ode/src/collision_cylinder_plane.cpp
changeset 0 2f259fa3e83a
equal deleted inserted replaced
-1:000000000000 0:2f259fa3e83a
       
     1 /*************************************************************************
       
     2 *                                                                       *
       
     3 * Open Dynamics Engine, Copyright (C) 2001-2003 Russell L. Smith.       *
       
     4 * All rights reserved.  Email: russ@q12.org   Web: www.q12.org          *
       
     5 *                                                                       *
       
     6 * This library is free software; you can redistribute it and/or         *
       
     7 * modify it under the terms of EITHER:                                  *
       
     8 *   (1) The GNU Lesser General Public License as published by the Free  *
       
     9 *       Software Foundation; either version 2.1 of the License, or (at  *
       
    10 *       your option) any later version. The text of the GNU Lesser      *
       
    11 *       General Public License is included with this library in the     *
       
    12 *       file LICENSE.TXT.                                               *
       
    13 *   (2) The BSD-style license that is included with this library in     *
       
    14 *       the file LICENSE-BSD.TXT.                                       *
       
    15 *                                                                       *
       
    16 * This library is distributed in the hope that it will be useful,       *
       
    17 * but WITHOUT ANY WARRANTY; without even the implied warranty of        *
       
    18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the files    *
       
    19 * LICENSE.TXT and LICENSE-BSD.TXT for more details.                     *
       
    20 *                                                                       *
       
    21 *************************************************************************/
       
    22 
       
    23 
       
    24 /*
       
    25  * Cylinder-Plane collider by Christoph Beyer ( boernerb@web.de )
       
    26  *
       
    27  * This testing basically comes down to testing the intersection
       
    28  * of the cylinder caps (discs) with the plane.
       
    29  * 
       
    30  */
       
    31 
       
    32 #include <ode/collision.h>
       
    33 #include <ode/matrix.h>
       
    34 #include <ode/rotation.h>
       
    35 #include <ode/odemath.h>
       
    36 #include <ode/objects.h>
       
    37 
       
    38 #include "collision_kernel.h"	// for dxGeom
       
    39 
       
    40 int dCollideCylinderPlane(dxGeom *Cylinder, dxGeom *Plane, int flags, dContactGeom *contact, int skip)
       
    41 {
       
    42 
       
    43 	unsigned char* pContactData = (unsigned char*)contact;
       
    44 	int GeomCount = 0; // count of used contactgeoms
       
    45 
       
    46 	const dReal toleranz = REAL(0.0001f);
       
    47 
       
    48 
       
    49 	// Get the properties of the cylinder (length+radius)
       
    50 	dReal radius, length;
       
    51 	dGeomCylinderGetParams(Cylinder, &radius, &length);
       
    52 	dVector3 &cylpos = Cylinder->final_posr->pos;
       
    53 	// and the plane
       
    54 	dVector4 planevec;
       
    55 	dGeomPlaneGetParams(Plane, planevec);
       
    56 	dVector3 PlaneNormal = {planevec[0],planevec[1],planevec[2]};
       
    57 
       
    58 	dVector3 G1Pos1, G1Pos2, vDir1;
       
    59 	vDir1[0] = Cylinder->final_posr->R[2];
       
    60 	vDir1[1] = Cylinder->final_posr->R[6];
       
    61 	vDir1[2] = Cylinder->final_posr->R[10];
       
    62 
       
    63 	dReal s;
       
    64 	s = dMUL(length,REAL(0.5));
       
    65 	G1Pos2[0] = dMUL(vDir1[0],s) + cylpos[0];
       
    66 	G1Pos2[1] = dMUL(vDir1[1],s) + cylpos[1];
       
    67 	G1Pos2[2] = dMUL(vDir1[2],s) + cylpos[2];
       
    68 
       
    69 	G1Pos1[0] = dMUL(vDir1[0],-s) + cylpos[0];
       
    70 	G1Pos1[1] = dMUL(vDir1[1],-s) + cylpos[1];
       
    71 	G1Pos1[2] = dMUL(vDir1[2],-s) + cylpos[2];
       
    72 
       
    73 	dVector3 C;
       
    74 
       
    75 	// parallel-check
       
    76 	s = dMUL(vDir1[0],PlaneNormal[0]) + dMUL(vDir1[1],PlaneNormal[1]) + dMUL(vDir1[2],PlaneNormal[2]);
       
    77 	if(s < 0)
       
    78 		s += REAL(1.0); // is ca. 0, if vDir1 and PlaneNormal are parallel
       
    79 	else
       
    80 		s -= REAL(1.0); // is ca. 0, if vDir1 and PlaneNormal are parallel
       
    81 	if(s < toleranz && s > (-toleranz))
       
    82 	{
       
    83 		// discs are parallel to the plane
       
    84 
       
    85 		// 1.compute if, and where contacts are
       
    86 		dVector3 P;
       
    87 		s = planevec[3] - dMUL(planevec[0],G1Pos1[0]) - dMUL(planevec[1],G1Pos1[1]) - dMUL(planevec[2],G1Pos1[2]);
       
    88 		dReal t;
       
    89 		t = planevec[3] - dMUL(planevec[0],G1Pos2[0]) - dMUL(planevec[1],G1Pos2[1]) - dMUL(planevec[2],G1Pos2[2]);
       
    90 		if(s >= t) // s == t does never happen, 
       
    91 		{
       
    92 			if(s >= 0)
       
    93 			{
       
    94 				// 1. Disc
       
    95 				P[0] = G1Pos1[0];
       
    96 				P[1] = G1Pos1[1];
       
    97 				P[2] = G1Pos1[2];
       
    98 			}
       
    99 			else
       
   100 				return GeomCount; // no contacts
       
   101 		}
       
   102 		else
       
   103 		{
       
   104 			if(t >= 0)
       
   105 			{
       
   106 				// 2. Disc
       
   107 				P[0] = G1Pos2[0];
       
   108 				P[1] = G1Pos2[1];
       
   109 				P[2] = G1Pos2[2];
       
   110 			}
       
   111 			else
       
   112 				return GeomCount; // no contacts
       
   113 		}
       
   114 
       
   115 		// 2. generate a coordinate-system on the disc
       
   116 		dVector3 V1, V2;
       
   117 		if(vDir1[0] < toleranz && vDir1[0] > (-toleranz))
       
   118 		{
       
   119 			// not x-axis
       
   120 			V1[0] = vDir1[0] + REAL(1.0); // random value
       
   121 			V1[1] = vDir1[1];
       
   122 			V1[2] = vDir1[2];
       
   123 		}
       
   124 		else
       
   125 		{
       
   126 			// maybe x-axis
       
   127 			V1[0] = vDir1[0];
       
   128 			V1[1] = vDir1[1] + REAL(1.0); // random value
       
   129 			V1[2] = vDir1[2];
       
   130 		}
       
   131 		// V1 is now another direction than vDir1
       
   132 		// Cross-product
       
   133 	    V2[0] = dMUL(V1[1],vDir1[2]) - dMUL(V1[2],vDir1[1]);
       
   134 		V2[1] = dMUL(V1[2],vDir1[0]) - dMUL(V1[0],vDir1[2]);
       
   135 		V2[2] = dMUL(V1[0],vDir1[1]) - dMUL(V1[1],vDir1[0]);
       
   136 		// make unit V2
       
   137 		t = dSqrt(dMUL(V2[0],V2[0]) + dMUL(V2[1],V2[1]) + dMUL(V2[2],V2[2]));
       
   138 		t = dDIV(radius,t);
       
   139 		V2[0] = dMUL(V2[0],t);
       
   140 		V2[1] = dMUL(V2[1],t);
       
   141 		V2[2] = dMUL(V2[2],t);
       
   142 		// cross again
       
   143 	    V1[0] = dMUL(V2[1],vDir1[2]) - dMUL(V2[2],vDir1[1]);
       
   144 		V1[1] = dMUL(V2[2],vDir1[0]) - dMUL(V2[0],vDir1[2]);
       
   145 		V1[2] = dMUL(V2[0],vDir1[1]) - dMUL(V2[1],vDir1[0]);
       
   146 		// |V2| is 'radius' and vDir1 unit, so |V1| is 'radius'
       
   147 		// V1 = first axis
       
   148 		// V2 = second axis
       
   149 
       
   150 		// 3. generate contactpoints
       
   151 
       
   152 		// Potential contact 1
       
   153 		contact->pos[0] = P[0] + V1[0];
       
   154 		contact->pos[1] = P[1] + V1[1];
       
   155 		contact->pos[2] = P[2] + V1[2];
       
   156 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   157 		if(contact->depth > 0)
       
   158 		{
       
   159 			contact->normal[0] = PlaneNormal[0];
       
   160 			contact->normal[1] = PlaneNormal[1];
       
   161 			contact->normal[2] = PlaneNormal[2];
       
   162 			contact->g1 = Cylinder;
       
   163 			contact->g2 = Plane;
       
   164 			GeomCount++;
       
   165 			if( GeomCount >= (flags & 0x0ffff))
       
   166 				return GeomCount; // enough contactgeoms
       
   167 			pContactData += skip;
       
   168 			contact = (dContactGeom*)pContactData;
       
   169 		}
       
   170 
       
   171 		// Potential contact 2
       
   172 		contact->pos[0] = P[0] - V1[0];
       
   173 		contact->pos[1] = P[1] - V1[1];
       
   174 		contact->pos[2] = P[2] - V1[2];
       
   175 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   176 		if(contact->depth > 0)
       
   177 		{
       
   178 			contact->normal[0] = PlaneNormal[0];
       
   179 			contact->normal[1] = PlaneNormal[1];
       
   180 			contact->normal[2] = PlaneNormal[2];
       
   181 			contact->g1 = Cylinder;
       
   182 			contact->g2 = Plane;
       
   183 			GeomCount++;
       
   184 			if( GeomCount >= (flags & 0x0ffff))
       
   185 				return GeomCount; // enough contactgeoms
       
   186 			pContactData += skip;
       
   187 			contact = (dContactGeom*)pContactData;
       
   188 		}
       
   189 
       
   190 		// Potential contact 3
       
   191 		contact->pos[0] = P[0] + V2[0];
       
   192 		contact->pos[1] = P[1] + V2[1];
       
   193 		contact->pos[2] = P[2] + V2[2];
       
   194 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   195 		if(contact->depth > 0)
       
   196 		{
       
   197 			contact->normal[0] = PlaneNormal[0];
       
   198 			contact->normal[1] = PlaneNormal[1];
       
   199 			contact->normal[2] = PlaneNormal[2];
       
   200 			contact->g1 = Cylinder;
       
   201 			contact->g2 = Plane;
       
   202 			GeomCount++;
       
   203 			if( GeomCount >= (flags & 0x0ffff))
       
   204 				return GeomCount; // enough contactgeoms
       
   205 			pContactData += skip;
       
   206 			contact = (dContactGeom*)pContactData;
       
   207 		}
       
   208 
       
   209 		// Potential contact 4
       
   210 		contact->pos[0] = P[0] - V2[0];
       
   211 		contact->pos[1] = P[1] - V2[1];
       
   212 		contact->pos[2] = P[2] - V2[2];
       
   213 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   214 		if(contact->depth > 0)
       
   215 		{
       
   216 			contact->normal[0] = PlaneNormal[0];
       
   217 			contact->normal[1] = PlaneNormal[1];
       
   218 			contact->normal[2] = PlaneNormal[2];
       
   219 			contact->g1 = Cylinder;
       
   220 			contact->g2 = Plane;
       
   221 			GeomCount++;
       
   222 			if( GeomCount >= (flags & 0x0ffff))
       
   223 				return GeomCount; // enough contactgeoms
       
   224 			pContactData += skip;
       
   225 			contact = (dContactGeom*)pContactData;
       
   226 		}
       
   227 	}
       
   228 	else
       
   229 	{
       
   230 		dReal t = -(dMUL((-PlaneNormal[0]),vDir1[0]) + dMUL((-PlaneNormal[1]),vDir1[1]) + dMUL((-PlaneNormal[2]),vDir1[2]));
       
   231 		C[0] = dMUL(vDir1[0],t) - PlaneNormal[0];
       
   232 		C[1] = dMUL(vDir1[1],t) - PlaneNormal[1];
       
   233 		C[2] = dMUL(vDir1[2],t) - PlaneNormal[2];
       
   234 		s = dSqrt(dMUL(C[0],C[0]) + dMUL(C[1],C[1]) + dMUL(C[2],C[2]));
       
   235 		// move C onto the circle
       
   236 		s = dDIV(radius,s);
       
   237 		C[0] = dMUL(C[0],s);
       
   238 		C[1] = dMUL(C[1],s);
       
   239 		C[2] = dMUL(C[2],s);
       
   240 
       
   241 		// deepest point of disc 1
       
   242 		contact->pos[0] = C[0] + G1Pos1[0];
       
   243 		contact->pos[1] = C[1] + G1Pos1[1];
       
   244 		contact->pos[2] = C[2] + G1Pos1[2];
       
   245 
       
   246 		// depth of the deepest point
       
   247 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   248 		if(contact->depth >= 0)
       
   249 		{
       
   250 			contact->normal[0] = PlaneNormal[0];
       
   251 			contact->normal[1] = PlaneNormal[1];
       
   252 			contact->normal[2] = PlaneNormal[2];
       
   253 			contact->g1 = Cylinder;
       
   254 			contact->g2 = Plane;
       
   255 			GeomCount++;
       
   256 			if( GeomCount >= (flags & 0x0ffff))
       
   257 				return GeomCount; // enough contactgeoms
       
   258 			pContactData += skip;
       
   259 			contact = (dContactGeom*)pContactData;
       
   260 		}
       
   261 
       
   262 		// C is still computed
       
   263 
       
   264 		// deepest point of disc 2
       
   265 		contact->pos[0] = C[0] + G1Pos2[0];
       
   266 		contact->pos[1] = C[1] + G1Pos2[1];
       
   267 		contact->pos[2] = C[2] + G1Pos2[2];
       
   268 
       
   269 		// depth of the deepest point
       
   270 		contact->depth = planevec[3] - dMUL(planevec[0],contact->pos[0]) - dMUL(planevec[1],contact->pos[1]) - dMUL(planevec[2],contact->pos[2]);
       
   271 		if(contact->depth >= 0)
       
   272 		{
       
   273 			contact->normal[0] = PlaneNormal[0];
       
   274 			contact->normal[1] = PlaneNormal[1];
       
   275 			contact->normal[2] = PlaneNormal[2];
       
   276 			contact->g1 = Cylinder;
       
   277 			contact->g2 = Plane;
       
   278 			GeomCount++;
       
   279 			if( GeomCount >= (flags & 0x0ffff))
       
   280 				return GeomCount; // enough contactgeoms
       
   281 			pContactData += skip;
       
   282 			contact = (dContactGeom*)pContactData;
       
   283 		}
       
   284 	}
       
   285 	return GeomCount;
       
   286 }