Help needed in Physics Engine!! (Game Development)

[swapwarick]

This is a code for Physics Implementation for game character in my engine..
I checked everything all code works well but when implemented in game no effect
is seen!! Plz check the bug in it... help will be more appreciated !

#include "../Physics/PhysicsActor.h"

#include "../Infrastructure/World.h"
#include "../Infrastructure/Log.h"
#include "../Util/MathUtil.h"

#include "Box2D.h"


PhysicsActor::PhysicsActor(void) :    
_physBody(NULL),
_density(1.f),
_friction(0.3f),
_restitution(0.0f),
_shapeType(SHAPETYPE_BOX),
_isSensor(false),
_groupIndex(0), 
_fixedRotation(false)
{
}

PhysicsActor::~PhysicsActor()
{
    if( _physBody != NULL )
    {
        _physBody->SetUserData(NULL);
        theWorld.GetPhysicsWorld().DestroyBody(_physBody);
    }
}

void PhysicsActor::SetDensity(float density)
{
    if (_physBody == NULL)
        _density = density;
    else
        sysLog.Log("WARNING: SetDensity() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetFriction(float friction)
{
    if (_physBody == NULL)
        _friction = friction;
    else
        sysLog.Log("WARNING: SetFriction() had no effect - don't change this actor after physics have been initialized.");    
}

void PhysicsActor::SetRestitution(float restitution)
{
    if (_physBody == NULL)
        _restitution = restitution;
    else
        sysLog.Log("WARNING: SetRestitution() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetShapeType(eShapeType shapeType)
{
    if (_physBody == NULL)
        _shapeType = shapeType;
    else
        sysLog.Log("WARNING: SetShapeType() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetIsSensor(bool isSensor)
{
    if (_physBody == NULL)
        _isSensor = isSensor;
    else
        sysLog.Log("WARNING: SetIsSensor() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetGroupIndex(int groupIndex)
{
    if (_physBody == NULL)
        _groupIndex = groupIndex;
    else
        sysLog.Log("WARNING: SetGroupIndex() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetFixedRotation(bool fixedRotation)
{
    if (_physBody == NULL)
        _fixedRotation = fixedRotation;
    else
        sysLog.Log("WARNING: SetFixedRotation() had no effect - don't change this actor after physics have been initialized.");
}


void PhysicsActor::InitPhysics()
{
    if (!theWorld.IsPhysicsSetUp())
    {
        sysLog.Log("ERROR: World physics must be initialized before Actor's.");
        return;
    }
    
    b2CircleDef circle;
    b2PolygonDef box;
    b2ShapeDef* shape = 0;
    if (_shapeType == SHAPETYPE_BOX)
    {
        // The extents is just a vector of the box's half widths. 
        // Box2D is tuned for meters, kilograms, and seconds. (Unless you've changed its units.)
        box.SetAsBox(0.5f*_size.X, 0.5f*_size.Y);
        shape = &box;
    }
    else if (_shapeType == SHAPETYPE_CIRCLE)
    {
        // TODO: handle ellipse?
        circle.radius = 0.5f*_size.X;
        shape = &circle;
    }
    else
    {
        sysLog.Log("ERROR: Invalid shape type given.");
        return;
    }
    
    shape->density = _density;
    shape->friction = _friction;
    shape->restitution = _restitution;
    shape->filter.groupIndex = _groupIndex;
    shape->isSensor = _isSensor;
    
    InitShape( shape );
    
    b2BodyDef bd;
    bd.userData = this;
    bd.position.Set(_position.X, _position.Y);
    bd.angle = MathUtil::ToRadians(_rotation);
    bd.fixedRotation = _fixedRotation;
    
    _physBody = theWorld.GetPhysicsWorld().CreateBody(&bd);
    _physBody->CreateShape(shape);
    _physBody->SetMassFromShapes();
    _physBody->SetUserData(this);
    CustomInitPhysics();
}

void PhysicsActor::ApplyForce(const Vector2& force, const Vector2& point)
{
    if (_physBody != NULL)
    {
        _physBody->ApplyForce(b2Vec2(force.X, force.Y), b2Vec2(point.X + _position.X, point.Y + _position.Y));
    }
}

void PhysicsActor::ApplyLocalForce(const Vector2& force, const Vector2& point)
{
    if (_physBody != NULL)
    {
        _physBody->ApplyForce(_physBody->GetWorldVector(b2Vec2(force.X, force.Y)), b2Vec2(point.X + _position.X, point.Y + _position.Y));
    }
}

void PhysicsActor::ApplyTorque(float torque)
{
    if (_physBody != NULL)
    {
        _physBody->ApplyTorque(torque);
    }
}

void PhysicsActor::ApplyImpulse(const Vector2& impulse, const Vector2& point)
{
    if (_physBody != NULL)
    {
        _physBody->ApplyImpulse(b2Vec2(impulse.X, impulse.Y), b2Vec2(point.X + _position.X, point.Y + _position.Y));
    }
}

void PhysicsActor::SetSize(float x, float y)
{
    if (_physBody == NULL)
        Actor::SetSize(x, y);
    else
        sysLog.Log("WARNING: SetSize() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetDrawSize(float x, float y)
{
    Actor::SetSize(x,y);
}

void PhysicsActor::SetPosition(float x, float y)
{
    if (_physBody == NULL)
        Actor::SetPosition(x, y);
    else
        sysLog.Log("WARNING: SetPosition() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetPosition(Vector2 pos)
{
    if (_physBody == NULL)
        Actor::SetPosition(pos);
    else
        sysLog.Log("WARNING: SetPosition() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::SetRotation(float rotation)
{
    if (_physBody == NULL)
        Actor::SetRotation(rotation);
    else
        sysLog.Log("WARNING: SetRotation() had no effect - don't change this actor after physics have been initialized.");
}

void PhysicsActor::_syncPosRot(float x, float y, float rotation)
{
    _position.X = x;
    _position.Y = y;
    _rotation = rotation;
    while (_rotation > 180.f)
        _rotation -= 360.f;
    while (_rotation < -180.f)
        _rotation += 360.f;