Now that's some nice changes. Woot! What breaks if the existing bn function is removed and bn_isect_lseg3_lseg3_new() is renamed to or merged with bn_isect_lseg3_lseg3()? Are there different arguments or different behavior expectations?
Understandably a work-in-progress, but I'd think that'd be an easy one to evaluate and merge into a single function even before the NMG code is ready to go live. That goes for all of the libbn changes. The two line segment intersection functions will have to be consolidated before the NMG changes can go live anyways just so we don't have duplicative maintenance and potentially dangerous usage behavior. Still, nice work. I still say that we'd vastly improve stability if LIBBN was scrutinized more closely with comprehensive unit tests. Cheers! Sean On Aug 17, 2011, at 3:16 PM, [email protected] wrote: > Revision: 46219 > http://brlcad.svn.sourceforge.net/brlcad/?rev=46219&view=rev > Author: r_weiss > Date: 2011-08-17 19:16:39 +0000 (Wed, 17 Aug 2011) > > Log Message: > ----------- > Within file 'plane.c' updated functions 'bn_coplanar', 'bn_isect_2planes' and > 'bn_isect_lseg3_lseg3_new'. Corrected a bug in 'bn_coplanar' when computing > the distance between planes. Within function 'bn_isect_2planes' changed some > floating point compares from zero to SMALL_FASTF and improved the comments. > Within 'bn_isect_lseg3_lseg3_new' fixed a bug when line segments are colinear > and the intersection in on the end point(s), the clamping of the exact end > point value was not being performed. The changes to function > 'bn_isect_lseg3_lseg3_new' are disabled by default and is a work in progress. > The function 'bn_isect_lseg3_lseg3_new' is a prototype function which > supports the prototype version of function 'nmg_triangulate_fu'. > > Modified Paths: > -------------- > brlcad/trunk/src/libbn/plane.c > > Modified: brlcad/trunk/src/libbn/plane.c > =================================================================== > --- brlcad/trunk/src/libbn/plane.c 2011-08-17 18:57:57 UTC (rev 46218) > +++ brlcad/trunk/src/libbn/plane.c 2011-08-17 19:16:39 UTC (rev 46219) > @@ -476,15 +476,15 @@ > * RPP. If this convention is unnecessary, just pass (0, 0, 0) as > * rpp_min. > * > - * @return 0 OK, line of intersection stored in `pt' and `dir'. > - * @return -1 FAIL, planes are identical (co-planar) > - * @return -2 FAIL, planes are parallel and distinct > - * @return -3 FAIL, unable to find line of intersection > + * @return 0 success, line of intersection stored in 'pt' and 'dir' > + * @return -1 planes are coplanar > + * @return -2 planes are parallel but not coplanar > + * @return -3 error, should be intersection but unable to find > * > * @param[out] pt Starting point of line of intersection > * @param[out] dir Direction vector of line of intersection (unit > length) > - * @param[in] a plane 1 > - * @param[in] b plane 2 > + * @param[in] a plane 1 (normal must be unit length) > + * @param[in] b plane 2 (normal must be unit length) > * @param[in] rpp_min minimum poit of model RPP > * @param[in] tol tolerance values > */ > @@ -500,17 +500,20 @@ > plane_t pl; > int i; > > + VSETALL(pt, 0.0); /* sanity */ > + VSETALL(dir, 0.0); /* sanity */ > + > if ((i = bn_coplanar(a, b, tol)) != 0) { > - if (i > 0) > - return -1; /* FAIL -- coplanar */ > - return -2; /* FAIL -- parallel & distinct */ > + if (i > 0) { > + return -1; /* planes are coplanar */ > + } > + return -2; /* planes are parallel but not coplanar */ > } > > /* Direction vector for ray is perpendicular to both plane > * normals. > */ > VCROSS(dir, a, b); > - VUNITIZE(dir); /* safety */ > > /* Select an axis-aligned plane which has its normal pointing > * along the same axis as the largest magnitude component of the > @@ -518,21 +521,31 @@ > * negative, reverse the direction vector, so that model is "in > * front" of start point. > */ > - abs_dir[X] = (dir[X] >= 0) ? dir[X] : (-dir[X]); > - abs_dir[Y] = (dir[Y] >= 0) ? dir[Y] : (-dir[Y]); > - abs_dir[Z] = (dir[Z] >= 0) ? dir[Z] : (-dir[Z]); > + abs_dir[X] = fabs(dir[X]); > + abs_dir[Y] = fabs(dir[Y]); > + abs_dir[Z] = fabs(dir[Z]); > > + if (ZERO(abs_dir[X])) { > + abs_dir[X] = 0.0; > + } > + if (ZERO(abs_dir[Y])) { > + abs_dir[Y] = 0.0; > + } > + if (ZERO(abs_dir[Z])) { > + abs_dir[Z] = 0.0; > + } > + > if (abs_dir[X] >= abs_dir[Y]) { > if (abs_dir[X] >= abs_dir[Z]) { > VSET(pl, 1, 0, 0); /* X */ > pl[W] = rpp_min[X]; > - if (dir[X] < 0) { > + if (dir[X] < -SMALL_FASTF) { > VREVERSE(dir, dir); > } > } else { > VSET(pl, 0, 0, 1); /* Z */ > pl[W] = rpp_min[Z]; > - if (dir[Z] < 0) { > + if (dir[Z] < -SMALL_FASTF) { > VREVERSE(dir, dir); > } > } > @@ -540,23 +553,25 @@ > if (abs_dir[Y] >= abs_dir[Z]) { > VSET(pl, 0, 1, 0); /* Y */ > pl[W] = rpp_min[Y]; > - if (dir[Y] < 0) { > + if (dir[Y] < -SMALL_FASTF) { > VREVERSE(dir, dir); > } > } else { > VSET(pl, 0, 0, 1); /* Z */ > pl[W] = rpp_min[Z]; > - if (dir[Z] < 0) { > + if (dir[Z] < -SMALL_FASTF) { > VREVERSE(dir, dir); > } > } > } > > /* Intersection of the 3 planes defines ray start point */ > - if (bn_mkpoint_3planes(pt, pl, a, b) < 0) > - return -3; /* FAIL -- no intersection */ > + if (bn_mkpoint_3planes(pt, pl, a, b) < 0) { > + return -3; /* error, should be intersection but unable to find */ > + } > > - return 0; /* OK */ > + /* success, line of intersection stored in 'pt' and 'dir' */ > + return 0; > } > > > @@ -1192,11 +1207,24 @@ > dist[0] = 1.0; > } > > - /* If 'q' within tol of either endpoint (0.0, 1.0), make exact. */ > - if (dist[1] > -qtol && dist[1] < qtol) { > - dist[1] = 0.0; > - } else if (dist[1] > 1.0-qtol && dist[1] < 1.0+qtol) { > - dist[1] = 1.0; > + if (status == 0) { /* infinite lines are colinear */ > + /* When line segments are colinear, dist[1] has an alternate > + * interpretation: it's the parameter along p (not q) > + * therefore dist[1] must use tolerance ptol not qtol. > + * If 'q' within tol of either endpoint (0.0, 1.0), make exact. > + */ > + if (dist[1] > -ptol && dist[1] < ptol) { > + dist[1] = 0.0; > + } else if (dist[1] > 1.0-ptol && dist[1] < 1.0+ptol) { > + dist[1] = 1.0; > + } > + } else { > + /* If 'q' within tol of either endpoint (0.0, 1.0), make exact. */ > + if (dist[1] > -qtol && dist[1] < qtol) { > + dist[1] = 0.0; > + } else if (dist[1] > 1.0-qtol && dist[1] < 1.0+qtol) { > + dist[1] = 1.0; > + } > } > > if (status == 0) { /* infinite lines are colinear */ > @@ -2798,9 +2826,9 @@ > bu_bomb("bn_coplanar(): input vector(s) 'a' and/or 'b' is not a unit > vector.\n"); > } > > + VSCALE(pt_a, a, fabs(a[W])); > + VSCALE(pt_b, b, fabs(b[W])); > dot = VDOT(a, b); > - VSCALE(pt_a, a, a[3]); > - VSCALE(pt_b, b, b[3]); > > if (NEAR_ZERO(dot, tol->perp)) { > return 0; /* planes are perpendicular */ > @@ -2809,11 +2837,12 @@ > /* parallel is when dot is within tol->perp of either -1 or 1 */ > if ((dot <= -SMALL_FASTF) ? (NEAR_EQUAL(dot, -1.0, tol->perp)) : > (NEAR_EQUAL(dot, 1.0, tol->perp))) { > if (bn_pt3_pt3_equal(pt_a, pt_b, tol)) { > - /* test for coplanar */ > + /* true when planes are coplanar */ > if (dot >= SMALL_FASTF) { > - /* test normals in same direction */ > + /* true when plane normals in same direction */ > return 1; > } else { > + /* true when plane normals in opposite direction */ > return 2; > } > } else { > > > This was sent by the SourceForge.net collaborative development platform, the > world's largest Open Source development site. > > ------------------------------------------------------------------------------ > Get a FREE DOWNLOAD! and learn more about uberSVN rich system, > user administration capabilities and model configuration. 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