[Bf-blender-cvs] [18af9da5729] blender-v3.4-release: Fix: Versioning problem with cyclic bezier NURBS

[Laurynas Duburas]

Commit: 18af9da572933af85371dddfefeb3cbafab968be
Author: Laurynas Duburas
Date:   Mon Nov 14 18:04:27 2022 -0600
Branches: blender-v3.4-release
https://developer.blender.org/rB18af9da572933af85371dddfefeb3cbafab968be

Fix: Versioning problem with cyclic bezier NURBS

Patch fixes versioning issue with NURBS files saved with Blender
version from commit 45d038181ae2 to 0602852860dd and opened with
Blender version from commit 0602852860dd. Cyclic Bezier NURBS
saved and then opened with Blender versions mentioned above
changed their shape.

Bug was reported in comments of T101160, circle problem.

Differential Revision: https://developer.blender.org/D16503

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

M	source/blender/blenloader/intern/versioning_300.cc

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

diff --git a/source/blender/blenloader/intern/versioning_300.cc b/source/blender/blenloader/intern/versioning_300.cc
index 65094655cfe..5e1fa17f1c6 100644
--- a/source/blender/blenloader/intern/versioning_300.cc
+++ b/source/blender/blenloader/intern/versioning_300.cc
@@ -2931,6 +2931,21 @@ void blo_do_versions_300(FileData *fd, Library * /*lib*/, Main *bmain)
       }
     }
 
+    LISTBASE_FOREACH (Curve *, curve, &bmain->curves) {
+      LISTBASE_FOREACH (Nurb *, nurb, &curve->nurb) {
+        /* Previously other flags were ignored if CU_NURB_CYCLIC is set. */
+        if (nurb->flagu & CU_NURB_CYCLIC) {
+          nurb->flagu = CU_NURB_CYCLIC;
+          BKE_nurb_knot_calc_u(nurb);
+        }
+        /* Previously other flags were ignored if CU_NURB_CYCLIC is set. */
+        if (nurb->flagv & CU_NURB_CYCLIC) {
+          nurb->flagv = CU_NURB_CYCLIC;
+          BKE_nurb_knot_calc_v(nurb);
+        }
+      }
+    }
+
     /* Initialize the bone wireframe opacity setting. */
     if (!DNA_struct_elem_find(fd->filesdna, "View3DOverlay", "float", "bone_wire_alpha")) {
       LISTBASE_FOREACH (bScreen *, screen, &bmain->screens) {
@@ -3006,32 +3021,35 @@ void blo_do_versions_300(FileData *fd, Library * /*lib*/, Main *bmain)
     /* Alter NURBS knot mode flags to fit new modes. */
     LISTBASE_FOREACH (Curve *, curve, &bmain->curves) {
       LISTBASE_FOREACH (Nurb *, nurb, &curve->nurb) {
-        /* Previously other flags were ignored if CU_NURB_CYCLIC is set. */
-        if (nurb->flagu & CU_NURB_CYCLIC) {
-          nurb->flagu = CU_NURB_CYCLIC;
-        }
         /* CU_NURB_BEZIER and CU_NURB_ENDPOINT were ignored if combined. */
-        else if (nurb->flagu & CU_NURB_BEZIER && nurb->flagu & CU_NURB_ENDPOINT) {
+        if (nurb->flagu & CU_NURB_BEZIER && nurb->flagu & CU_NURB_ENDPOINT) {
           nurb->flagu &= ~(CU_NURB_BEZIER | CU_NURB_ENDPOINT);
           BKE_nurb_knot_calc_u(nurb);
         }
+        else if (nurb->flagu & CU_NURB_CYCLIC) {
+          /* In 45d038181ae2 cyclic bezier support is added, but CU_NURB_ENDPOINT still ignored. */
+          nurb->flagu = CU_NURB_CYCLIC | (nurb->flagu & CU_NURB_BEZIER);
+          BKE_nurb_knot_calc_u(nurb);
+        }
         /* Bezier NURBS of order 3 were clamped to first control point. */
-        else if (nurb->orderu == 3 && (nurb->flagu & CU_NURB_BEZIER)) {
+        if (nurb->orderu == 3 && (nurb->flagu & CU_NURB_BEZIER)) {
           nurb->flagu |= CU_NURB_ENDPOINT;
+          BKE_nurb_knot_calc_u(nurb);
         }
-
-        /* Previously other flags were ignored if CU_NURB_CYCLIC is set. */
-        if (nurb->flagv & CU_NURB_CYCLIC) {
-          nurb->flagv = CU_NURB_CYCLIC;
-        }
-        /* CU_NURB_BEZIER and CU_NURB_ENDPOINT were ignored if used together. */
-        else if (nurb->flagv & CU_NURB_BEZIER && nurb->flagv & CU_NURB_ENDPOINT) {
+        /* CU_NURB_BEZIER and CU_NURB_ENDPOINT were ignored if combined. */
+        if (nurb->flagv & CU_NURB_BEZIER && nurb->flagv & CU_NURB_ENDPOINT) {
           nurb->flagv &= ~(CU_NURB_BEZIER | CU_NURB_ENDPOINT);
           BKE_nurb_knot_calc_v(nurb);
         }
+        else if (nurb->flagv & CU_NURB_CYCLIC) {
+          /* In 45d038181ae2 cyclic bezier support is added, but CU_NURB_ENDPOINT still ignored. */
+          nurb->flagv = CU_NURB_CYCLIC | (nurb->flagv & CU_NURB_BEZIER);
+          BKE_nurb_knot_calc_v(nurb);
+        }
         /* Bezier NURBS of order 3 were clamped to first control point. */
-        else if (nurb->orderv == 3 && (nurb->flagv & CU_NURB_BEZIER)) {
+        if (nurb->orderv == 3 && (nurb->flagv & CU_NURB_BEZIER)) {
           nurb->flagv |= CU_NURB_ENDPOINT;
+          BKE_nurb_knot_calc_v(nurb);
         }
       }
     }