/*************************************************************************
* *
* Open Dynamics Engine, Copyright (C) 2001-2003 Russell L. Smith. *
* All rights reserved. Email: russ@q12.org Web: www.q12.org *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of EITHER: *
* (1) The GNU Lesser General Public License as published by the Free *
* Software Foundation; either version 2.1 of the License, or (at *
* your option) any later version. The text of the GNU Lesser *
* General Public License is included with this library in the *
* file LICENSE.TXT. *
* (2) The BSD-style license that is included with this library in *
* the file LICENSE-BSD.TXT. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files *
* LICENSE.TXT and LICENSE-BSD.TXT for more details. *
* *
*************************************************************************/
/*
standard ODE geometry primitives: public API and pairwise collision functions.
the rule is that only the low level primitive collision functions should set
dContactGeom::g1 and dContactGeom::g2.
*/
#include <ode/common.h>
#include <ode/collision.h>
#include <ode/matrix.h>
#include <ode/rotation.h>
#include <ode/odemath.h>
#include "collision_kernel.h"
#include "collision_std.h"
#include "collision_util.h"
//****************************************************************************
// ray public API
dxRay::dxRay (dSpaceID space, dReal _length) : dxGeom (space,1)
{
type = dRayClass;
length = _length;
}
void dxRay::computeAABB()
{
dVector3 e;
e[0] = final_posr->pos[0] + dMUL(final_posr->R[0*4+2],length);
e[1] = final_posr->pos[1] + dMUL(final_posr->R[1*4+2],length);
e[2] = final_posr->pos[2] + dMUL(final_posr->R[2*4+2],length);
if (final_posr->pos[0] < e[0]){
aabb[0] = final_posr->pos[0];
aabb[1] = e[0];
}
else{
aabb[0] = e[0];
aabb[1] = final_posr->pos[0];
}
if (final_posr->pos[1] < e[1]){
aabb[2] = final_posr->pos[1];
aabb[3] = e[1];
}
else{
aabb[2] = e[1];
aabb[3] = final_posr->pos[1];
}
if (final_posr->pos[2] < e[2]){
aabb[4] = final_posr->pos[2];
aabb[5] = e[2];
}
else{
aabb[4] = e[2];
aabb[5] = final_posr->pos[2];
}
}
EXPORT_C dGeomID dCreateRay (dSpaceID space, dReal length)
{
return new dxRay (space,length);
}
EXPORT_C void dGeomRaySetLength (dGeomID g, dReal length)
{
dxRay *r = (dxRay*) g;
r->length = length;
dGeomMoved (g);
}
EXPORT_C dReal dGeomRayGetLength (dGeomID g)
{
dxRay *r = (dxRay*) g;
return r->length;
}
EXPORT_C void dGeomRaySet (dGeomID g, dReal px, dReal py, dReal pz,
dReal dx, dReal dy, dReal dz)
{
g->recomputePosr();
dReal* rot = g->final_posr->R;
dReal* pos = g->final_posr->pos;
dVector3 n;
pos[0] = px;
pos[1] = py;
pos[2] = pz;
n[0] = dx;
n[1] = dy;
n[2] = dz;
dNormalize3(n);
rot[0*4+2] = n[0];
rot[1*4+2] = n[1];
rot[2*4+2] = n[2];
dGeomMoved (g);
}
EXPORT_C void dGeomRayGet (dGeomID g, dVector3 start, dVector3 dir)
{
g->recomputePosr();
start[0] = g->final_posr->pos[0];
start[1] = g->final_posr->pos[1];
start[2] = g->final_posr->pos[2];
dir[0] = g->final_posr->R[0*4+2];
dir[1] = g->final_posr->R[1*4+2];
dir[2] = g->final_posr->R[2*4+2];
}
EXPORT_C void dGeomRaySetParams (dxGeom *g, int FirstContact, int BackfaceCull)
{
if (FirstContact){
g->gflags |= RAY_FIRSTCONTACT;
}
else g->gflags &= ~RAY_FIRSTCONTACT;
if (BackfaceCull){
g->gflags |= RAY_BACKFACECULL;
}
else g->gflags &= ~RAY_BACKFACECULL;
}
EXPORT_C void dGeomRayGetParams (dxGeom *g, int *FirstContact, int *BackfaceCull)
{
(*FirstContact) = ((g->gflags & RAY_FIRSTCONTACT) != 0);
(*BackfaceCull) = ((g->gflags & RAY_BACKFACECULL) != 0);
}
EXPORT_C void dGeomRaySetClosestHit (dxGeom *g, int closestHit)
{
if (closestHit){
g->gflags |= RAY_CLOSEST_HIT;
}
else g->gflags &= ~RAY_CLOSEST_HIT;
}
EXPORT_C int dGeomRayGetClosestHit (dxGeom *g)
{
return ((g->gflags & RAY_CLOSEST_HIT) != 0);
}
// if mode==1 then use the sphere exit contact, not the entry contact
static int ray_sphere_helper (dxRay *ray, dVector3 sphere_pos, dReal radius,
dContactGeom *contact, int mode)
{
dVector3 q;
q[0] = ray->final_posr->pos[0] - sphere_pos[0];
q[1] = ray->final_posr->pos[1] - sphere_pos[1];
q[2] = ray->final_posr->pos[2] - sphere_pos[2];
dReal B = dDOT14(q,ray->final_posr->R+2);
dReal C = dDOT(q,q) - dMUL(radius,radius);
// note: if C <= 0 then the start of the ray is inside the sphere
dReal k = dMUL(B,B) - C;
if (k < 0) return 0;
k = dSqrt(k);
dReal alpha;
if (mode && C >= 0) {
alpha = -B + k;
if (alpha < 0) return 0;
}
else {
alpha = -B - k;
if (alpha < 0) {
alpha = -B + k;
if (alpha < 0) return 0;
}
}
if (alpha > ray->length) return 0;
contact->pos[0] = ray->final_posr->pos[0] + dMUL(alpha,ray->final_posr->R[0*4+2]);
contact->pos[1] = ray->final_posr->pos[1] + dMUL(alpha,ray->final_posr->R[1*4+2]);
contact->pos[2] = ray->final_posr->pos[2] + dMUL(alpha,ray->final_posr->R[2*4+2]);
dReal nsign = (C < 0 || mode) ? REAL(-1.0) : REAL(1.0);
contact->normal[0] = dMUL(nsign,(contact->pos[0] - sphere_pos[0]));
contact->normal[1] = dMUL(nsign,(contact->pos[1] - sphere_pos[1]));
contact->normal[2] = dMUL(nsign,(contact->pos[2] - sphere_pos[2]));
dNormalize3 (contact->normal);
contact->depth = alpha;
return 1;
}
int dCollideRaySphere (dxGeom *o1, dxGeom *o2, int /*flags*/,
dContactGeom *contact, int /*skip*/)
{
dxRay *ray = (dxRay*) o1;
dxSphere *sphere = (dxSphere*) o2;
contact->g1 = ray;
contact->g2 = sphere;
return ray_sphere_helper (ray,sphere->final_posr->pos,sphere->radius,contact,0);
}
int dCollideRayBox (dxGeom *o1, dxGeom *o2, int /*flags*/,
dContactGeom *contact, int /*skip*/)
{
dxRay *ray = (dxRay*) o1;
dxBox *box = (dxBox*) o2;
contact->g1 = ray;
contact->g2 = box;
int i;
// compute the start and delta of the ray relative to the box.
// we will do all subsequent computations in this box-relative coordinate
// system. we have to do a translation and rotation for each point.
dVector3 tmp,s,v;
tmp[0] = ray->final_posr->pos[0] - box->final_posr->pos[0];
tmp[1] = ray->final_posr->pos[1] - box->final_posr->pos[1];
tmp[2] = ray->final_posr->pos[2] - box->final_posr->pos[2];
dMULTIPLY1_331 (s,box->final_posr->R,tmp);
tmp[0] = ray->final_posr->R[0*4+2];
tmp[1] = ray->final_posr->R[1*4+2];
tmp[2] = ray->final_posr->R[2*4+2];
dMULTIPLY1_331 (v,box->final_posr->R,tmp);
// mirror the line so that v has all components >= 0
dVector3 sign;
for (i=0; i<3; i++) {
if (v[i] < 0) {
s[i] = -s[i];
v[i] = -v[i];
sign[i] = REAL(1.0);
}
else sign[i] = REAL(-1.0);
}
// compute the half-sides of the box
dReal h[3];
h[0] = dMUL(REAL(0.5),box->side[0]);
h[1] = dMUL(REAL(0.5),box->side[1]);
h[2] = dMUL(REAL(0.5),box->side[2]);
// do a few early exit tests
if ((s[0] < -h[0] && v[0] <= 0) || s[0] > h[0] ||
(s[1] < -h[1] && v[1] <= 0) || s[1] > h[1] ||
(s[2] < -h[2] && v[2] <= 0) || s[2] > h[2] ||
(v[0] == 0 && v[1] == 0 && v[2] == 0)) {
return 0;
}
// compute the t=[lo..hi] range for where s+v*t intersects the box
dReal lo = -dInfinity;
dReal hi = dInfinity;
int nlo = 0, nhi = 0;
for (i=0; i<3; i++) {
if (v[i] != 0) {
dReal k = dDIV((-h[i] - s[i]),v[i]);
if (k > lo) {
lo = k;
nlo = i;
}
k = dDIV((h[i] - s[i]),v[i]);
if (k < hi) {
hi = k;
nhi = i;
}
}
}
// check if the ray intersects
if (lo > hi) return 0;
dReal alpha;
int n;
if (lo >= 0) {
alpha = lo;
n = nlo;
}
else {
alpha = hi;
n = nhi;
}
if (alpha < 0 || alpha > ray->length) return 0;
contact->pos[0] = ray->final_posr->pos[0] + dMUL(alpha,ray->final_posr->R[0*4+2]);
contact->pos[1] = ray->final_posr->pos[1] + dMUL(alpha,ray->final_posr->R[1*4+2]);
contact->pos[2] = ray->final_posr->pos[2] + dMUL(alpha,ray->final_posr->R[2*4+2]);
contact->normal[0] = dMUL(box->final_posr->R[0*4+n],sign[n]);
contact->normal[1] = dMUL(box->final_posr->R[1*4+n],sign[n]);
contact->normal[2] = dMUL(box->final_posr->R[2*4+n],sign[n]);
contact->depth = alpha;
return 1;
}
int dCollideRayCapsule (dxGeom *o1, dxGeom *o2,
int /*flags*/, dContactGeom *contact, int /*skip*/)
{
dxRay *ray = (dxRay*) o1;
dxCapsule *ccyl = (dxCapsule*) o2;
contact->g1 = ray;
contact->g2 = ccyl;
dReal lz2 = dMUL(ccyl->lz,REAL(0.5));
// compute some useful info
dVector3 cs,q,r;
dReal C,k;
cs[0] = ray->final_posr->pos[0] - ccyl->final_posr->pos[0];
cs[1] = ray->final_posr->pos[1] - ccyl->final_posr->pos[1];
cs[2] = ray->final_posr->pos[2] - ccyl->final_posr->pos[2];
k = dDOT41(ccyl->final_posr->R+2,cs); // position of ray start along ccyl axis
q[0] = dMUL(k,ccyl->final_posr->R[0*4+2]) - cs[0];
q[1] = dMUL(k,ccyl->final_posr->R[1*4+2]) - cs[1];
q[2] = dMUL(k,ccyl->final_posr->R[2*4+2]) - cs[2];
C = dDOT(q,q) - dMUL(ccyl->radius,ccyl->radius);
// if C < 0 then ray start position within infinite extension of cylinder
// see if ray start position is inside the capped cylinder
int inside_ccyl = 0;
if (C < 0) {
if (k < -lz2) k = -lz2;
else if (k > lz2) k = lz2;
r[0] = ccyl->final_posr->pos[0] + dMUL(k,ccyl->final_posr->R[0*4+2]);
r[1] = ccyl->final_posr->pos[1] + dMUL(k,ccyl->final_posr->R[1*4+2]);
r[2] = ccyl->final_posr->pos[2] + dMUL(k,ccyl->final_posr->R[2*4+2]);
if (dMUL((ray->final_posr->pos[0]-r[0]),(ray->final_posr->pos[0]-r[0])) +
dMUL((ray->final_posr->pos[1]-r[1]),(ray->final_posr->pos[1]-r[1])) +
dMUL((ray->final_posr->pos[2]-r[2]),(ray->final_posr->pos[2]-r[2])) < dMUL(ccyl->radius,ccyl->radius)) {
inside_ccyl = 1;
}
}
// compute ray collision with infinite cylinder, except for the case where
// the ray is outside the capped cylinder but within the infinite cylinder
// (it that case the ray can only hit endcaps)
if (!inside_ccyl && C < 0) {
// set k to cap position to check
if (k < 0) k = -lz2; else k = lz2;
}
else {
dReal uv = dDOT44(ccyl->final_posr->R+2,ray->final_posr->R+2);
r[0] = dMUL(uv,ccyl->final_posr->R[0*4+2]) - ray->final_posr->R[0*4+2];
r[1] = dMUL(uv,ccyl->final_posr->R[1*4+2]) - ray->final_posr->R[1*4+2];
r[2] = dMUL(uv,ccyl->final_posr->R[2*4+2]) - ray->final_posr->R[2*4+2];
dReal A = dDOT(r,r);
dReal B = 2*dDOT(q,r);
k = dMUL(B,B)-4*dMUL(A,C);
if (k < 0) {
// the ray does not intersect the infinite cylinder, but if the ray is
// inside and parallel to the cylinder axis it may intersect the end
// caps. set k to cap position to check.
if (!inside_ccyl) return 0;
if (uv < 0) k = -lz2; else k = lz2;
}
else {
k = dSqrt(k);
A = dRecip (2*A);
dReal alpha = dMUL((-B-k),A);
if (alpha < 0) {
alpha = dMUL((-B+k),A);
if (alpha < 0) return 0;
}
if (alpha > ray->length) return 0;
// the ray intersects the infinite cylinder. check to see if the
// intersection point is between the caps
contact->pos[0] = ray->final_posr->pos[0] + dMUL(alpha,ray->final_posr->R[0*4+2]);
contact->pos[1] = ray->final_posr->pos[1] + dMUL(alpha,ray->final_posr->R[1*4+2]);
contact->pos[2] = ray->final_posr->pos[2] + dMUL(alpha,ray->final_posr->R[2*4+2]);
q[0] = contact->pos[0] - ccyl->final_posr->pos[0];
q[1] = contact->pos[1] - ccyl->final_posr->pos[1];
q[2] = contact->pos[2] - ccyl->final_posr->pos[2];
k = dDOT14(q,ccyl->final_posr->R+2);
dReal nsign = inside_ccyl ? REAL(-1.0) : REAL(1.0);
if (k >= -lz2 && k <= lz2) {
contact->normal[0] = dMUL(nsign,(contact->pos[0] -
(ccyl->final_posr->pos[0] + dMUL(k,ccyl->final_posr->R[0*4+2]))));
contact->normal[1] = dMUL(nsign,(contact->pos[1] -
(ccyl->final_posr->pos[1] + dMUL(k,ccyl->final_posr->R[1*4+2]))));
contact->normal[2] = dMUL(nsign,(contact->pos[2] -
(ccyl->final_posr->pos[2] + dMUL(k,ccyl->final_posr->R[2*4+2]))));
dNormalize3 (contact->normal);
contact->depth = alpha;
return 1;
}
// the infinite cylinder intersection point is not between the caps.
// set k to cap position to check.
if (k < 0) k = -lz2; else k = lz2;
}
}
// check for ray intersection with the caps. k must indicate the cap
// position to check
q[0] = ccyl->final_posr->pos[0] + dMUL(k,ccyl->final_posr->R[0*4+2]);
q[1] = ccyl->final_posr->pos[1] + dMUL(k,ccyl->final_posr->R[1*4+2]);
q[2] = ccyl->final_posr->pos[2] + dMUL(k,ccyl->final_posr->R[2*4+2]);
return ray_sphere_helper (ray,q,ccyl->radius,contact, inside_ccyl);
}
int dCollideRayPlane (dxGeom *o1, dxGeom *o2, int /*flags*/,
dContactGeom *contact, int /*skip*/)
{
dxRay *ray = (dxRay*) o1;
dxPlane *plane = (dxPlane*) o2;
dReal alpha = plane->p[3] - dDOT (plane->p,ray->final_posr->pos);
// note: if alpha > 0 the starting point is below the plane
dReal nsign = (alpha > 0) ? REAL(-1.0) : REAL(1.0);
dReal k = dDOT14(plane->p,ray->final_posr->R+2);
if (k==0) return 0; // ray parallel to plane
alpha = dDIV(alpha,k);
if (alpha < 0 || alpha > ray->length) return 0;
contact->pos[0] = ray->final_posr->pos[0] + dMUL(alpha,ray->final_posr->R[0*4+2]);
contact->pos[1] = ray->final_posr->pos[1] + dMUL(alpha,ray->final_posr->R[1*4+2]);
contact->pos[2] = ray->final_posr->pos[2] + dMUL(alpha,ray->final_posr->R[2*4+2]);
contact->normal[0] = dMUL(nsign,plane->p[0]);
contact->normal[1] = dMUL(nsign,plane->p[1]);
contact->normal[2] = dMUL(nsign,plane->p[2]);
contact->depth = alpha;
contact->g1 = ray;
contact->g2 = plane;
return 1;
}
// Ray - Cylinder collider by David Walters (June 2006)
int dCollideRayCylinder( dxGeom *o1, dxGeom *o2, int /*flags*/, dContactGeom *contact, int /*skip*/ )
{
dxRay* ray = (dxRay*)( o1 );
dxCylinder* cyl = (dxCylinder*)( o2 );
// Fill in contact information.
contact->g1 = ray;
contact->g2 = cyl;
const dReal half_length = dMUL(cyl->lz,REAL( 0.5 ));
//
// Compute some useful info
//
dVector3 q, r;
dReal d, C, k;
// Vector 'r', line segment from C to R (ray start) ( r = R - C )
r[ 0 ] = ray->final_posr->pos[0] - cyl->final_posr->pos[0];
r[ 1 ] = ray->final_posr->pos[1] - cyl->final_posr->pos[1];
r[ 2 ] = ray->final_posr->pos[2] - cyl->final_posr->pos[2];
// Distance that ray start is along cyl axis ( Z-axis direction )
d = dDOT41( cyl->final_posr->R + 2, r );
//
// Compute vector 'q' representing the shortest line from R to the cylinder z-axis (Cz).
//
// Point on axis ( in world space ): cp = ( d * Cz ) + C
//
// Line 'q' from R to cp: q = cp - R
// q = ( d * Cz ) + C - R
// q = ( d * Cz ) - ( R - C )
q[ 0 ] = dMUL( d,cyl->final_posr->R[0*4+2] ) - r[ 0 ];
q[ 1 ] = dMUL( d,cyl->final_posr->R[1*4+2] ) - r[ 1 ];
q[ 2 ] = dMUL( d,cyl->final_posr->R[2*4+2] ) - r[ 2 ];
// Compute square length of 'q'. Subtract from radius squared to
// get square distance 'C' between the line q and the radius.
// if C < 0 then ray start position is within infinite extension of cylinder
C = dDOT( q, q ) - dMUL( cyl->radius,cyl->radius );
// Compute the projection of ray direction normal onto cylinder direction normal.
dReal uv = dDOT44( cyl->final_posr->R+2, ray->final_posr->R+2 );
//
// Find ray collision with infinite cylinder
//
// Compute vector from end of ray direction normal to projection on cylinder direction normal.
r[ 0 ] = dMUL( uv,cyl->final_posr->R[0*4+2] ) - ray->final_posr->R[0*4+2];
r[ 1 ] = dMUL( uv,cyl->final_posr->R[1*4+2] ) - ray->final_posr->R[1*4+2];
r[ 2 ] = dMUL( uv,cyl->final_posr->R[2*4+2] ) - ray->final_posr->R[2*4+2];
// Quadratic Formula Magic
// Compute discriminant 'k':
// k < 0 : No intersection
// k = 0 : Tangent
// k > 0 : Intersection
dReal A = dDOT( r, r );
dReal B = 2 * dDOT( q, r );
k = dMUL(B,B) - 4*dMUL(A,C);
//
// Collision with Flat Caps ?
//
// No collision with cylinder edge. ( Use epsilon here or we miss some obvious cases )
if ( k < dEpsilon && C <= 0 )
{
// The ray does not intersect the edge of the infinite cylinder,
// but the ray start is inside and so must run parallel to the axis.
// It may yet intersect an end cap. The following cases are valid:
// -ve-cap , -half centre +half , +ve-cap
// <<================|-------------------|------------->>>---|================>>
// | |
// | d-------------------> 1.
// 2. d------------------> |
// 3. <------------------d |
// | <-------------------d 4.
// | |
// <<================|-------------------|------------->>>---|===============>>
// Negative if the ray and cylinder axes point in opposite directions.
const dReal uvsign = ( uv < 0 ) ? REAL( -1.0 ) : REAL( 1.0 );
// Negative if the ray start is inside the cylinder
const dReal internal = ( d >= -half_length && d <= +half_length ) ? REAL( -1.0 ) : REAL( 1.0 );
// Ray and Cylinder axes run in the same direction ( cases 1, 2 )
// Ray and Cylinder axes run in opposite directions ( cases 3, 4 )
if ( ( ( uv > 0 ) && ( d + dMUL( uvsign,ray->length ) < dMUL(half_length,internal) ) ) ||
( ( uv < 0 ) && ( d + dMUL( uvsign,ray->length ) > dMUL(half_length,internal) ) ) )
{
return 0; // No intersection with caps or curved surface.
}
// Compute depth (distance from ray to cylinder)
contact->depth = ( dMUL( -uvsign,d ) - dMUL( internal,half_length ) );
// Compute contact point.
contact->pos[0] = ray->final_posr->pos[0] + dMUL( contact->depth,ray->final_posr->R[0*4+2] );
contact->pos[1] = ray->final_posr->pos[1] + dMUL( contact->depth,ray->final_posr->R[1*4+2] );
contact->pos[2] = ray->final_posr->pos[2] + dMUL( contact->depth,ray->final_posr->R[2*4+2] );
// Compute reflected contact normal.
contact->normal[0] = dMUL(uvsign,( cyl->final_posr->R[0*4+2] ));
contact->normal[1] = dMUL(uvsign,( cyl->final_posr->R[1*4+2] ));
contact->normal[2] = dMUL(uvsign,( cyl->final_posr->R[2*4+2] ));
// Contact!
return 1;
}
//
// Collision with Curved Edge ?
//
if ( k > 0 )
{
// Finish off quadratic formula to get intersection co-efficient
k = dSqrt( k );
A = dRecip( 2 * A );
// Compute distance along line to contact point.
dReal alpha = dMUL(( -B - k ),A);
if ( alpha < 0 )
{
// Flip in the other direction.
alpha = dMUL(( -B + k ),A);
}
// Intersection point is within ray length?
if ( alpha >= 0 && alpha <= ray->length )
{
// The ray intersects the infinite cylinder!
// Compute contact point.
contact->pos[0] = ray->final_posr->pos[0] + dMUL( alpha,ray->final_posr->R[0*4+2] );
contact->pos[1] = ray->final_posr->pos[1] + dMUL( alpha,ray->final_posr->R[1*4+2] );
contact->pos[2] = ray->final_posr->pos[2] + dMUL( alpha,ray->final_posr->R[2*4+2] );
// q is the vector from the cylinder centre to the contact point.
q[0] = contact->pos[0] - cyl->final_posr->pos[0];
q[1] = contact->pos[1] - cyl->final_posr->pos[1];
q[2] = contact->pos[2] - cyl->final_posr->pos[2];
// Compute the distance along the cylinder axis of this contact point.
d = dDOT14( q, cyl->final_posr->R+2 );
// Check to see if the intersection point is between the flat end caps
if ( d >= -half_length && d <= +half_length )
{
// Flip the normal if the start point is inside the cylinder.
const dReal nsign = ( C < 0 ) ? REAL( -1.0 ) : REAL( 1.0 );
// Compute contact normal.
contact->normal[0] = dMUL(nsign,(contact->pos[0] - (cyl->final_posr->pos[0] + dMUL(d,cyl->final_posr->R[0*4+2]))));
contact->normal[1] = dMUL(nsign,(contact->pos[1] - (cyl->final_posr->pos[1] + dMUL(d,cyl->final_posr->R[1*4+2]))));
contact->normal[2] = dMUL(nsign,(contact->pos[2] - (cyl->final_posr->pos[2] + dMUL(d,cyl->final_posr->R[2*4+2]))));
dNormalize3( contact->normal );
// Store depth.
contact->depth = alpha;
// Contact!
return 1;
}
}
}
// No contact with anything.
return 0;
}