//Test
// now the object is in the local coordinate rather than the global
bool Square::intersectLocal( const ray& r, isect& i ) const
{
// get the parameters of the ray
Vec3d p = r.getPosition();
Vec3d d = r.getDirection();
// if the ray is perpendicular to the z-axis
if( d[2] == 0.0 ) {
return false;
}
// calculate the value of t
double t = -p[2]/d[2];
// if the intersection is too close to the source
// then we don't count that as a intersection
if( t <= RAY_EPSILON ) {
return false;
}
Vec3d P = r.at( t );
if( P[0] < -0.5 || P[0] > 0.5 ) {
return false;
}
if( P[1] < -0.5 || P[1] > 0.5 ) {
return false;
}
i.obj = this;
i.t = t;
if( d[2] > 0.0 ) {
i.N = Vec3d( 0.0, 0.0, -1.0 );
} else {
i.N = Vec3d( 0.0, 0.0, 1.0 );
}
i.setUVCoordinates( Vec2d(P[0] + 0.5, P[1] + 0.5) );
return true;
}
//Test
bool Square::intersectLocal(ray& r, isect& i) const
{
Vec3d p = r.getPosition();
Vec3d d = r.getDirection();
if( d[2] == 0.0 ) {
return false;
}
double t = -p[2]/d[2];
if( t <= RAY_EPSILON ) {
return false;
}
Vec3d P = r.at( t );
if( P[0] < -0.5 || P[0] > 0.5 ) {
return false;
}
if( P[1] < -0.5 || P[1] > 0.5 ) {
return false;
}
i.obj = this;
i.setMaterial(this->getMaterial());
i.t = t;
if( d[2] > 0.0 ) {
i.N = Vec3d( 0.0, 0.0, -1.0 );
} else {
i.N = Vec3d( 0.0, 0.0, 1.0 );
}
i.setUVCoordinates( Vec2d(P[0] + 0.5, P[1] + 0.5) );
return true;
}
bool Box::intersectLocal( const ray& r, isect& i ) const
{
Vec3d p = r.getPosition();
Vec3d d = r.getDirection();
int it;
double x, y, t, bestT;
int mod0, mod1, mod2, bestIndex;
bestT = HUGE_DOUBLE;
bestIndex = -1;
for(it=0; it<6; it++){
mod0 = it%3;
if(d[mod0] == 0){
continue;
}
t = ((it/3) - 0.5 - p[mod0]) / d[mod0];
if(t < RAY_EPSILON || t > bestT){
continue;
}
mod1 = (it+1)%3;
mod2 = (it+2)%3;
x = p[mod1]+t*d[mod1];
y = p[mod2]+t*d[mod2];
if( x<=0.5 && x>=-0.5 &&
y<=0.5 && y>=-0.5)
{
if(bestT > t){
bestT = t;
bestIndex = it;
}
}
}
if(bestIndex < 0) return false;
i.setT(bestT);
i.setObject(this);
Vec3d intersect_point = r.at(i.t);
int i1 = (bestIndex + 1) % 3;
int i2 = (bestIndex + 2) % 3;
if(bestIndex < 3)
{
i.setN(Vec3d(-double(bestIndex == 0), -double(bestIndex == 1), -double(bestIndex == 2)));
i.setUVCoordinates( Vec2d( 0.5 - intersect_point[ min(i1, i2) ],
0.5 + intersect_point[ max(i1, i2) ] ) );
}
else
{
i.setN(Vec3d(double(bestIndex==3), double(bestIndex == 4), double(bestIndex == 5)));
i.setUVCoordinates( Vec2d( 0.5 + intersect_point[ min(i1, i2) ],
0.5 + intersect_point[ max(i1, i2) ] ) );
}
return true;
}
