Fix #30406: Hooks ignore Automatic handles setting in curves

Update handles positions after applying modifiers which seems to be expected behavior.
The only currently unsolved issue is about updating aligned handles because this needs
to determine in which order handles need to be recalculated which currently depends on
selection flags and which is quite tricky to do when running modifiers and animation data,
so currently just not update their positions for now.

1 files changed, 22 insertions, 3 deletions

diff --git a/source/blender/blenkernel/intern/curve.c b/source/blender/blenkernel/intern/curve.c
index 5af72e6115c..0a10b894551 100644
--- a/source/blender/blenkernel/intern/curve.c
+++ b/source/blender/blenkernel/intern/curve.c
@@ -2480,7 +2480,7 @@ void makeBevelList(Object *ob)
  */
 
 /* mode: is not zero when FCurve, is 2 when forced horizontal for autohandles */
-void calchandleNurb(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode)
+static void calchandleNurb_intern(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode, int skip_align)
 {
 	float *p1,*p2,*p3, pt[3];
 	float dvec_a[3], dvec_b[3];
@@ -2627,6 +2627,13 @@ void calchandleNurb(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode)
 		madd_v3_v3v3fl(p2+3, p2, dvec_b,  1.0f/3.0f);
 	}
 
+	if(skip_align) {
+		/* handles need to be updated during animation and applying stuff like hooks,
+		 * but in such situatios it's quite difficult to distinguish in which order
+		 * align handles should be aligned so skip them for now */
+		return;
+	}
+
 	len_b= len_v3v3(p2, p2+3);
 	len_a= len_v3v3(p2, p2-3);
 	if(len_a==0.0f) len_a= 1.0f;
@@ -2670,7 +2677,7 @@ void calchandleNurb(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode)
 	}
 }
 
-void calchandlesNurb(Nurb *nu) /* first, if needed, set handle flags */
+static void calchandlesNurb_intern(Nurb *nu, int skip_align)
 {
 	BezTriple *bezt, *prev, *next;
 	short a;
@@ -2685,7 +2692,7 @@ void calchandlesNurb(Nurb *nu) /* first, if needed, set handle flags */
 	next= bezt+1;
 
 	while(a--) {
-		calchandleNurb(bezt, prev, next, 0);
+		calchandleNurb_intern(bezt, prev, next, 0, skip_align);
 		prev= bezt;
 		if(a==1) {
 			if(nu->flagu & CU_NURB_CYCLIC) next= nu->bezt;
@@ -2697,6 +2704,16 @@ void calchandlesNurb(Nurb *nu) /* first, if needed, set handle flags */
 	}
 }
 
+void calchandleNurb(BezTriple *bezt, BezTriple *prev, BezTriple *next, int mode)
+{
+	calchandleNurb_intern(bezt, prev, next, mode, FALSE);
+}
+
+void calchandlesNurb(Nurb *nu) /* first, if needed, set handle flags */
+{
+	calchandlesNurb_intern(nu, FALSE);
+}
+
 
 void testhandlesNurb(Nurb *nu)
 {
@@ -3080,6 +3097,8 @@ void curve_applyVertexCos(Curve *UNUSED(cu), ListBase *lb, float (*vertexCos)[3]
 				copy_v3_v3(bp->vec, co); co+=3;
 			}
 		}
+
+		calchandlesNurb_intern(nu, TRUE);
 	}
 }