Bullet核心类介绍（Bullet 2.82 HelloWorld程序及其详解，附程序代码）

  1 #include"GL/glew.h"
  2 #include"GL/freeglut.h"
  3 #include"btBulletDynamicsCommon.h"
  4 #include"omp.h"
  5 
  6 btDiscreteDynamicsWorld* m_DynamicsWorld;
  7 btBroadphaseInterface* m_Broadphase;
  8 btCollisionDispatcher* m_Dispatcher;
  9 btSequentialImpulseConstraintSolver* m_ConstraintSolver;
 10 btDefaultCollisionConfiguration* m_CollisionConfiguration;
 11 btAlignedObjectArray<btCollisionShape*> m_CollisionShapes;
 12 
 13 void bt_rundraw(bool run)
 14 {
 15     static double t_Last = omp_get_wtime();
 16     if(run){
 17         double t2 = omp_get_wtime();
 18         m_DynamicsWorld->stepSimulation(float(t2-t_Last),10);
 19         t_Last = t2;
 20     }else{
 21         t_Last = omp_get_wtime();
 22     }
 23 
 24     btCollisionObjectArray& rigidArray = m_DynamicsWorld->getCollisionObjectArray();
 25     for(int i=0; i<rigidArray.size(); ++i){
 26         btRigidBody* body = btRigidBody::upcast(rigidArray[i]);
 27         btTransform trans;
 28         body->getMotionState()->getWorldTransform(trans);
 29         float m[16];
 30         trans.getOpenGLMatrix(m);
 31         GLfloat color[]={.5f, .6f, .7f, 1.0f};
 32         if(i==0){
 33             glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, color);
 34             glMatrixMode(GL_MODELVIEW);
 35             glPushMatrix();
 36             glMultMatrixf(m);
 37             glTranslatef(0,-1,0);
 38             glScalef(100.0f,1.0f,100.0f);
 39             glutSolidCube(1.f);
 40             glPopMatrix();
 41         }else{
 42             if(i%2){
 43                 color[0]=0.0f;color[1]=0.9f;color[2]=0.0f;color[3]=1.0f;
 44             }else{
 45                 color[0]=0.9f;color[1]=0.0f;color[2]=0.0f;color[3]=1.0f;
 46             }
 47             glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT_AND_DIFFUSE, color);
 48             glMatrixMode(GL_MODELVIEW);
 49             glPushMatrix();
 50             glMultMatrixf(m);
 51             glScalef(3.0f,2.0f,4.0f);
 52             glutSolidCube(1.f);
 53             glPopMatrix();
 54         }
 55     }
 56 }
 57 
 58 void bt_start()
 59 {
 60     ///-----initialization_start-----
 61     m_CollisionConfiguration = new btDefaultCollisionConfiguration();
 62     m_Dispatcher = new    btCollisionDispatcher(m_CollisionConfiguration);
 63     m_Broadphase = new btDbvtBroadphase();
 64     m_ConstraintSolver = new btSequentialImpulseConstraintSolver;
 65     m_DynamicsWorld = new btDiscreteDynamicsWorld(
 66         m_Dispatcher,m_Broadphase,m_ConstraintSolver,m_CollisionConfiguration);
 67     m_DynamicsWorld->setGravity(btVector3(0,-10,0));
 68     ///-----initialization_end-----
 69 
 70     { // floor
 71         btCollisionShape* groundShape = new btBoxShape(btVector3(btScalar(50.f),btScalar(0.f),btScalar(50.f)));
 72         m_CollisionShapes.push_back(groundShape);
 73 
 74         btTransform groundTransform;
 75         groundTransform.setIdentity();
 76         groundTransform.setOrigin(btVector3(0,0,0));
 77         btScalar mass(0.f);
 78 
 79         btVector3 localInertia(0,0,0);
 80         if( mass != 0.f )
 81             groundShape->calculateLocalInertia(mass,localInertia);
 82 
 83         //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes ‘active‘ objects
 84         btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
 85         btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,groundShape,localInertia);
 86         btRigidBody* body = new btRigidBody(rbInfo);
 87 
 88         //add the body to the dynamics world
 89         m_DynamicsWorld->addRigidBody(body);
 90     }
 91 
 92     for(int i=0; i<20; ++i){
 93         btCollisionShape* boxShape = new btBoxShape(btVector3(btScalar(1.5f),btScalar(1.f),btScalar(2.f)));
 94         m_CollisionShapes.push_back(boxShape);
 95 
 96         btTransform groundTransform;
 97         groundTransform.setIdentity();
 98         groundTransform.setOrigin(btVector3(0,i*2.0f+1.0f,i*0.5f));
 99         btScalar mass(6.f);
100 
101         btVector3 localInertia(0,0,0);
102         if( mass != 0.f )
103             boxShape->calculateLocalInertia(mass,localInertia);
104 
105         //using motionstate is recommended, it provides interpolation capabilities, and only synchronizes ‘active‘ objects
106         btDefaultMotionState* myMotionState = new btDefaultMotionState(groundTransform);
107         btRigidBody::btRigidBodyConstructionInfo rbInfo(mass,myMotionState,boxShape,localInertia);
108         btRigidBody* body = new btRigidBody(rbInfo);
109 
110         //add the body to the dynamics world
111         m_DynamicsWorld->addRigidBody(body);
112     }
113     
114 }
115 
116 void bt_end()
117 {
118     //remove the rigidbodies from the dynamics world and delete them
119     for (int i=m_DynamicsWorld->getNumCollisionObjects()-1; i>=0 ;i--)
120     {
121         btCollisionObject* obj = m_DynamicsWorld->getCollisionObjectArray()[i];
122         btRigidBody* body = btRigidBody::upcast(obj);
123         if (body && body->getMotionState())
124             delete body->getMotionState();
125         m_DynamicsWorld->removeCollisionObject( obj );
126         delete obj;
127     }
128     //delete collision shapes
129     for (int i=0;i<m_CollisionShapes.size();i++)
130     {
131         btCollisionShape* shape = m_CollisionShapes[i];
132         m_CollisionShapes[i] = 0;
133         delete shape;
134     }
135     //delete dynamicsworld and ...
136     delete m_DynamicsWorld;
137     delete m_ConstraintSolver;
138     delete m_Broadphase;
139     delete m_Dispatcher;
140     delete m_CollisionConfiguration;
141     m_CollisionShapes.clear();
142 }