colmathfrustum.cpp

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/*
**  Command & Conquer Generals Zero Hour(tm)
**  Copyright 2025 Electronic Arts Inc.
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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 : WWMath                                                       *
 *                                                                                             *
 *                     $Archive:: /Commando/Code/wwmath/colmathfrustum.cpp                    $*
 *                                                                                             *
 *                       Author:: Greg Hjelstrom                                               *
 *                                                                                             *
 *                     $Modtime:: 3/29/00 5:40p                                               $*
 *                                                                                             *
 *                    $Revision:: 7                                                           $*
 *                                                                                             *
 *---------------------------------------------------------------------------------------------*
 * Functions:                                                                                  *
 * - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
 
 
#include "colmath.h"
#include "colmathinlines.h"
#include "aaplane.h"
#include "plane.h"
#include "lineseg.h"
#include "tri.h"
#include "sphere.h"
#include "aabox.h"
#include "obbox.h"
#include "frustum.h"
#include "wwdebug.h"
 
 
// TODO: Most of these overlap functions actually do not catch all cases of when
// the primitive is outside of the frustum...
 
 
// Frustum functions
CollisionMath::OverlapType
CollisionMath::Overlap_Test(const FrustumClass & frustum,const Vector3 & point)
{
    int mask = 0;
    
    for (int i = 0; i < 6; i++) {
        int result = CollisionMath::Overlap_Test(frustum.Planes[i],point);
        if (result == OUTSIDE) {
            return OUTSIDE;
        }
        mask |= result;
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}
 
CollisionMath::OverlapType
CollisionMath::Overlap_Test(const FrustumClass & frustum,const TriClass & tri)
{
    int mask = 0;
    
    // TODO: doesn't catch all cases...
    for (int i = 0; i < 6; i++) {
        int result = CollisionMath::Overlap_Test(frustum.Planes[i],tri);
        if (result == OUTSIDE) {
            return OUTSIDE;
        }
        mask |= result;
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}
 
CollisionMath::OverlapType
CollisionMath::Overlap_Test(const FrustumClass & frustum,const SphereClass & sphere)
{
    int mask = 0;
    
    // TODO: doesn't catch all cases...
    for (int i = 0; i < 6; i++) {
        int result = CollisionMath::Overlap_Test(frustum.Planes[i],sphere);
        if (result == OUTSIDE) {
            return OUTSIDE;
        }
        mask |= result;
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}
 
CollisionMath::OverlapType
CollisionMath::Overlap_Test(const FrustumClass & frustum,const AABoxClass & box)
{
    int mask = 0;
    
    // TODO: doesn't catch all cases...
    for (int i = 0; i < 6; i++) {
        int result = CollisionMath::Overlap_Test(frustum.Planes[i],box);
        if (result == OUTSIDE) {
            return OUTSIDE;
        }
        mask |= result;
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}
 
 
CollisionMath::OverlapType
CollisionMath::Overlap_Test(const FrustumClass & frustum,const OBBoxClass & box)
{
    int mask = 0;
    
    // TODO: doesn't catch all cases...
    for (int i = 0; i < 6; i++) {
        int result = CollisionMath::Overlap_Test(frustum.Planes[i],box);
        if (result == OUTSIDE) {
            return OUTSIDE;
        }
        mask |= result;
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}
 
 
CollisionMath::OverlapType    
CollisionMath::Overlap_Test(const FrustumClass & frustum,const OBBoxClass & box,int & planes_passed)
{
    int mask = 0;
    
    // TODO: doesn't catch all cases...
    for (int i = 0; i < 6; i++) {
 
        int plane_bit = (1<<i);
 
        // only check this plane if we have to  
        if ((planes_passed & plane_bit) == 0) {
            
            int result = CollisionMath::Overlap_Test(frustum.Planes[i],box);
            if (result == OUTSIDE) {
                return OUTSIDE;
            } else if (result == INSIDE) {
                planes_passed |= plane_bit;
            }
            mask |= result;
 
        } else {
        
            mask |= INSIDE;
 
        }
    }
 
    if (mask == INSIDE) {
        return INSIDE;
    }
    return OVERLAPPED;
}