[Plib-cvs] plib/src/sg sg.cxx,1.43,1.44 sgd.cxx,1.14,1.15

[James J. <pu...@us...>]

Update of /cvsroot/plib/plib/src/sg
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv19375

Modified Files:
	sg.cxx sgd.cxx 
Log Message:
SG efficiency: "sg[d]DistSquaredToLineSegmentVec3" with fewer square root invocations (John Fay)


Index: sg.cxx
===================================================================
RCS file: /cvsroot/plib/plib/src/sg/sg.cxx,v
retrieving revision 1.43
retrieving revision 1.44
diff -u -d -r1.43 -r1.44
--- sg.cxx	9 Apr 2004 01:41:11 -0000	1.43
+++ sg.cxx	5 Aug 2004 01:07:09 -0000	1.44
@@ -860,16 +860,14 @@
 SGfloat sgDistSquaredToLineSegmentVec3 ( const sgLineSegment3 line,
                                          const sgVec3 pnt )
 {
-  sgLine3 l ; sgLineSegment3ToLine3 ( & l, line ) ;
- 
-  sgVec3 v  ; sgSubVec3 ( v , line.b, line.a ) ; sgNormalizeVec3 ( v ) ;
-  sgVec3 r1 ; sgSubVec3 ( r1, pnt   , line.a ) ;
- 
+  sgVec3 v ; sgSubVec3 ( v, line.b, line.a ) ;
+  sgVec3 r1 ; sgSubVec3 ( r1, pnt, line.a ) ;
+
   SGfloat r1_dot_v = sgScalarProductVec3 ( r1, v ) ;
- 
+
   if ( r1_dot_v <= 0 )  /* Off the "A" end  */
     return sgScalarProductVec3 ( r1, r1 ) ;
- 
+
   sgVec3 r2 ; sgSubVec3 ( r2, pnt, line.b ) ;
 
   SGfloat r2_dot_v = sgScalarProductVec3 ( r2, v ) ;
@@ -879,7 +877,7 @@
  
   /* Closest point on line is on the line segment */
  
-  return sgScalarProductVec3 ( r1, r1 ) - r1_dot_v * r1_dot_v ;
+  return sgScalarProductVec3 ( r1, r1 ) - r1_dot_v * r1_dot_v / sgScalarProductVec3 ( v, v ) ;
 }
 
 

Index: sgd.cxx
===================================================================
RCS file: /cvsroot/plib/plib/src/sg/sgd.cxx,v
retrieving revision 1.14
retrieving revision 1.15
diff -u -d -r1.14 -r1.15
--- sgd.cxx	9 Apr 2004 01:41:11 -0000	1.14
+++ sgd.cxx	5 Aug 2004 01:07:09 -0000	1.15
@@ -859,26 +859,24 @@
 SGDfloat sgdDistSquaredToLineSegmentVec3 ( const sgdLineSegment3 line,
                                          const sgdVec3 pnt )
 {
-  sgdLine3 l ; sgdLineSegment3ToLine3 ( & l, line ) ;
- 
-  sgdVec3 v ; sgdSubVec3 ( v, line.b, line.a ) ; sgdNormalizeVec3 ( v ) ;
+  sgdVec3 v ; sgdSubVec3 ( v, line.b, line.a ) ;
   sgdVec3 r1 ; sgdSubVec3 ( r1, pnt, line.a ) ;
- 
-  SGDfloat r1_dot_v = sgdScalarProductVec3 ( r1, v /*l.direction_vector*/ ) ;
- 
+
+  SGDfloat r1_dot_v = sgdScalarProductVec3 ( r1, v ) ;
+
   if ( r1_dot_v <= 0 )  /* Off the "A" end  */
     return sgdScalarProductVec3 ( r1, r1 ) ;
- 
+
   sgdVec3 r2 ; sgdSubVec3 ( r2, pnt, line.b ) ;
 
-  SGDfloat r2_dot_v = sgdScalarProductVec3 ( r2, v /*l.direction_vector*/ ) ;
- 
+  SGDfloat r2_dot_v = sgdScalarProductVec3 ( r2, v ) ;
+
   if ( r2_dot_v >= 0 )  /* Off the "B" end */
     return sgdScalarProductVec3 ( r2, r2 ) ;
 
   /* Closest point on line is on the line segment */
  
-  return sgdScalarProductVec3 ( r1, r1 ) - r1_dot_v * r1_dot_v ;
+  return sgdScalarProductVec3 ( r1, r1 ) - r1_dot_v * r1_dot_v / sgdScalarProductVec3 ( v, v ) ;
 }