Attributes and Behaviors of Primitives - Essentials of Interactive Computer Graphics - page 176

class UWB _ Primitive {

Source file.
uwbgl _ Primitive2.h file in
the

// exactly the same as Listing 7.9 ...
// except the following three additional functions
.
// Collision Detection / Response
virtual const UWB _ BoundingVolume * GetBoundingVolume( eLevelOfDetail lod ) const ;
virtual void CollisionResponse( const UWB _ Primitive * pOther, vec3 other _ location);
void DrawBoundingVolume( eLevelOfDetail lod, UWB _ DrawHelper * pRenderer,
UWB _ Color color ) const ;

Common Files/Prim-

itives subfolder of the

UWBGL _ D3D _ Lib6 project.

};

Listing 7.17. The UWB _ Primitive class (Tutorial 7.3).

Source file.
Sample code for working with
bounding volumes and prim-
itive collision response.

// assume ... pPrimA and pPrimB are pointers to Primitives
// Get the bounding volume from pPrimA
UWB _ BoundingVolume * pBVA = pPrimA->GetBoundingVolume();
// Get the bounding volume from pPrimB
UWB _ BoundingVolume * pBVB = pPrimB->GetBoundingVolume();

No

source file.

// Test if the two bounding volumes overlaps
if ( pBVA->Intersects(pBVB) ) {
// pPrimA responses to the collision
pPrimA->CollisionResponse( pPrimB, pPrimB->GetLocation() );
// pPrimB responses to the collision
pPrimB->CollisionResponse( pPrimA, pPrimA->GetLocation() );

}
.

Listing 7.18. Working with the Primitive collision interface (Tutorial 7.3).

void UWB _ Primitive::CollisionResponse( const UWB _ Primitive * pOther, vec3 other _ location) {
// vector points from the other _ location towards the primitive
dir = GetLocation() - other _ location;

Source file.
uwbgl _ Primitive2.cpp file
in the Common Files/Prim-
itives

// direction pointing away from other _ location
dir = normalize(dir);
// speed of the current velocity
mySpeed = length(GetVelocity());
// new velocity is the same speed, but away from other _ location
SetVelocity(mySpeed * dir);

subfolder of the

UWBGL _ D3D _ Lib6 project.

}

Listing 7.19. The default primitive CollisionResponse() function (Tutorial 7.3).