Update of /cvsroot/plib/plib/src/ssg
In directory sc8-pr-cvs1:/tmp/cvs-serv28801
Modified Files:
ssgEntity.cxx
Log Message:
More LOS fixes - John Fay
----------------------------------------------------------------------
Index: ssgEntity.cxx
===================================================================
RCS file: /cvsroot/plib/plib/src/ssg/ssgEntity.cxx,v
retrieving revision 1.24
retrieving revision 1.25
diff -u -d -r1.24 -r1.25
--- ssgEntity.cxx 21 May 2003 23:41:59 -0000 1.24
+++ ssgEntity.cxx 24 May 2003 17:08:09 -0000 1.25
@@ -380,19 +380,40 @@
sgSetVec3 ( p1, 0.0, 0.0, 0.0 ) ; /* Eye point always at origin */
- /* Get the center of the sphere */
- sgFloat const *center = tmp.getCenter () ;
+ /* Get the center and square the radius of the sphere */
+ sgFloat const *center = tmp.getCenter () ;
+ sgFloat radius2 = sgSquare ( tmp.getRadius () ) ;
/* Calculate the distance from the line to the center of the sphere */
sgVec3 oc ;
sgSubVec3 ( oc, p1, center ) ;
- float dmin2 = sgSquare ( oc[0] ) + sgSquare ( oc[1] ) + sgSquare ( oc[2] )
- - sgSquare ( oc[0] * s[0] + oc[1] * s[1] + oc[2] * s[2] ) /
- ( sgSquare ( s[0] ) + sgSquare ( s[1] ) + sgSquare ( s[2] ) ) ;
+ /* Check whether the eyepoint is within the sphere */
+ sgFloat eye_to_center_squared = sgSquare ( oc[0] ) + sgSquare ( oc[1] ) + sgSquare ( oc[2] ) ;
+ if ( eye_to_center_squared < radius2 )
+ {
+ stats_los_straddle++ ;
+ return SSG_STRADDLE ;
+ }
+
+ /* Calculate the dot product of the vector from the center to the eyepoint and the
+ * line of sight vector. If this dot product is positive or zero, then the point of
+ * closest approach to the sphere is behind the eyepoint or at the eyepoint. Since the
+ * eyepoint is outside the sphere, this means that the line of sight forward from the
+ * eyepoint will not intersect the sphere.
+ */
+ sgFloat oc_dot_s = oc[0] * s[0] + oc[1] * s[1] + oc[2] * s[2] ;
+ if ( oc_dot_s >= 0.0 )
+ {
+ stats_los_radius_reject++ ;
+ return SSG_OUTSIDE ;
+ }
+
+ float dmin2 = eye_to_center_squared - sgSquare ( oc_dot_s ) /
+ ( sgSquare ( s[0] ) + sgSquare ( s[1] ) + sgSquare ( s[2] ) ) ;
/* Compare minimum distance squared with sphere radius squared */
- if ( dmin2 > sgSquare ( tmp.getRadius () ) )
+ if ( dmin2 > radius2 )
{
stats_los_radius_reject++;
return SSG_OUTSIDE;
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