Add mutable_bone_axes to IKs

scene/3d/chain_ik_3d.cpp

@@ -258,7 +258,7 @@ void ChainIK3D::set_extend_end_bone(int p_index, bool p_enabled) {
 	}
 	notify_property_list_changed();
 #ifdef TOOLS_ENABLED
-	update_gizmos();
+	_make_gizmo_dirty();
 #endif // TOOLS_ENABLED
 }
 
@@ -270,14 +270,17 @@ bool ChainIK3D::is_end_bone_extended(int p_index) const {
 void ChainIK3D::set_end_bone_direction(int p_index, BoneDirection p_bone_direction) {
 	ERR_FAIL_INDEX(p_index, (int)settings.size());
 	chain_settings[p_index]->end_bone_direction = p_bone_direction;
-	_make_simulation_dirty(p_index);
 	Skeleton3D *sk = get_skeleton();
 	if (sk && !chain_settings[p_index]->joints.is_empty()) {
 		_validate_axis(sk, p_index, chain_settings[p_index]->joints.size() - 1);
 	}
 #ifdef TOOLS_ENABLED
-	update_gizmos();
+	_make_gizmo_dirty();
 #endif // TOOLS_ENABLED
+	if (mutable_bone_axes) {
+		return; // Chain dir will be recaluclated in _update_bone_axis().
+	}
+	_make_simulation_dirty(p_index);
 }
 
 SkeletonModifier3D::BoneDirection ChainIK3D::get_end_bone_direction(int p_index) const {
@@ -287,11 +290,15 @@ SkeletonModifier3D::BoneDirection ChainIK3D::get_end_bone_direction(int p_index)
 
 void ChainIK3D::set_end_bone_length(int p_index, float p_length) {
 	ERR_FAIL_INDEX(p_index, (int)settings.size());
+	float old = chain_settings[p_index]->end_bone_length;
 	chain_settings[p_index]->end_bone_length = p_length;
-	_make_simulation_dirty(p_index);
 #ifdef TOOLS_ENABLED
-	update_gizmos();
+	_make_gizmo_dirty();
 #endif // TOOLS_ENABLED
+	if (mutable_bone_axes && Math::is_zero_approx(old) == Math::is_zero_approx(p_length)) {
+		return; // If chain size is not changed, length will be recaluclated in _update_bone_axis().
+	}
+	_make_simulation_dirty(p_index);
 }
 
 float ChainIK3D::get_end_bone_length(int p_index) const {
@@ -472,7 +479,7 @@ void ChainIK3D::_update_joints(int p_index) {
 	}
 
 #ifdef TOOLS_ENABLED
-	update_gizmos();
+	_make_gizmo_dirty();
 #endif // TOOLS_ENABLED
 }
 
@@ -480,6 +487,59 @@ void ChainIK3D::_process_ik(Skeleton3D *p_skeleton, double p_delta) {
 	//
 }
 
+#ifdef TOOLS_ENABLED
+void ChainIK3D::_update_mutable_info() {
+	if (!is_inside_tree()) {
+		return;
+	}
+	Skeleton3D *skeleton = get_skeleton();
+	if (!skeleton) {
+		for (uint32_t i = 0; i < settings.size(); i++) {
+			chain_settings[i]->root_global_rest = Transform3D();
+		}
+	}
+	bool changed = false;
+	for (uint32_t i = 0; i < settings.size(); i++) {
+		int root_bone = chain_settings[i]->root_bone.bone;
+		if (root_bone < 0) {
+			continue;
+		}
+		Transform3D new_tr = get_bone_global_rest_mutable(skeleton, root_bone);
+		changed = changed || !chain_settings[i]->root_global_rest.is_equal_approx(new_tr);
+		chain_settings[i]->root_global_rest = new_tr;
+	}
+	if (changed) {
+		_make_gizmo_dirty();
+	}
+}
+
+Transform3D ChainIK3D::get_bone_global_rest_mutable(Skeleton3D *p_skeleton, int p_bone) {
+	int current = p_bone;
+	Transform3D accum;
+	int parent = p_skeleton->get_bone_parent(current);
+	if (parent >= 0) {
+		accum = p_skeleton->get_bone_global_rest(parent);
+	}
+	Transform3D tr = p_skeleton->get_bone_rest(current);
+	// Note:
+	// Chain IK gizmo might not be able to retrieve this pose in SkeletonModifier update process.
+	// So the gizmo uses bone_vector insteads but parent of root bone doesn't have bone_vector.
+	// Then, we needs to cache this pose in IK node.
+	tr.origin = p_skeleton->get_bone_pose_position(current);
+	accum *= tr;
+	return accum;
+}
+
+Transform3D ChainIK3D::get_chain_root_global_rest(int p_index) {
+	ERR_FAIL_INDEX_V(p_index, (int)settings.size(), Transform3D());
+	return chain_settings[p_index]->root_global_rest;
+}
+
+Vector3 ChainIK3D::get_bone_vector(int p_index, int p_joint) const {
+	return Vector3();
+}
+#endif // TOOLS_ENABLED
+
 ChainIK3D::~ChainIK3D() {
 	clear_settings();
 }