testing bullet physics collision in Cinder

bullet-collision.cpp

Voxel* VoxelMapperApp::findVoxel(btRigidBody* pBody) {
    // search through our list of gameobjects finding
    // the one with a rigid body that matches the given one
    for (std::vector<Voxel>::iterator iter = mVoxels.begin(); iter != mVoxels.end(); ++iter) {
        if ((iter)->getPhyObj().get()->getRigidBody().get() == pBody) {
            // found the body, so return the corresponding Voxel object
            return &(*iter);//this feels janky!
        }
    }
    return 0;
}

void VoxelMapperApp::onCollisionBegin( btRigidBody *rigid0, btRigidBody *rigid1 )
{
    using namespace bullet;
    
    Voxel *phyObj0 = findVoxel( (btRigidBody*) rigid0);
    phyObj0->setCol(ColorAT<float>(0,1,0));//arbitrary color green
    
    Voxel *phyObj1 = findVoxel( (btRigidBody*) rigid1);
    phyObj1->setCol(ColorAT<float>(0,0,1));//arbitrary color blue
}

void VoxelMapperApp::onCollisionEnd( btRigidBody *rigid0, btRigidBody *rigid1 )
{
    using namespace bullet;
    
    Voxel *phyObj0 = findVoxel( (btRigidBody*) rigid0);
    phyObj0->setCol(ColorAT<float>(1,1,0));
    
    Voxel *phyObj1 = findVoxel( (btRigidBody*) rigid1);
    phyObj1->setCol(ColorAT<float>(1,0,0));
    
}

void VoxelMapperApp::createVoxel(const glm::vec3 &pos)
{
    auto scale = vec3( 1, 1, 1 );
    // We create a Cube batch. The cube's points are conveniently from 0, 0, 0 origin, with a scale of 1, 1, 1.
    auto batch = gl::Batch::create( geom::Cube(), gl::getStockShader( gl::ShaderDef().color() ) );
    // All I need to do is create a Box Shape at a scale of 1, 1, 1.
    auto rigidBody = bullet::RigidBody::create( bullet::RigidBody::Format()
                                               .collisionShape( bullet::createSphereShape( scale.x ) )
                                       .mass( 0 )
                                       .initialPosition( pos )
                                       .addToWorld( true ) );
    // Then put them together in the Voxel object.
    mVoxels.emplace_back( batch, rigidBody );
    rigidBody->setUserPointerRigidBody(&mVoxels.back());
}


void VoxelMapperApp::createMovable(const glm::vec3 &pos)
{
    auto scale = vec3( 1, 1, 1 );
    // We create a Cube batch. The cube's points are conveniently from 0, 0, 0 origin, with a scale of 1, 1, 1.
    auto batch = gl::Batch::create( geom::Cube(), gl::getStockShader( gl::ShaderDef().color() ) );
    // All I need to do is create a Box Shape at a scale of 1, 1, 1.
    auto rigidBody = bullet::RigidBody::create( bullet::RigidBody::Format()
                                               .collisionShape( bullet::createBoxShape( scale ) )
                                               .mass( 1 )
                                               .initialPosition( pos )
                                               .addToWorld( true ) );
    // Then put them together in the Voxel object.
    mVoxels.emplace_back( batch, rigidBody );
    rigidBody->setUserPointerRigidBody(&mVoxels.back());
}