hit.h

#ifndef __HIT_H__
#define __HIT_H__

class Object;

// Records information about an intersection, which may be needed later for
// Boolean operations or for a subsequent call to Normal.
struct Hit
{
    // The primitive geometry whose surface was intersected.  This should
    // not point at a Union, Difference, or Intersection object.  Instead it
    // should point at the particular component.
    const Object* object;

    // Distance along the ray at which this occurred
    double t;

    // For complex primitives (eg, cylinders), use this to record what part
    // was intersected, since you will need to know this to compute the
    // normal reliably.
    int part;

    // Was the ray entering or exiting the primitive geometry stored in
    // "object"?  This will tell you whether you will need to reverse the
    // normal that you compute.
    bool ray_exiting;
};

#endif