T77086 Animation: Passing Dependency Graph to Drivers

Custom driver functions need access to the dependency graph that is
triggering the evaluation of the driver. This patch passes the
dependency graph pointer through all the animation-related calls.

Instead of passing the evaluation time to functions, the code now passes
an `AnimationEvalContext` pointer:

```
typedef struct AnimationEvalContext {
  struct Depsgraph *const depsgraph;
  const float eval_time;
} AnimationEvalContext;
```

These structs are read-only, meaning that the code cannot change the
evaluation time. Note that the `depsgraph` pointer itself is const, but
it points to a non-const depsgraph.

FCurves and Drivers can be evaluated at a different time than the
current scene time, for example when evaluating NLA strips. This means
that, even though the current time is stored in the dependency graph, we
need an explicit evaluation time.

There are two functions that allow creation of `AnimationEvalContext`
objects:

- `BKE_animsys_eval_context_construct(Depsgraph *depsgraph, float
  eval_time)`, which creates a new context object from scratch, and
- `BKE_animsys_eval_context_construct_at(AnimationEvalContext
  *anim_eval_context, float eval_time)`, which can be used to create a
  `AnimationEvalContext` with the same depsgraph, but at a different
  time. This makes it possible to later add fields without changing any
  of the code that just want to change the eval time.

This also provides a fix for T75553, although it does require a change
to the custom driver function. The driver should call
`custom_function(depsgraph)`, and the function should use that depsgraph
instead of information from `bpy.context`.

Reviewed By: brecht, sergey

Differential Revision: https://developer.blender.org/D8047

1 files changed, 62 insertions, 30 deletions

diff --git a/source/blender/editors/animation/keyframing.c b/source/blender/editors/animation/keyframing.c
index 9cb41e06aa0..8c2f4216aa9 100644
--- a/source/blender/editors/animation/keyframing.c
+++ b/source/blender/editors/animation/keyframing.c
@@ -1113,7 +1113,7 @@ static bool insert_keyframe_value(ReportList *reports,
                                   PointerRNA *ptr,
                                   PropertyRNA *prop,
                                   FCurve *fcu,
-                                  float cfra,
+                                  const AnimationEvalContext *anim_eval_context,
                                   float curval,
                                   eBezTriple_KeyframeType keytype,
                                   eInsertKeyFlags flag)
@@ -1130,13 +1130,15 @@ static bool insert_keyframe_value(ReportList *reports,
     return false;
   }
 
+  float cfra = anim_eval_context->eval_time;
+
   /* adjust frame on which to add keyframe */
   if ((flag & INSERTKEY_DRIVER) && (fcu->driver)) {
     PathResolvedRNA anim_rna;
 
     if (RNA_path_resolved_create(ptr, prop, fcu->array_index, &anim_rna)) {
       /* for making it easier to add corrective drivers... */
-      cfra = evaluate_driver(&anim_rna, fcu->driver, fcu->driver, cfra);
+      cfra = evaluate_driver(&anim_rna, fcu->driver, fcu->driver, anim_eval_context);
     }
     else {
       cfra = 0.0f;
@@ -1202,7 +1204,7 @@ bool insert_keyframe_direct(ReportList *reports,
                             PointerRNA ptr,
                             PropertyRNA *prop,
                             FCurve *fcu,
-                            float cfra,
+                            const AnimationEvalContext *anim_eval_context,
                             eBezTriple_KeyframeType keytype,
                             struct NlaKeyframingContext *nla_context,
                             eInsertKeyFlags flag)
@@ -1274,7 +1276,7 @@ bool insert_keyframe_direct(ReportList *reports,
     MEM_freeN(values);
   }
 
-  return insert_keyframe_value(reports, &ptr, prop, fcu, cfra, curval, keytype, flag);
+  return insert_keyframe_value(reports, &ptr, prop, fcu, anim_eval_context, curval, keytype, flag);
 }
 
 /* Find or create the FCurve based on the given path, and insert the specified value into it. */
@@ -1286,7 +1288,7 @@ static bool insert_keyframe_fcurve_value(Main *bmain,
                                          const char group[],
                                          const char rna_path[],
                                          int array_index,
-                                         float cfra,
+                                         const AnimationEvalContext *anim_eval_context,
                                          float curval,
                                          eBezTriple_KeyframeType keytype,
                                          eInsertKeyFlags flag)
@@ -1320,12 +1322,35 @@ static bool insert_keyframe_fcurve_value(Main *bmain,
     update_autoflags_fcurve_direct(fcu, prop);
 
     /* insert keyframe */
-    return insert_keyframe_value(reports, ptr, prop, fcu, cfra, curval, keytype, flag);
+    return insert_keyframe_value(
+        reports, ptr, prop, fcu, anim_eval_context, curval, keytype, flag);
   }
 
   return false;
 }
 
+static AnimationEvalContext nla_time_remap(const AnimationEvalContext *anim_eval_context,
+                                           PointerRNA *id_ptr,
+                                           AnimData *adt,
+                                           bAction *act,
+                                           ListBase *nla_cache,
+                                           NlaKeyframingContext **r_nla_context)
+{
+  if (adt && adt->action == act) {
+    /* Get NLA context for value remapping. */
+    *r_nla_context = BKE_animsys_get_nla_keyframing_context(
+        nla_cache, id_ptr, adt, anim_eval_context, false);
+
+    /* Apply NLA-mapping to frame. */
+    const float remapped_frame = BKE_nla_tweakedit_remap(
+        adt, anim_eval_context->eval_time, NLATIME_CONVERT_UNMAP);
+    return BKE_animsys_eval_context_construct_at(anim_eval_context, remapped_frame);
+  }
+
+  *r_nla_context = NULL;
+  return *anim_eval_context;
+}
+
 /**
  * Main Keyframing API call
  *
@@ -1346,7 +1371,7 @@ int insert_keyframe(Main *bmain,
                     const char group[],
                     const char rna_path[],
                     int array_index,
-                    float cfra,
+                    const AnimationEvalContext *anim_eval_context,
                     eBezTriple_KeyframeType keytype,
                     ListBase *nla_cache,
                     eInsertKeyFlags flag)
@@ -1393,15 +1418,8 @@ int insert_keyframe(Main *bmain,
 
   /* apply NLA-mapping to frame to use (if applicable) */
   adt = BKE_animdata_from_id(id);
-
-  if (adt && adt->action == act) {
-    /* Get NLA context for value remapping. */
-    nla_context = BKE_animsys_get_nla_keyframing_context(
-        nla_cache ? nla_cache : &tmp_nla_cache, &id_ptr, adt, cfra, false);
-
-    /* Apply NLA-mapping to frame. */
-    cfra = BKE_nla_tweakedit_remap(adt, cfra, NLATIME_CONVERT_UNMAP);
-  }
+  const AnimationEvalContext remapped_context = nla_time_remap(
+      anim_eval_context, &id_ptr, adt, act, nla_cache ? nla_cache : &tmp_nla_cache, &nla_context);
 
   /* Obtain values to insert. */
   float value_buffer[RNA_MAX_ARRAY_LENGTH];
@@ -1435,7 +1453,7 @@ int insert_keyframe(Main *bmain,
                                            group,
                                            rna_path,
                                            array_index,
-                                           cfra,
+                                           &remapped_context,
                                            values[array_index],
                                            keytype,
                                            flag)) {
@@ -1458,7 +1476,7 @@ int insert_keyframe(Main *bmain,
                                                   group,
                                                   rna_path,
                                                   array_index,
-                                                  cfra,
+                                                  &remapped_context,
                                                   values[array_index],
                                                   keytype,
                                                   flag);
@@ -1477,7 +1495,7 @@ int insert_keyframe(Main *bmain,
                                               group,
                                               rna_path,
                                               array_index,
-                                              cfra,
+                                              &remapped_context,
                                               values[array_index],
                                               keytype,
                                               flag);
@@ -1495,7 +1513,7 @@ int insert_keyframe(Main *bmain,
                                             group,
                                             rna_path,
                                             array_index,
-                                            cfra,
+                                            &remapped_context,
                                             values[array_index],
                                             keytype,
                                             flag);
@@ -2375,7 +2393,8 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
   PropertyRNA *prop = NULL;
   char *path;
   uiBut *but;
-  float cfra = (float)CFRA;
+  const AnimationEvalContext anim_eval_context = BKE_animsys_eval_context_construct(
+      CTX_data_depsgraph_pointer(C), (float)CFRA);
   bool changed = false;
   int index;
   const bool all = RNA_boolean_get(op->ptr, "all");
@@ -2401,7 +2420,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
 
       if (fcu) {
         changed = insert_keyframe_direct(
-            op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, 0);
+            op->reports, ptr, prop, fcu, &anim_eval_context, ts->keyframe_type, NULL, 0);
       }
       else {
         BKE_report(op->reports,
@@ -2417,8 +2436,14 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
       fcu = BKE_fcurve_find_by_rna_context_ui(C, &ptr, prop, index, NULL, NULL, &driven, &special);
 
       if (fcu && driven) {
-        changed = insert_keyframe_direct(
-            op->reports, ptr, prop, fcu, cfra, ts->keyframe_type, NULL, INSERTKEY_DRIVER);
+        changed = insert_keyframe_direct(op->reports,
+                                         ptr,
+                                         prop,
+                                         fcu,
+                                         &anim_eval_context,
+                                         ts->keyframe_type,
+                                         NULL,
+                                         INSERTKEY_DRIVER);
       }
     }
     else {
@@ -2461,7 +2486,7 @@ static int insert_key_button_exec(bContext *C, wmOperator *op)
                                    group,
                                    path,
                                    index,
-                                   cfra,
+                                   &anim_eval_context,
                                    ts->keyframe_type,
                                    NULL,
                                    flag) != 0);
@@ -2769,7 +2794,10 @@ bool fcurve_frame_has_keyframe(FCurve *fcu, float frame, short filter)
 }
 
 /* Returns whether the current value of a given property differs from the interpolated value. */
-bool fcurve_is_changed(PointerRNA ptr, PropertyRNA *prop, FCurve *fcu, float frame)
+bool fcurve_is_changed(PointerRNA ptr,
+                       PropertyRNA *prop,
+                       FCurve *fcu,
+                       const AnimationEvalContext *anim_eval_context)
 {
   PathResolvedRNA anim_rna;
   anim_rna.ptr = ptr;
@@ -2780,7 +2808,7 @@ bool fcurve_is_changed(PointerRNA ptr, PropertyRNA *prop, FCurve *fcu, float fra
   int count, index = fcu->array_index;
   float *values = setting_get_rna_values(&ptr, prop, buffer, RNA_MAX_ARRAY_LENGTH, &count);
 
-  float fcurve_val = calculate_fcurve(&anim_rna, fcu, frame);
+  float fcurve_val = calculate_fcurve(&anim_rna, fcu, anim_eval_context);
   float cur_val = (index >= 0 && index < count) ? values[index] : 0.0f;
 
   if (values != buffer) {
@@ -2987,6 +3015,9 @@ bool ED_autokeyframe_property(
     bContext *C, Scene *scene, PointerRNA *ptr, PropertyRNA *prop, int rnaindex, float cfra)
 {
   Main *bmain = CTX_data_main(C);
+  Depsgraph *depsgraph = CTX_data_depsgraph_pointer(C);
+  const AnimationEvalContext anim_eval_context = BKE_animsys_eval_context_construct(depsgraph,
+                                                                                    cfra);
   ID *id;
   bAction *action;
   FCurve *fcu;
@@ -3007,7 +3038,8 @@ bool ED_autokeyframe_property(
       ReportList *reports = CTX_wm_reports(C);
       ToolSettings *ts = scene->toolsettings;
 
-      changed = insert_keyframe_direct(reports, *ptr, prop, fcu, cfra, ts->keyframe_type, NULL, 0);
+      changed = insert_keyframe_direct(
+          reports, *ptr, prop, fcu, &anim_eval_context, ts->keyframe_type, NULL, 0);
       WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_EDITED, NULL);
     }
   }
@@ -3020,7 +3052,7 @@ bool ED_autokeyframe_property(
       ToolSettings *ts = scene->toolsettings;
 
       changed = insert_keyframe_direct(
-          reports, *ptr, prop, fcu, cfra, ts->keyframe_type, NULL, INSERTKEY_DRIVER);
+          reports, *ptr, prop, fcu, &anim_eval_context, ts->keyframe_type, NULL, INSERTKEY_DRIVER);
       WM_event_add_notifier(C, NC_ANIMATION | ND_KEYFRAME | NA_EDITED, NULL);
     }
   }
@@ -3044,7 +3076,7 @@ bool ED_autokeyframe_property(
                                 ((fcu->grp) ? (fcu->grp->name) : (NULL)),
                                 fcu->rna_path,
                                 rnaindex,
-                                cfra,
+                                &anim_eval_context,
                                 ts->keyframe_type,
                                 NULL,
                                 flag) != 0;