agraph_t * graph)
{
    int (*polyf)(Poly *, Agnode_t *, double, double);
 
    assert(agnnodes(graph) >= 0);
    nsites = (size_t)agnnodes(graph);
    geominit();
 
    nodeInfo = gv_calloc(nsites, sizeof(Info_t));
 
    Agnode_t *node = agfstnode(graph);
 
    expand_t pmargin = sepFactor (graph);
 
    if (pmargin.doAdd) {
        polyf = makeAddPoly;
        /* we need inches for makeAddPoly */
        pmargin.x = PS2INCH(pmargin.x);
        pmargin.y = PS2INCH(pmargin.y);
    }
        
    else polyf = makePoly;
    for (size_t i = 0; i < nsites; i++) {
        Info_t *ip = &nodeInfo[i];
        ip->site.coord.x = ND_pos(node)[0];
        ip->site.coord.y = ND_pos(node)[1];
 
        if (polyf(&ip->poly, node, pmargin.x, pmargin.y)) {
            free (nodeInfo);
            nodeInfo = NULL;
            return 1;
        }
 
        ip->site.sitenbr = i;
        ip->node = node;
        ip->verts = NULL;
        ip->n_verts = 0;
        node = agnxtnode(graph, node);
    }
    return 0;
}
 
/* sort sites on y, then x, coord */
static int scomp(const void *S1, const void *S2)
{
    const Site *s1 = *(Site *const *)S1;
    const Site *s2 = *(Site *const *)S2;
    if (s1->coord.y < s2->coord.y)
        return -1;
    if (s1->coord.y > s2->coord.y)
        return 1;
    if (s1->coord.x < s2->coord.x)
        return -1;
    if (s1->coord.x > s2->coord.x)
        return 1;
    return 0;
}
 
static void sortSites(state_t *st) {
    if (st->sites == NULL) {
        st->sites = gv_calloc(nsites, sizeof(Site*));
        st->endSite = st->sites + nsites;
    }
 
    for (size_t i = 0; i < nsites; i++) {
        Info_t *ip = &nodeInfo[i];
        st->sites[i] = &ip->site;
        ip->verts = NULL;
        ip->n_verts = 0;
    }
 
    qsort(st->sites, nsites, sizeof(Site *), scomp);
 
    /* Reset site index for nextOne */
    st->nextSite = st->sites;
 
}
 
static void geomUpdate(state_t *st, int doSort) {
    if (doSort)
        sortSites(st);
 
    /* compute ranges */
    xmin = DBL_MAX;
    xmax = -DBL_MAX;
    assert(nsites > 0);
    for (size_t i = 0; i < nsites; ++i) {
        xmin = fmin(xmin, st->sites[i]->coord.x);
        xmax = fmax(xmax, st->sites[i]->coord.x);
    }
    ymin = st->sites[0]->coord.y;
    ymax = st->sites[nsites - 1]->coord.y;
 
    deltax = xmax - xmin;
}
 
static Site *nextOne(void *state) {
    state_t *st = state;
    if (st->nextSite < st->endSite) {
        return *st->nextSite++;
    } else
        return NULL;
}
 
static void rmEquality(state_t *st) {
    sortSites(st);
 
    for (Site **ip = st->sites; ip < st->endSite; ) {
        Site **jp = ip + 1;
        if (jp >= st->endSite ||
            (*jp)->coord.x != (*ip)->coord.x ||
            (*jp)->coord.y != (*ip)->coord.y) {
            ip = jp;
            continue;
        }
 
        /* Find first node kp with position different from ip */
        int cnt = 2;
        Site **kp = jp + 1;
        while (kp < st->endSite &&
               (*kp)->coord.x == (*ip)->coord.x &&
               (*kp)->coord.y == (*ip)->coord.y) {
            cnt++;
            jp = kp;
            kp = jp + 1;
        }
 
        /* If next node exists and is on the same line */
        if (kp < st->endSite && (*kp)->coord.y == (*ip)->coord.y) {
            const double xdel = ((*kp)->coord.x - (*ip)->coord.x) / cnt;
            int i = 1;
            for (jp = ip + 1; jp < kp; jp++) {
                (*jp)->coord.x += i * xdel;
                i++;
            }
        } else {                /* nothing is to the right */
            Info_t *info;
            for (jp = ip + 1; jp < kp; ip++, jp++) {
                info = nodeInfo + (*ip)->sitenbr;
                double xdel = info->poly.corner.x - info->poly.origin.x;
                info = nodeInfo + (*jp)->sitenbr;
                xdel += info->poly.corner.x - info->poly.origin.x;
                (*jp)->coord.x = (*ip)->coord.x + xdel / 2;
            }
        }
        ip = kp;
    }
}
 
static unsigned countOverlap(unsigned iter) {
    unsigned count = 0;
 
    for (size_t i = 0; i < nsites; i++)
        nodeInfo[i].overlaps = false;
 
    for (size_t i = 0; i < nsites - 1; i++) {
        Info_t *ip = &nodeInfo[i];
        for (size_t j = i + 1; j < nsites; j++) {
            Info_t *jp = &nodeInfo[j];
            if (polyOverlap(ip->site.coord, &ip->poly, jp->site.coord, &jp->poly)) {
                count++;
                ip->overlaps = true;
                jp->overlaps = true;
            }
        }
    }
 
    if (Verbose > 1)
        fprintf(stderr, "overlap [%u] : %u\n", iter, count);
    return count;
}
 
static void increaseBoundBox(state_t *st) {
    Point ur = {.x = pxmax, .y = pymax};
    Point ll = {.x = pxmin, .y = pymin};
 
    const double ydelta = incr * (ur.y - ll.y);
    const double xdelta = incr * (ur.x - ll.x);
 
    ur.x += xdelta;
    ur.y += ydelta;
    ll.x -= xdelta;
    ll.y -= ydelta;
 
    setBoundBox(st, &ll, &ur);
}
 
static double areaOf(Point a, Point b, Point c)
{
    return fabs(a.x * (b.y - c.y) + b.x * (c.y - a.y) + c.x * (a.y - b.y)) / 2;
}
 
/* Compute centroid of triangle with vertices a, b, c.
 * Return coordinates in x and y.
 */
static void centroidOf(Point a, Point b, Point c, double *x, double *y)
{
    *x = (a.x + b.x + c.x) / 3;
    *y = (a.y + b.y + c.y) / 3;
}
 
/* The new position is the centroid of the voronoi polygon. This is the weighted
 * sum of the centroids of a triangulation, normalized to the total area.
 */
static void newpos(Info_t * ip)
{
    const Point anchor = ip->verts[0];
    double totalArea = 0.0;
    double cx = 0.0;
    double cy = 0.0;
    double x;
    double y;
 
    for (size_t i = 1; i + 1 < ip->n_verts; ++i) {
        const Point p = ip->verts[i];
        const Point q = ip->verts[i + 1];
        const double area = areaOf(anchor, p, q);
        centroidOf(anchor, p, q, &x, &y);
        cx += area * x;
        cy += area * y;
        totalArea += area;
    }
 
    ip->site.coord.x = cx / totalArea;
    ip->site.coord.y = cy / totalArea;
}
 
 /* Add corners of clipping window to appropriate sites.
  * A site gets a corner if it is the closest site to that corner.
  */
static void addCorners(const state_t *st) {
    Info_t *ip = nodeInfo;
    Info_t *sws = ip;
    Info_t *nws = ip;
    Info_t *ses = ip;
    Info_t *nes = ip;
    double swd = dist_2(ip->site.coord, st->sw);
    double nwd = dist_2(ip->site.coord, st->nw);
    double sed = dist_2(ip->site.coord, st->se);
    double ned = dist_2(ip->site.coord, st->ne);
 
    for (size_t i = 1; i < nsites; i++) {
        ip = &nodeInfo[i];
        double d = dist_2(ip->site.coord, st->sw);
        if (d < swd) {
            swd = d;
            sws = ip;
        }
        d = dist_2(ip->site.coord, st->se);
        if (d < sed) {
            sed = d;
            ses = ip;
        }
        d = dist_2(ip->site.coord, st->nw);
        if (d < nwd) {
            nwd = d;
            nws = ip;
        }
        d = dist_2(ip->site.coord, st->ne);
        if (d < ned) {
            ned = d;
            nes = ip;
        }
    }
 
    addVertex(&sws->site, st->sw.x, st->sw.y);
    addVertex(&ses->site, st->se.x, st->se.y);
    addVertex(&nws->site, st->nw.x, st->nw.y);
    addVertex(&nes->site, st->ne.x, st->ne.y);
}
 
 /* Calculate the new position of a site as the centroid
  * of its voronoi polygon, if it overlaps other nodes.
  * The polygons are finite by being clipped to the clipping
  * window.
  * We first add the corner of the clipping windows to the
  * vertex lists of the appropriate sites.
  *
  * @param st Algorithm state
  * @param doAll Move all nodes, regardless of overlap
  */
static void newPos(const state_t *st, bool doAll) {
    addCorners(st);
    for (size_t i = 0; i < nsites; i++) {
        Info_t *ip = &nodeInfo[i];
        if (doAll || ip->overlaps)
            newpos(ip);
    }
}
 
static int vAdjust(state_t *st) {
    unsigned iterCnt = 0;
    unsigned badLevel = 0;
    unsigned increaseCnt = 0;
 
    unsigned overlapCnt = countOverlap(iterCnt);
 
    if (overlapCnt == 0)
        return 0;
 
    rmEquality(st);
    geomUpdate(st, 0);
    voronoi(nextOne, st);
    for (bool doAll = false;;) {
        newPos(st, doAll);
        iterCnt++;
 
        const unsigned cnt = countOverlap(iterCnt);
        if (cnt == 0)
            break;
        if (cnt >= overlapCnt)
            badLevel++;
        else
            badLevel = 0;
        overlapCnt = cnt;
 
        switch (badLevel) {
        case 0:
            doAll = true;
            break;
        default:
            doAll = true;
            increaseCnt++;
            increaseBoundBox(st);
            break;
        }
 
        geomUpdate(st, 1);
        voronoi(nextOne, st);
    }
 
    GV_DEBUG("Number of iterations = %u", iterCnt);
    GV_DEBUG("Number of increases = %u", increaseCnt);
 
    return 1;
}
 
static void rePos(void) {
    double f = 1.0 + incr;
 
    for (size_t i = 0; i < nsites; i++) {
        Info_t *ip = &nodeInfo[i];
        ip->site.coord.x *= f;
        ip->site.coord.y *= f;
    }
}
 
static int sAdjust(state_t *st) {
    unsigned iterCnt = 0;
 
    const unsigned overlapCnt = countOverlap(iterCnt);
 
    if (overlapCnt == 0)
        return 0;
 
    rmEquality(st);
    while (1) {
        rePos();
        iterCnt++;
 
        const unsigned cnt = countOverlap(iterCnt);
        if (cnt == 0)
            break;
    }
 
    if (Verbose) {
        fprintf(stderr, "Number of iterations = %u\n", iterCnt);
    }
 
    return 1;
}
 
static void updateGraph(void)
{
    for (size_t i = 0; i < nsites; i++) {
        Info_t *ip = &nodeInfo[i];
        ND_pos(ip->node)[0] = ip->site.coord.x;
        ND_pos(ip->node)[1] = ip->site.coord.y;
    }
}
 
#define ELS "|edgelabel|"
  /* Return true if node name starts with ELS */
#define IS_LNODE(n) startswith(agnameof(n), ELS)
 
double *getSizes(Agraph_t * g, pointf pad, int* n_elabels, int** elabels)
{
    double *sizes = gv_calloc(Ndim * agnnodes(g), sizeof(double));
    int nedge_nodes = 0;
 
    for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n)) {
        if (elabels && IS_LNODE(n)) nedge_nodes++;
 
        const int i = ND_id(n);
        sizes[i * Ndim] = ND_width(n) * .5 + pad.x;
        sizes[i * Ndim + 1] = ND_height(n) * .5 + pad.y;
    }
 
    if (elabels && nedge_nodes) {
        int* elabs = gv_calloc(nedge_nodes, sizeof(int));
        nedge_nodes = 0;
        for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n)) {
            if (IS_LNODE(n))
                elabs[nedge_nodes++] = ND_id(n);
        }
        *elabels = elabs;
        *n_elabels = nedge_nodes;
    }
 
    return sizes;
}
 
/* Assumes g is connected and simple, i.e., we can have a->b and b->a
 * but not a->b and a->b
 */
SparseMatrix makeMatrix(Agraph_t *g) {
    if (!g)
        return NULL;
    const int nnodes = agnnodes(g);
    const int nedges = agnedges(g);
 
    /* Assign node ids */
    int i = 0;
    for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n))
        ND_id(n) = i++;
 
    int *I = gv_calloc(nedges, sizeof(int));
    int *J = gv_calloc(nedges, sizeof(int));
    double *val = gv_calloc(nedges, sizeof(double));
 
    Agsym_t *sym = agfindedgeattr(g, "weight");
 
    i = 0;
    for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n)) {
        const int row = ND_id(n);
        for (Agedge_t *e = agfstout(g, n); e; e = agnxtout(g, e)) {
            I[i] = row;
            J[i] = ND_id(aghead(e));
            double v;
            if (!sym || sscanf(agxget(e, sym), "%lf", &v) != 1)
                v = 1;
            val[i] = v;
        /* edge length */
            i++;
        }
    }
 
    SparseMatrix A = SparseMatrix_from_coordinate_arrays(nedges, nnodes, nnodes,
                                                         I, J, val,
                                                         MATRIX_TYPE_REAL,
                                                         sizeof(double));
 
    free(I);
    free(J);
    free(val);
 
    return A;
}
 
#if defined(HAVE_GTS) && defined(SFDP)
static void fdpAdjust(graph_t *g, adjust_data *am) {
    SparseMatrix A0 = makeMatrix(g);
    SparseMatrix A = A0;
    double *pos = gv_calloc(Ndim * agnnodes(g), sizeof(double));
    expand_t sep = sepFactor(g);
    pointf pad;
 
    if (sep.doAdd) {
        pad.x = PS2INCH(sep.x);
        pad.y = PS2INCH(sep.y);
    } else {
        pad.x = PS2INCH(DFLT_MARGIN);
        pad.y = PS2INCH(DFLT_MARGIN);
    }
    double *sizes = getSizes(g, pad, NULL, NULL);
 
    for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n)) {
        double* npos = pos + Ndim * ND_id(n);
        for (int i = 0; i < Ndim; i++) {
            npos[i] = ND_pos(n)[i];
        }
    }
 
    if (!SparseMatrix_is_symmetric(A, false) || A->type != MATRIX_TYPE_REAL) {
        A = SparseMatrix_get_real_adjacency_matrix_symmetrized(A);
    } else {
        A = SparseMatrix_remove_diagonal(A);
    }
 
    remove_overlap(Ndim, A, pos, sizes, am->value, am->scaling, 
                   ELSCHEME_NONE, 0, NULL, NULL,
                   mapBool(agget(g, "overlap_shrink"), true));
 
    for (Agnode_t *n = agfstnode(g); n; n = agnxtnode(g, n)) {
        double *npos = pos + Ndim * ND_id(n);
        for (int i = 0; i < Ndim; i++) {
            ND_pos(n)[i] = npos[i];
        }
    }
 
    free(sizes);
    free(pos);
    if (A != A0)
        SparseMatrix_delete(A);
    SparseMatrix_delete (A0);
}
#endif
 
#ifdef IPSEPCOLA
static int
vpscAdjust(graph_t* G)
{
    enum { dim = 2 };
    int nnodes = agnnodes(G);
    ipsep_options opt;
    pointf *nsize = gv_calloc(nnodes, sizeof(pointf));
    float* coords[dim];
    float *f_storage = gv_calloc(dim * nnodes, sizeof(float));
 
    for (size_t i = 0; i < dim; i++) {
        coords[i] = f_storage + i * nnodes;
    }
 
    size_t j = 0;
    for (Agnode_t *v = agfstnode(G); v; v = agnxtnode(G, v)) {
        for (size_t i = 0; i < dim; i++) {
            coords[i][j] =  (float)ND_pos(v)[i];
        }
        nsize[j].x = ND_width(v);
        nsize[j].y = ND_height(v);
        j++;
    }
 
    opt.diredges = 0;
    opt.edge_gap = 0;
    opt.noverlap = 2;
    opt.clusters = (cluster_data){0};
    expand_t exp_margin = sepFactor (G);
        /* Multiply by 2 since opt.gap is the gap size, not the margin */
    if (exp_margin.doAdd) {
        opt.gap.x = 2.0*PS2INCH(exp_margin.x);
        opt.gap.y = 2.0*PS2INCH(exp_margin.y);
    }
    else {
        opt.gap.x = opt.gap.y = 2.0*PS2INCH(DFLT_MARGIN);
    }
    opt.nsize = nsize;
 
    removeoverlaps(nnodes, coords, &opt);
 
    j = 0;
    for (Agnode_t *v = agfstnode(G); v; v = agnxtnode(G, v)) {
        for (size_t i = 0; i < dim; i++) {
            ND_pos(v)[i] = coords[i][j];
        }
        j++;
    }
 
    free (f_storage);
    free (nsize);
    return 0;
}
#endif
 
/* Return true if "normalize" is defined and valid; return angle in phi.
 * Read angle as degrees, convert to radians.
 * Guarantee -PI < phi <= PI.
 */
static int
angleSet (graph_t* g, double* phi)
{
    char* p;
    char* a = agget(g, "normalize");
 
    if (!a || *a == '\0')
        return 0;
    double ang = strtod (a, &p);
    if (p == a) {  /* no number */
        if (mapbool(a))
            ang = 0.0;
        else
            return 0;
    }
    while (ang > 180) ang -= 360;
    while (ang <= -180) ang += 360;
 
    *phi = RADIANS(ang);
    return 1;
}
 
/* If normalize is set, move first node to origin, then
 * rotate graph so that the angle of the first edge is given
 * by the degrees from normalize.
 * FIX: Generalize to allow rotation determined by graph shape.
 */
int normalize(graph_t * g)
{
    double phi;
    int ret;
 
    if (!angleSet(g, &phi))
        return 0;
 
    node_t *v = agfstnode(g);
    pointf p = {.x = ND_pos(v)[0], .y = ND_pos(v)[1]};
    for (v = agfstnode(g); v; v = agnxtnode(g, v)) {
        ND_pos(v)[0] -= p.x;
        ND_pos(v)[1] -= p.y;
    }
    if (p.x || p.y) ret = 1;
    else ret = 0;
 
    edge_t *e = NULL;
    for (v = agfstnode(g); v; v = agnxtnode(g, v))
        if ((e = agfstout(g, v)))
            break;
    if (e == NULL)
        return ret;
 
        /* rotation necessary; pos => ccw */
    phi -= atan2(ND_pos(aghead(e))[1] - ND_pos(agtail(e))[1],
                   ND_pos(aghead(e))[0] - ND_pos(agtail(e))[0]);
 
    if (phi) {
        const pointf orig = {.x = ND_pos(agtail(e))[0],
                             .y = ND_pos(agtail(e))[1]};
        const double cosv = cos(phi);
        const double sinv = sin(phi);
        for (v = agfstnode(g); v; v = agnxtnode(g, v)) {
            p.x = ND_pos(v)[0] - orig.x;
            p.y = ND_pos(v)[1] - orig.y;
            ND_pos(v)[0] = p.x * cosv - p.y * sinv + orig.x;
            ND_pos(v)[1] = p.x * sinv + p.y * cosv + orig.y;
        }
        return 1;
    }
    else return ret;
}
 
typedef struct {
    adjust_mode mode;
    char *attrib;
    char *print;
} lookup_t;
 
/* Translation table from overlap values to algorithms.
 * adjustMode[0] corresponds to overlap=true
 * adjustMode[1] corresponds to overlap=false
 */
static const lookup_t adjustMode[] = {
    {AM_NONE, "", "none"},
#if defined(HAVE_GTS) && defined(SFDP)
    {AM_PRISM, "prism", "prism"},
#endif
    {AM_VOR, "voronoi", "Voronoi"},
    {AM_NSCALE, "scale", "scaling"},
    {AM_COMPRESS, "compress", "compress"},
    {AM_VPSC, "vpsc", "vpsc"},
    {AM_IPSEP, "ipsep", "ipsep"},
    {AM_SCALE, "oscale", "old scaling"},
    {AM_SCALEXY, "scalexy", "x and y scaling"},
    {AM_ORTHO, "ortho", "orthogonal constraints"},
    {AM_ORTHO_YX, "ortho_yx", "orthogonal constraints"},
    {AM_ORTHOXY, "orthoxy", "xy orthogonal constraints"},
    {AM_ORTHOYX, "orthoyx", "yx orthogonal constraints"},
    {AM_PORTHO, "portho", "pseudo-orthogonal constraints"},
    {AM_PORTHO_YX, "portho_yx", "pseudo-orthogonal constraints"},
    {AM_PORTHOXY, "porthoxy", "xy pseudo-orthogonal constraints"},
    {AM_PORTHOYX, "porthoyx", "yx pseudo-orthogonal constraints"},
#if !(defined(HAVE_GTS) && defined(SFDP))
    {AM_PRISM, "prism", 0},
#endif
    {0}
};
 
static void setPrismValues(Agraph_t *g, const char *s, adjust_data *dp) {
    int v;
 
    if (sscanf (s, "%d", &v) > 0 && v >= 0)
        dp->value = v;
    else
        dp->value = 1000;
    dp->scaling = late_double(g, agfindgraphattr(g, "overlap_scaling"), -4.0, -1.e10);
}
 
static void getAdjustMode(Agraph_t *g, const char *s, adjust_data *dp) {
    const lookup_t *ap = adjustMode + 1;
    if (s == NULL || *s == '\0') {
        dp->mode = adjustMode[0].mode;
        dp->print = adjustMode[0].print;
    }
    else {
        while (ap->attrib) {
            bool matches = strcasecmp(s, ap->attrib) == 0;
            // "prism" takes parameters, so needs to match "prism.*"
            matches |= ap->mode == AM_PRISM
                    && strncasecmp(s, ap->attrib, strlen(ap->attrib)) == 0;
            if (matches) {
                if (ap->print == NULL) {
                    agwarningf("Overlap value \"%s\" unsupported - ignored\n", ap->attrib);
                    ap = &adjustMode[1];
                }
                dp->mode = ap->mode;
                dp->print = ap->print;
                if (ap->mode == AM_PRISM)
                    setPrismValues(g, s + strlen(ap->attrib), dp);
                break;
            }
            ap++;
        }
        if (ap->attrib == NULL ) {
            bool v = mapbool(s);
            bool unmappable = v != mapBool(s, true);
            if (unmappable) {
                agwarningf("Unrecognized overlap value \"%s\" - using false\n", s);
                v = false;
            }
            if (v) {
                dp->mode = adjustMode[0].mode;
                dp->print = adjustMode[0].print;
            }
            else {
                dp->mode = adjustMode[1].mode;
                dp->print = adjustMode[1].print;
            }
            if (dp->mode == AM_PRISM)
                setPrismValues (g, "", dp);
        }
    }
    if (Verbose) {
        fprintf(stderr, "overlap: %s value %d scaling %.04f\n", dp->print, dp->value, dp->scaling);
    }
}
 
void graphAdjustMode(graph_t *G, adjust_data *dp, char *dflt) {
    char* am = agget(G, "overlap");
    getAdjustMode (G, am ? am : (dflt ? dflt : ""), dp);
}
 
#define ISZERO(d) (fabs(d) < 0.000000001)
 
static int simpleScale (graph_t* g) 
{
    pointf sc;
    int i;
    char* p;
 
    if ((p = agget(g, "scale"))) {
        if ((i = sscanf(p, "%lf,%lf", &sc.x, &sc.y))) {
            if (ISZERO(sc.x)) return 0;
            if (i == 1) sc.y = sc.x;
            else if (ISZERO(sc.y)) return 0;
            if (sc.y == 1 && sc.x == 1) return 0;
            if (Verbose)
                fprintf (stderr, "scale = (%.03f,%.03f)\n", sc.x, sc.y);
            for (node_t *n = agfstnode(g); n; n = agnxtnode(g,n)) {
                ND_pos(n)[0] *= sc.x;
                ND_pos(n)[1] *= sc.y;
            }
            return 1;
        }
    }
    return 0;
}
 
/* Use adjust_data to determine if and how to remove
 * node overlaps.
 * Return non-zero if nodes are moved.
 */
int 
removeOverlapWith (graph_t * G, adjust_data* am)
{
    int ret;
 
    if (agnnodes(G) < 2)
        return 0;
 
    int nret = normalize (G);
    nret += simpleScale (G);
 
    if (am->mode == AM_NONE)
        return nret;
 
    if (Verbose)
        fprintf(stderr, "Adjusting %s using %s\n", agnameof(G), am->print);
 
    if (am->mode > AM_SCALE) {
        switch (am->mode) {
        case AM_NSCALE:
            ret = scAdjust(G, 1);
            break;
        case AM_SCALEXY:
            ret = scAdjust(G, 0);
            break;
        case AM_PORTHO_YX:
        case AM_PORTHO:
        case AM_PORTHOXY:
        case AM_PORTHOYX:
        case AM_ORTHO_YX:
        case AM_ORTHO:
        case AM_ORTHOXY:
        case AM_ORTHOYX:
            cAdjust(G, am->mode);
        ret = 0;
            break;
        case AM_COMPRESS:
            ret = scAdjust(G, -1);
            break;
#if defined(HAVE_GTS) && defined(SFDP)
        case AM_PRISM:
            fdpAdjust(G, am);
            ret = 0;
            break;
#endif
#ifdef IPSEPCOLA
        case AM_IPSEP:
            return nret;   /* handled during layout */
            break;
        case AM_VPSC:
            ret = vpscAdjust(G);
            break;
#endif
        default:                /* to silence warnings */
            if (am->mode != AM_VOR && am->mode != AM_SCALE)
                agwarningf("Unhandled adjust option %s\n", am->print);
            ret = 0;
            break;
        }
        return nret+ret;
    }
 
    /* create main array */
    if (makeInfo(G)) {
        freeNodes();
        return nret;
    }
 
    /* establish and verify bounding box */
    state_t st = {0};
    chkBoundBox(&st, G);
 
    if (am->mode == AM_SCALE)
        ret = sAdjust(&st);
    else
        ret = vAdjust(&st);
 
    if (ret)
        updateGraph();
 
    freeNodes();
    free(st.sites);
 
    return ret+nret;
}
 
int 
removeOverlapAs(graph_t * G, char* flag)
{
    adjust_data am;
 
    if (agnnodes(G) < 2)
        return 0;
    getAdjustMode(G, flag, &am);
    return removeOverlapWith (G, &am);
}
 
/* Remove node overlap relying on graph's overlap attribute.
 * Return non-zero if graph has changed.
 */
int adjustNodes(graph_t * G)
{
    return removeOverlapAs(G, agget(G, "overlap"));
}
 
/* Convert "sep" attribute into expand_t.
 * Input "+x,y" becomes {x,y,true}
 * Input "x,y" becomes {1 + x/sepfact,1 + y/sepfact,false}
 * Return 1 on success, 0 on failure
 */
static int parseFactor(char *s, expand_t *pp, double sepfact, double dflt) {
    int i;
 
    while (gv_isspace(*s)) s++;
    if (*s == '+') {
        s++;
        pp->doAdd = true;
    }
    else pp->doAdd = false;
 
    double x, y;
    if ((i = sscanf(s, "%lf,%lf", &x, &y))) {
        if (i == 1) y = x;
        if (pp->doAdd) {
            if (sepfact > 1) {
                pp->x = fmin(dflt, x / sepfact);
                pp->y = fmin(dflt, y / sepfact);
            }
            else if (sepfact < 1) {
                pp->x = fmax(dflt, x / sepfact);
                pp->y = fmax(dflt, y / sepfact);
            }
            else {
                pp->x = x;
                pp->y = y;
            }
        }
        else {
            pp->x = 1.0 + x / sepfact;
            pp->y = 1.0 + y / sepfact;
        }
        return 1;
    }
    else return 0;
}
 
expand_t
sepFactor(graph_t* g)
{
    expand_t pmargin;
    char*  marg;
 
    if ((marg = agget(g, "sep")) && parseFactor(marg, &pmargin, 1.0, 0)) {
    }
    else if ((marg = agget(g, "esep")) && parseFactor(marg, &pmargin, SEPFACT, DFLT_MARGIN)) {
    }
    else { /* default */
        pmargin.x = pmargin.y = DFLT_MARGIN;
        pmargin.doAdd = true;
    }
    if (Verbose)
        fprintf (stderr, "Node separation: add=%d (%f,%f)\n",
            pmargin.doAdd, pmargin.x, pmargin.y);
    return pmargin;
}
 
/* This value should be smaller than the sep value used to expand
 * nodes during adjustment. If not, when the adjustment pass produces
 * a fairly tight layout, the spline code will find that some nodes
 * still overlap.
 */
expand_t
esepFactor(graph_t* g)
{
    expand_t pmargin;
    char*  marg;
 
    if ((marg = agget(g, "esep")) && parseFactor(marg, &pmargin, 1.0, 0)) {
    }
    else if ((marg = agget(g, "sep")) &&
             parseFactor(marg, &pmargin, 1.0 / SEPFACT, SEPFACT * DFLT_MARGIN)) {
    }
    else {
        pmargin.x = pmargin.y = SEPFACT*DFLT_MARGIN;
        pmargin.doAdd = true;
    }
    if (Verbose)
        fprintf (stderr, "Edge separation: add=%d (%f,%f)\n",
            pmargin.doAdd, pmargin.x, pmargin.y);
    return pmargin;
}