Demos/HelloWorld/HelloWorld.cpp

   1 /*
   2 Bullet Continuous Collision Detection and Physics Library
   3 Copyright (c) 2003-2007 Erwin Coumans  http://continuousphysics.com/Bullet/
   4
   5 This software is provided 'as-is', without any express or implied warranty.
   6 In no event will the authors be held liable for any damages arising from the use of this software.
   7 Permission is granted to anyone to use this software for any purpose,
   8 including commercial applications, and to alter it and redistribute it freely,
   9 subject to the following restrictions:
  10
  11 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
  12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
  13 3. This notice may not be removed or altered from any source distribution.
  14 */
  15
  16 ///-----includes_start-----
  17 #include "btBulletDynamicsCommon.h"
  18 #include <stdio.h>
  19
  20 /// This is a Hello World program for running a basic Bullet physics simulation
  21
  22 int main(int argc, char** argv)
  23 {
  24         ///-----includes_end-----
  25
  26         int i;
  27         ///-----initialization_start-----
  28
  29         ///collision configuration contains default setup for memory, collision setup. Advanced users can create their own configuration.
  30         btDefaultCollisionConfiguration* collisionConfiguration = new btDefaultCollisionConfiguration();
  31
  32         ///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
  33         btCollisionDispatcher* dispatcher = new btCollisionDispatcher(collisionConfiguration);
  34
  35         ///btDbvtBroadphase is a good general purpose broadphase. You can also try out btAxis3Sweep.
  36         btBroadphaseInterface* overlappingPairCache = new btDbvtBroadphase();
  37
  38         ///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
  39         btSequentialImpulseConstraintSolver* solver = new btSequentialImpulseConstraintSolver;
  40
  41         btDiscreteDynamicsWorld* dynamicsWorld = new btDiscreteDynamicsWorld(dispatcher,overlappingPairCache,solver,collisionConfiguration);
  42
  43         dynamicsWorld->setGravity(btVector3(0,-10,0));
  44
  45         ///-----initialization_end-----
  46
  47         ///create a few basic rigid bodies
  48         btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(50.),btScalar(50.),btScalar(50.)));
  49
  50         //keep track of the shapes, we release memory at exit.
  51         //make sure to re-use collision shapes among rigid bodies whenever possible!
  52         btAlignedObjectArray<btCollisionShape*> collisionShapes;
  53
  54         collisionShapes.push_back(groundShape);
  55
  56         btTransform groundTransform;
  57         groundTransform.setIdentity();
  58         groundTransform.setOrigin(btVector3(0,-56,0));
  59
  60         {
  61                 btScalar mass(0.);
  62
  63                 //rigidbody is dynamic if and only if mass is non zero, otherwise static
  64                 bool isDynamic = (mass != 0.f);
  65
  66                 btVector3 localInertia(0,0,0);
  67                 if (isDynamic)
  68                         groundShape->calculateLocalInertia(mass,localInertia);
  69
  70                 //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
  71                 btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
  72                 btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,groundShape,localInertia);
  73                 btRigidBody* body = new btRigidBody(rbInfo);
  74
  75                 //add the body to the dynamics world
  76                 dynamicsWorld->addRigidBody(body);
  77         }
  78
  79
  80         {
  81                 //create a dynamic rigidbody
  82
  83                 //btCollisionShape* colShape = new btBoxShape(btVector3(1,1,1));
  84                 btCollisionShape* colShape = new btSphereShape(btScalar(1.));
  85                 collisionShapes.push_back(colShape);
  86
  87                 /// Create Dynamic Objects
  88                 btTransform startTransform;
  89                 startTransform.setIdentity();
  90
  91                 btScalar        mass(1.f);
  92
  93                 //rigidbody is dynamic if and only if mass is non zero, otherwise static
  94                 bool isDynamic = (mass != 0.f);
  95
  96                 btVector3 localInertia(0,0,0);
  97                 if (isDynamic)
  98                         colShape->calculateLocalInertia(mass,localInertia);
  99
 100                         startTransform.setOrigin(btVector3(2,10,0));
 101
 102                         //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
 103                         btDefaultMotionState* myMotionState = new btDefaultMotionState(startTransform);
 104                         btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,colShape,localInertia);
 105                         btRigidBody* body = new btRigidBody(rbInfo);
 106
 107                         dynamicsWorld->addRigidBody(body);
 108         }
 109
 110
 111
 112 /// Do some simulation
 113
 114
 115         ///-----stepsimulation_start-----
 116         for (i=0;i<100;i++)
 117         {
 118                 dynamicsWorld->stepSimulation(1.f/60.f,10);
 119
 120                 //print positions of all objects
 121                 for (int j=dynamicsWorld->getNumCollisionObjects()-1; j>=0 ;j--)
 122                 {
 123                         btCollisionObject* obj = dynamicsWorld->getCollisionObjectArray()[j];
 124                         btRigidBody* body = btRigidBody::upcast(obj);
 125                         if (body && body->getMotionState())
 126                         {
 127                                 btTransform trans;
 128                                 body->getMotionState()->getWorldTransform(trans);
 129                                 printf("world pos = %f,%f,%f\n",float(trans.getOrigin().getX()),float(trans.getOrigin().getY()),float(trans.getOrigin().getZ()));
 130                         }
 131                 }
 132         }
 133
 134         ///-----stepsimulation_end-----
 135
 136         //cleanup in the reverse order of creation/initialization
 137
 138         ///-----cleanup_start-----
 139
 140         //remove the rigidbodies from the dynamics world and delete them
 141         for (i=dynamicsWorld->getNumCollisionObjects()-1; i>=0 ;i--)
 142         {
 143                 btCollisionObject* obj = dynamicsWorld->getCollisionObjectArray()[i];
 144                 btRigidBody* body = btRigidBody::upcast(obj);
 145                 if (body && body->getMotionState())
 146                 {
 147                         delete body->getMotionState();
 148                 }
 149                 dynamicsWorld->removeCollisionObject( obj );
 150                 delete obj;
 151         }
 152
 153         //delete collision shapes
 154         for (int j=0;j<collisionShapes.size();j++)
 155         {
 156                 btCollisionShape* shape = collisionShapes[j];
 157                 collisionShapes[j] = 0;
 158                 delete shape;
 159         }
 160
 161         //delete dynamics world
 162         delete dynamicsWorld;
 163
 164         //delete solver
 165         delete solver;
 166
 167         //delete broadphase
 168         delete overlappingPairCache;
 169
 170         //delete dispatcher
 171         delete dispatcher;
 172
 173         delete collisionConfiguration;
 174
 175         //next line is optional: it will be cleared by the destructor when the array goes out of scope
 176         collisionShapes.clear();
 177
 178         ///-----cleanup_end-----
 179 }
 180