source: GTP/trunk/App/Demos/Vis/FriendlyCulling/VisibilitySolutionConverter/SimpleVec.cpp @ 3234

#include "SimpleVec.h"
#include <float.h>



// Given min a vector to minimize and a candidate vector, replace
// elements of min whose corresponding elements in Candidate are
// smaller.  This function is used for finding objects' bounds,
// among other things.
void Minimize(SimpleVec &min, const SimpleVec &Candidate)
{
        if (Candidate.x < min.x)
                min.x = Candidate.x;
        if (Candidate.y < min.y)
                min.y = Candidate.y;
        if (Candidate.z < min.z)
                min.z = Candidate.z;
}

// Given min a vector to minimize and a candidate vector, replace
// elements of min whose corresponding elements in Candidate are
// larger.  This function is used for finding objects' bounds,
// among other things.
void Maximize(SimpleVec &max, const SimpleVec &Candidate)
{
        if (Candidate.x > max.x)
                max.x = Candidate.x;
        if (Candidate.y > max.y)
                max.y = Candidate.y;
        if (Candidate.z > max.z)
                max.z = Candidate.z;
}

// Project the vector onto the YZ, XZ, or XY plane depending on which.
// which      Coordinate plane to project onto
// 0          YZ
// 1          XZ
// 2          XY
// This function is used by the polygon intersection code.

void SimpleVec::ExtractVerts(float *px, float *py, int which) const
{
        switch (which) {
        case 0:
                *px = y;
                *py = z;
                break;
        case 1:
                *px = x;
                *py = z;
                break;
        case 2:
                *px = x;
                *py = y;
                break;
        }
}

// returns the axis, where the vector has the largest value
int
SimpleVec::DrivingAxis(void) const
{
        int axis = 0;
        float val = fabs(x);

        if (fabs(y) > val) {
                val = fabs(y);
                axis = 1;
        }

        if (fabs(z) > val)
                axis = 2;

        return axis;
}


// returns the axis, where the vector has the smallest value
int SimpleVec::TinyAxis(void) const
{
        int axis = 0;
        float val = fabs(x);

        if (fabs(y) < val) {
                val = fabs(y);
                axis = 1;
        }

        if (fabs(z) < val)
                axis = 2;

        return axis;
}


bool SimpleVec::CheckValidity() const
{
#ifdef _WIN32
        return !(_isnan(x) || _isnan(y) || _isnan(z));
#else
        return !(isnan(x) || isnan(y) || isnan(z));
#endif  
}