source: GTP/trunk/Lib/Vis/Preprocessing/src/RayInfo.cpp @ 2239

#include "RayInfo.h"
#include "Ray.h"
#include "VssRay.h"
#include "Plane3.h"

using namespace std;

namespace GtpVisibilityPreprocessor {

RayInfo::RayInfo(): mRay(NULL), mMinT(0),
#if USE_FIXEDPOINT_T
#define FIXEDPOINT_ONE 0x7FFE
        // mMaxT(0xFFFF)
        mMaxT(FIXEDPOINT_ONE)
#else
        mMaxT(1.0f)
#endif
{}
                
RayInfo::RayInfo(VssRay *r):mRay(r), mMinT(0),
#if USE_FIXEDPOINT_T
#define FIXEDPOINT_ONE 0x7FFE
        // mMaxT(0xFFFF)
        mMaxT(FIXEDPOINT_ONE)
#else
        mMaxT(1.0f)
#endif
{}
                
RayInfo::RayInfo(VssRay *r,     const float _min, const float _max):
mRay(r) 
{
        SetMinT(_min);
        SetMaxT(_max);
}
                
RayInfo::RayInfo(VssRay *r, const short _min, const float _max):
mRay(r), mMinT(_min) 
{
        SetMaxT(_max);
}
                
RayInfo::RayInfo(VssRay *r,     const float _min, const short _max): 
mRay(r), mMaxT(_max) 
{
        SetMinT(_min);
}


int RayInfo::ComputeRayIntersection(const int axis, const float position, float &t) const
{               
        // intersect the ray with the plane
        const float denom = mRay->GetDir(axis);

        if (fabs(denom) < 1e-20)
                //if (denom == 0.0f)
                return (mRay->GetOrigin(axis) > position) ? 1 : -1;

        t = (position - mRay->GetOrigin(axis)) / denom;

        if (t < GetMinT())
                return (denom > 0) ? 1 : -1;

        if (t > GetMaxT())
                return (denom > 0) ? -1 : 1;

        return 0;
}


int RayInfo::ComputeRayIntersection(const Plane3 &splitPlane, float &t) const
{       
        t = splitPlane.FindT(mRay->GetOrigin(), mRay->GetTermination());

        if (0)
                Debug << "t: " << t << " mint " << GetMinT() << " maxt " << GetMaxT() 
                      << " orig: " << mRay->GetOrigin() << " term " << mRay->GetTermination() << endl;

        // NOTE: if plane equals end point of ray, the ray should be classified
        // non-intersecting, otherwise polygon-plane intersections of bsp tree
        // approaches are not eliminating any rays intersecting the polygon!
        const float thresh = 1e-6f;

        // segment is not intersecting plane: fond out if on front or back side
        if (t >= (GetMaxT() - thresh))
        {
                return splitPlane.Side(ExtrapOrigin());
        }
                
        if (t <= (GetMinT() + thresh))
        {
                return splitPlane.Side(ExtrapTermination());
        }
        
        return 0;
}


float RayInfo::SegmentLength() const
{
        return Distance(ExtrapOrigin(), ExtrapTermination());
}


float RayInfo::SqrSegmentLength() const
{
        return SqrDistance(ExtrapOrigin(), ExtrapTermination());
}


void GetRayInfoSets(const RayInfoContainer &sourceRays,
                    const int maxSize,
                                        RayInfoContainer &usedRays,
                                        RayInfoContainer *savedRays)
{
        const int limit = min(maxSize, (int)sourceRays.size());
        const float prop = (float)limit / ((float)sourceRays.size() + Limits::Small);

        RayInfoContainer::const_iterator it, it_end = sourceRays.end();

        for (it = sourceRays.begin(); it != it_end; ++ it)
        {
                if (Random(1.0f) < prop)
                        usedRays.push_back(*it);
                else if (savedRays)
                        savedRays->push_back(*it);
        }
}

}