[Bf-blender-cvs] [64ab084ca5f] master: Grease Pencil: adjust behavior of target object detection

[Campbell Barton]

Commit: 64ab084ca5fa171d39e799f143cff1d661267cf3
Author: Campbell Barton
Date:   Mon Nov 16 16:48:44 2020 +1100
Branches: master
https://developer.blender.org/rB64ab084ca5fa171d39e799f143cff1d661267cf3

Grease Pencil: adjust behavior of target object detection

First detect the other selected object, then check it can be written to.

Otherwise the target object could be the first one found when
looping over objects which is random from the user perspective.

Move the type check to the operator, which also checks the data isn't
library data which was being ignored.

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

M	source/blender/blenkernel/BKE_layer.h
M	source/blender/blenkernel/intern/layer_utils.c
M	source/blender/editors/gpencil/gpencil_mesh.c
M	source/blender/editors/gpencil/gpencil_trace_ops.c

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

diff --git a/source/blender/blenkernel/BKE_layer.h b/source/blender/blenkernel/BKE_layer.h
index 5682e3b9815..7091a060243 100644
--- a/source/blender/blenkernel/BKE_layer.h
+++ b/source/blender/blenkernel/BKE_layer.h
@@ -377,9 +377,8 @@ struct Object **BKE_view_layer_array_selected_objects_params(
     uint *r_len,
     const struct ObjectsInViewLayerParams *params);
 
-struct Object *BKE_view_layer_first_selected_object_by_type(struct ViewLayer *view_layer,
-                                                            const struct View3D *v3d,
-                                                            const short ob_type);
+struct Object *BKE_view_layer_non_active_selected_object(struct ViewLayer *view_layer,
+                                                         const struct View3D *v3d);
 
 #define BKE_view_layer_array_selected_objects(view_layer, v3d, r_len, ...) \
   BKE_view_layer_array_selected_objects_params( \
diff --git a/source/blender/blenkernel/intern/layer_utils.c b/source/blender/blenkernel/intern/layer_utils.c
index b48aef2d05e..974a5a24e8a 100644
--- a/source/blender/blenkernel/intern/layer_utils.c
+++ b/source/blender/blenkernel/intern/layer_utils.c
@@ -192,15 +192,28 @@ bool BKE_view_layer_filter_edit_mesh_has_edges(Object *ob, void *UNUSED(user_dat
   return false;
 }
 
-/** Select first selected object of the type specified. */
-Object *BKE_view_layer_first_selected_object_by_type(struct ViewLayer *view_layer,
-                                                     const struct View3D *v3d,
-                                                     const short ob_type)
+/**
+ * Use this in rare cases we need to detect a pair of objects (active, selected).
+ * This returns the other non-active selected object.
+ *
+ * Returns NULL with it finds multiple other selected objects
+ * as behavior in this case would be random from the user perspective.
+ */
+Object *BKE_view_layer_non_active_selected_object(struct ViewLayer *view_layer,
+                                                  const struct View3D *v3d)
 {
+  Object *ob_active = OBACT(view_layer);
   Object *ob_result = NULL;
   FOREACH_SELECTED_OBJECT_BEGIN (view_layer, v3d, ob_iter) {
-    if (ob_iter->type == ob_type) {
+    if (ob_iter == ob_active) {
+      continue;
+    }
+
+    if (ob_result == NULL) {
       ob_result = ob_iter;
+    }
+    else {
+      ob_result = NULL;
       break;
     }
   }
diff --git a/source/blender/editors/gpencil/gpencil_mesh.c b/source/blender/editors/gpencil/gpencil_mesh.c
index 2f3a4d747a7..84314202dfc 100644
--- a/source/blender/editors/gpencil/gpencil_mesh.c
+++ b/source/blender/editors/gpencil/gpencil_mesh.c
@@ -224,12 +224,22 @@ static int gpencil_bake_mesh_animation_exec(bContext *C, wmOperator *op)
   const int project_type = RNA_enum_get(op->ptr, "project_type");
   eGP_TargetObjectMode target = RNA_enum_get(op->ptr, "target");
 
-  /* Create a new grease pencil object in origin or resuse selected. */
+  /* Create a new grease pencil object in origin or reuse selected. */
   Object *ob_gpencil = NULL;
   bool newob = false;
+
   if (target == GP_TARGET_OB_SELECTED) {
-    ob_gpencil = BKE_view_layer_first_selected_object_by_type(
-        CTX_data_view_layer(C), v3d, OB_GPENCIL);
+    ob_gpencil = BKE_view_layer_non_active_selected_object(CTX_data_view_layer(C), v3d);
+    if (ob_gpencil != NULL) {
+      if (ob_gpencil->type != OB_GPENCIL) {
+        BKE_report(op->reports, RPT_WARNING, "Target object not a grease pencil, ignoring!");
+        ob_gpencil = NULL;
+      }
+      else if (BKE_object_obdata_is_libdata(ob_gpencil)) {
+        BKE_report(op->reports, RPT_WARNING, "Target object library-data, ignoring!");
+        ob_gpencil = NULL;
+      }
+    }
   }
 
   if (ob_gpencil == NULL) {
diff --git a/source/blender/editors/gpencil/gpencil_trace_ops.c b/source/blender/editors/gpencil/gpencil_trace_ops.c
index 75683c9ccf3..0be9d74278e 100644
--- a/source/blender/editors/gpencil/gpencil_trace_ops.c
+++ b/source/blender/editors/gpencil/gpencil_trace_ops.c
@@ -321,12 +321,22 @@ static int gpencil_trace_image_exec(bContext *C, wmOperator *op)
   job->image = (Image *)job->ob_active->data;
   job->frame_target = CFRA;
 
-  /* Create a new grease pencil object or resuse selected. */
+  /* Create a new grease pencil object or reuse selected. */
   eGP_TargetObjectMode target = RNA_enum_get(op->ptr, "target");
-  job->ob_gpencil = (target == GP_TARGET_OB_SELECTED) ?
-                        BKE_view_layer_first_selected_object_by_type(
-                            CTX_data_view_layer(C), job->v3d, OB_GPENCIL) :
-                        NULL;
+  job->ob_gpencil = (target == GP_TARGET_OB_SELECTED) ? BKE_view_layer_non_active_selected_object(
+                                                            CTX_data_view_layer(C), job->v3d) :
+                                                        NULL;
+
+  if (job->ob_gpencil != NULL) {
+    if (job->ob_gpencil->type != OB_GPENCIL) {
+      BKE_report(op->reports, RPT_WARNING, "Target object not a grease pencil, ignoring!");
+      job->ob_gpencil = NULL;
+    }
+    else if (BKE_object_obdata_is_libdata(job->ob_gpencil)) {
+      BKE_report(op->reports, RPT_WARNING, "Target object library-data, ignoring!");
+      job->ob_gpencil = NULL;
+    }
+  }
 
   job->was_ob_created = false;