root/trunk/dep/include/g3dlite/G3D/AABox.h @ 2

/**
  @file AABox.h
 
  Axis-aligned box class
 
  @maintainer Morgan McGuire, matrix@graphics3d.com
 
  @created 2004-01-10
  @edited  2006-02-10

  Copyright 2000-2006, Morgan McGuire.
  All rights reserved.
 */

#ifndef G3D_AABOX_H
#define G3D_AABOX_H

#include "G3D/platform.h"
#include "G3D/Vector3.h"
#include "G3D/debug.h"
#include "G3D/Array.h"

namespace G3D {

/**
 An axis-aligned box.
 */
class AABox {
private:

    /** Optional argument placeholder */
    static int dummy;

    Vector3  lo;
    Vector3  hi;

public:

    /** Does not initialize the fields */
    inline AABox() {}

    /**
     Constructs a zero-area AABox at v.
     */
    inline AABox(const Vector3& v) {
        lo = hi = v;
    }

    /** Assumes that low is less than or equal to high along each dimension.
        To have this automatically enforced, use
        <code>AABox(low.min(high), low.max(high));</code>
    */
    inline AABox(const Vector3& low, const Vector3& high) {
        set(low, high);
    }

    /** Assumes that low is less than or equal to high along each dimension.
    */
    inline void set(const Vector3& low, const Vector3& high) {
        debugAssert(
            (low.x <= high.x) &&
            (low.y <= high.y) &&
            (low.z <= high.z));
        lo = low;
        hi = high;
    }


    inline const Vector3& low() const {
        return lo;
    }

    inline const Vector3& high() const {
        return hi;
    }

    /**
     The largest possible finite box.
     */
    static inline const AABox& maxFinite() {
        static const AABox b = AABox(Vector3::minFinite(), Vector3::maxFinite());
        return b;
    }

    static inline const AABox& inf() {
        static const AABox b = AABox(-Vector3::inf(), Vector3::inf());
        return b;
    }

    static inline const AABox& zero() {
        static const AABox b = AABox(Vector3::zero(), Vector3::zero());
        return b;
    }

    /**
      Returns the centroid of the box.
     */
    inline Vector3 center() const {
        return (lo + hi) * 0.5;
    }

    /**
     Distance from corner(0) to the next corner along axis a.
     */
    inline double extent(int a) const {
        debugAssert(a < 3);
        return hi[a] - lo[a];
    }

    inline Vector3 extent() const {
        return hi - lo;
    }

    /**
         @deprecated Use culledBy(Array<Plane>&)
     */
    bool culledBy(
        const class Plane*  plane,
        int                 numPlanes,
                int32&                          cullingPlaneIndex,
                const uint32            testMask,
        uint32&             childMask) const;

    /**
         @deprecated Use culledBy(Array<Plane>&)
     */
    bool culledBy(
        const class Plane*  plane,
        int                 numPlanes,
                int32&                          cullingPlaneIndex = dummy,
                const uint32            testMask = 0xFFFFFF) const;

    /**
     Splits the box into two AABoxes along the specified axis.  low contains
     the part that was closer to negative infinity along axis, high contains
     the other part.  Either may have zero volume.
     */
    void split(const Vector3::Axis& axis, float location, AABox& low, AABox& high) const;

        /**
         Conservative culling test for up to 32 planes. 
         Returns true if there exists a <CODE>plane[p]</CODE> for
     which the entire object is in the negative half space
     (opposite the plane normal).

         <CODE>testMask</CODE> and <CODE>childMask</CODE>
         are used for optimizing bounding volume hierarchies.
     The version of this method that produces childMask
     is slower than the version without; it should only
     be used for parent nodes.

         @param cullingPlaneIndex The index of the first plane for which
          the entire object is in the negative half-space.  The function
          exits early when one plane is found.  -1 when the function
          returns false (i.e. when no plane culls the whole object).

         @param testMask  If bit <I>p</I> is 0, the 
           bounding volume automatically passes the culling test for
           <CODE>plane[p]</CODE> (i.e. it is known that the volume
           is entirely within the positive half space).  The function
       must return false if testMask is 0 and test all planes
       when testMask is -1 (0xFFFFFFFF).

     @param childMask Test mask for the children of this volume.
       
         */
        bool culledBy(
                const Array<Plane>&             plane,
                int32&                                  cullingPlaneIndex,
                const uint32                    testMask,
        uint32&                 childMask) const;

    /**
     Conservative culling test that does not produce a mask for children.
     */
        bool culledBy(
                const Array<Plane>&             plane,
                int32&                                  cullingPlaneIndex = dummy,
                const uint32                    testMask                  = -1) const;

    inline bool contains(
        const Vector3&      point) const {
        return
            (point.x >= lo.x) &&
            (point.y >= lo.y) &&
            (point.z >= lo.z) &&
            (point.x <= hi.x) &&
            (point.y <= hi.y) &&
            (point.z <= hi.z);
    }

    /** @deprecated */
    inline float surfaceArea() const {
        Vector3 diag = hi - lo;
        return 2.0f * (diag.x * diag.y + diag.y * diag.z + diag.x * diag.z);
    }

    inline float area() const {
        return surfaceArea();
    }

    inline float volume() const {
        Vector3 diag = hi - lo;
        return diag.x * diag.y * diag.z;
    }

    Vector3 randomInteriorPoint() const;

    Vector3 randomSurfacePoint() const;

    /** @deprecated use Box constructor */
    class Box toBox() const;

    /** Returns true if there is any overlap */
    bool intersects(const AABox& other) const;

    /** Returns true if there is any overlap.
        @cite Jim Arvo's algorithm from Graphics Gems II*/
    bool intersects(const class Sphere& other) const;

    /** Return the intersection of the two boxes */
    AABox intersect(const AABox& other) const {
        Vector3 H = hi.min(other.hi);
        Vector3 L = lo.max(other.lo).min(H);
        return AABox(L, H);
    }

    inline unsigned int hashCode() const {
        return lo.hashCode() + hi.hashCode();
    }

    inline bool operator==(const AABox& b) const {
        return (lo == b.lo) && (hi == b.hi);
    }

    inline bool operator!=(const AABox& b) const {
        return !((lo == b.lo) && (hi == b.hi));
    }

    void getBounds(AABox& out) const {
        out = *this;
    }
};

}

/**
 Hashing function for use with Table.
 */
inline unsigned int hashCode(const G3D::AABox& b) {
        return b.hashCode();
}


#endif