GeColliderEngine Class Reference

#include <lib_collider.h>

Detailed Description

Collision engine : contains algorithms for collision detection.

Note

Has to be created with Alloc() and destroyed with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

BaseDocument* doc = GetActiveDocument(); if (!doc) return;
 
// Get the first object
AutoAlloc<GeColliderCache> o1;
if (!o1)
  return;
BaseObject* obj1 = doc->GetFirstObject();
if (!obj1)
  return;
FillColliderCache(*o1, *obj1);
 
// Use the next object as second object
AutoAlloc<GeColliderCache> o2;
if (!o2)
  return;
BaseObject* obj2 = obj1->GetNext();
if (!obj2)
  return;
FillColliderCache(*o2, *obj2);
 
// Create the engine
AutoAlloc<GeColliderEngine> e;
if (!e)
  return;
 
// Check for collisions
GePrint("DoCollide():");
e->DoCollide(obj1->GetMg(), o1, obj2->GetMg(), o2, COL_ALL_CONTACTS);
GePrint(" " + String::IntToString(e->GetNumPairs()) + " pairs;");
for (int k = 0; k < e->GetNumPairs(); ++k)
{
  GePrint("  " + String::IntToString(e->GetId1(k)) + " - " + String::IntToString(e->GetId2(k)));
}

Public Member Functions
Int32	DoCollide (const Matrix &M1, GeColliderCache *o1, const Matrix &M2, GeColliderCache *o2, Int32 flag)
Int32	DoPolyPairs (const Matrix &M1, GeColliderCache *o1, const Matrix &M2, GeColliderCache *o2, Float tolerance)
Int32	DoTolerance (const Matrix &M1, GeColliderCache *o1, const Matrix &M2, GeColliderCache *o2, Float tolerance)
Int32	DoDistance (const Matrix &M1, GeColliderCache *o1, const Matrix &M2, GeColliderCache *o2, Float rel_err, Float abs_err)
void	FreePairsList ()
Int32	GetNumPairs ()
Int32	GetId1 (Int32 k)
Int32	GetId2 (Int32 k)
Bool	IsCloser ()
Float	GetDistance ()
const Vector &	GetP1 ()
const Vector &	GetP2 ()
Int32	DoRayCollide (GeColliderCache *o1, const Vector &ray_p, const Vector &ray_dir, Float ray_length)

Static Public Member Functions
static GeColliderEngine *	Alloc ()
static void	Free (GeColliderEngine *&data)

Private Member Functions
	GeColliderEngine ()
	~GeColliderEngine ()

Constructor & Destructor Documentation

GeColliderEngine()

GeColliderEngine ( )

private

~GeColliderEngine()

~GeColliderEngine ( )

private

Member Function Documentation

Alloc()

static GeColliderEngine* Alloc ( )

static

Allocates a collider engine. Destroy the allocated collider engine with Free(). Use AutoAlloc to automate the allocation and destruction based on scope.

Returns

The allocated collider engine, or nullptr if the allocation failed.

Free()

static void Free ( GeColliderEngine *&  data )

static

Destructs collider engines allocated with Alloc(). Use AutoAlloc to automate the allocation and destruction based on scope.

Parameters

[in,out]

data

The collider engine to destruct. If the pointer is nullptr nothing happens. The pointer is assigned nullptr afterwards.

DoCollide()

Int32 DoCollide	(	const Matrix &	M1,
		GeColliderCache *	o1,
		const Matrix &	M2,
		GeColliderCache *	o2,
		Int32	flag
	)

Checks for intersecting triangles in o1 and o2.
If the function succeeds retrieve a list of colliding triangle pairs with GetNumPairs(), GetId1() and GetId2().

Note

The matrices must be orthonormal!

Parameters

[in]	M1	The world matrix of first object.
[in]	o1	The cache for first object.
[in]	M2	The world matrix of second object.
[in]	o2	The cache for second object.
[in]	flag	The method: COL_CONTACT

Returns

The result: COL

DoPolyPairs()

Int32 DoPolyPairs	(	const Matrix &	M1,
		GeColliderCache *	o1,
		const Matrix &	M2,
		GeColliderCache *	o2,
		Float	tolerance
	)

Checks for triangles in o1 and o2 that are closer than tolerance to each other.
If the function succeeds retrieve a list of colliding triangle pairs with GetNumPairs(), GetId1() and GetId2().

Note

The matrices must be orthonormal!

Parameters

[in]	M1	The world matrix of first object.
[in]	o1	The cache for first object.
[in]	M2	The world matrix of second object.
[in]	o2	The cache for second object.
[in]	tolerance	The tolerance.

Returns

The result: COL

DoTolerance()

Int32 DoTolerance	(	const Matrix &	M1,
		GeColliderCache *	o1,
		const Matrix &	M2,
		GeColliderCache *	o2,
		Float	tolerance
	)

Checks if o1 and o2 are closer to each other than tolerance.
If the function succeeds check the result with IsCloser(): if it returns true, the proof is in GetDistance(), GetP1() and GetP2().

Note

The matrices must be orthonormal!

Parameters

[in]	M1	The world matrix of first object.
[in]	o1	The cache for first object.
[in]	M2	The world matrix of second object.
[in]	o2	The cache for second object.
[in]	tolerance	The tolerance.

Returns

The result: COL

DoDistance()

Int32 DoDistance	(	const Matrix &	M1,
		GeColliderCache *	o1,
		const Matrix &	M2,
		GeColliderCache *	o2,
		Float	rel_err,
		Float	abs_err
	)

Calculates the minimum distance between o1 and o2 with the accuracy specified by rel_err and abs_err.
If the function succeeds check the result with GetDistance(). The two closest points can be retrieved with GetP1() and GetP2().

Note

The matrices must be orthonormal!

Parameters

[in]	M1	The world matrix of first object.
[in]	o1	The cache for first object.
[in]	M2	The world matrix of second object.
[in]	o2	The cache for second object.
[in]	rel_err	The maximum relative error.
[in]	abs_err	The maximum absolute error.

Returns

The result: COL

FreePairsList()

void FreePairsList

(

)

Frees the pairs list.

GetNumPairs()

Int32 GetNumPairs

(

)

Retrieves the number of pairs found by DoCollide() or DoPolyPairs().

Returns

The number of pairs.

GetId1()

Int32 GetId1

(

Int32

k

)

Retrieves the ID of the first triangle in the pair at k found by DoCollide() or DoPolyPairs().

Parameters

[in]

k

The pair index: 0 <= k < GetNumPairs()

Returns

The first triangle ID in pair.

GetId2()

Int32 GetId2

(

Int32

k

)

Retrieves the ID of the second triangle in the pair at k found by DoCollide() or DoPolyPairs().

Parameters

[in]

k

The pair index: 0 <= k < GetNumPairs()

Returns

The second triangle ID in pair.

IsCloser()

Bool IsCloser

(

)

Checks the result of the tolerance check done with DoTolerance().

Returns

true if the objects are closer than the tolerance, otherwise false.

GetDistance()

Float GetDistance

(

)

Retrieves the result of the distance calculation done with DoDistance() or DoTolerance().

Returns

The calculated distance.

GetP1()

const Vector& GetP1

(

)

Retrieves the closest point found on the first object during the distance calculation done with DoDistance() or DoTolerance().

Returns

The closest point on the first object, in object coordinates.

GetP2()

const Vector& GetP2

(

)

Retrieves the closest point found on the second object during the distance calculation done with DoDistance() or DoTolerance().

Returns

The closest point on the second object, in object coordinates.

DoRayCollide()

Int32 DoRayCollide	(	GeColliderCache *	o1,
		const Vector &	ray_p,
		const Vector &	ray_dir,
		Float	ray_length
	)

Checks if the line segment specified by ray_p to ray_p + ray_dir*ray_length intersects the object.
If the function succeeds retrieve the list of intersections with GetNumPairs(), GetId1() and GetId2().

Parameters

[in]	o1	The cache for the object.
[in]	ray_p	The start point of the ray in object coordinates
[in]	ray_dir	The ray direction in object coordinates.
[in]	ray_length	The ray length.

Returns

The result: COL