View related geometric clipping

Collaboration diagram for View related geometric clipping:

Files
file	clip.h

Functions
int	bg_lseg_clip (fastf_t *xp1, fastf_t *yp1, fastf_t *xp2, fastf_t *yp2, fastf_t clip_min, fastf_t clip_max)
	Clip a 2-D integer line seg against the size of the display. More...
int	bg_ray_vclip (point_t a, point_t b, fastf_t *min_pt, fastf_t *max_pt)
	Clip a line segment against a rectangular parallelepiped (RPP). More...

Detailed Description

Clipping functions for comment geometric operations needed when drawing wireframes in a view window.

Function Documentation

bg_lseg_clip()

int bg_lseg_clip	(	fastf_t *	xp1,
		fastf_t *	yp1,
		fastf_t *	xp2,
		fastf_t *	yp2,
		fastf_t	clip_min,
		fastf_t	clip_max
	)

Clip a 2-D integer line seg against the size of the display.

bg_ray_vclip()

int bg_ray_vclip	(	point_t	a,
		point_t	b,
		fastf_t *	min_pt,
		fastf_t *	max_pt
	)

Clip a line segment against a rectangular parallelepiped (RPP).

The RPP has faces parallel to the coordinate planes and is defined by a minimum point and a maximum point.

Todo:

the function name implies this takes a point,dir for a,b but it actually takes a line segment going from points a to b!

Returns - 0 if ray does not hit RPP, !0 if ray hits RPP.

Implicit Return - if !0 was returned, "a" and "b" have been clipped to the RPP.