Pose Library: remove assumption about Action group names

Remove the assumption of the pose library that Action groups are named
after the bones in the armature. Even though this assumption is correct
when the keys are created by Blender, action groups can be renamed. Keys
created by Python scripts can also use arbitrary group names.

Since there is more code in Blender making this assumption, and looping
over selected bones is also a common occurrence, this commit contains
some generic functionality to aid in this:

- `BKE_armature_find_selected_bones`: function that iterates over all
  bones in an armature and calls a callback for each selected one. It
  returns a struct with info about the selection states (all or no bones
  selected).
- `BKE_armature_find_selected_bone_names(armature)` uses the above
  function to return a set of selected bone names.
- `BKE_pose_find_fcurves_with_bones()` calls a callback for each FCurve
  in an Action that targets a bone, also passing it the bone name.

1 files changed, 27 insertions, 24 deletions

diff --git a/source/blender/editors/armature/pose_backup.cc b/source/blender/editors/armature/pose_backup.cc
index 8d53bd8064b..9b2d3e37d98 100644
--- a/source/blender/editors/armature/pose_backup.cc
+++ b/source/blender/editors/armature/pose_backup.cc
@@ -31,9 +31,12 @@
 #include "DNA_object_types.h"
 
 #include "BKE_action.h"
-#include "BKE_armature.h"
+#include "BKE_action.hh"
+#include "BKE_armature.hh"
 #include "BKE_idprop.h"
 
+using namespace blender::bke;
+
 /* simple struct for storing backup info for one pose channel */
 typedef struct PoseChannelBackup {
   struct PoseChannelBackup *next, *prev;
@@ -51,21 +54,27 @@ struct PoseBackup {
 
 static PoseBackup *pose_backup_create(const Object *ob,
                                       const bAction *action,
-                                      const bool is_bone_selection_relevant)
+                                      const BoneNameSet &selected_bone_names)
 {
   ListBase backups = {nullptr, nullptr};
-  const bArmature *armature = static_cast<const bArmature *>(ob->data);
+  const bool is_bone_selection_relevant = !selected_bone_names.is_empty();
+
+  BoneNameSet backed_up_bone_names;
+  /* Make a backup of the given pose channel. */
+  auto store_animated_pchans = [&](FCurve *, const char *bone_name) {
+    if (backed_up_bone_names.contains(bone_name)) {
+      /* Only backup each bone once. */
+      return;
+    }
 
-  /* TODO(Sybren): reuse same approach as in `armature_pose.cc` in this function, as that doesn't
-   * have the assumption that action group names are bone names. */
-  LISTBASE_FOREACH (bActionGroup *, agrp, &action->groups) {
-    bPoseChannel *pchan = BKE_pose_channel_find_name(ob->pose, agrp->name);
+    bPoseChannel *pchan = BKE_pose_channel_find_name(ob->pose, bone_name);
     if (pchan == nullptr) {
-      continue;
+      /* FCurve targets non-existent bone. */
+      return;
     }
 
-    if (is_bone_selection_relevant && !PBONE_SELECTED(armature, pchan->bone)) {
-      continue;
+    if (is_bone_selection_relevant && !selected_bone_names.contains(bone_name)) {
+      return;
     }
 
     PoseChannelBackup *chan_bak = static_cast<PoseChannelBackup *>(
@@ -78,7 +87,11 @@ static PoseBackup *pose_backup_create(const Object *ob,
     }
 
     BLI_addtail(&backups, chan_bak);
-  }
+    backed_up_bone_names.add_new(bone_name);
+  };
+
+  /* Call `store_animated_pchans()` for each FCurve that targets a bone. */
+  BKE_action_find_fcurves_with_bones(action, store_animated_pchans);
 
   /* PoseBackup is constructed late, so that the above loop can use stack variables. */
   PoseBackup *pose_backup = static_cast<PoseBackup *>(MEM_callocN(sizeof(*pose_backup), __func__));
@@ -89,24 +102,14 @@ static PoseBackup *pose_backup_create(const Object *ob,
 
 PoseBackup *ED_pose_backup_create_all_bones(const Object *ob, const bAction *action)
 {
-  return pose_backup_create(ob, action, false);
+  return pose_backup_create(ob, action, BoneNameSet());
 }
 
 PoseBackup *ED_pose_backup_create_selected_bones(const Object *ob, const bAction *action)
 {
-  /* See if bone selection is relevant. */
-  bool all_bones_selected = true;
-  bool no_bones_selected = true;
   const bArmature *armature = static_cast<const bArmature *>(ob->data);
-  LISTBASE_FOREACH (bPoseChannel *, pchan, &ob->pose->chanbase) {
-    const bool is_selected = PBONE_SELECTED(armature, pchan->bone);
-    all_bones_selected &= is_selected;
-    no_bones_selected &= !is_selected;
-  }
-
-  /* If no bones are selected, act as if all are. */
-  const bool is_bone_selection_relevant = !all_bones_selected && !no_bones_selected;
-  return pose_backup_create(ob, action, is_bone_selection_relevant);
+  const BoneNameSet selected_bone_names = BKE_armature_find_selected_bone_names(armature);
+  return pose_backup_create(ob, action, selected_bone_names);
 }
 
 bool ED_pose_backup_is_selection_relevant(const struct PoseBackup *pose_backup)