AABB/Ray Intersection Tests

Collaboration diagram for AABB/Ray Intersection Tests:

Functions
void	bg_ray_invdir (vect_t *invdir, const vect_t dir)
	Intersection between an infinite line and an axis-aligned box.
int	bg_isect_aabb_ray (fastf_t *r_min, fastf_t *r_max, const point_t opt, const fastf_t *invdir, const fastf_t *aabb_min, const fastf_t *aabb_max)

Detailed Description

Function Documentation

bg_ray_invdir()

void bg_ray_invdir ( vect_t *  invdir, const vect_t  dir  )

extern

Intersection between an infinite line and an axis-aligned box.

Compute the inverse direction components for use with bg_isect_aabb_ray(). Components within SQRT_SMALL_FASTF of zero are represented by INFINITY. The input direction is not modified.

bg_isect_aabb_ray()

int bg_isect_aabb_ray ( fastf_t *  r_min, fastf_t *  r_max, const point_t  opt, const fastf_t *  invdir, const fastf_t *  aabb_min, const fastf_t *  aabb_max  )

extern

Test the infinite line defined by opt and the reciprocal direction vector invdir against an axis-aligned bounding box. Despite its historical name, this function does not reject intersections behind opt: a successful result can have both output parameters negative. Callers that require a forward ray must additionally require *r_max >= 0.0.

On success, r_min and r_max are the entry and exit line parameters. They are valid only when the function returns 1.