#rem

'Im still very new at box2d but im starting to understand its principle.
'its not an easy to understand engine since the tutorials are not dealing with explaning the core principle of this engine.
'I will try to do that with what ive figured out till now.

'In box2d you First define things and then create them.
'First you define the your 2D world.

'Example:
  Field BXworld        : b2World          'Box2D physical World Object
  Field m_velocityIterations  : int   = 10        'Dont know whats this yet.
    Field m_positionIterations  : int   = 10        'Either that.
    Field m_timeStep      : Float = 1.0/60      'Hmm, I know whats this but no changes accured when presetting.
    Field m_physScale      : Float = 1 ' 30           'I Change its value but same results.
  Field m_debugdrawscale    : Float  = 10  

Then you create it.
  BXworld = New b2World(New b2Vec2(0,9.7),True) 

Now that you have created your world you can create objects.
Same here, first you need to define the object and then create it.

Example:
  Field ABody:b2Body        'The Actual Body
  Field BodyDef:b2BodyDef         
  Field BodyShape:b2PolygonShape 
  Field BodyFixture:b2FixtureDef

  BodyDef.type=b2Body.b2_Body  'A dynamic body set
  BodyFixture.density     =1.0
  BodyFixture.friction     =0.5
  BodyFixture.restitution   =0.1
  BodyShape.SetAsBox(10,10)
  BodyFixture.shape=BodyShape

You create the object using the World...

   ABody=BXworld.CreateBody(BodyDef)
   ABody.CreateFixture(BodyFixture) 

I still not totaly understand this engine but you can run the demo and check stuff out.
My next demo will be a joint demo.

#End

'----Imports----'
Import box2d.collision
Import box2d.collision.shapes
Import box2d.common.math
Import box2d.dynamics.contacts
Import box2d.dynamics
Import box2d.flash.flashtypes
Import box2d.common.math.b2vec2

'----Test Zone----'
Function Main()
  New Box2DLoop  
End Function

'----Main Loop----'

Class Box2DLoop Extends App

  'Box 2D World Definitions 
  Field BXworld        : b2World          'Box2D physical World Object
  Field m_velocityIterations  : Int   = 10        'Dont know whats this yet.
    Field m_positionIterations  : Int   = 10        'Either that.
    Field m_timeStep      : Float = 1.0/60      'Hmm, I know whats this but no changes accured when presetting.
    Field m_physScale      : Float = 1 ' 30           'I Change its value but same results.
  Field m_debugdrawscale    : Float  = 10         'This Affects the size of the physical Body Display

  'A Box2D Object Definition
  Field ABody:b2Body      'The Actual Body
  Field BodyDef:b2BodyDef         
  Field BodyShape:b2PolygonShape 
  Field BodyFixture:b2FixtureDef

  Method OnCreate()

    'Display Setup
    SetUpdateRate(60)

    '--Box2D Section--'

    'World Setups
    BXworld = New b2World(New b2Vec2(0,9.7),True)     

    'Creating a Simple Box (simple.. right..)
     BodyDef  =New b2BodyDef
     BodyShape  =New b2PolygonShape()
     BodyFixture=New b2FixtureDef

     BodyDef.type=b2Body.b2_Body  'A dynamic body set
     BodyFixture.density     =1.0
     BodyFixture.friction     =0.5
     BodyFixture.restitution   =0.1
     BodyShape.SetAsBox(10,10)
     BodyFixture.shape=BodyShape

     ABody=BXworld.CreateBody(BodyDef)
     ABody.CreateFixture(BodyFixture)
     ABody.SetPosition(New b2Vec2(20,20))

    'Debug Settings  'Delete this section if you dont need to see the physical process.
    Local dbgDraw :b2DebugDraw = New b2DebugDraw()        
      dbgDraw.SetDrawScale(m_debugdrawscale)
    dbgDraw.SetFillAlpha(0.3)
    dbgDraw.SetLineThickness(1.0)
    dbgDraw.SetFlags(b2DebugDraw.e_shapeBit | b2DebugDraw.e_jointBit)'| b2DebugDraw.e_pairBit)

    BXworld.SetDebugDraw(dbgDraw)

  End Method

  Method OnRender()
    Cls    
    'Box2D Display Section
     BXworld.DrawDebugData() 'Delete this line if you dont need to see the physical process in graphics. (must also delete 'Box2D Debug Settings section above)
  End Method

  Method OnUpdate()
    'The Stepping of Box2D Engine
    BXworld.TimeStep(m_timeStep,m_velocityIterations,m_positionIterations)
    BXworld.ClearForces()                          'Dont know why you need this..  
  End Method

End Class