Split line-surface intersection and shell raycasting stuff into its
own file. [git-p4: depot-paths = "//depot/solvespace/": change = 1992]solver
Jonathan Westhues
parent
d3dcd8fb23
commit
4c8f535305
1
Makefile
1
Makefile
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@ -47,6 +47,7 @@ SRFOBJS = $(OBJDIR)\ratpoly.obj \
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$(OBJDIR)\triangulate.obj \
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$(OBJDIR)\boolean.obj \
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$(OBJDIR)\surfinter.obj \
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$(OBJDIR)\raycast.obj \
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$(OBJDIR)\merge.obj \
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@ -0,0 +1,612 @@
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//-----------------------------------------------------------------------------
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// Routines for ray-casting: intersecting a line segment or an infinite line
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// with a surface or shell. Ray-casting against a shell is used for point-in-
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// shell testing, and the intersection of edge line segments against surfaces
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// is used to get rough surface-curve intersections, which are later refined
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// numerically.
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//-----------------------------------------------------------------------------
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#include "solvespace.h"
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// Dot product tolerance for perpendicular.
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const double SShell::DOTP_TOL = 1e-3;
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extern int FLAG;
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double SSurface::DepartureFromCoplanar(void) {
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int i, j;
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int ia, ja, ib, jb, ic, jc;
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double best;
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// Grab three points to define a plane; first choose (0, 0) arbitrarily.
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ia = ja = 0;
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// Then the point farthest from pt a.
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best = VERY_NEGATIVE;
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for(i = 0; i <= degm; i++) {
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for(j = 0; j <= degn; j++) {
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if(i == ia && j == ja) continue;
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double dist = (ctrl[i][j]).Minus(ctrl[ia][ja]).Magnitude();
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if(dist > best) {
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best = dist;
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ib = i;
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jb = j;
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}
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}
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}
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// Then biggest magnitude of ab cross ac.
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best = VERY_NEGATIVE;
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for(i = 0; i <= degm; i++) {
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for(j = 0; j <= degn; j++) {
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if(i == ia && j == ja) continue;
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if(i == ib && j == jb) continue;
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double mag =
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((ctrl[ia][ja].Minus(ctrl[ib][jb]))).Cross(
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(ctrl[ia][ja].Minus(ctrl[i ][j ]))).Magnitude();
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if(mag > best) {
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best = mag;
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ic = i;
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jc = j;
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}
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}
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}
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Vector n = ((ctrl[ia][ja].Minus(ctrl[ib][jb]))).Cross(
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(ctrl[ia][ja].Minus(ctrl[ic][jc])));
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n = n.WithMagnitude(1);
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double d = (ctrl[ia][ja]).Dot(n);
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// Finally, calculate the deviation from each point to the plane.
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double farthest = VERY_NEGATIVE;
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for(i = 0; i <= degm; i++) {
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for(j = 0; j <= degn; j++) {
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double dist = fabs(n.Dot(ctrl[i][j]) - d);
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if(dist > farthest) {
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farthest = dist;
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}
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}
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}
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return farthest;
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}
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void SSurface::WeightControlPoints(void) {
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int i, j;
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for(i = 0; i <= degm; i++) {
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for(j = 0; j <= degn; j++) {
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ctrl[i][j] = (ctrl[i][j]).ScaledBy(weight[i][j]);
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}
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}
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}
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void SSurface::UnWeightControlPoints(void) {
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int i, j;
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for(i = 0; i <= degm; i++) {
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for(j = 0; j <= degn; j++) {
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ctrl[i][j] = (ctrl[i][j]).ScaledBy(1.0/weight[i][j]);
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}
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}
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}
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void SSurface::CopyRowOrCol(bool row, int this_ij, SSurface *src, int src_ij) {
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if(row) {
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int j;
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for(j = 0; j <= degn; j++) {
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ctrl [this_ij][j] = src->ctrl [src_ij][j];
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weight[this_ij][j] = src->weight[src_ij][j];
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}
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} else {
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int i;
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for(i = 0; i <= degm; i++) {
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ctrl [i][this_ij] = src->ctrl [i][src_ij];
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weight[i][this_ij] = src->weight[i][src_ij];
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}
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}
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}
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void SSurface::BlendRowOrCol(bool row, int this_ij, SSurface *a, int a_ij,
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SSurface *b, int b_ij)
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{
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if(row) {
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int j;
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for(j = 0; j <= degn; j++) {
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Vector c = (a->ctrl [a_ij][j]).Plus(b->ctrl [b_ij][j]);
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double w = (a->weight[a_ij][j] + b->weight[b_ij][j]);
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ctrl [this_ij][j] = c.ScaledBy(0.5);
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weight[this_ij][j] = w / 2;
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}
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} else {
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int i;
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for(i = 0; i <= degm; i++) {
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Vector c = (a->ctrl [i][a_ij]).Plus(b->ctrl [i][b_ij]);
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double w = (a->weight[i][a_ij] + b->weight[i][b_ij]);
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ctrl [i][this_ij] = c.ScaledBy(0.5);
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weight[i][this_ij] = w / 2;
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}
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}
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}
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void SSurface::SplitInHalf(bool byU, SSurface *sa, SSurface *sb) {
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sa->degm = sb->degm = degm;
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sa->degn = sb->degn = degn;
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// by de Casteljau's algorithm in a projective space; so we must work
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// on points (w*x, w*y, w*z, w)
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WeightControlPoints();
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switch(byU ? degm : degn) {
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case 1:
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sa->CopyRowOrCol (byU, 0, this, 0);
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sb->CopyRowOrCol (byU, 1, this, 1);
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sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
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sb->BlendRowOrCol(byU, 0, this, 0, this, 1);
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break;
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case 2:
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sa->CopyRowOrCol (byU, 0, this, 0);
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sb->CopyRowOrCol (byU, 2, this, 2);
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sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
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sb->BlendRowOrCol(byU, 1, this, 1, this, 2);
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sa->BlendRowOrCol(byU, 2, sa, 1, sb, 1);
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sb->BlendRowOrCol(byU, 0, sa, 1, sb, 1);
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break;
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case 3: {
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SSurface st;
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st.degm = degm; st.degn = degn;
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sa->CopyRowOrCol (byU, 0, this, 0);
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sb->CopyRowOrCol (byU, 3, this, 3);
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sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
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sb->BlendRowOrCol(byU, 2, this, 2, this, 3);
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st. BlendRowOrCol(byU, 0, this, 1, this, 2); // scratch var
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sa->BlendRowOrCol(byU, 2, sa, 1, &st, 0);
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sb->BlendRowOrCol(byU, 1, sb, 2, &st, 0);
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sa->BlendRowOrCol(byU, 3, sa, 2, sb, 1);
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sb->BlendRowOrCol(byU, 0, sa, 2, sb, 1);
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break;
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}
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default: oops();
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}
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sa->UnWeightControlPoints();
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sb->UnWeightControlPoints();
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UnWeightControlPoints();
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}
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//-----------------------------------------------------------------------------
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// Find all points where the indicated finite (if segment) or infinite (if not
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// segment) line intersects our surface. Report them in uv space in the list.
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// We first do a bounding box check; if the line doesn't intersect, then we're
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// done. If it does, then we check how small our surface is. If it's big,
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// then we subdivide into quarters and recurse. If it's small, then we refine
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// by Newton's method and record the point.
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//-----------------------------------------------------------------------------
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void SSurface::AllPointsIntersectingUntrimmed(Vector a, Vector b,
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int *cnt, int *level,
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List<Inter> *l, bool segment,
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SSurface *sorig)
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{
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// Test if the line intersects our axis-aligned bounding box; if no, then
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// no possibility of an intersection
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if(LineEntirelyOutsideBbox(a, b, segment)) return;
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if(*cnt > 2000) {
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dbp("!!! too many subdivisions (level=%d)!", *level);
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dbp("degm = %d degn = %d", degm, degn);
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return;
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}
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(*cnt)++;
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// If we might intersect, and the surface is small, then switch to Newton
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// iterations.
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if(DepartureFromCoplanar() < 0.2*SS.ChordTolMm()) {
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Vector p = (ctrl[0 ][0 ]).Plus(
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ctrl[0 ][degn]).Plus(
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ctrl[degm][0 ]).Plus(
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ctrl[degm][degn]).ScaledBy(0.25);
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Inter inter;
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sorig->ClosestPointTo(p, &(inter.p.x), &(inter.p.y), false);
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if(sorig->PointIntersectingLine(a, b, &(inter.p.x), &(inter.p.y))) {
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Vector p = sorig->PointAt(inter.p.x, inter.p.y);
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// Debug check, verify that the point lies in both surfaces
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// (which it ought to, since the surfaces should be coincident)
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double u, v;
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ClosestPointTo(p, &u, &v);
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l->Add(&inter);
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} else {
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// Might not converge if line is almost tangent to surface...
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}
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return;
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}
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// But the surface is big, so split it, alternating by u and v
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SSurface surf0, surf1;
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SplitInHalf((*level & 1) == 0, &surf0, &surf1);
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int nextLevel = (*level) + 1;
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(*level) = nextLevel;
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surf0.AllPointsIntersectingUntrimmed(a, b, cnt, level, l, segment, sorig);
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(*level) = nextLevel;
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surf1.AllPointsIntersectingUntrimmed(a, b, cnt, level, l, segment, sorig);
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}
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//-----------------------------------------------------------------------------
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// Find all points where a line through a and b intersects our surface, and
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// add them to the list. If seg is true then report only intersections that
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// lie within the finite line segment (not including the endpoints); otherwise
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// we work along the infinite line. And we report either just intersections
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// inside the trim curve, or any intersection with u, v in [0, 1]. And we
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// either disregard or report tangent points.
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//-----------------------------------------------------------------------------
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void SSurface::AllPointsIntersecting(Vector a, Vector b,
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List<SInter> *l,
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bool seg, bool trimmed, bool inclTangent)
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{
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if(LineEntirelyOutsideBbox(a, b, seg)) return;
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Vector ba = b.Minus(a);
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double bam = ba.Magnitude();
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List<Inter> inters;
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ZERO(&inters);
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// All the intersections between the line and the surface; either special
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// cases that we can quickly solve in closed form, or general numerical.
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Vector center, axis, start, finish;
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double radius;
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if(degm == 1 && degn == 1) {
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// Against a plane, easy.
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Vector n = NormalAt(0, 0).WithMagnitude(1);
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double d = n.Dot(PointAt(0, 0));
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// Trim to line segment now if requested, don't generate points that
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// would just get discarded later.
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if(!seg ||
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(n.Dot(a) > d + LENGTH_EPS && n.Dot(b) < d - LENGTH_EPS) ||
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(n.Dot(b) > d + LENGTH_EPS && n.Dot(a) < d - LENGTH_EPS))
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{
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Vector p = Vector::AtIntersectionOfPlaneAndLine(n, d, a, b, NULL);
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Inter inter;
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ClosestPointTo(p, &(inter.p.x), &(inter.p.y));
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inters.Add(&inter);
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}
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} else if(IsCylinder(&axis, ¢er, &radius, &start, &finish)) {
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// This one can be solved in closed form too.
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Vector ab = b.Minus(a);
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if(axis.Cross(ab).Magnitude() < LENGTH_EPS) {
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// edge is parallel to axis of cylinder, no intersection points
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return;
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}
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// A coordinate system centered at the center of the circle, with
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// the edge under test horizontal
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Vector u, v, n = axis.WithMagnitude(1);
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u = (ab.Minus(n.ScaledBy(ab.Dot(n)))).WithMagnitude(1);
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v = n.Cross(u);
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Point2d ap = (a.Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
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bp = (b.Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
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sp = (start. Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
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fp = (finish.Minus(center)).DotInToCsys(u, v, n).ProjectXy();
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double thetas = atan2(sp.y, sp.x), thetaf = atan2(fp.y, fp.x);
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Point2d ip[2];
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int ip_n = 0;
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if(fabs(fabs(ap.y) - radius) < LENGTH_EPS) {
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// tangent
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if(inclTangent) {
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ip[0] = Point2d::From(0, ap.y);
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ip_n = 1;
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}
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} else if(fabs(ap.y) < radius) {
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// two intersections
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double xint = sqrt(radius*radius - ap.y*ap.y);
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ip[0] = Point2d::From(-xint, ap.y);
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ip[1] = Point2d::From( xint, ap.y);
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ip_n = 2;
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}
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int i;
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for(i = 0; i < ip_n; i++) {
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double t = (ip[i].Minus(ap)).DivPivoting(bp.Minus(ap));
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// This is a point on the circle; but is it on the arc?
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Point2d pp = ap.Plus((bp.Minus(ap)).ScaledBy(t));
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double theta = atan2(pp.y, pp.x);
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double dp = WRAP_SYMMETRIC(theta - thetas, 2*PI),
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df = WRAP_SYMMETRIC(thetaf - thetas, 2*PI);
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double tol = LENGTH_EPS/radius;
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if((df > 0 && ((dp < -tol) || (dp > df + tol))) ||
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(df < 0 && ((dp > tol) || (dp < df - tol))))
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{
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continue;
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}
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Vector p = a.Plus((b.Minus(a)).ScaledBy(t));
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Inter inter;
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ClosestPointTo(p, &(inter.p.x), &(inter.p.y));
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inters.Add(&inter);
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}
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} else {
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// General numerical solution by subdivision, fallback
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int cnt = 0, level = 0;
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AllPointsIntersectingUntrimmed(a, b, &cnt, &level, &inters, seg, this);
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}
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// Remove duplicate intersection points
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inters.ClearTags();
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int i, j;
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for(i = 0; i < inters.n; i++) {
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for(j = i + 1; j < inters.n; j++) {
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if(inters.elem[i].p.Equals(inters.elem[j].p)) {
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inters.elem[j].tag = 1;
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}
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}
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}
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inters.RemoveTagged();
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for(i = 0; i < inters.n; i++) {
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Point2d puv = inters.elem[i].p;
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// Make sure the point lies within the finite line segment
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Vector pxyz = PointAt(puv.x, puv.y);
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double t = (pxyz.Minus(a)).DivPivoting(ba);
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if(seg && (t > 1 - LENGTH_EPS/bam || t < LENGTH_EPS/bam)) {
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continue;
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}
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// And that it lies inside our trim region
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Point2d dummy = { 0, 0 }, ia = { 0, 0 }, ib = { 0, 0 };
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int c = bsp->ClassifyPoint(puv, dummy, &ia, &ib);
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if(trimmed && c == SBspUv::OUTSIDE) {
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continue;
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}
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// It does, so generate the intersection
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SInter si;
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si.p = pxyz;
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si.surfNormal = NormalAt(puv.x, puv.y);
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si.pinter = puv;
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si.srf = this;
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si.onEdge = (c != SBspUv::INSIDE);
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si.edgeA = ia;
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si.edgeB = ib;
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l->Add(&si);
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}
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inters.Clear();
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}
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void SShell::AllPointsIntersecting(Vector a, Vector b,
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List<SInter> *il,
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bool seg, bool trimmed, bool inclTangent)
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{
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SSurface *ss;
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for(ss = surface.First(); ss; ss = surface.NextAfter(ss)) {
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ss->AllPointsIntersecting(a, b, il, seg, trimmed, inclTangent);
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}
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}
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int SShell::ClassifyRegion(Vector edge_n, Vector inter_surf_n,
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Vector edge_surf_n)
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{
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double dot = inter_surf_n.Dot(edge_n);
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if(fabs(dot) < DOTP_TOL) {
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// The edge's surface and the edge-on-face surface
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// are coincident. Test the edge's surface normal
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// to see if it's with same or opposite normals.
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if(inter_surf_n.Dot(edge_surf_n) > 0) {
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return COINC_SAME;
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} else {
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return COINC_OPP;
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}
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} else if(dot > 0) {
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return OUTSIDE;
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} else {
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return INSIDE;
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}
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}
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//-----------------------------------------------------------------------------
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// Does the given point lie on our shell? There are many cases; inside and
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// outside are obvious, but then there's all the edge-on-edge and edge-on-face
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// possibilities.
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//
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// To calculate, we intersect a ray through p with our shell, and classify
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// using the closest intersection point. If the ray hits a surface on edge,
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// then just reattempt in a different random direction.
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//-----------------------------------------------------------------------------
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bool SShell::ClassifyEdge(int *indir, int *outdir,
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Vector ea, Vector eb,
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Vector p,
|
||||
Vector edge_n_in, Vector edge_n_out, Vector surf_n)
|
||||
{
|
||||
List<SInter> l;
|
||||
ZERO(&l);
|
||||
|
||||
srand(0);
|
||||
|
||||
// First, check for edge-on-edge
|
||||
int edge_inters = 0;
|
||||
Vector inter_surf_n[2], inter_edge_n[2];
|
||||
SSurface *srf;
|
||||
for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
|
||||
if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;
|
||||
|
||||
SEdgeList *sel = &(srf->edges);
|
||||
SEdge *se;
|
||||
for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
|
||||
if((ea.Equals(se->a) && eb.Equals(se->b)) ||
|
||||
(eb.Equals(se->a) && ea.Equals(se->b)) ||
|
||||
p.OnLineSegment(se->a, se->b))
|
||||
{
|
||||
if(edge_inters < 2) {
|
||||
// Edge-on-edge case
|
||||
Point2d pm;
|
||||
srf->ClosestPointTo(p, &pm, false);
|
||||
// A vector normal to the surface, at the intersection point
|
||||
inter_surf_n[edge_inters] = srf->NormalAt(pm);
|
||||
// A vector normal to the intersecting edge (but within the
|
||||
// intersecting surface) at the intersection point, pointing
|
||||
// out.
|
||||
inter_edge_n[edge_inters] =
|
||||
(inter_surf_n[edge_inters]).Cross((se->b).Minus((se->a)));
|
||||
}
|
||||
|
||||
edge_inters++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if(edge_inters == 2) {
|
||||
// TODO, make this use the appropriate curved normals
|
||||
double dotp[2];
|
||||
for(int i = 0; i < 2; i++) {
|
||||
dotp[i] = edge_n_out.Dot(inter_surf_n[i]);
|
||||
}
|
||||
|
||||
if(fabs(dotp[1]) < DOTP_TOL) {
|
||||
SWAP(double, dotp[0], dotp[1]);
|
||||
SWAP(Vector, inter_surf_n[0], inter_surf_n[1]);
|
||||
SWAP(Vector, inter_edge_n[0], inter_edge_n[1]);
|
||||
}
|
||||
|
||||
int coinc = (surf_n.Dot(inter_surf_n[0])) > 0 ? COINC_SAME : COINC_OPP;
|
||||
|
||||
if(fabs(dotp[0]) < DOTP_TOL && fabs(dotp[1]) < DOTP_TOL) {
|
||||
// This is actually an edge on face case, just that the face
|
||||
// is split into two pieces joining at our edge.
|
||||
*indir = coinc;
|
||||
*outdir = coinc;
|
||||
} else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] > DOTP_TOL) {
|
||||
if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
|
||||
*indir = coinc;
|
||||
*outdir = OUTSIDE;
|
||||
} else {
|
||||
*indir = INSIDE;
|
||||
*outdir = coinc;
|
||||
}
|
||||
} else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] < -DOTP_TOL) {
|
||||
if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
|
||||
*indir = coinc;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = coinc;
|
||||
}
|
||||
} else if(dotp[0] > DOTP_TOL && dotp[1] > DOTP_TOL) {
|
||||
*indir = INSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
} else if(dotp[0] < -DOTP_TOL && dotp[1] < -DOTP_TOL) {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
// Edge is tangent to the shell at shell's edge, so can't be
|
||||
// a boundary of the surface.
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
if(edge_inters != 0) dbp("bad, edge_inters=%d", edge_inters);
|
||||
|
||||
// Next, check for edge-on-surface. The ray-casting for edge-inside-shell
|
||||
// would catch this too, but test separately, for speed (since many edges
|
||||
// are on surface) and for numerical stability, so we don't pick up
|
||||
// the additional error from the line intersection.
|
||||
|
||||
for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
|
||||
if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;
|
||||
|
||||
Point2d puv;
|
||||
srf->ClosestPointTo(p, &(puv.x), &(puv.y), false);
|
||||
Vector pp = srf->PointAt(puv);
|
||||
|
||||
if((pp.Minus(p)).Magnitude() > LENGTH_EPS) continue;
|
||||
Point2d dummy = { 0, 0 }, ia = { 0, 0 }, ib = { 0, 0 };
|
||||
int c = srf->bsp->ClassifyPoint(puv, dummy, &ia, &ib);
|
||||
if(c == SBspUv::OUTSIDE) continue;
|
||||
|
||||
// Edge-on-face (unless edge-on-edge above superceded)
|
||||
Point2d pin, pout;
|
||||
srf->ClosestPointTo(p.Plus(edge_n_in), &pin, false);
|
||||
srf->ClosestPointTo(p.Plus(edge_n_out), &pout, false);
|
||||
|
||||
Vector surf_n_in = srf->NormalAt(pin),
|
||||
surf_n_out = srf->NormalAt(pout);
|
||||
|
||||
*indir = ClassifyRegion(edge_n_in, surf_n_in, surf_n);
|
||||
*outdir = ClassifyRegion(edge_n_out, surf_n_out, surf_n);
|
||||
return true;
|
||||
}
|
||||
|
||||
// Edge is not on face or on edge; so it's either inside or outside
|
||||
// the shell, and we'll determine which by raycasting.
|
||||
int cnt = 0;
|
||||
for(;;) {
|
||||
// Cast a ray in a random direction (two-sided so that we test if
|
||||
// the point lies on a surface, but use only one side for in/out
|
||||
// testing)
|
||||
Vector ray = Vector::From(Random(1), Random(1), Random(1));
|
||||
|
||||
AllPointsIntersecting(
|
||||
p.Minus(ray), p.Plus(ray), &l, false, true, false);
|
||||
|
||||
// no intersections means it's outside
|
||||
*indir = OUTSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
double dmin = VERY_POSITIVE;
|
||||
bool onEdge = false;
|
||||
edge_inters = 0;
|
||||
|
||||
SInter *si;
|
||||
for(si = l.First(); si; si = l.NextAfter(si)) {
|
||||
double t = ((si->p).Minus(p)).DivPivoting(ray);
|
||||
if(t*ray.Magnitude() < -LENGTH_EPS) {
|
||||
// wrong side, doesn't count
|
||||
continue;
|
||||
}
|
||||
|
||||
double d = ((si->p).Minus(p)).Magnitude();
|
||||
|
||||
// We actually should never hit this case; it should have been
|
||||
// handled above.
|
||||
if(d < LENGTH_EPS && si->onEdge) {
|
||||
edge_inters++;
|
||||
}
|
||||
|
||||
if(d < dmin) {
|
||||
dmin = d;
|
||||
// Edge does not lie on surface; either strictly inside
|
||||
// or strictly outside
|
||||
if((si->surfNormal).Dot(ray) > 0) {
|
||||
*indir = INSIDE;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
}
|
||||
onEdge = si->onEdge;
|
||||
}
|
||||
}
|
||||
l.Clear();
|
||||
|
||||
// If the point being tested lies exactly on an edge of the shell,
|
||||
// then our ray always lies on edge, and that's okay. Otherwise
|
||||
// try again in a different random direction.
|
||||
if(!onEdge) break;
|
||||
if(cnt++ > 5) {
|
||||
dbp("can't find a ray that doesn't hit on edge!");
|
||||
dbp("on edge = %d, edge_inters = %d", onEdge, edge_inters);
|
||||
SS.nakedEdges.AddEdge(ea, eb);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
|
|
@ -1,8 +1,10 @@
|
|||
//-----------------------------------------------------------------------------
|
||||
// How to intersect two surfaces, to get some type of curve. This is either
|
||||
// an exact special case (e.g., two planes to make a line), or a numerical
|
||||
// thing.
|
||||
//-----------------------------------------------------------------------------
|
||||
#include "solvespace.h"
|
||||
|
||||
// Dot product tolerance for perpendicular.
|
||||
const double SShell::DOTP_TOL = 1e-3;
|
||||
|
||||
extern int FLAG;
|
||||
|
||||
void SSurface::AddExactIntersectionCurve(SBezier *sb, SSurface *srfB,
|
||||
|
|
@ -423,602 +425,6 @@ void SSurface::IntersectAgainst(SSurface *b, SShell *agnstA, SShell *agnstB,
|
|||
}
|
||||
}
|
||||
|
||||
|
||||
double SSurface::DepartureFromCoplanar(void) {
|
||||
int i, j;
|
||||
int ia, ja, ib, jb, ic, jc;
|
||||
double best;
|
||||
|
||||
// Grab three points to define a plane; first choose (0, 0) arbitrarily.
|
||||
ia = ja = 0;
|
||||
// Then the point farthest from pt a.
|
||||
best = VERY_NEGATIVE;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
for(j = 0; j <= degn; j++) {
|
||||
if(i == ia && j == ja) continue;
|
||||
|
||||
double dist = (ctrl[i][j]).Minus(ctrl[ia][ja]).Magnitude();
|
||||
if(dist > best) {
|
||||
best = dist;
|
||||
ib = i;
|
||||
jb = j;
|
||||
}
|
||||
}
|
||||
}
|
||||
// Then biggest magnitude of ab cross ac.
|
||||
best = VERY_NEGATIVE;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
for(j = 0; j <= degn; j++) {
|
||||
if(i == ia && j == ja) continue;
|
||||
if(i == ib && j == jb) continue;
|
||||
|
||||
double mag =
|
||||
((ctrl[ia][ja].Minus(ctrl[ib][jb]))).Cross(
|
||||
(ctrl[ia][ja].Minus(ctrl[i ][j ]))).Magnitude();
|
||||
if(mag > best) {
|
||||
best = mag;
|
||||
ic = i;
|
||||
jc = j;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
Vector n = ((ctrl[ia][ja].Minus(ctrl[ib][jb]))).Cross(
|
||||
(ctrl[ia][ja].Minus(ctrl[ic][jc])));
|
||||
n = n.WithMagnitude(1);
|
||||
double d = (ctrl[ia][ja]).Dot(n);
|
||||
|
||||
// Finally, calculate the deviation from each point to the plane.
|
||||
double farthest = VERY_NEGATIVE;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
for(j = 0; j <= degn; j++) {
|
||||
double dist = fabs(n.Dot(ctrl[i][j]) - d);
|
||||
if(dist > farthest) {
|
||||
farthest = dist;
|
||||
}
|
||||
}
|
||||
}
|
||||
return farthest;
|
||||
}
|
||||
|
||||
void SSurface::WeightControlPoints(void) {
|
||||
int i, j;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
for(j = 0; j <= degn; j++) {
|
||||
ctrl[i][j] = (ctrl[i][j]).ScaledBy(weight[i][j]);
|
||||
}
|
||||
}
|
||||
}
|
||||
void SSurface::UnWeightControlPoints(void) {
|
||||
int i, j;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
for(j = 0; j <= degn; j++) {
|
||||
ctrl[i][j] = (ctrl[i][j]).ScaledBy(1.0/weight[i][j]);
|
||||
}
|
||||
}
|
||||
}
|
||||
void SSurface::CopyRowOrCol(bool row, int this_ij, SSurface *src, int src_ij) {
|
||||
if(row) {
|
||||
int j;
|
||||
for(j = 0; j <= degn; j++) {
|
||||
ctrl [this_ij][j] = src->ctrl [src_ij][j];
|
||||
weight[this_ij][j] = src->weight[src_ij][j];
|
||||
}
|
||||
} else {
|
||||
int i;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
ctrl [i][this_ij] = src->ctrl [i][src_ij];
|
||||
weight[i][this_ij] = src->weight[i][src_ij];
|
||||
}
|
||||
}
|
||||
}
|
||||
void SSurface::BlendRowOrCol(bool row, int this_ij, SSurface *a, int a_ij,
|
||||
SSurface *b, int b_ij)
|
||||
{
|
||||
if(row) {
|
||||
int j;
|
||||
for(j = 0; j <= degn; j++) {
|
||||
Vector c = (a->ctrl [a_ij][j]).Plus(b->ctrl [b_ij][j]);
|
||||
double w = (a->weight[a_ij][j] + b->weight[b_ij][j]);
|
||||
ctrl [this_ij][j] = c.ScaledBy(0.5);
|
||||
weight[this_ij][j] = w / 2;
|
||||
}
|
||||
} else {
|
||||
int i;
|
||||
for(i = 0; i <= degm; i++) {
|
||||
Vector c = (a->ctrl [i][a_ij]).Plus(b->ctrl [i][b_ij]);
|
||||
double w = (a->weight[i][a_ij] + b->weight[i][b_ij]);
|
||||
ctrl [i][this_ij] = c.ScaledBy(0.5);
|
||||
weight[i][this_ij] = w / 2;
|
||||
}
|
||||
}
|
||||
}
|
||||
void SSurface::SplitInHalf(bool byU, SSurface *sa, SSurface *sb) {
|
||||
sa->degm = sb->degm = degm;
|
||||
sa->degn = sb->degn = degn;
|
||||
|
||||
// by de Casteljau's algorithm in a projective space; so we must work
|
||||
// on points (w*x, w*y, w*z, w)
|
||||
WeightControlPoints();
|
||||
|
||||
switch(byU ? degm : degn) {
|
||||
case 1:
|
||||
sa->CopyRowOrCol (byU, 0, this, 0);
|
||||
sb->CopyRowOrCol (byU, 1, this, 1);
|
||||
|
||||
sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
|
||||
sb->BlendRowOrCol(byU, 0, this, 0, this, 1);
|
||||
break;
|
||||
|
||||
case 2:
|
||||
sa->CopyRowOrCol (byU, 0, this, 0);
|
||||
sb->CopyRowOrCol (byU, 2, this, 2);
|
||||
|
||||
sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
|
||||
sb->BlendRowOrCol(byU, 1, this, 1, this, 2);
|
||||
|
||||
sa->BlendRowOrCol(byU, 2, sa, 1, sb, 1);
|
||||
sb->BlendRowOrCol(byU, 0, sa, 1, sb, 1);
|
||||
break;
|
||||
|
||||
case 3: {
|
||||
SSurface st;
|
||||
st.degm = degm; st.degn = degn;
|
||||
|
||||
sa->CopyRowOrCol (byU, 0, this, 0);
|
||||
sb->CopyRowOrCol (byU, 3, this, 3);
|
||||
|
||||
sa->BlendRowOrCol(byU, 1, this, 0, this, 1);
|
||||
sb->BlendRowOrCol(byU, 2, this, 2, this, 3);
|
||||
st. BlendRowOrCol(byU, 0, this, 1, this, 2); // scratch var
|
||||
|
||||
sa->BlendRowOrCol(byU, 2, sa, 1, &st, 0);
|
||||
sb->BlendRowOrCol(byU, 1, sb, 2, &st, 0);
|
||||
|
||||
sa->BlendRowOrCol(byU, 3, sa, 2, sb, 1);
|
||||
sb->BlendRowOrCol(byU, 0, sa, 2, sb, 1);
|
||||
break;
|
||||
}
|
||||
|
||||
default: oops();
|
||||
}
|
||||
|
||||
sa->UnWeightControlPoints();
|
||||
sb->UnWeightControlPoints();
|
||||
UnWeightControlPoints();
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// Find all points where the indicated finite (if segment) or infinite (if not
|
||||
// segment) line intersects our surface. Report them in uv space in the list.
|
||||
// We first do a bounding box check; if the line doesn't intersect, then we're
|
||||
// done. If it does, then we check how small our surface is. If it's big,
|
||||
// then we subdivide into quarters and recurse. If it's small, then we refine
|
||||
// by Newton's method and record the point.
|
||||
//-----------------------------------------------------------------------------
|
||||
void SSurface::AllPointsIntersectingUntrimmed(Vector a, Vector b,
|
||||
int *cnt, int *level,
|
||||
List<Inter> *l, bool segment,
|
||||
SSurface *sorig)
|
||||
{
|
||||
// Test if the line intersects our axis-aligned bounding box; if no, then
|
||||
// no possibility of an intersection
|
||||
if(LineEntirelyOutsideBbox(a, b, segment)) return;
|
||||
|
||||
if(*cnt > 2000) {
|
||||
dbp("!!! too many subdivisions (level=%d)!", *level);
|
||||
dbp("degm = %d degn = %d", degm, degn);
|
||||
return;
|
||||
}
|
||||
(*cnt)++;
|
||||
|
||||
// If we might intersect, and the surface is small, then switch to Newton
|
||||
// iterations.
|
||||
if(DepartureFromCoplanar() < 0.2*SS.ChordTolMm()) {
|
||||
Vector p = (ctrl[0 ][0 ]).Plus(
|
||||
ctrl[0 ][degn]).Plus(
|
||||
ctrl[degm][0 ]).Plus(
|
||||
ctrl[degm][degn]).ScaledBy(0.25);
|
||||
Inter inter;
|
||||
sorig->ClosestPointTo(p, &(inter.p.x), &(inter.p.y), false);
|
||||
if(sorig->PointIntersectingLine(a, b, &(inter.p.x), &(inter.p.y))) {
|
||||
Vector p = sorig->PointAt(inter.p.x, inter.p.y);
|
||||
// Debug check, verify that the point lies in both surfaces
|
||||
// (which it ought to, since the surfaces should be coincident)
|
||||
double u, v;
|
||||
ClosestPointTo(p, &u, &v);
|
||||
l->Add(&inter);
|
||||
} else {
|
||||
// Might not converge if line is almost tangent to surface...
|
||||
}
|
||||
return;
|
||||
}
|
||||
|
||||
// But the surface is big, so split it, alternating by u and v
|
||||
SSurface surf0, surf1;
|
||||
SplitInHalf((*level & 1) == 0, &surf0, &surf1);
|
||||
|
||||
int nextLevel = (*level) + 1;
|
||||
(*level) = nextLevel;
|
||||
surf0.AllPointsIntersectingUntrimmed(a, b, cnt, level, l, segment, sorig);
|
||||
(*level) = nextLevel;
|
||||
surf1.AllPointsIntersectingUntrimmed(a, b, cnt, level, l, segment, sorig);
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// Find all points where a line through a and b intersects our surface, and
|
||||
// add them to the list. If seg is true then report only intersections that
|
||||
// lie within the finite line segment (not including the endpoints); otherwise
|
||||
// we work along the infinite line. And we report either just intersections
|
||||
// inside the trim curve, or any intersection with u, v in [0, 1]. And we
|
||||
// either disregard or report tangent points.
|
||||
//-----------------------------------------------------------------------------
|
||||
void SSurface::AllPointsIntersecting(Vector a, Vector b,
|
||||
List<SInter> *l,
|
||||
bool seg, bool trimmed, bool inclTangent)
|
||||
{
|
||||
if(LineEntirelyOutsideBbox(a, b, seg)) return;
|
||||
|
||||
Vector ba = b.Minus(a);
|
||||
double bam = ba.Magnitude();
|
||||
|
||||
List<Inter> inters;
|
||||
ZERO(&inters);
|
||||
|
||||
// All the intersections between the line and the surface; either special
|
||||
// cases that we can quickly solve in closed form, or general numerical.
|
||||
Vector center, axis, start, finish;
|
||||
double radius;
|
||||
if(degm == 1 && degn == 1) {
|
||||
// Against a plane, easy.
|
||||
Vector n = NormalAt(0, 0).WithMagnitude(1);
|
||||
double d = n.Dot(PointAt(0, 0));
|
||||
// Trim to line segment now if requested, don't generate points that
|
||||
// would just get discarded later.
|
||||
if(!seg ||
|
||||
(n.Dot(a) > d + LENGTH_EPS && n.Dot(b) < d - LENGTH_EPS) ||
|
||||
(n.Dot(b) > d + LENGTH_EPS && n.Dot(a) < d - LENGTH_EPS))
|
||||
{
|
||||
Vector p = Vector::AtIntersectionOfPlaneAndLine(n, d, a, b, NULL);
|
||||
Inter inter;
|
||||
ClosestPointTo(p, &(inter.p.x), &(inter.p.y));
|
||||
inters.Add(&inter);
|
||||
}
|
||||
} else if(IsCylinder(&axis, ¢er, &radius, &start, &finish)) {
|
||||
// This one can be solved in closed form too.
|
||||
Vector ab = b.Minus(a);
|
||||
if(axis.Cross(ab).Magnitude() < LENGTH_EPS) {
|
||||
// edge is parallel to axis of cylinder, no intersection points
|
||||
return;
|
||||
}
|
||||
// A coordinate system centered at the center of the circle, with
|
||||
// the edge under test horizontal
|
||||
Vector u, v, n = axis.WithMagnitude(1);
|
||||
u = (ab.Minus(n.ScaledBy(ab.Dot(n)))).WithMagnitude(1);
|
||||
v = n.Cross(u);
|
||||
Point2d ap = (a.Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
|
||||
bp = (b.Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
|
||||
sp = (start. Minus(center)).DotInToCsys(u, v, n).ProjectXy(),
|
||||
fp = (finish.Minus(center)).DotInToCsys(u, v, n).ProjectXy();
|
||||
|
||||
double thetas = atan2(sp.y, sp.x), thetaf = atan2(fp.y, fp.x);
|
||||
|
||||
Point2d ip[2];
|
||||
int ip_n = 0;
|
||||
if(fabs(fabs(ap.y) - radius) < LENGTH_EPS) {
|
||||
// tangent
|
||||
if(inclTangent) {
|
||||
ip[0] = Point2d::From(0, ap.y);
|
||||
ip_n = 1;
|
||||
}
|
||||
} else if(fabs(ap.y) < radius) {
|
||||
// two intersections
|
||||
double xint = sqrt(radius*radius - ap.y*ap.y);
|
||||
ip[0] = Point2d::From(-xint, ap.y);
|
||||
ip[1] = Point2d::From( xint, ap.y);
|
||||
ip_n = 2;
|
||||
}
|
||||
int i;
|
||||
for(i = 0; i < ip_n; i++) {
|
||||
double t = (ip[i].Minus(ap)).DivPivoting(bp.Minus(ap));
|
||||
// This is a point on the circle; but is it on the arc?
|
||||
Point2d pp = ap.Plus((bp.Minus(ap)).ScaledBy(t));
|
||||
double theta = atan2(pp.y, pp.x);
|
||||
double dp = WRAP_SYMMETRIC(theta - thetas, 2*PI),
|
||||
df = WRAP_SYMMETRIC(thetaf - thetas, 2*PI);
|
||||
double tol = LENGTH_EPS/radius;
|
||||
|
||||
if((df > 0 && ((dp < -tol) || (dp > df + tol))) ||
|
||||
(df < 0 && ((dp > tol) || (dp < df - tol))))
|
||||
{
|
||||
continue;
|
||||
}
|
||||
|
||||
Vector p = a.Plus((b.Minus(a)).ScaledBy(t));
|
||||
|
||||
Inter inter;
|
||||
ClosestPointTo(p, &(inter.p.x), &(inter.p.y));
|
||||
inters.Add(&inter);
|
||||
}
|
||||
} else {
|
||||
// General numerical solution by subdivision, fallback
|
||||
int cnt = 0, level = 0;
|
||||
AllPointsIntersectingUntrimmed(a, b, &cnt, &level, &inters, seg, this);
|
||||
}
|
||||
|
||||
// Remove duplicate intersection points
|
||||
inters.ClearTags();
|
||||
int i, j;
|
||||
for(i = 0; i < inters.n; i++) {
|
||||
for(j = i + 1; j < inters.n; j++) {
|
||||
if(inters.elem[i].p.Equals(inters.elem[j].p)) {
|
||||
inters.elem[j].tag = 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
inters.RemoveTagged();
|
||||
|
||||
for(i = 0; i < inters.n; i++) {
|
||||
Point2d puv = inters.elem[i].p;
|
||||
|
||||
// Make sure the point lies within the finite line segment
|
||||
Vector pxyz = PointAt(puv.x, puv.y);
|
||||
double t = (pxyz.Minus(a)).DivPivoting(ba);
|
||||
if(seg && (t > 1 - LENGTH_EPS/bam || t < LENGTH_EPS/bam)) {
|
||||
continue;
|
||||
}
|
||||
|
||||
// And that it lies inside our trim region
|
||||
Point2d dummy = { 0, 0 }, ia = { 0, 0 }, ib = { 0, 0 };
|
||||
int c = bsp->ClassifyPoint(puv, dummy, &ia, &ib);
|
||||
if(trimmed && c == SBspUv::OUTSIDE) {
|
||||
continue;
|
||||
}
|
||||
|
||||
// It does, so generate the intersection
|
||||
SInter si;
|
||||
si.p = pxyz;
|
||||
si.surfNormal = NormalAt(puv.x, puv.y);
|
||||
si.pinter = puv;
|
||||
si.srf = this;
|
||||
si.onEdge = (c != SBspUv::INSIDE);
|
||||
si.edgeA = ia;
|
||||
si.edgeB = ib;
|
||||
l->Add(&si);
|
||||
}
|
||||
|
||||
inters.Clear();
|
||||
}
|
||||
|
||||
void SShell::AllPointsIntersecting(Vector a, Vector b,
|
||||
List<SInter> *il,
|
||||
bool seg, bool trimmed, bool inclTangent)
|
||||
{
|
||||
SSurface *ss;
|
||||
for(ss = surface.First(); ss; ss = surface.NextAfter(ss)) {
|
||||
ss->AllPointsIntersecting(a, b, il, seg, trimmed, inclTangent);
|
||||
}
|
||||
}
|
||||
|
||||
int SShell::ClassifyRegion(Vector edge_n, Vector inter_surf_n,
|
||||
Vector edge_surf_n)
|
||||
{
|
||||
double dot = inter_surf_n.Dot(edge_n);
|
||||
if(fabs(dot) < DOTP_TOL) {
|
||||
// The edge's surface and the edge-on-face surface
|
||||
// are coincident. Test the edge's surface normal
|
||||
// to see if it's with same or opposite normals.
|
||||
if(inter_surf_n.Dot(edge_surf_n) > 0) {
|
||||
return COINC_SAME;
|
||||
} else {
|
||||
return COINC_OPP;
|
||||
}
|
||||
} else if(dot > 0) {
|
||||
return OUTSIDE;
|
||||
} else {
|
||||
return INSIDE;
|
||||
}
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// Does the given point lie on our shell? There are many cases; inside and
|
||||
// outside are obvious, but then there's all the edge-on-edge and edge-on-face
|
||||
// possibilities.
|
||||
//
|
||||
// To calculate, we intersect a ray through p with our shell, and classify
|
||||
// using the closest intersection point. If the ray hits a surface on edge,
|
||||
// then just reattempt in a different random direction.
|
||||
//-----------------------------------------------------------------------------
|
||||
bool SShell::ClassifyEdge(int *indir, int *outdir,
|
||||
Vector ea, Vector eb,
|
||||
Vector p,
|
||||
Vector edge_n_in, Vector edge_n_out, Vector surf_n)
|
||||
{
|
||||
List<SInter> l;
|
||||
ZERO(&l);
|
||||
|
||||
srand(0);
|
||||
|
||||
// First, check for edge-on-edge
|
||||
int edge_inters = 0;
|
||||
Vector inter_surf_n[2], inter_edge_n[2];
|
||||
SSurface *srf;
|
||||
for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
|
||||
if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;
|
||||
|
||||
SEdgeList *sel = &(srf->edges);
|
||||
SEdge *se;
|
||||
for(se = sel->l.First(); se; se = sel->l.NextAfter(se)) {
|
||||
if((ea.Equals(se->a) && eb.Equals(se->b)) ||
|
||||
(eb.Equals(se->a) && ea.Equals(se->b)) ||
|
||||
p.OnLineSegment(se->a, se->b))
|
||||
{
|
||||
if(edge_inters < 2) {
|
||||
// Edge-on-edge case
|
||||
Point2d pm;
|
||||
srf->ClosestPointTo(p, &pm, false);
|
||||
// A vector normal to the surface, at the intersection point
|
||||
inter_surf_n[edge_inters] = srf->NormalAt(pm);
|
||||
// A vector normal to the intersecting edge (but within the
|
||||
// intersecting surface) at the intersection point, pointing
|
||||
// out.
|
||||
inter_edge_n[edge_inters] =
|
||||
(inter_surf_n[edge_inters]).Cross((se->b).Minus((se->a)));
|
||||
}
|
||||
|
||||
edge_inters++;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
if(edge_inters == 2) {
|
||||
// TODO, make this use the appropriate curved normals
|
||||
double dotp[2];
|
||||
for(int i = 0; i < 2; i++) {
|
||||
dotp[i] = edge_n_out.Dot(inter_surf_n[i]);
|
||||
}
|
||||
|
||||
if(fabs(dotp[1]) < DOTP_TOL) {
|
||||
SWAP(double, dotp[0], dotp[1]);
|
||||
SWAP(Vector, inter_surf_n[0], inter_surf_n[1]);
|
||||
SWAP(Vector, inter_edge_n[0], inter_edge_n[1]);
|
||||
}
|
||||
|
||||
int coinc = (surf_n.Dot(inter_surf_n[0])) > 0 ? COINC_SAME : COINC_OPP;
|
||||
|
||||
if(fabs(dotp[0]) < DOTP_TOL && fabs(dotp[1]) < DOTP_TOL) {
|
||||
// This is actually an edge on face case, just that the face
|
||||
// is split into two pieces joining at our edge.
|
||||
*indir = coinc;
|
||||
*outdir = coinc;
|
||||
} else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] > DOTP_TOL) {
|
||||
if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
|
||||
*indir = coinc;
|
||||
*outdir = OUTSIDE;
|
||||
} else {
|
||||
*indir = INSIDE;
|
||||
*outdir = coinc;
|
||||
}
|
||||
} else if(fabs(dotp[0]) < DOTP_TOL && dotp[1] < -DOTP_TOL) {
|
||||
if(edge_n_out.Dot(inter_edge_n[0]) > 0) {
|
||||
*indir = coinc;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = coinc;
|
||||
}
|
||||
} else if(dotp[0] > DOTP_TOL && dotp[1] > DOTP_TOL) {
|
||||
*indir = INSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
} else if(dotp[0] < -DOTP_TOL && dotp[1] < -DOTP_TOL) {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
// Edge is tangent to the shell at shell's edge, so can't be
|
||||
// a boundary of the surface.
|
||||
return false;
|
||||
}
|
||||
return true;
|
||||
}
|
||||
|
||||
if(edge_inters != 0) dbp("bad, edge_inters=%d", edge_inters);
|
||||
|
||||
// Next, check for edge-on-surface. The ray-casting for edge-inside-shell
|
||||
// would catch this too, but test separately, for speed (since many edges
|
||||
// are on surface) and for numerical stability, so we don't pick up
|
||||
// the additional error from the line intersection.
|
||||
|
||||
for(srf = surface.First(); srf; srf = surface.NextAfter(srf)) {
|
||||
if(srf->LineEntirelyOutsideBbox(ea, eb, true)) continue;
|
||||
|
||||
Point2d puv;
|
||||
srf->ClosestPointTo(p, &(puv.x), &(puv.y), false);
|
||||
Vector pp = srf->PointAt(puv);
|
||||
|
||||
if((pp.Minus(p)).Magnitude() > LENGTH_EPS) continue;
|
||||
Point2d dummy = { 0, 0 }, ia = { 0, 0 }, ib = { 0, 0 };
|
||||
int c = srf->bsp->ClassifyPoint(puv, dummy, &ia, &ib);
|
||||
if(c == SBspUv::OUTSIDE) continue;
|
||||
|
||||
// Edge-on-face (unless edge-on-edge above superceded)
|
||||
Point2d pin, pout;
|
||||
srf->ClosestPointTo(p.Plus(edge_n_in), &pin, false);
|
||||
srf->ClosestPointTo(p.Plus(edge_n_out), &pout, false);
|
||||
|
||||
Vector surf_n_in = srf->NormalAt(pin),
|
||||
surf_n_out = srf->NormalAt(pout);
|
||||
|
||||
*indir = ClassifyRegion(edge_n_in, surf_n_in, surf_n);
|
||||
*outdir = ClassifyRegion(edge_n_out, surf_n_out, surf_n);
|
||||
return true;
|
||||
}
|
||||
|
||||
// Edge is not on face or on edge; so it's either inside or outside
|
||||
// the shell, and we'll determine which by raycasting.
|
||||
int cnt = 0;
|
||||
for(;;) {
|
||||
// Cast a ray in a random direction (two-sided so that we test if
|
||||
// the point lies on a surface, but use only one side for in/out
|
||||
// testing)
|
||||
Vector ray = Vector::From(Random(1), Random(1), Random(1));
|
||||
|
||||
AllPointsIntersecting(
|
||||
p.Minus(ray), p.Plus(ray), &l, false, true, false);
|
||||
|
||||
// no intersections means it's outside
|
||||
*indir = OUTSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
double dmin = VERY_POSITIVE;
|
||||
bool onEdge = false;
|
||||
edge_inters = 0;
|
||||
|
||||
SInter *si;
|
||||
for(si = l.First(); si; si = l.NextAfter(si)) {
|
||||
double t = ((si->p).Minus(p)).DivPivoting(ray);
|
||||
if(t*ray.Magnitude() < -LENGTH_EPS) {
|
||||
// wrong side, doesn't count
|
||||
continue;
|
||||
}
|
||||
|
||||
double d = ((si->p).Minus(p)).Magnitude();
|
||||
|
||||
// We actually should never hit this case; it should have been
|
||||
// handled above.
|
||||
if(d < LENGTH_EPS && si->onEdge) {
|
||||
edge_inters++;
|
||||
}
|
||||
|
||||
if(d < dmin) {
|
||||
dmin = d;
|
||||
// Edge does not lie on surface; either strictly inside
|
||||
// or strictly outside
|
||||
if((si->surfNormal).Dot(ray) > 0) {
|
||||
*indir = INSIDE;
|
||||
*outdir = INSIDE;
|
||||
} else {
|
||||
*indir = OUTSIDE;
|
||||
*outdir = OUTSIDE;
|
||||
}
|
||||
onEdge = si->onEdge;
|
||||
}
|
||||
}
|
||||
l.Clear();
|
||||
|
||||
// If the point being tested lies exactly on an edge of the shell,
|
||||
// then our ray always lies on edge, and that's okay. Otherwise
|
||||
// try again in a different random direction.
|
||||
if(!onEdge) break;
|
||||
if(cnt++ > 5) {
|
||||
dbp("can't find a ray that doesn't hit on edge!");
|
||||
dbp("on edge = %d, edge_inters = %d", onEdge, edge_inters);
|
||||
SS.nakedEdges.AddEdge(ea, eb);
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
return true;
|
||||
}
|
||||
|
||||
//-----------------------------------------------------------------------------
|
||||
// Are two surfaces coincident, with the same (or with opposite) normals?
|
||||
// Currently handles planes only.
|
||||
|
|
|
|||
Loading…
Reference in New Issue