Revision: 45569
http://brlcad.svn.sourceforge.net/brlcad/?rev=45569&view=rev
Author: r_weiss
Date: 2011-07-21 23:31:06 +0000 (Thu, 21 Jul 2011)
Log Message:
-----------
Updated the prototype version of function bn_isect_line_lseg and
bn_isect_line3_line3_new within the libbn library within file plane.c. These
changes are disabled by default. These functions support the prototype function
nmg_triangulate_fu. Made changes to code logic and performed code cleanup. This
is a work in progress.
Modified Paths:
--------------
brlcad/trunk/src/libbn/plane.c
Modified: brlcad/trunk/src/libbn/plane.c
===================================================================
--- brlcad/trunk/src/libbn/plane.c 2011-07-21 21:24:56 UTC (rev 45568)
+++ brlcad/trunk/src/libbn/plane.c 2011-07-21 23:31:06 UTC (rev 45569)
@@ -1414,7 +1414,6 @@
int parallel = 0;
int colinear = 0;
- int error_occured = 0;
fastf_t dot, d1, d2, d3, d4;
vect_t pdir, qdir;
@@ -1424,7 +1423,7 @@
pdir_mag_sq = MAGSQ(pdir);
qdir_mag_sq = MAGSQ(qdir);
- if (NEAR_ZERO(pdir_mag_sq, SMALL_FASTF) || NEAR_ZERO(qdir_mag_sq,
SMALL_FASTF)) {
+ if ((pdir_mag_sq < tol->dist_sq) || (qdir_mag_sq < tol->dist_sq)) {
bu_log(" p0 = %g %g %g\n", V3ARGS(p0));
bu_log("pdir = %g %g %g\n", V3ARGS(pdir));
bu_log(" q0 = %g %g %g\n", V3ARGS(q0));
@@ -1432,23 +1431,6 @@
bu_bomb("bn_isect_line3_line3_new(): input vector(s) 'pdir' and/or
'qdir' is zero magnitude.\n");
}
- if (NEAR_ZERO(pdir_mag_sq - 1.0, SMALL_FASTF)) {
- VSCALE(pdir, pdir, 304800); /* 304800mm = 1000ft */
- pdir_mag_sq = MAGSQ(pdir);
- error_occured++;
- }
-
- if (NEAR_ZERO(qdir_mag_sq - 1.0, SMALL_FASTF)) {
- VSCALE(qdir, qdir, 304800); /* 304800mm = 1000ft */
- qdir_mag_sq = MAGSQ(qdir);
- error_occured++;
- }
-
- if (error_occured == 2) {
- bu_log("pdir = %g %g %g qdir = %g %g %g\n", V3ARGS(pdir_i),
V3ARGS(qdir_i));
- bu_log("bn_isect_line3_line3_new(): input vector(s) 'pdir' and 'qdir'
are unit vectors.\n");
- }
-
*pdist = 0.0;
*qdist = 0.0;
@@ -1458,27 +1440,27 @@
VSUB2(p0_to_q1, q1, p0);
- d1 = bn_dist_line3_pt3(q0,qdir,p0);
- d2 = bn_dist_line3_pt3(q0,qdir,p1);
- d3 = bn_dist_line3_pt3(p0,pdir,q0);
- d4 = bn_dist_line3_pt3(p0,pdir,q1);
+ d1 = bn_distsq_line3_pt3(q0,qdir,p0);
+ d2 = bn_distsq_line3_pt3(q0,qdir,p1);
+ d3 = bn_distsq_line3_pt3(p0,pdir,q0);
+ d4 = bn_distsq_line3_pt3(p0,pdir,q1);
/* if all distances are within distance tolerance of each
* other then they a parallel
*/
- if (NEAR_EQUAL(d1, d2, tol->dist) &&
- NEAR_EQUAL(d1, d3, tol->dist) &&
- NEAR_EQUAL(d1, d4, tol->dist) &&
- NEAR_EQUAL(d2, d3, tol->dist) &&
- NEAR_EQUAL(d2, d4, tol->dist) &&
- NEAR_EQUAL(d3, d4, tol->dist)) {
+ if (NEAR_EQUAL(d1, d2, tol->dist_sq) &&
+ NEAR_EQUAL(d1, d3, tol->dist_sq) &&
+ NEAR_EQUAL(d1, d4, tol->dist_sq) &&
+ NEAR_EQUAL(d2, d3, tol->dist_sq) &&
+ NEAR_EQUAL(d2, d4, tol->dist_sq) &&
+ NEAR_EQUAL(d3, d4, tol->dist_sq)) {
parallel = 1;
}
- if (NEAR_ZERO(d1, tol->dist) &&
- NEAR_ZERO(d2, tol->dist) &&
- NEAR_ZERO(d3, tol->dist) &&
- NEAR_ZERO(d4, tol->dist)) {
+ if (NEAR_ZERO(d1, tol->dist_sq) &&
+ NEAR_ZERO(d2, tol->dist_sq) &&
+ NEAR_ZERO(d3, tol->dist_sq) &&
+ NEAR_ZERO(d4, tol->dist_sq)) {
colinear = 1;
}
@@ -1859,18 +1841,21 @@
{
#ifdef TRI_PROTOTYPE
vect_t ab, pa, pb; /* direction vectors a->b, p->a, p->b */
- auto fastf_t u; /* As in, A + u * C = X */
- register int ret;
-
fastf_t ab_mag;
fastf_t pa_mag_sq;
fastf_t pb_mag_sq;
fastf_t d_mag_sq;
+ int code;
+ fastf_t dist1, dist2, d1, d2;
+ int colinear = 0;
+ fastf_t dot;
BN_CK_TOL(tol);
+ *t = 0.0;
+
d_mag_sq = MAGSQ(d);
- if (ZERO(d_mag_sq)) {
+ if (NEAR_ZERO(d_mag_sq, tol->dist_sq)) {
bu_bomb("bn_isect_line_lseg(): ray direction vector zero magnitude\n");
}
@@ -1897,87 +1882,164 @@
return 2;
}
- /* Detecting colinearity is difficult, and very very important.
- * As a first step, check to see if both points A and B lie within
- * tolerance of the line. If so, then the line segment AC is ON
- * the line.
+ /* just check that the vertices of the line segement are
+ * within distance tolerance of the ray. it may cause problems
+ * to also require the ray start and end points to be within
+ * distance tolerance of the infinite line associated with
+ * the line segement.
*/
- if (bn_distsq_line3_pt3(p, d, a) <= tol->dist_sq &&
- bn_distsq_line3_pt3(p, d, b) <= tol->dist_sq) {
- if (bu_debug & BU_DEBUG_MATH) {
- bu_log("bn_isect_line3_lseg3() pts A and B within tol of line\n");
- }
- /* Find the parametric distance along the ray */
- *t = bn_dist_pt3_along_line3(p, d, a);
+ d1 = bn_distsq_line3_pt3(p,d,a); /* distance of point a to ray */
+ d2 = bn_distsq_line3_pt3(p,d,b); /* distance of point b to ray */
- if (*t < -tol->dist) {
- /* intersection of ray and line segment but in the
- * negative direction of the ray
- */
- return -1;
- } else {
- if (ZERO(*t)) {
- *t = 0.0;
- }
- /* co-linear (t was computed for point A, u=0) */
- return 0;
+ colinear = 0;
+ if (NEAR_ZERO(d1, tol->dist_sq) && NEAR_ZERO(d2, tol->dist_sq)) {
+ colinear = 1;
+
+ dist1 = sqrt(pa_mag_sq);
+ dist2 = sqrt(pb_mag_sq);
+
+ /* if the direction of the pa vector is in the
+ * opposite direction of the ray, then make the
+ * distance negative
+ */
+ dot = VDOT(pa, d);
+ if (dot < -SMALL_FASTF) {
+ dist1 = -dist1;
}
+
+ /* if the direction of the pb vector is in the
+ * opposite direction of the ray, then make the
+ * distance negative
+ */
+ dot = VDOT(pb, d);
+ if (dot < -SMALL_FASTF) {
+ dist2 = -dist2;
+ }
}
- if ((ret = bn_isect_line3_line3_new(t, &u, p, d, a, ab, tol)) < 0) {
- /* No intersection found */
- return -1;
+ if (colinear && dist1 < SMALL_FASTF && dist2 < SMALL_FASTF) {
+ /* lines are colinear but 'a' and 'b' are not on the ray */
+ return -1; /* no intersection */
}
- if (ret == 0) {
- /* co-linear (t was computed for point A, u=0) */
- return 0;
+ if (colinear && (dist1 > SMALL_FASTF) && (dist2 > SMALL_FASTF)) {
+ /* lines are colinear and both points 'a' and 'b' are on the ray. */
+ /* return the distance to the closest point */
+ if (dist2 > dist1) {
+ *t = dist1;
+ } else {
+ *t = dist2;
+ }
+ return 0;
}
- if (ZERO(*t)) {
- *t = 0.0;
+ if (colinear && (dist1 > SMALL_FASTF) && (dist2 < SMALL_FASTF)) {
+ /* lines are colinear and 'a' is on the ray but 'b' is not. */
+ /* return the distance to 'a' */
+ *t = dist1;
+ return 0;
}
- if (ZERO(u)) {
- u = 0.0;
+ if (colinear && (dist1 < SMALL_FASTF) && (dist2 > SMALL_FASTF)) {
+ /* lines are colinear and 'b' is on the ray but 'a' is not. */
+ /* return the distance to 'b' */
+ *t = dist2;
+ return 0;
}
- if (*t < -tol->dist) {
- /* intersection of ray and line segment but in the
- * negative direction of the ray
- */
- return -1;
+ dist1 = 0.0; /* sanity */
+ dist2 = 0.0; /* sanity */
+ code = bn_isect_line3_line3_new(&dist1, &dist2, p, d, a, ab, tol);
+
+ if (code == 0) {
+ bu_bomb("bn_isect_line_lseg(): we should have already detected a
colinear condition\n");
}
- if (NEAR_ZERO(u, tol->dist)) {
- /* Intersection at vertex A */
- /* use actual distance instead of hit point */
- *t = sqrt(pa_mag_sq);
- return 1;
+ if (code < 0) {
+ return -1; /* no intersection */
}
- if (u < -tol->dist) {
- /* Intersection exists, < A (t is returned) */
- return -3;
- }
- /* the computation (u - ab_mag) might cause some problems
- * because 'u' can be negative but 'ab_mag' can not
- */
- if (NEAR_ZERO(u - ab_mag, tol->dist)) {
- /* Intersection at vertex B */
- /* use actual distance instead of hit point */
- *t = sqrt(pb_mag_sq);
- return 2;
+ if (code == 1) {
+ if (dist1 < -(tol->dist)) {
+ /* the ray did isect the line segment but in the
+ * negative direction so this is not really a hit
+ */
+ return -1; /* no intersection */
+ }
}
- if (u > ab_mag + tol->dist) {
- /* Intersection exists, > B (t is returned) */
- return -2;
+ if (code == 1) {
+ /* determine if isect was before a, between a & b or after b */
+ vect_t d_unit;
+ vect_t a_to_isect_pt, b_to_isect_pt;
+ point_t isect_pt;
+ fastf_t a_to_isect_pt_mag_sq, b_to_isect_pt_mag_sq;
+
+ VMOVE(d_unit, d);
+ VUNITIZE(d_unit);
+
+#if 0
+ if (NEAR_ZERO(dist1, tol->dist)) {
+ bu_log("bn_isect_line_lseg(): dist1 = %.15f\n", dist1);
+ bu_bomb("bn_isect_line_lseg(): dist1 is zero\n");
+ }
+#endif
+
+ dist1 = fabs(dist1); /* sanity */
+ VSCALE(isect_pt, d_unit, dist1);
+ VSUB2(a_to_isect_pt, isect_pt, a);
+ VSUB2(b_to_isect_pt, isect_pt, b);
+
+ a_to_isect_pt_mag_sq = MAGSQ(a_to_isect_pt);
+ b_to_isect_pt_mag_sq = MAGSQ(b_to_isect_pt);
+
+ *t = dist1;
+
+ if (a_to_isect_pt_mag_sq < tol->dist_sq) {
+ /* isect at point a of line segement */
+ return 1;
+ }
+
+ if (b_to_isect_pt_mag_sq < tol->dist_sq) {
+ /* isect at point b of line segement */
+ return 2;
+ }
+
+ if ((a_to_isect_pt_mag_sq < tol->dist_sq) && (b_to_isect_pt_mag_sq <
tol->dist_sq)) {
+ bu_bomb("bn_isect_line_lseg(): this case should already been
caught. i.e. zero length line segment\n");
+ }
+
+ dot = VDOT(a_to_isect_pt, ab);
+ if (dot < -SMALL_FASTF) {
+ /* isect before point a of infinite line associated
+ * with the line segment a->b
+ */
+ return -3;
+ }
+
+ dot = VDOT(b_to_isect_pt, ab);
+ if (dot > SMALL_FASTF) {
+ /* isect after point b of infinite line associated
+ * with the line segment a->b
+ */
+ return -2;
+ }
+
+#if 0
+ bu_log("p = %f %f %f a = %f %f %f b = %f %f %f isect = %f %f %f dist1
= %f d = %f %f %f\n",
+ V3ARGS(p), V3ARGS(a), V3ARGS(b), V3ARGS(isect_pt), dist1,
V3ARGS(d));
+ bu_log("bn_isect_line_lseg(): isect on line segement\n");
+#endif
+
+ return 3; /* isect on line segement a->b but
+ * not on the end points
+ */
}
- /* Intersection between A and B */
- return 3;
+ bu_bomb("bn_isect_line_lseg(): logic error, should not be here\n");
+ return 0; /* quite compiler warning */
+
#else
vect_t c; /* Direction vector from A to B */
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