Function BaseWindingForPlane

code/qcommon/cm_polylib.cpp:101–165

================= BaseWindingForPlane ================= */

=================
*/
winding_t *BaseWindingForPlane (vec3_t normal, vec_t dist)
{
	int		i, x;
	vec_t	max, v;
	vec3_t	org, vright, vup;
	winding_t	*w;

// find the major axis

	max = -MAX_MAP_BOUNDS;
	x = -1;
	for (i=0 ; i<3; i++)
	{
		v = fabs(normal[i]);
		if (v > max)
		{
			x = i;
			max = v;
		}
	}
	if (x==-1)
		Com_Error (ERR_DROP, "BaseWindingForPlane: no axis found");

	VectorCopy (vec3_origin, vup);
	switch (x)
	{
	case 0:
	case 1:
		vup[2] = 1;
		break;
	case 2:
		vup[0] = 1;
		break;
	}

	v = DotProduct (vup, normal);
	VectorMA (vup, -v, normal, vup);
	VectorNormalize2(vup, vup);

	VectorScale (normal, dist, org);

	CrossProduct (vup, normal, vright);

	VectorScale (vup, MAX_MAP_BOUNDS, vup);
	VectorScale (vright, MAX_MAP_BOUNDS, vright);

// project a really big	axis aligned box onto the plane
	w = AllocWinding (4);

	VectorSubtract (org, vright, w->p[0]);
	VectorAdd (w->p[0], vup, w->p[0]);

	VectorAdd (org, vright, w->p[1]);
	VectorAdd (w->p[1], vup, w->p[1]);

	VectorAdd (org, vright, w->p[2]);
	VectorSubtract (w->p[2], vup, w->p[2]);