CNautilusGear Class Reference

A system of 5 interlocking nautilus gears. More...

#include <NautilusGear.h>

Inheritance diagram for CNautilusGear:

Public Member Functions
	CNautilusGear (float, float)
	Constructor. More...
void	move ()
	Move gears in synchrony. More...
void	reverse ()
	Reverse gears. More...

Private Member Functions
b2Body *	CreateBase (float, float)
	Create invisible base in Physics World. More...
b2Body *	CreateGear (float, float, eSprite, bool)
	Create gear wheel in Physics World. More...

Private Attributes
std::vector< b2Body * >	m_stdGear
	Gear pointers.
b2RevoluteJoint *	m_pJoint = nullptr
	Pointer to revolute joint for center gear.

Additional Inherited Members
Static Protected Attributes inherited from CCommon
static b2World *	m_pPhysicsWorld = nullptr
	Pointer to Box2D Physics World.
static CRenderer *	m_pRenderer = nullptr
	Pointer to the renderer.
static CObjectManager *	m_pObjectManager = nullptr
	Pointer to the object manager.
static CWindmill *	m_pWindmill = nullptr
	Pointer to windmill.
static CGear *	m_pGear = nullptr
	Pointer to gear system.
static CNautilusGear *	m_pNautilusGear = nullptr
	Pointer to Nautilus gear system.
static CRackAndPinion *	m_pRackAndPinion = nullptr
	Pointer to rack-and-pinion.
static CCar *	m_pCar = nullptr
	Pointer to car.
static CRamp *	m_pRamp = nullptr
	Pointer to ramp.
static CNewtonsCradle *	m_pNewtonsCradle = nullptr
	Pointer to Newton's Cradle.
static CPulley *	m_pPulley = nullptr
	Pointer to pulley system.
static eLevel	m_eCurLevel = eLevel::Windmill
	Current level.

Detailed Description

A system of 5 interlocking nautilus gears.

A nautilus gear is a gear in the shape of a nautilus shell. The center gear has a revolute joint with a motor. The other gears have variable speed, so they cannot be animated by Box2D. We have to animate them ourselves which means doing a little math.
The number and positions of the gears are hard-coded but there is enough storage for any number of them.

Constructor & Destructor Documentation

CNautilusGear()

CNautilusGear::CNautilusGear	(	float	x,
		float	y
	)

Constructor.

Parameters

x	X coordinate in Physics World units.
y	Y coordinate in Physics World units.

Member Function Documentation

CreateBase()

b2Body * CNautilusGear::CreateBase ( float  x, float  y  )

private

Create invisible base in Physics World.

Create an invisible base to attach the largest gear wheel to. The base has no sprite and no shape in Physics World. The latter means it doesn't collide with anything.

Parameters

x	X coordinate in Physics World units.
y	Y coordinate in Physics World units.

Returns

Pointer to the cog wheel body in Physics World.

CreateGear()

b2Body * CNautilusGear::CreateGear ( float  x, float  y, eSprite  t, bool  dynamic  )

private

Create gear wheel in Physics World.

Create a gear wheel at a given position in Physics World.

Parameters

x	X coordinate in Physics World units.
y	Y coordinate in Physics World units.
t	Sprite type of the gear wheel.
dynamic	true if this is to be rotated by Box2D, false if we're going to take care of it ourselves.

Returns

Pointer to the cog wheel body in Physics World.

move()

void CNautilusGear::move

(

)

Move gears in synchrony.

Make the four gears surrounding the center gear rotate in synchrony with the center gear. We use the fact that the radius of a nautilus gear at angle \(\theta\) is \(ae^{b\theta}\), where \(a\) and \(b\) are the maximum and minimum radius of the gear, respectively, and \(d = \ln(b/a)/2\pi\).

reverse()

void CNautilusGear::reverse

(

)

Reverse gears.

Reverse the gears by setting the motor speed on the revolute joint for the first gear.