Function CM_FindPlane

code/qcommon/cm_patch.cpp:533–578

================== CM_FindPlane ================== */

==================
*/
static int CM_FindPlane( float *p1, float *p2, float *p3 ) {
	float	plane[4];
	int		i;
	float	d;

	if ( !CM_PlaneFromPoints( plane, p1, p2, p3 ) ) {
		return -1;
	}

	// see if the points are close enough to an existing plane
	for ( i = 0 ; i < numPlanes ; i++ ) {
		if ( DotProduct( plane, planes[i].plane ) < 0 ) {
			continue;	// allow backwards planes?
		}

		d = DotProduct( p1, planes[i].plane ) - planes[i].plane[3];
		if ( d < -PLANE_TRI_EPSILON || d > PLANE_TRI_EPSILON ) {
			continue;
		}

		d = DotProduct( p2, planes[i].plane ) - planes[i].plane[3];
		if ( d < -PLANE_TRI_EPSILON || d > PLANE_TRI_EPSILON ) {
			continue;
		}

		d = DotProduct( p3, planes[i].plane ) - planes[i].plane[3];
		if ( d < -PLANE_TRI_EPSILON || d > PLANE_TRI_EPSILON ) {
			continue;
		}

		// found it
		return i;
	}

	// add a new plane
	if ( numPlanes == MAX_PATCH_PLANES ) {
		Com_Error( ERR_DROP, "MAX_PATCH_PLANES" );
	}

	VectorCopy4( plane, planes[numPlanes].plane );
	planes[numPlanes].signbits = CM_SignbitsForNormal( plane );

	numPlanes++;

	return numPlanes-1;
}


/*