Box2D Forums

 #include "DragonFireSDK.h"
#include <Box2D/Box2D.h>

const float SCALE = 1.0f / 32.0f;
const float DELTA = 1.0f / 30.0f;
const float BODY_SIZE = (50.f * SCALE) / 2.0f;
const float EARTH_GRAVITY = 9.81f;
const bool AllowSleep = true;

b2World* myWorld;
b2BodyDef ballBodyDef;
b2BodyDef carBodyDef;
b2CircleShape CircleShape;
b2PolygonShape BoxShape;
b2Body *bBall;
b2Body *bCar;
b2Vec2 Gravity;
int vwBall;

b2BodyDef floorBodyDef;
b2Body *bFloor;
b2PolygonShape FloorEdge;
float xTilt;
float yTilt;
int Car8View;

void AppMain()
{
    myWorld = new b2World(b2Vec2(0.0f, 0.8f), true);
    ballBodyDef.type = b2_dynamicBody;
    ballBodyDef.position.Set((130 * SCALE), (50 * SCALE));
    CircleShape.m_radius = BODY_SIZE;
    b2FixtureDef CircleFixture;
    CircleFixture.shape = &CircleShape;
    CircleFixture.density = 1.f;
    CircleFixture.restitution = .5f;   
    CircleFixture.friction = .2f;   
    bBall  = myWorld->CreateBody(&ballBodyDef);
    bBall->CreateFixture(&CircleFixture);   
    vwBall = ViewAdd("Images/ball.png", 0, 0);
    carBodyDef.type = b2_kinematicBody;
    carBodyDef.position.Set((130 * SCALE), (180 * SCALE));
    BoxShape.SetAsBox(BODY_SIZE, BODY_SIZE);
    b2FixtureDef BoxFixture;
    BoxFixture.shape = &BoxShape;
    BoxFixture.density = 1.0f;
    BoxFixture.restitution = 1.0f;   
    BoxFixture.friction = 1.2f;   
    bCar  = myWorld->CreateBody(&carBodyDef);
    bCar ->CreateFixture(&BoxFixture);
    Car8View = ViewAdd("Images/Car4.png", 0, 0);
    floorBodyDef.position.Set(0.0f, 480 * SCALE);
    bFloor = myWorld->CreateBody(&floorBodyDef);
    FloorEdge.SetAsEdge(b2Vec2(-0,0), b2Vec2(320 * SCALE,0));
    bFloor->CreateFixture(&FloorEdge, 0.0f);
    //Gravity.Set(0.0f, EARTH_GRAVITY);               // Set default gravity vector:
   //myWorld = new b2World(Gravity, AllowSleep);       // Initialize the World object:
}

void OnTimer()
//{
 
    myWorld->Step(DELTA , 10, 10);
    ViewSetxy(vwBall ,((bBall ->GetPosition().x - BODY_SIZE) / SCALE),((bBall ->GetPosition().y - BODY_SIZE) / SCALE));
    ViewSetxy(Car8View ,((bCar ->GetPosition().x - BODY_SIZE) / SCALE),((bCar ->GetPosition().y - BODY_SIZE) / SCALE));
{
    xTilt = TiltGetx()/50.0f;
   yTilt = TiltGety()/50.0f;
    bBall->ApplyLinearImpulse(b2Vec2(xTilt, yTilt), bBall->GetWorldCenter());
    //bCar->ApplyLinearImpulse(b2Vec2(xTilt, yTilt), bCar->GetWorldCenter());
    bCar->SetLinearVelocity(b2Vec2(-2, 0));
     

   // If tilt not available, give the yTilt a default value (Earth-like gravity):
   if (yTilt==0.0)
      yTilt=EARTH_GRAVITY;
           
   // Update the gravity vector:
   Gravity.Set(xTilt, yTilt);
   
   // Set the updated gravity vector to the World object:
   myWorld->SetGravity(Gravity);

}
}

void AppExit()
{

}