/graphviz-cmake/lib/dotgen/compound.c
C | 489 lines | 337 code | 41 blank | 111 comment | 102 complexity | 70ea973eae7185178d5a78a60a5d3dcb MD5 | raw file
Possible License(s): MPL-2.0-no-copyleft-exception, EPL-1.0, CPL-1.0, BSD-3-Clause, LGPL-2.1
- /* $Id: compound.c,v 1.12 2011/01/25 16:30:48 ellson Exp $ $Revision: 1.12 $ */
- /* vim:set shiftwidth=4 ts=8: */
- /*************************************************************************
- * 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
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors: See CVS logs. Details at http://www.graphviz.org/
- *************************************************************************/
- /* Module for clipping splines to cluster boxes.
- */
- #include "dot.h"
- /* pf2s:
- * Convert a pointf to its string representation.
- */
- static char *pf2s(pointf p, char *buf)
- {
- sprintf(buf, "(%.5g,%.5g)", p.x, p.y);
- return buf;
- }
- /* Return point where line segment [pp,cp] intersects
- * the box bp. Assume cp is outside the box, and pp is
- * on or in the box.
- */
- static pointf boxIntersectf(pointf pp, pointf cp, boxf * bp)
- {
- pointf ipp;
- double ppx = pp.x;
- double ppy = pp.y;
- double cpx = cp.x;
- double cpy = cp.y;
- pointf ll;
- pointf ur;
- ll = bp->LL;
- ur = bp->UR;
- if (cp.x < ll.x) {
- ipp.x = ll.x;
- ipp.y = pp.y + (int) ((ipp.x - ppx) * (ppy - cpy) / (ppx - cpx));
- if (ipp.y >= ll.y && ipp.y <= ur.y)
- return ipp;
- }
- if (cp.x > ur.x) {
- ipp.x = ur.x;
- ipp.y = pp.y + (int) ((ipp.x - ppx) * (ppy - cpy) / (ppx - cpx));
- if (ipp.y >= ll.y && ipp.y <= ur.y)
- return ipp;
- }
- if (cp.y < ll.y) {
- ipp.y = ll.y;
- ipp.x = pp.x + (int) ((ipp.y - ppy) * (ppx - cpx) / (ppy - cpy));
- if (ipp.x >= ll.x && ipp.x <= ur.x)
- return ipp;
- }
- if (cp.y > ur.y) {
- ipp.y = ur.y;
- ipp.x = pp.x + (int) ((ipp.y - ppy) * (ppx - cpx) / (ppy - cpy));
- if (ipp.x >= ll.x && ipp.x <= ur.x)
- return ipp;
- }
- /* failure */
- {
- char ppbuf[100], cpbuf[100], llbuf[100], urbuf[100];
- agerr(AGERR,
- "segment [%s,%s] does not intersect box ll=%s,ur=%s\n",
- pf2s(pp, ppbuf), pf2s(cp, cpbuf),
- pf2s(ll, llbuf), pf2s(ur, urbuf));
- assert(0);
- }
- return ipp;
- }
- /* inBoxf:
- * Returns true if p is on or in box bb
- */
- static int inBoxf(pointf p, boxf * bb)
- {
- return INSIDE(p, *bb);
- }
- /* getCluster:
- * Returns subgraph of g with given name.
- * Returns NULL if no name is given, or subgraph of
- * that name does not exist.
- */
- static graph_t *getCluster(graph_t * g, char *cluster_name)
- {
- graph_t *sg;
- if (!cluster_name || (*cluster_name == '\0'))
- return NULL;
- #ifndef WITH_CGRAPH
- sg = agfindsubg(g, cluster_name);
- #else
- sg = agsubg(g, cluster_name, 0);
- #endif
- if (sg == NULL)
- agerr(AGWARN, "cluster named %s not found\n", cluster_name);
- return sg;
- }
- /* The following functions are derived from pp. 411-415 (pp. 791-795)
- * of Graphics Gems. In the code there, they use a SGN function to
- * count crossings. This doesn't seem to handle certain special cases,
- * as when the last point is on the line. It certainly didn't work
- * for us when we used int values; see bug 145. We needed to use CMP instead.
- *
- * Possibly unnecessary with double values, but harmless.
- */
- /* countVertCross:
- * Return the number of times the Bezier control polygon crosses
- * the vertical line x = xcoord.
- */
- static int countVertCross(pointf * pts, double xcoord)
- {
- int i;
- int sign, old_sign;
- int num_crossings = 0;
- sign = CMP(pts[0].x, xcoord);
- if (sign == 0)
- num_crossings++;
- for (i = 1; i <= 3; i++) {
- old_sign = sign;
- sign = CMP(pts[i].x, xcoord);
- if ((sign != old_sign) && (old_sign != 0))
- num_crossings++;
- }
- return num_crossings;
- }
- /* countHorzCross:
- * Return the number of times the Bezier control polygon crosses
- * the horizontal line y = ycoord.
- */
- static int countHorzCross(pointf * pts, double ycoord)
- {
- int i;
- int sign, old_sign;
- int num_crossings = 0;
- sign = CMP(pts[0].y, ycoord);
- if (sign == 0)
- num_crossings++;
- for (i = 1; i <= 3; i++) {
- old_sign = sign;
- sign = CMP(pts[i].y, ycoord);
- if ((sign != old_sign) && (old_sign != 0))
- num_crossings++;
- }
- return num_crossings;
- }
- /* findVertical:
- * Given 4 Bezier control points pts, corresponding to the portion
- * of an initial spline with path parameter in the range
- * 0.0 <= tmin <= t <= tmax <= 1.0, return t where the spline
- * first crosses a vertical line segment
- * [(xcoord,ymin),(xcoord,ymax)]. Return -1 if not found.
- * This is done by binary subdivision.
- */
- static double
- findVertical(pointf * pts, double tmin, double tmax,
- double xcoord, double ymin, double ymax)
- {
- pointf Left[4];
- pointf Right[4];
- double t;
- int no_cross = countVertCross(pts, xcoord);
- if (no_cross == 0)
- return -1.0;
- /* if 1 crossing and on the line x == xcoord (within 1 point) */
- if ((no_cross == 1) && (ROUND(pts[3].x) == ROUND(xcoord))) {
- if ((ymin <= pts[3].y) && (pts[3].y <= ymax)) {
- return tmax;
- } else
- return -1.0;
- }
- /* split the Bezier into halves, trying the first half first. */
- Bezier(pts, 3, 0.5, Left, Right);
- t = findVertical(Left, tmin, (tmin + tmax) / 2.0, xcoord, ymin, ymax);
- if (t >= 0.0)
- return t;
- return findVertical(Right, (tmin + tmax) / 2.0, tmax, xcoord, ymin,
- ymax);
- }
- /* findHorizontal:
- * Given 4 Bezier control points pts, corresponding to the portion
- * of an initial spline with path parameter in the range
- * 0.0 <= tmin <= t <= tmax <= 1.0, return t where the spline
- * first crosses a horizontal line segment
- * [(xmin,ycoord),(xmax,ycoord)]. Return -1 if not found.
- * This is done by binary subdivision.
- */
- static double
- findHorizontal(pointf * pts, double tmin, double tmax,
- double ycoord, double xmin, double xmax)
- {
- pointf Left[4];
- pointf Right[4];
- double t;
- int no_cross = countHorzCross(pts, ycoord);
- if (no_cross == 0)
- return -1.0;
- /* if 1 crossing and on the line y == ycoord (within 1 point) */
- if ((no_cross == 1) && (ROUND(pts[3].y) == ROUND(ycoord))) {
- if ((xmin <= pts[3].x) && (pts[3].x <= xmax)) {
- return tmax;
- } else
- return -1.0;
- }
- /* split the Bezier into halves, trying the first half first. */
- Bezier(pts, 3, 0.5, Left, Right);
- t = findHorizontal(Left, tmin, (tmin + tmax) / 2.0, ycoord, xmin,
- xmax);
- if (t >= 0.0)
- return t;
- return findHorizontal(Right, (tmin + tmax) / 2.0, tmax, ycoord, xmin,
- xmax);
- }
- /* splineIntersectf:
- * Given four spline control points and a box,
- * find the shortest portion of the spline from
- * pts[0] to the intersection with the box, if any.
- * If an intersection is found, the four points are stored in pts[0..3]
- * with pts[3] being on the box, and 1 is returned. Otherwise, pts
- * is left unchanged and 0 is returned.
- */
- static int splineIntersectf(pointf * pts, boxf * bb)
- {
- double tmin = 2.0;
- double t;
- pointf origpts[4];
- int i;
- for (i = 0; i < 4; i++) {
- origpts[i] = pts[i];
- }
- t = findVertical(pts, 0.0, 1.0, bb->LL.x, bb->LL.y, bb->UR.y);
- if ((t >= 0) && (t < tmin)) {
- Bezier(origpts, 3, t, pts, NULL);
- tmin = t;
- }
- t = findVertical(pts, 0.0, MIN(1.0, tmin), bb->UR.x, bb->LL.y,
- bb->UR.y);
- if ((t >= 0) && (t < tmin)) {
- Bezier(origpts, 3, t, pts, NULL);
- tmin = t;
- }
- t = findHorizontal(pts, 0.0, MIN(1.0, tmin), bb->LL.y, bb->LL.x,
- bb->UR.x);
- if ((t >= 0) && (t < tmin)) {
- Bezier(origpts, 3, t, pts, NULL);
- tmin = t;
- }
- t = findHorizontal(pts, 0.0, MIN(1.0, tmin), bb->UR.y, bb->LL.x,
- bb->UR.x);
- if ((t >= 0) && (t < tmin)) {
- Bezier(origpts, 3, t, pts, NULL);
- tmin = t;
- }
- if (tmin < 2.0) {
- return 1;
- } else
- return 0;
- }
- /* makeCompoundEdge:
- * If edge e has a cluster head and/or cluster tail,
- * clip spline to outside of cluster.
- * Requirement: spline is composed of only one part,
- * with n control points where n >= 4 and n (mod 3) = 1.
- * If edge has arrowheads, reposition them.
- */
- static void makeCompoundEdge(graph_t * g, edge_t * e)
- {
- graph_t *lh; /* cluster containing head */
- graph_t *lt; /* cluster containing tail */
- bezier *bez; /* original Bezier for e */
- bezier *nbez; /* new Bezier for e */
- int starti = 0, endi = 0; /* index of first and last control point */
- node_t *head;
- node_t *tail;
- boxf *bb;
- int i, j;
- int size;
- pointf pts[4];
- pointf p;
- int fixed;
- /* find head and tail target clusters, if defined */
- lh = getCluster(g, agget(e, "lhead"));
- lt = getCluster(g, agget(e, "ltail"));
- if (!lt && !lh)
- return;
- if (!ED_spl(e)) return;
- /* at present, we only handle single spline case */
- if (ED_spl(e)->size > 1) {
- agerr(AGWARN, "%s -> %s: spline size > 1 not supported\n",
- agnameof(agtail(e)), agnameof(aghead(e)));
- return;
- }
- bez = ED_spl(e)->list;
- size = bez->size;
- head = aghead(e);
- tail = agtail(e);
- /* allocate new Bezier */
- nbez = GNEW(bezier);
- nbez->eflag = bez->eflag;
- nbez->sflag = bez->sflag;
- /* if Bezier has four points, almost collinear,
- * make line - unimplemented optimization?
- */
- /* If head cluster defined, find first Bezier
- * crossing head cluster, and truncate spline to
- * box edge.
- * Otherwise, leave end alone.
- */
- fixed = 0;
- if (lh) {
- bb = &(GD_bb(lh));
- if (!inBoxf(ND_coord(head), bb)) {
- agerr(AGWARN, "%s -> %s: head not inside head cluster %s\n",
- agnameof(agtail(e)), agnameof(aghead(e)), agget(e, "lhead"));
- } else {
- /* If first control point is in bb, degenerate case. Spline
- * reduces to four points between the arrow head and the point
- * where the segment between the first control point and arrow head
- * crosses box.
- */
- if (inBoxf(bez->list[0], bb)) {
- if (inBoxf(ND_coord(tail), bb)) {
- agerr(AGWARN,
- "%s -> %s: tail is inside head cluster %s\n",
- agnameof(agtail(e)), agnameof(aghead(e)), agget(e, "lhead"));
- } else {
- assert(bez->sflag); /* must be arrowhead on tail */
- p = boxIntersectf(bez->list[0], bez->sp, bb);
- bez->list[3] = p;
- bez->list[1] = mid_pointf(p, bez->sp);
- bez->list[0] = mid_pointf(bez->list[1], bez->sp);
- bez->list[2] = mid_pointf(bez->list[1], p);
- if (bez->eflag)
- endi = arrowEndClip(e, bez->list,
- starti, 0, nbez, bez->eflag);
- endi += 3;
- fixed = 1;
- }
- } else {
- for (endi = 0; endi < size - 1; endi += 3) {
- if (splineIntersectf(&(bez->list[endi]), bb))
- break;
- }
- if (endi == size - 1) { /* no intersection */
- assert(bez->eflag);
- nbez->ep = boxIntersectf(bez->ep, bez->list[endi], bb);
- } else {
- if (bez->eflag)
- endi =
- arrowEndClip(e, bez->list,
- starti, endi, nbez, bez->eflag);
- endi += 3;
- }
- fixed = 1;
- }
- }
- }
- if (fixed == 0) { /* if no lh, or something went wrong, use original head */
- endi = size - 1;
- if (bez->eflag)
- nbez->ep = bez->ep;
- }
- /* If tail cluster defined, find last Bezier
- * crossing tail cluster, and truncate spline to
- * box edge.
- * Otherwise, leave end alone.
- */
- fixed = 0;
- if (lt) {
- bb = &(GD_bb(lt));
- if (!inBoxf(ND_coord(tail), bb)) {
- agerr(AGWARN, "%s -> %s: tail not inside tail cluster %s\n",
- agnameof(agtail(e)), agnameof(aghead(e)), agget(e, "ltail"));
- } else {
- /* If last control point is in bb, degenerate case. Spline
- * reduces to four points between arrow head, and the point
- * where the segment between the last control point and the
- * arrow head crosses box.
- */
- if (inBoxf(bez->list[endi], bb)) {
- if (inBoxf(ND_coord(head), bb)) {
- agerr(AGWARN,
- "%s -> %s: head is inside tail cluster %s\n",
- agnameof(agtail(e)), agnameof(aghead(e)), agget(e, "ltail"));
- } else {
- assert(bez->eflag); /* must be arrowhead on head */
- p = boxIntersectf(bez->list[endi], nbez->ep, bb);
- starti = endi - 3;
- bez->list[starti] = p;
- bez->list[starti + 2] = mid_pointf(p, nbez->ep);
- bez->list[starti + 3] = mid_pointf(bez->list[starti + 2], nbez->ep);
- bez->list[starti + 1] = mid_pointf(bez->list[starti + 2], p);
- if (bez->sflag)
- starti = arrowStartClip(e, bez->list, starti,
- endi - 3, nbez, bez->sflag);
- fixed = 1;
- }
- } else {
- for (starti = endi; starti > 0; starti -= 3) {
- for (i = 0; i < 4; i++)
- pts[i] = bez->list[starti - i];
- if (splineIntersectf(pts, bb)) {
- for (i = 0; i < 4; i++)
- bez->list[starti - i] = pts[i];
- break;
- }
- }
- if (starti == 0) {
- assert(bez->sflag);
- nbez->sp =
- boxIntersectf(bez->sp, bez->list[starti], bb);
- } else {
- starti -= 3;
- if (bez->sflag)
- starti = arrowStartClip(e, bez->list, starti,
- endi - 3, nbez, bez->sflag);
- }
- fixed = 1;
- }
- }
- }
- if (fixed == 0) { /* if no lt, or something went wrong, use original tail */
- /* Note: starti == 0 */
- if (bez->sflag)
- nbez->sp = bez->sp;
- }
- /* complete Bezier, free garbage and attach new Bezier to edge
- */
- nbez->size = endi - starti + 1;
- nbez->list = N_GNEW(nbez->size, pointf);
- for (i = 0, j = starti; i < nbez->size; i++, j++)
- nbez->list[i] = bez->list[j];
- free(bez->list);
- free(bez);
- ED_spl(e)->list = nbez;
- }
- /* dot_compoundEdges:
- */
- void dot_compoundEdges(graph_t * g)
- {
- edge_t *e;
- node_t *n;
- for (n = agfstnode(g); n; n = agnxtnode(g, n)) {
- for (e = agfstout(g, n); e; e = agnxtout(g, e)) {
- makeCompoundEdge(g, e);
- }
- }
- }