// Finds if the two rays intersect
public bool intersects(ref Ray ray)
{
// Variables
Vector vec= direction.getCrossProduct(ray.direction);
float a= vec.getMagnitude();
if(a== 0f && position.x== ray.position.x && position.y== ray.position.y && position.z== ray.position.z)
return true;
// Variables
float[] n= new float[27];
Vector vox;
a*= a;
n[0]= ray.position.x-position.x;
n[1]= ray.position.y-position.y;
n[2]= ray.position.z-position.z;
n[3]= vec.x;
n[4]= vec.y;
n[5]= vec.z;
n[6]= (n[0]*ray.direction.y*n[5]+n[1]*ray.direction.z*n[3]+n[2]*ray.direction.x*n[4]-n[0]*ray.direction.z*n[4]-n[1]*ray.direction.x*n[5]-n[2]*ray.direction.y*n[3]);
n[7]= (n[0]*direction.y*n[5]+n[1]*direction.z*n[3]+n[2]*direction.x*n[4]-n[0]*direction.z*n[4]-n[1]*direction.x*n[5]-n[2]*direction.y*n[3]);
n[8]= n[6]/a;
n[9]= n[7]/a;
vec= (position.toVector())+n[8]*direction;
vox= (ray.position.toVector())+n[8]*ray.direction;
if(!vec.Equals(vox))
return false;
return true;
}
// Gets the picking ray of the mouse and the world
public Ray getPickingRay(float[] viewport)
{
// Variables
OpenTK.Matrix4 mdlv, proj;
float mx, my;
float nx, ny, nz;
float fx, fy, fz;
Ray ray;
GL.GetFloat(GetPName.ProjectionMatrix, out proj);
GL.GetFloat(GetPName.ModelviewMatrix, out mdlv);
mx= mouse.position.x;
my= viewport[3]-mouse.position.y;
// Unproject
unproject(ref mx, ref my, 0f, ref mdlv, ref proj, ref viewport, out nx, out ny, out nz);
unproject(ref mx, ref my, 1f, ref mdlv, ref proj, ref viewport, out fx, out fy, out fz);
ray= new Ray(new Point(nx, ny, nz), new Point(fx, fy, fz));
return ray;
}
public bool intersects(Ray ray)
{
return intersects(ref ray);
}
// Finds if the given ray intersects the box
public bool intersects(Ray ray)
{
// Variables
bool bInside= true;
byte[] quad= new byte[3];
int plane;
float[] maxT= new float[3];
Point cPlane= Point.ORIGIN;
Point min= position;
Point max= position+size;
if(ray.position.x< min.x)
{
quad[0]= 0;
cPlane.x= min.x;
bInside= false;
}
else if(ray.position.x> max.x)
{
quad[0]= 1;
cPlane.x= max.x;
bInside= false;
}
else
quad[0]= 2;
if(ray.position.y< min.y)
{
quad[1]= 0;
cPlane.y= min.y;
bInside= false;
}
else if(ray.position.y> max.y)
{
quad[1]= 1;
cPlane.y= max.y;
bInside= false;
}
else
quad[1]= 2;
if(ray.position.z< min.z)
{
quad[2]= 0;
cPlane.z= min.z;
bInside= false;
}
else if(ray.position.z> max.z)
{
quad[2]= 1;
cPlane.z= max.z;
bInside= false;
}
else
quad[2]= 2;
if(bInside)
return true;
if(quad[0]!= 2 && ray.direction.x!= 0)
maxT[0]= (cPlane.x-ray.position.x)/ray.direction.x;
else
maxT[0]= -1;
if(quad[1]!= 2 && ray.direction.y!= 0)
maxT[1]= (cPlane.y-ray.position.y)/ray.direction.y;
else
maxT[1]= -1;
if(quad[2]!= 2 && ray.direction.z!= 0)
maxT[2]= (cPlane.z-ray.position.z)/ray.direction.z;
else
maxT[2]= -1;
plane= 0;
for(int i= 0; i< maxT.Length; i++)
{
if(maxT[plane]< maxT[i])
plane= i;
}
if(maxT[plane]< 0)
return false;
if(plane!= 0)
{
cPlane.x= ray.position.x+maxT[plane]*ray.direction.x;
if(cPlane.x< min.x || cPlane.x> max.x)
return false;
}
if(plane!= 1)
{
cPlane.y= ray.position.y+maxT[plane]*ray.direction.y;
if(cPlane.y< min.y || cPlane.y> max.y)
return false;
}
if(plane!= 2)
{
cPlane.z= ray.position.z+maxT[plane]*ray.direction.z;
if(cPlane.z< min.z || cPlane.z> max.z)
return false;
}
return (maxT[plane]< 1f);
}
