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
  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
  25         int i;
  26
  27         ///collision configuration contains default setup for memory, collision setup. Advanced users can create their own configuration.
  28         btDefaultCollisionConfiguration* collisionConfiguration = new btDefaultCollisionConfiguration();
  29
  30         ///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
  31         btCollisionDispatcher* dispatcher = new btCollisionDispatcher(collisionConfiguration);
  32
  33         ///btDbvtBroadphase is a good general purpose broadphase. You can also try out btAxis3Sweep.
  34         btBroadphaseInterface* overlappingPairCache = new btDbvtBroadphase();
  35
  36         ///the default constraint solver. For parallel processing you can use a different solver (see Extras/BulletMultiThreaded)
  37         btSequentialImpulseConstraintSolver* solver = new btSequentialImpulseConstraintSolver;
  38
  39         btDiscreteDynamicsWorld* dynamicsWorld = new btDiscreteDynamicsWorld(dispatcher,overlappingPairCache,solver,collisionConfiguration);
  40
  41         dynamicsWorld->setGravity(btVector3(0,-10,0));
  42
  43         ///create a few basic rigid bodies
  44         btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(50.),btScalar(50.),btScalar(50.)));
  45
  46         //keep track of the shapes, we release memory at exit.
  47         //make sure to re-use collision shapes among rigid bodies whenever possible!
  48         btAlignedObjectArray<btCollisionShape*> collisionShapes;
  49
  50         collisionShapes.push_back(groundShape);
  51
  52         btTransform groundTransform;
  53         groundTransform.setIdentity();
  54         groundTransform.setOrigin(btVector3(0,-56,0));
  55
  56         {
  57                 btScalar mass(0.);
  58
  59                 //rigidbody is dynamic if and only if mass is non zero, otherwise static
  60                 bool isDynamic = (mass != 0.f);
  61
  62                 btVector3 localInertia(0,0,0);
  63                 if (isDynamic)
  64                         groundShape->calculateLocalInertia(mass,localInertia);
  65
  66                 //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
  67                 btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
  68                 btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,groundShape,localInertia);
  69                 btRigidBody* body = new btRigidBody(rbInfo);
  70
  71                 //add the body to the dynamics world
  72                 dynamicsWorld->addRigidBody(body);
  73         }
  74
  75
  76         {
  77                 //create a dynamic rigidbody
  78
  79                 //btCollisionShape* colShape = new btBoxShape(btVector3(1,1,1));
  80                 btCollisionShape* colShape = new btSphereShape(btScalar(1.));
  81                 collisionShapes.push_back(colShape);
  82
  83                 /// Create Dynamic Objects
  84                 btTransform startTransform;
  85                 startTransform.setIdentity();
  86
  87                 btScalar        mass(1.f);
  88
  89                 //rigidbody is dynamic if and only if mass is non zero, otherwise static
  90                 bool isDynamic = (mass != 0.f);
  91
  92                 btVector3 localInertia(0,0,0);
  93                 if (isDynamic)
  94                         colShape->calculateLocalInertia(mass,localInertia);
  95
  96                         startTransform.setOrigin(btVector3(2,10,0));
  97
  98                         //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes 'active' objects
  99                         btDefaultMotionState* myMotionState = new btDefaultMotionState(startTransform);
 100                         btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,colShape,localInertia);
 101                         btRigidBody* body = new btRigidBody(rbInfo);
 102
 103                         dynamicsWorld->addRigidBody(body);
 104         }
 105
 106
 107
 108 /// Do some simulation
 109
 110
 111
 112         for (i=0;i<100;i++)
 113         {
 114                 dynamicsWorld->stepSimulation(1.f/60.f,10);
 115
 116                 //print positions of all objects
 117                 for (int j=dynamicsWorld->getNumCollisionObjects()-1; j>=0 ;j--)
 118                 {
 119                         btCollisionObject* obj = dynamicsWorld->getCollisionObjectArray()[j];
 120                         btRigidBody* body = btRigidBody::upcast(obj);
 121                         if (body && body->getMotionState())
 122                         {
 123                                 btTransform trans;
 124                                 body->getMotionState()->getWorldTransform(trans);
 125                                 printf("world pos = %f,%f,%f\n",float(trans.getOrigin().getX()),float(trans.getOrigin().getY()),float(trans.getOrigin().getZ()));
 126                         }
 127                 }
 128         }
 129
 130
 131         //cleanup in the reverse order of creation/initialization
 132
 133         //remove the rigidbodies from the dynamics world and delete them
 134         for (i=dynamicsWorld->getNumCollisionObjects()-1; i>=0 ;i--)
 135         {
 136                 btCollisionObject* obj = dynamicsWorld->getCollisionObjectArray()[i];
 137                 btRigidBody* body = btRigidBody::upcast(obj);
 138                 if (body && body->getMotionState())
 139                 {
 140                         delete body->getMotionState();
 141                 }
 142                 dynamicsWorld->removeCollisionObject( obj );
 143                 delete obj;
 144         }
 145
 146         //delete collision shapes
 147         for (int j=0;j<collisionShapes.size();j++)
 148         {
 149                 btCollisionShape* shape = collisionShapes[j];
 150                 collisionShapes[j] = 0;
 151                 delete shape;
 152         }
 153
 154         //delete dynamics world
 155         delete dynamicsWorld;
 156
 157         //delete solver
 158         delete solver;
 159
 160         //delete broadphase
 161         delete overlappingPairCache;
 162
 163         //delete dispatcher
 164         delete dispatcher;
 165
 166         delete collisionConfiguration;
 167
 168         //next line is optional: it will be cleared by the destructor when the array goes out of scope
 169         collisionShapes.clear();
 170
 171 }
 172