[Bf-blender-cvs] [302d912] hair_immediate_fixes: Added a comment and use the new CG solver as the "official" version now.

[Lukas Tönne]

Commit: 302d9127326353fa84928a606d2adf39badf03a7
Author: Lukas Tönne
Date:   Thu Sep 4 09:26:40 2014 +0200
Branches: hair_immediate_fixes
https://developer.blender.org/rB302d9127326353fa84928a606d2adf39badf03a7

Added a comment and use the new CG solver as the "official" version now.

===================================================================

M	source/blender/blenkernel/intern/implicit.c

===================================================================

diff --git a/source/blender/blenkernel/intern/implicit.c b/source/blender/blenkernel/intern/implicit.c
index f77574c..2956a29 100644
--- a/source/blender/blenkernel/intern/implicit.c
+++ b/source/blender/blenkernel/intern/implicit.c
@@ -920,7 +920,7 @@ DO_INLINE void filter(lfVector *V, fmatrix3x3 *S)
 	}
 }
 
-#if 0
+#if 0 /* this version of the CG algorithm does not work very well with partial constraints (where S has non-zero elements) */
 static int  cg_filtered(lfVector *ldV, fmatrix3x3 *lA, lfVector *lB, lfVector *z, fmatrix3x3 *S)
 {
 	// Solves for unknown X in equation AX=B
@@ -985,7 +985,8 @@ static int  cg_filtered(lfVector *ldV, fmatrix3x3 *lA, lfVector *lB, lfVector *z
 
 	return conjgrad_loopcount<conjgrad_looplimit;  // true means we reached desired accuracy in given time - ie stable
 }
-#else
+#endif
+
 static int cg_filtered(lfVector *ldV, fmatrix3x3 *lA, lfVector *lB, lfVector *z, fmatrix3x3 *S)
 {
 	// Solves for unknown X in equation AX=B
@@ -1051,7 +1052,6 @@ static int cg_filtered(lfVector *ldV, fmatrix3x3 *lA, lfVector *lB, lfVector *z,
 
 	return conjgrad_loopcount < conjgrad_looplimit;  // true means we reached desired accuracy in given time - ie stable
 }
-#endif
 
 // block diagonalizer
 DO_INLINE void BuildPPinv(fmatrix3x3 *lA, fmatrix3x3 *P, fmatrix3x3 *Pinv)