GPencil: Patch old files after the change in how the first frame is used

This patching duplicates the first frame of the layer if the first frame number is not equals to the scene first frame number.

Related to T79567

Differential Revision: https://developer.blender.org/D8486

Some minor cleanup in the patch.

1 files changed, 19 insertions, 0 deletions

diff --git a/source/blender/blenloader/intern/versioning_290.c b/source/blender/blenloader/intern/versioning_290.c
index b6caa018756..a96b82e2e91 100644
--- a/source/blender/blenloader/intern/versioning_290.c
+++ b/source/blender/blenloader/intern/versioning_290.c
@@ -28,6 +28,7 @@
 #include "DNA_constraint_types.h"
 #include "DNA_genfile.h"
 #include "DNA_gpencil_modifier_types.h"
+#include "DNA_gpencil_types.h"
 #include "DNA_modifier_types.h"
 #include "DNA_object_types.h"
 #include "DNA_screen_types.h"
@@ -35,6 +36,7 @@
 
 #include "BKE_collection.h"
 #include "BKE_colortools.h"
+#include "BKE_gpencil.h"
 #include "BKE_lib_id.h"
 #include "BKE_main.h"
 #include "BKE_node.h"
@@ -183,6 +185,23 @@ void do_versions_after_linking_290(Main *bmain, ReportList *UNUSED(reports))
         }
       }
     }
+
+    /* Patch first frame for old files. */
+    Scene *scene = bmain->scenes.first;
+    LISTBASE_FOREACH (Object *, ob, &bmain->objects) {
+      if (ob->type != OB_GPENCIL) {
+        continue;
+      }
+      bGPdata *gpd = ob->data;
+      LISTBASE_FOREACH (bGPDlayer *, gpl, &gpd->layers) {
+        bGPDframe *gpf = gpl->frames.first;
+        if (gpf && gpf->framenum > scene->r.sfra) {
+          bGPDframe *gpf_dup = BKE_gpencil_frame_duplicate(gpf);
+          gpf_dup->framenum = scene->r.sfra;
+          BLI_addhead(&gpl->frames, gpf_dup);
+        }
+      }
+    }
   }
 
   /**