inttest.h

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/***********************************************************************************************
 ***              C O N F I D E N T I A L  ---  W E S T W O O D  S T U D I O S               ***
 ***********************************************************************************************
 *                                                                                             *
 *                 Project Name : WW3D                                                         *
 *                                                                                             *
 *                     $Archive:: /Commando/Code/ww3d2/inttest.h                              $*
 *                                                                                             *
 *              Original Author:: Greg Hjelstrom                                               *
 *                                                                                             *
 *                      $Author:: Greg_h                                                      $*
 *                                                                                             *
 *                     $Modtime:: 3/14/01 9:19a                                               $*
 *                                                                                             *
 *                    $Revision:: 2                                                           $*
 *                                                                                             *
 *---------------------------------------------------------------------------------------------*
 * Functions:                                                                                  *
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
#if defined(_MSC_VER)
#pragma once
#endif
 
#ifndef INTTEST_H
#define INTTEST_H
 
#include "always.h"
#include "aabox.h"
#include "obbox.h"
#include "tri.h"
#include "colmath.h"
#include "coltype.h"
 

// IntersectionTestClass
//
// This is the base class for all of the 'Intersection' functions.  The intersection tests are 
// purely boolean tests.  The base class only contains the CollisionType of the test.  
//
// Every IntersectionTestClass should have the following functions:
//
//      bool Cull(const Vector3 & min,const Vector3 & max);
//      bool Cull(const AABoxClass & box);
//      bool Intersect_Triangle(const TriClass & tri);
//
// These are not virtual because I don't want to pay the price of virtual function
// calls at the point in the code where these are used.  It may be possible to 
// write template functions if we use these exact function prototpyes for all 
// collision test classes though.
//  
class IntersectionTestClass
{
public:
    IntersectionTestClass(int collision_type) : CollisionType(collision_type)                             { }
    IntersectionTestClass(const IntersectionTestClass & that) :   CollisionType(that.CollisionType) { }
 
public:
    int                             CollisionType; 
};
 

// AABoxIntersectionTestClass
//
// This is an intersection test which uses an Axis-Aligned Box
//  
class AABoxIntersectionTestClass : public IntersectionTestClass
{
public:
    AABoxIntersectionTestClass(const AABoxClass & box,int collision_type) :
        IntersectionTestClass(collision_type),
        Box(box)
    {
    }
 
    AABoxIntersectionTestClass(const AABoxIntersectionTestClass & that) :
        IntersectionTestClass(that),
        Box(that.Box)
    {
    }
 
    bool                                Cull(const Vector3 & cull_min,const Vector3 & cull_max);
    bool                                Cull(const AABoxClass & cull_box);
    bool                                Intersect_Triangle(const TriClass & tri);
 
public:
    AABoxClass                        Box;                 // world space aabox that we want to test with
 
};
 
inline bool AABoxIntersectionTestClass::Cull(const Vector3 & cull_min,const Vector3 & cull_max)
{
    Vector3 box_min;
    Vector3::Subtract(Box.Center,Box.Extent,&box_min);
    
    Vector3 box_max;
    Vector3::Add(Box.Center,Box.Extent,&box_max);
 
    if ((box_min.X > cull_max.X) || (box_max.X < cull_min.X)) return true;
    if ((box_min.Y > cull_max.Y) || (box_max.Y < cull_min.Y)) return true;
    if ((box_min.Z > cull_max.Z) || (box_max.Z < cull_min.Z)) return true;
 
    return false;
}
 
inline bool AABoxIntersectionTestClass::Cull(const AABoxClass & cull_box)
{
    Vector3 dc;
    Vector3 r;
    Vector3::Subtract(cull_box.Center,Box.Center,&dc);
    Vector3::Add(cull_box.Extent,Box.Extent,&r);
 
    if (WWMath::Fabs(dc.X) > r.X) return true;
    if (WWMath::Fabs(dc.Y) > r.Y) return true;
    if (WWMath::Fabs(dc.Z) > r.Z) return true;
 
    return false;
}
 
inline bool AABoxIntersectionTestClass::Intersect_Triangle(const TriClass & tri)
{
    return CollisionMath::Intersection_Test(Box,tri);
}
 

// OBBoxIntersectionTestClass
//
// This is an intersection test which uses an Axis-Aligned Box
//  
class OBBoxIntersectionTestClass : public IntersectionTestClass
{
public:
 
    OBBoxIntersectionTestClass(const OBBoxClass & box,int collision_type);
    OBBoxIntersectionTestClass(const OBBoxIntersectionTestClass & that);
    OBBoxIntersectionTestClass(const OBBoxIntersectionTestClass & that,const Matrix3D & tm);
    OBBoxIntersectionTestClass(const AABoxIntersectionTestClass & that,const Matrix3D & tm);
 
    bool                                Cull(const Vector3 & min,const Vector3 & max);
    bool                                Cull(const AABoxClass & box);
    bool                                Intersect_Triangle(const TriClass & tri);
 
protected:  
    void                                update_bounding_box(void);
 
public:
    OBBoxClass                        Box;                 // world space obbox that we want to test with
    AABoxClass                        BoundingBox;     // axis aligned w-s bounding box
};
 
 
inline OBBoxIntersectionTestClass::OBBoxIntersectionTestClass(const OBBoxClass & box,int collision_type) :
    IntersectionTestClass(collision_type),
    Box(box)
{
    update_bounding_box();
}
 
inline OBBoxIntersectionTestClass::OBBoxIntersectionTestClass(const OBBoxIntersectionTestClass & that) :
    IntersectionTestClass(that),
    Box(that.Box)
{
    update_bounding_box();
}
 
inline OBBoxIntersectionTestClass::OBBoxIntersectionTestClass
(
    const OBBoxIntersectionTestClass & that,
    const Matrix3D & tm
) :
    IntersectionTestClass(that)
{
    OBBoxClass::Transform(tm,that.Box,&Box);
    update_bounding_box();
}
 
inline OBBoxIntersectionTestClass::OBBoxIntersectionTestClass
(
    const AABoxIntersectionTestClass & that,
    const Matrix3D & tm
) :
    IntersectionTestClass(that)
{
    Matrix3D::Transform_Vector(tm,that.Box.Center,&(Box.Center));
    Box.Extent = that.Box.Extent;
    Box.Basis = tm; // copies the 3x3 rotation portion of the transform
    update_bounding_box();
}
 
inline bool OBBoxIntersectionTestClass::Cull(const Vector3 & cull_min,const Vector3 & cull_max)
{
    Vector3 box_min;
    Vector3::Subtract(BoundingBox.Center,BoundingBox.Extent,&box_min);
    
    Vector3 box_max;
    Vector3::Add(BoundingBox.Center,BoundingBox.Extent,&box_max);
 
    if ((box_min.X > cull_max.X) || (box_max.X < cull_min.X)) return true;
    if ((box_min.Y > cull_max.Y) || (box_max.Y < cull_min.Y)) return true;
    if ((box_min.Z > cull_max.Z) || (box_max.Z < cull_min.Z)) return true;
    
    return false;
}
 
inline bool OBBoxIntersectionTestClass::Cull(const AABoxClass & cull_box)
{
    Vector3 dc;
    Vector3 r;
    Vector3::Subtract(cull_box.Center,BoundingBox.Center,&dc);
    Vector3::Add(cull_box.Extent,BoundingBox.Extent,&r);
 
    if (WWMath::Fabs(dc.X) > r.X) return true;
    if (WWMath::Fabs(dc.Y) > r.Y) return true;
    if (WWMath::Fabs(dc.Z) > r.Z) return true;
 
    return false;
}
 
inline bool OBBoxIntersectionTestClass::Intersect_Triangle(const TriClass & tri)
{
    return CollisionMath::Intersection_Test(Box,tri);
}
 
inline void OBBoxIntersectionTestClass::update_bounding_box(void)
{
    BoundingBox.Center = Box.Center;
    Box.Basis.Rotate_AABox_Extent(Box.Extent,&BoundingBox.Extent);
}
 
 
 
#endif