#include <Parts.h>

Inheritance diagram for CGate:

Public Member Functions
	CGate (CLineSeg *)
	Constructor. More...

	~CGate ()
	Destructor.

void	CloseGate ()
	Check latch to see if gate should be closed. More...

bool	NarrowPhase (CDynamicCircle *)
	Narrow phase collision detection and response. More...

Private Attributes
CLineSeg *	m_pLineSeg = nullptr
	Pointer to line segment representing gate.

bool	m_bOpen = false
	true if gate is open.

bool	m_bOccupied = false
	true if ball is holding gate open.

Additional Inherited Members
Static Protected Attributes inherited from CCommon
static CRenderer *	m_pRenderer = nullptr
	Pointer to the renderer.

static CObjectManager *	m_pObjectManager = nullptr
	Pointer to the object manager.

static LParticleEngine2D *	m_pFrontParticleEngine = nullptr
	Pointer to front particle engine.

static LParticleEngine2D *	m_pBackParticleEngine = nullptr
	Pointer to front particle engine.

static bool	m_bShowTrack = false
	Show trail of breadcrumbs.

static bool	m_bShowReticles = false
	Show reticle at hit point.

static bool	m_bShowImpacts = false
	Draw dots at collision points.

static bool	m_bShowArrows = false
	Draw arrows for velocity vectors.

static bool	m_bShowTangents = false
	Draw arrows for tangents.

static bool	m_bShowSectors = false
	Draw arc sentinels and normals.

static bool	m_bShowAABBs = false
	Draw shape AABBs.

static bool	m_bShowLights = false
	Light up shapes on collision.

static bool	m_bRotate = false
	Rotate kinematic shapes.

static bool	m_bLaunch = false
	Launch a ball.

static bool	m_bMute = false
	Mute the sound.

static float	m_fNextBallScale = 0.5f
	Scale factor for ball size.

static int	m_nMIterationsInit = 4
	Initial number of motion iterations.

static int	m_nCIterationsInit = 6
	Initial number of collision iterations.

static int	m_nMIterations = CCommon::m_nMIterationsInit
	Current number of motion iterations.

static int	m_nCIterations = CCommon::m_nCIterationsInit
	Current number of collision iterations.

static bool	m_bUseQuadTree = false
	Whether to use a quadtree.

static HWND	m_hDlg = nullptr
	Control dialog box handle.

static float	m_fLoad = 0.0f
	Processor load.

static float	m_fLaunchSpeed = 1000.0f
	Speed at which the next ball will be launched.

static int	m_nDesiredLaunchCnt = 1
	Number of balls to launch at next multilaunch.

static int	m_nLaunched = 0
	Number of balls launched in current multilaunch.

static bool	m_bMultiLaunch = false
	Whether launching multiple balls.

static int	m_nBallsLaunched = 0
	Number of balls in play.

static float	m_fFrequency = 60.0f*m_nMIterations
	Frequency, number of physics iterations per second.

Detailed Description

A gate allows balls to cross in one direction only. It's essentially a line segment with a couple of Boolean variables and some code that handles the crossing-in-one-direction requirement. Care must be taken to do the right thing when a ball gets nudged back while in the process of crossing.

A gate can be open or closed, latched or unlatched. When it is open, there can be no collisions. When it is closed, balls collide with it if they are travelling from one side but not the other. More specifically, if the vector from the ball's center to the POI is in the opposite direction to the line segment's normal vector CLineSeg::m_vNormal, then they can cross. Recall that the direction of CLineSeg::m_vNormal depends on the order in which CLineSeg's end points were specified, so make sure you get it right.

Constructor & Destructor Documentation

◆ CGate()

CGate::CGate ( CLineSeg * p )

Construct a closed and unlatched gate from a line segment.

Parameters

p	Pointer to a line segment.

Member Function Documentation

◆ CloseGate()

void CGate::CloseGate ( )

Close gate if open and there is no ball currently holding it open. Unset the occupied flag ready for use the the next frame. We assume that this is called at the end of the frame.

◆ NarrowPhase()

bool CGate::NarrowPhase ( CDynamicCircle * p )

If a dynamic circle collides with a gate and it is moving in the correct direction, then the gate opens and the dynamic circle is allowed through. Otherwise the dynamic circle bounces off the gate as usual.