ID Static Override, part II: RNA changes.

This is essentially a huge refactor/extension of our existing RNA
compare & copy code, since static override needs more advanced handling here.

Note that not all new features are implemented yet, advanced things like
collections insertion/deletion are still TODO (medium priority).

This completes the ground work for overrides, remaining commits will be
about UI and some basic/testing activation of overrides for a limited
set of data-blocks & properties.

For details see https://developer.blender.org/D2417

1 files changed, 62 insertions, 0 deletions

diff --git a/source/blender/makesrna/intern/rna_internal_types.h b/source/blender/makesrna/intern/rna_internal_types.h
index b43423464e9..fd0b655e41e 100644
--- a/source/blender/makesrna/intern/rna_internal_types.h
+++ b/source/blender/makesrna/intern/rna_internal_types.h
@@ -40,6 +40,9 @@ struct PointerRNA;
 struct FunctionRNA;
 struct CollectionPropertyIterator;
 struct bContext;
+struct IDOverrideStatic;
+struct IDOverrideStaticProperty;
+struct IDOverrideStaticPropertyOperation;
 struct IDProperty;
 struct GHash;
 struct Main;
@@ -117,6 +120,60 @@ typedef void (*PropStringSetFuncEx)(struct PointerRNA *ptr, struct PropertyRNA *
 typedef int (*PropEnumGetFuncEx)(struct PointerRNA *ptr, struct PropertyRNA *prop);
 typedef void (*PropEnumSetFuncEx)(struct PointerRNA *ptr, struct PropertyRNA *prop, int value);
 
+/* Handling override operations, and also comparison. */
+enum {
+	/* Do not compare properties that are not overridable. */
+	RNA_OVERRIDE_COMPARE_IGNORE_NON_OVERRIDABLE = 1 << 0,
+	/* Do not compare properties that are already overridden. */
+	RNA_OVERRIDE_COMPARE_IGNORE_OVERRIDDEN = 1 << 1,
+};
+
+/**
+ * If \a override is NULL, merely do comparison between prop_a from ptr_a and prop_b from ptr_b,
+ * following comparison mode given.
+ * If \a override and \a rna_path are not NULL, it will add a new override operation for overridable properties
+ * that differ and have not yet been overridden (and set accordingly \a r_override_changed if given).
+ *
+ * \note Given PropertyRNA are final (in case of IDProps...).
+ * \note In non-array cases, \a len values are 0.
+ * \note \a override, \a rna_path and \a r_override_changed may be NULL pointers.
+ */
+typedef int (*RNAPropOverrideDiff)(
+        struct PointerRNA *ptr_a, struct PointerRNA *ptr_b,
+        struct PropertyRNA *prop_a, struct PropertyRNA *prop_b,
+        const int len_a, const int len_b,
+        const int mode,
+        struct IDOverrideStatic *override, const char *rna_path,
+        const int flags, bool *r_override_changed);
+
+/**
+ * Only used for differential override (add, sub, etc.).
+ * Store into storage the value needed to transform reference's value into local's value.
+ *
+ * \note Given PropertyRNA are final (in case of IDProps...).
+ * \note In non-array cases, \a len values are 0.
+ * \note Might change given override operation (e.g. change 'add' one into 'sub'), in case computed storage value
+ *       is out of range (or even change it to basic 'set' operation if nothing else works).
+ */
+typedef bool (*RNAPropOverrideStore)(
+        struct PointerRNA *ptr_local, struct PointerRNA *ptr_reference, struct PointerRNA *ptr_storage,
+        struct PropertyRNA *prop_local, struct PropertyRNA *prop_reference, struct PropertyRNA *prop_storage,
+        const int len_local, const int len_reference, const int len_storage,
+        struct IDOverrideStaticPropertyOperation *opop);
+
+/**
+ * Apply given override operation from src to dst (using value from storage as second operand
+ * for differential operations).
+ *
+ * \note Given PropertyRNA are final (in case of IDProps...).
+ * \note In non-array cases, \a len values are 0.
+ */
+typedef bool (*RNAPropOverrideApply)(
+        struct PointerRNA *ptr_dst, struct PointerRNA *ptr_src, struct PointerRNA *ptr_storage,
+        struct PropertyRNA *prop_dst, struct PropertyRNA *prop_src, struct PropertyRNA *prop_storage,
+        const int len_dst, const int len_src, const int len_storage,
+        struct IDOverrideStaticPropertyOperation *opop);
+
 /* Container - generic abstracted container of RNA properties */
 typedef struct ContainerRNA {
 	void *next, *prev;
@@ -194,6 +251,11 @@ struct PropertyRNA {
 	/* callback for testing if array-item editable (if applicable) */
 	ItemEditableFunc itemeditable;
 
+	/* Override handling callbacks (diff is also used for comparison). */
+	RNAPropOverrideDiff override_diff;
+	RNAPropOverrideStore override_store;
+	RNAPropOverrideApply override_apply;
+
 	/* raw access */
 	int rawoffset;
 	RawPropertyType rawtype;