Merge pull request #64647 from TokageItLab/auto-tangent

11 files changed, 469 insertions, 272 deletions

diff --git a/doc/classes/Animation.xml b/doc/classes/Animation.xml
index fef65181ae..faa9ae3569 100644
--- a/doc/classes/Animation.xml
+++ b/doc/classes/Animation.xml
@@ -130,14 +130,6 @@
 				Sets the stream of the key identified by [param key_idx] to value [param stream]. The [param track_idx] must be the index of an Audio Track.
 			</description>
 		</method>
-		<method name="bezier_track_get_key_handle_mode" qualifiers="const">
-			<return type="int" />
-			<param index="0" name="track_idx" type="int" />
-			<param index="1" name="key_idx" type="int" />
-			<description>
-				Returns the handle mode of the key identified by [param key_idx]. See [enum HandleMode] for possible values. The [param track_idx] must be the index of a Bezier Track.
-			</description>
-		</method>
 		<method name="bezier_track_get_key_in_handle" qualifiers="const">
 			<return type="Vector2" />
 			<param index="0" name="track_idx" type="int" />
@@ -169,7 +161,6 @@
 			<param index="2" name="value" type="float" />
 			<param index="3" name="in_handle" type="Vector2" default="Vector2(0, 0)" />
 			<param index="4" name="out_handle" type="Vector2" default="Vector2(0, 0)" />
-			<param index="5" name="handle_mode" type="int" enum="Animation.HandleMode" default="1" />
 			<description>
 				Inserts a Bezier Track key at the given [param time] in seconds. The [param track_idx] must be the index of a Bezier Track.
 				[param in_handle] is the left-side weight of the added Bezier curve point, [param out_handle] is the right-side one, while [param value] is the actual value at this point.
@@ -183,16 +174,6 @@
 				Returns the interpolated value at the given [param time] (in seconds). The [param track_idx] must be the index of a Bezier Track.
 			</description>
 		</method>
-		<method name="bezier_track_set_key_handle_mode">
-			<return type="void" />
-			<param index="0" name="track_idx" type="int" />
-			<param index="1" name="key_idx" type="int" />
-			<param index="2" name="key_handle_mode" type="int" enum="Animation.HandleMode" />
-			<param index="3" name="balanced_value_time_ratio" type="float" default="1.0" />
-			<description>
-				Changes the handle mode of the keyframe at the given [param key_idx]. See [enum HandleMode] for possible values. The [param track_idx] must be the index of a Bezier Track.
-			</description>
-		</method>
 		<method name="bezier_track_set_key_in_handle">
 			<return type="void" />
 			<param index="0" name="track_idx" type="int" />
@@ -643,11 +624,5 @@
 		<constant name="LOOP_PINGPONG" value="2" enum="LoopMode">
 			Repeats playback and reverse playback at both ends of the animation.
 		</constant>
-		<constant name="HANDLE_MODE_FREE" value="0" enum="HandleMode">
-			Assigning the free handle mode to a Bezier Track's keyframe allows you to edit the keyframe's left and right handles independently from one another.
-		</constant>
-		<constant name="HANDLE_MODE_BALANCED" value="1" enum="HandleMode">
-			Assigning the balanced handle mode to a Bezier Track's keyframe makes it so the two handles of the keyframe always stay aligned when changing either the keyframe's left or right handle.
-		</constant>
 	</constants>
 </class>
diff --git a/editor/animation_bezier_editor.cpp b/editor/animation_bezier_editor.cpp
index 11e46152ef..9af8b907c4 100644
--- a/editor/animation_bezier_editor.cpp
+++ b/editor/animation_bezier_editor.cpp
@@ -41,7 +41,7 @@
 float AnimationBezierTrackEdit::_bezier_h_to_pixel(float p_h) {
 	float h = p_h;
 	h = (h - v_scroll) / v_zoom;
-	h = (get_size().height / 2) - h;
+	h = (get_size().height / 2.0) - h;
 	return h;
 }
 
@@ -52,10 +52,10 @@ void AnimationBezierTrackEdit::_draw_track(int p_track, const Color &p_color) {
 	int right_limit = get_size().width;
 
 	//selection may have altered the order of keys
-	RBMap<float, int> key_order;
+	RBMap<real_t, int> key_order;
 
 	for (int i = 0; i < animation->track_get_key_count(p_track); i++) {
-		float ofs = animation->track_get_key_time(p_track, i);
+		real_t ofs = animation->track_get_key_time(p_track, i);
 		if (moving_selection && selection.has(IntPair(p_track, i))) {
 			ofs += moving_selection_offset.x;
 		}
@@ -63,7 +63,7 @@ void AnimationBezierTrackEdit::_draw_track(int p_track, const Color &p_color) {
 		key_order[ofs] = i;
 	}
 
-	for (RBMap<float, int>::Element *E = key_order.front(); E; E = E->next()) {
+	for (RBMap<real_t, int>::Element *E = key_order.front(); E; E = E->next()) {
 		int i = E->get();
 
 		if (!E->next()) {
@@ -75,7 +75,7 @@ void AnimationBezierTrackEdit::_draw_track(int p_track, const Color &p_color) {
 		float offset = animation->track_get_key_time(p_track, i);
 		float height = animation->bezier_track_get_key_value(p_track, i);
 		Vector2 out_handle = animation->bezier_track_get_key_out_handle(p_track, i);
-		if (p_track == moving_handle_track && moving_handle != 0 && moving_handle_key == i) {
+		if (p_track == moving_handle_track && (moving_handle == -1 || moving_handle == 1) && moving_handle_key == i) {
 			out_handle = moving_handle_right;
 		}
 
@@ -89,7 +89,7 @@ void AnimationBezierTrackEdit::_draw_track(int p_track, const Color &p_color) {
 		float offset_n = animation->track_get_key_time(p_track, i_n);
 		float height_n = animation->bezier_track_get_key_value(p_track, i_n);
 		Vector2 in_handle = animation->bezier_track_get_key_in_handle(p_track, i_n);
-		if (p_track == moving_handle_track && moving_handle != 0 && moving_handle_key == i_n) {
+		if (p_track == moving_handle_track && (moving_handle == -1 || moving_handle == 1) && moving_handle_key == i_n) {
 			in_handle = moving_handle_left;
 		}
 
@@ -139,7 +139,7 @@ void AnimationBezierTrackEdit::_draw_track(int p_track, const Color &p_color) {
 
 				//narrow high and low as much as possible
 				for (int k = 0; k < iterations; k++) {
-					float middle = (low + high) / 2;
+					float middle = (low + high) / 2.0;
 
 					Vector2 interp = start.bezier_interpolate(out_handle, in_handle, end, middle);
 
@@ -316,7 +316,7 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 
 						int h = MAX(text_buf.get_size().y, icon->get_height());
 
-						draw_texture(icon, Point2(ofs, vofs + int(h - icon->get_height()) / 2));
+						draw_texture(icon, Point2(ofs, vofs + int(h - icon->get_height()) / 2.0));
 						ofs += icon->get_width();
 
 						margin = icon->get_width();
@@ -403,29 +403,29 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 					Vector2 string_pos = Point2(margin, vofs);
 					text_buf.draw(get_canvas_item(), string_pos, cc);
 
-					float icon_start_height = vofs + rect.size.y / 2;
-					Rect2 remove_rect = Rect2(remove_hpos, icon_start_height - remove->get_height() / 2, remove->get_width(), remove->get_height());
+					float icon_start_height = vofs + rect.size.y / 2.0;
+					Rect2 remove_rect = Rect2(remove_hpos, icon_start_height - remove->get_height() / 2.0, remove->get_width(), remove->get_height());
 					if (read_only) {
 						draw_texture(remove, remove_rect.position, dc);
 					} else {
 						draw_texture(remove, remove_rect.position);
 					}
 
-					Rect2 lock_rect = Rect2(lock_hpos, icon_start_height - lock->get_height() / 2, lock->get_width(), lock->get_height());
+					Rect2 lock_rect = Rect2(lock_hpos, icon_start_height - lock->get_height() / 2.0, lock->get_width(), lock->get_height());
 					if (locked_tracks.has(current_track)) {
 						draw_texture(lock, lock_rect.position);
 					} else {
 						draw_texture(unlock, lock_rect.position);
 					}
 
-					Rect2 visible_rect = Rect2(visibility_hpos, icon_start_height - visible->get_height() / 2, visible->get_width(), visible->get_height());
+					Rect2 visible_rect = Rect2(visibility_hpos, icon_start_height - visible->get_height() / 2.0, visible->get_width(), visible->get_height());
 					if (hidden_tracks.has(current_track)) {
 						draw_texture(hidden, visible_rect.position);
 					} else {
 						draw_texture(visible, visible_rect.position);
 					}
 
-					Rect2 solo_rect = Rect2(solo_hpos, icon_start_height - solo->get_height() / 2, solo->get_width(), solo->get_height());
+					Rect2 solo_rect = Rect2(solo_hpos, icon_start_height - solo->get_height() / 2.0, solo->get_width(), solo->get_height());
 					draw_texture(solo, solo_rect.position);
 
 					RBMap<int, Rect2> track_icons;
@@ -456,7 +456,7 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 				bool first = true;
 				int prev_iv = 0;
 				for (int i = font->get_height(font_size); i < get_size().height; i++) {
-					float ofs = get_size().height / 2 - i;
+					float ofs = get_size().height / 2.0 - i;
 					ofs *= v_zoom;
 					ofs += v_scroll;
 
@@ -495,7 +495,7 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 						Vector2 pos((offset - timeline->get_value()) * scale + limit, _bezier_h_to_pixel(value));
 
 						if (pos.x >= limit && pos.x <= right_limit) {
-							draw_texture(point, pos - point->get_size() / 2, E.value);
+							draw_texture(point, pos - point->get_size() / 2.0, E.value);
 						}
 					}
 				}
@@ -547,14 +547,15 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 						Vector2 pos((offset - timeline->get_value()) * scale + limit, _bezier_h_to_pixel(value));
 
 						Vector2 in_vec = animation->bezier_track_get_key_in_handle(i, j);
-						if (moving_handle != 0 && moving_handle_track == i && moving_handle_key == j) {
+
+						if ((moving_handle == 1 || moving_handle == -1) && moving_handle_track == i && moving_handle_key == j) {
 							in_vec = moving_handle_left;
 						}
 						Vector2 pos_in(((offset + in_vec.x) - timeline->get_value()) * scale + limit, _bezier_h_to_pixel(value + in_vec.y));
 
 						Vector2 out_vec = animation->bezier_track_get_key_out_handle(i, j);
 
-						if (moving_handle != 0 && moving_handle_track == i && moving_handle_key == j) {
+						if ((moving_handle == 1 || moving_handle == -1) && moving_handle_track == i && moving_handle_key == j) {
 							out_vec = moving_handle_right;
 						}
 
@@ -569,7 +570,7 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 						ep.track = i;
 						ep.key = j;
 						if (pos.x >= limit && pos.x <= right_limit) {
-							ep.point_rect.position = (pos - bezier_icon->get_size() / 2).floor();
+							ep.point_rect.position = (pos - bezier_icon->get_size() / 2.0).floor();
 							ep.point_rect.size = bezier_icon->get_size();
 							if (selection.has(IntPair(i, j))) {
 								draw_texture(selected_icon, ep.point_rect.position);
@@ -584,18 +585,22 @@ void AnimationBezierTrackEdit::_notification(int p_what) {
 							}
 							ep.point_rect = ep.point_rect.grow(ep.point_rect.size.width * 0.5);
 						}
+						ep.point_rect = ep.point_rect.grow(ep.point_rect.size.width * 0.5);
+
 						if (i == selected_track || selection.has(IntPair(i, j))) {
-							if (pos_in.x >= limit && pos_in.x <= right_limit) {
-								ep.in_rect.position = (pos_in - bezier_handle_icon->get_size() / 2).floor();
-								ep.in_rect.size = bezier_handle_icon->get_size();
-								draw_texture(bezier_handle_icon, ep.in_rect.position);
-								ep.in_rect = ep.in_rect.grow(ep.in_rect.size.width * 0.5);
-							}
-							if (pos_out.x >= limit && pos_out.x <= right_limit) {
-								ep.out_rect.position = (pos_out - bezier_handle_icon->get_size() / 2).floor();
-								ep.out_rect.size = bezier_handle_icon->get_size();
-								draw_texture(bezier_handle_icon, ep.out_rect.position);
-								ep.out_rect = ep.out_rect.grow(ep.out_rect.size.width * 0.5);
+							if (animation->bezier_track_get_key_handle_mode(i, j) != Animation::HANDLE_MODE_LINEAR) {
+								if (pos_in.x >= limit && pos_in.x <= right_limit) {
+									ep.in_rect.position = (pos_in - bezier_handle_icon->get_size() / 2.0).floor();
+									ep.in_rect.size = bezier_handle_icon->get_size();
+									draw_texture(bezier_handle_icon, ep.in_rect.position);
+									ep.in_rect = ep.in_rect.grow(ep.in_rect.size.width * 0.5);
+								}
+								if (pos_out.x >= limit && pos_out.x <= right_limit) {
+									ep.out_rect.position = (pos_out - bezier_handle_icon->get_size() / 2.0).floor();
+									ep.out_rect.size = bezier_handle_icon->get_size();
+									draw_texture(bezier_handle_icon, ep.out_rect.position);
+									ep.out_rect = ep.out_rect.grow(ep.out_rect.size.width * 0.5);
+								}
 							}
 						}
 						if (!locked_tracks.has(i)) {
@@ -664,7 +669,6 @@ void AnimationBezierTrackEdit::set_editor(AnimationTrackEditor *p_editor) {
 	editor = p_editor;
 	connect("clear_selection", Callable(editor, "_clear_selection").bind(false));
 	connect("select_key", Callable(editor, "_key_selected"), CONNECT_DEFERRED);
-	connect("deselect_key", Callable(editor, "_key_deselected"), CONNECT_DEFERRED);
 }
 
 void AnimationBezierTrackEdit::_play_position_draw() {
@@ -685,7 +689,7 @@ void AnimationBezierTrackEdit::_play_position_draw() {
 	}
 }
 
-void AnimationBezierTrackEdit::set_play_position(float p_pos) {
+void AnimationBezierTrackEdit::set_play_position(real_t p_pos) {
 	play_position_pos = p_pos;
 	play_position->update();
 }
@@ -786,13 +790,14 @@ void AnimationBezierTrackEdit::_clear_selection() {
 	update();
 }
 
-void AnimationBezierTrackEdit::_change_selected_keys_handle_mode(Animation::HandleMode p_mode) {
+void AnimationBezierTrackEdit::_change_selected_keys_handle_mode(Animation::HandleMode p_mode, bool p_auto) {
 	undo_redo->create_action(TTR("Update Selected Key Handles"));
-	double ratio = timeline->get_zoom_scale() * v_zoom;
-	for (const IntPair &E : selection) {
-		const IntPair track_key_pair = E;
-		undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_handle_mode", track_key_pair.first, track_key_pair.second, animation->bezier_track_get_key_handle_mode(track_key_pair.first, track_key_pair.second), ratio);
-		undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_handle_mode", track_key_pair.first, track_key_pair.second, p_mode, ratio);
+	for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
+		const IntPair track_key_pair = E->get();
+		undo_redo->add_undo_method(editor, "_bezier_track_set_key_handle_mode", animation.ptr(), track_key_pair.first, track_key_pair.second, animation->bezier_track_get_key_handle_mode(track_key_pair.first, track_key_pair.second), Animation::HANDLE_SET_MODE_NONE);
+		undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_in_handle", track_key_pair.first, track_key_pair.second, animation->bezier_track_get_key_in_handle(track_key_pair.first, track_key_pair.second));
+		undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_out_handle", track_key_pair.first, track_key_pair.second, animation->bezier_track_get_key_out_handle(track_key_pair.first, track_key_pair.second));
+		undo_redo->add_do_method(editor, "_bezier_track_set_key_handle_mode", animation.ptr(), track_key_pair.first, track_key_pair.second, p_mode, p_auto ? Animation::HANDLE_SET_MODE_AUTO : Animation::HANDLE_SET_MODE_RESET);
 	}
 	undo_redo->commit_action();
 }
@@ -804,7 +809,7 @@ void AnimationBezierTrackEdit::_clear_selection_for_anim(const Ref<Animation> &p
 	_clear_selection();
 }
 
-void AnimationBezierTrackEdit::_select_at_anim(const Ref<Animation> &p_anim, int p_track, float p_pos) {
+void AnimationBezierTrackEdit::_select_at_anim(const Ref<Animation> &p_anim, int p_track, real_t p_pos) {
 	if (!(animation == p_anim)) {
 		return;
 	}
@@ -813,7 +818,7 @@ void AnimationBezierTrackEdit::_select_at_anim(const Ref<Animation> &p_anim, int
 	ERR_FAIL_COND(idx < 0);
 
 	selection.insert(IntPair(p_track, idx));
-	emit_signal(SNAME("select_key"), p_track, idx, true);
+	emit_signal(SNAME("select_key"), idx, true, p_track);
 	update();
 }
 
@@ -869,16 +874,16 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				return;
 			}
 
-			float minimum_time = INFINITY;
-			float maximum_time = -INFINITY;
-			float minimum_value = INFINITY;
-			float maximum_value = -INFINITY;
+			real_t minimum_time = INFINITY;
+			real_t maximum_time = -INFINITY;
+			real_t minimum_value = INFINITY;
+			real_t maximum_value = -INFINITY;
 
 			for (const IntPair &E : selection) {
 				IntPair key_pair = E;
 
-				float time = animation->track_get_key_time(key_pair.first, key_pair.second);
-				float value = animation->bezier_track_get_key_value(key_pair.first, key_pair.second);
+				real_t time = animation->track_get_key_time(key_pair.first, key_pair.second);
+				real_t value = animation->bezier_track_get_key_value(key_pair.first, key_pair.second);
 
 				minimum_time = MIN(time, minimum_time);
 				maximum_time = MAX(time, maximum_time);
@@ -888,8 +893,8 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 
 			float width = get_size().width - timeline->get_name_limit() - timeline->get_buttons_width();
 			float padding = width * 0.1;
-			float desired_scale = (width - padding / 2) / (maximum_time - minimum_time);
-			minimum_time = MAX(0, minimum_time - (padding / 2) / desired_scale);
+			float desired_scale = (width - padding / 2.0) / (maximum_time - minimum_time);
+			minimum_time = MAX(0, minimum_time - (padding / 2.0) / desired_scale);
 
 			float zv = Math::pow(100 / desired_scale, 0.125f);
 			if (zv < 1) {
@@ -943,7 +948,12 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 					menu->add_icon_item(get_theme_icon(SNAME("Remove"), SNAME("EditorIcons")), TTR("Delete Selected Key(s)"), MENU_KEY_DELETE);
 					menu->add_separator();
 					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesFree"), SNAME("EditorIcons")), TTR("Make Handles Free"), MENU_KEY_SET_HANDLE_FREE);
+					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesLinear"), SNAME("EditorIcons")), TTR("Make Handles Linear"), MENU_KEY_SET_HANDLE_LINEAR);
 					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesBalanced"), SNAME("EditorIcons")), TTR("Make Handles Balanced"), MENU_KEY_SET_HANDLE_BALANCED);
+					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesMirror"), SNAME("EditorIcons")), TTR("Make Handles Mirrored"), MENU_KEY_SET_HANDLE_MIRRORED);
+					menu->add_separator();
+					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesBalanced"), SNAME("EditorIcons")), TTR("Make Handles Balanced (Auto Tangent)"), MENU_KEY_SET_HANDLE_AUTO_BALANCED);
+					menu->add_icon_item(get_theme_icon(SNAME("BezierHandlesMirror"), SNAME("EditorIcons")), TTR("Make Handles Mirrored (Auto Tangent)"), MENU_KEY_SET_HANDLE_AUTO_MIRRORED);
 				}
 
 				if (menu->get_item_count()) {
@@ -985,9 +995,10 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 
 							for (int i = 0; i < animation->track_get_key_count(track); ++i) {
 								undo_redo->add_undo_method(
-										animation.ptr(),
-										"bezier_track_insert_key",
-										track, animation->track_get_key_time(track, i),
+										this,
+										"_bezier_track_insert_key",
+										track,
+										animation->track_get_key_time(track, i),
 										animation->bezier_track_get_key_value(track, i),
 										animation->bezier_track_get_key_in_handle(track, i),
 										animation->bezier_track_get_key_out_handle(track, i),
@@ -1094,6 +1105,9 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 						moving_selection = false;
 						moving_selection_from_key = pair.second;
 						moving_selection_from_track = pair.first;
+						moving_handle_track = pair.first;
+						moving_handle_left = animation->bezier_track_get_key_in_handle(pair.first, pair.second);
+						moving_handle_right = animation->bezier_track_get_key_out_handle(pair.first, pair.second);
 						moving_selection_offset = Vector2();
 						select_single_attempt = pair;
 						update();
@@ -1103,10 +1117,12 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 						moving_selection_from_key = pair.second;
 						moving_selection_from_track = pair.first;
 						moving_selection_offset = Vector2();
-						set_animation_and_track(animation, pair.first, read_only);
+						moving_handle_track = pair.first;
+						moving_handle_left = animation->bezier_track_get_key_in_handle(pair.first, pair.second);
+						moving_handle_right = animation->bezier_track_get_key_out_handle(pair.first, pair.second);
 						selection.clear();
 						selection.insert(pair);
-						update();
+						set_animation_and_track(animation, pair.first, read_only);
 					}
 					return;
 				}
@@ -1138,24 +1154,23 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 		//insert new point
 		if (mb->get_position().x >= limit && mb->get_position().x < get_size().width && mb->is_command_pressed()) {
 			Array new_point;
-			new_point.resize(6);
+			new_point.resize(5);
 
-			float h = (get_size().height / 2 - mb->get_position().y) * v_zoom + v_scroll;
+			float h = (get_size().height / 2.0 - mb->get_position().y) * v_zoom + v_scroll;
 
 			new_point[0] = h;
 			new_point[1] = -0.25;
 			new_point[2] = 0;
 			new_point[3] = 0.25;
 			new_point[4] = 0;
-			new_point[5] = 0;
 
-			float time = ((mb->get_position().x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
+			real_t time = ((mb->get_position().x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
 			while (animation->track_find_key(selected_track, time, true) != -1) {
 				time += 0.001;
 			}
 
 			undo_redo->create_action(TTR("Add Bezier Point"));
-			undo_redo->add_do_method(animation.ptr(), "track_insert_key", selected_track, time, new_point);
+			undo_redo->add_do_method(animation.ptr(), "bezier_track_insert_key", selected_track, time, new_point);
 			undo_redo->add_undo_method(animation.ptr(), "track_remove_key_at_time", selected_track, time);
 			undo_redo->commit_action();
 
@@ -1219,10 +1234,10 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 			//select by clicking on curve
 			int track_count = animation->get_track_count();
 
-			float animation_length = animation->get_length();
+			real_t animation_length = animation->get_length();
 			animation->set_length(real_t(INT_MAX)); //bezier_track_interpolate doesn't find keys if they exist beyond anim length
 
-			float time = ((mb->get_position().x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
+			real_t time = ((mb->get_position().x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
 
 			for (int i = 0; i < track_count; ++i) {
 				if (animation->track_get_type(i) != Animation::TrackType::TYPE_BEZIER || hidden_tracks.has(i) || locked_tracks.has(i)) {
@@ -1246,20 +1261,6 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 		update();
 	}
 
-	if (moving_handle != 0 && mb.is_valid() && !mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT) {
-		if (!read_only) {
-			undo_redo->create_action(TTR("Move Bezier Points"));
-			undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_in_handle", selected_track, moving_handle_key, moving_handle_left);
-			undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_out_handle", selected_track, moving_handle_key, moving_handle_right);
-			undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_in_handle", selected_track, moving_handle_key, animation->bezier_track_get_key_in_handle(selected_track, moving_handle_key));
-			undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_out_handle", selected_track, moving_handle_key, animation->bezier_track_get_key_out_handle(selected_track, moving_handle_key));
-			undo_redo->commit_action();
-
-			moving_handle = 0;
-			update();
-		}
-	}
-
 	if (moving_selection_attempt && mb.is_valid() && !mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT) {
 		if (!read_only) {
 			if (moving_selection) {
@@ -1268,13 +1269,14 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				undo_redo->create_action(TTR("Move Bezier Points"));
 
 				List<AnimMoveRestore> to_restore;
+				List<Animation::HandleMode> to_restore_handle_modes;
 				// 1-remove the keys
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
 					undo_redo->add_do_method(animation.ptr(), "track_remove_key", E->get().first, E->get().second);
 				}
 				// 2- remove overlapped keys
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-					float newtime = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
+					real_t newtime = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
 
 					int idx = animation->track_find_key(E->get().first, newtime, true);
 					if (idx == -1) {
@@ -1293,33 +1295,62 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 					amr.time = newtime;
 
 					to_restore.push_back(amr);
+					to_restore_handle_modes.push_back(animation->bezier_track_get_key_handle_mode(E->get().first, idx));
 				}
 
 				// 3-move the keys (re insert them)
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-					float newpos = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
+					real_t newpos = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
 					Array key = animation->track_get_key_value(E->get().first, E->get().second);
-					float h = key[0];
+					real_t h = key[0];
 					h += moving_selection_offset.y;
 					key[0] = h;
-					undo_redo->add_do_method(animation.ptr(), "track_insert_key", E->get().first, newpos, key, 1);
+					undo_redo->add_do_method(
+							this,
+							"_bezier_track_insert_key",
+							E->get().first,
+							newpos,
+							key[0],
+							Vector2(key[1], key[2]),
+							Vector2(key[3], key[4]),
+							animation->bezier_track_get_key_handle_mode(E->get().first, E->get().second));
 				}
 
 				// 4-(undo) remove inserted keys
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-					float newpos = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
+					real_t newpos = editor->snap_time(animation->track_get_key_time(E->get().first, E->get().second) + moving_selection_offset.x);
 					undo_redo->add_undo_method(animation.ptr(), "track_remove_key_at_time", E->get().first, newpos);
 				}
 
 				// 5-(undo) reinsert keys
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-					float oldpos = animation->track_get_key_time(E->get().first, E->get().second);
-					undo_redo->add_undo_method(animation.ptr(), "track_insert_key", E->get().first, oldpos, animation->track_get_key_value(E->get().first, E->get().second), 1);
+					real_t oldpos = animation->track_get_key_time(E->get().first, E->get().second);
+					Array key = animation->track_get_key_value(E->get().first, E->get().second);
+					undo_redo->add_undo_method(
+							this,
+							"_bezier_track_insert_key",
+							E->get().first,
+							oldpos,
+							key[0],
+							Vector2(key[1], key[2]),
+							Vector2(key[3], key[4]),
+							animation->bezier_track_get_key_handle_mode(E->get().first, E->get().second));
 				}
 
 				// 6-(undo) reinsert overlapped keys
-				for (const AnimMoveRestore &amr : to_restore) {
+				for (int i = 0; i < to_restore.size(); i++) {
+					const AnimMoveRestore &amr = to_restore[i];
+					Array key = amr.key;
 					undo_redo->add_undo_method(animation.ptr(), "track_insert_key", amr.track, amr.time, amr.key, 1);
+					undo_redo->add_undo_method(
+							this,
+							"_bezier_track_insert_key",
+							amr.track,
+							amr.time,
+							key[0],
+							Vector2(key[1], key[2]),
+							Vector2(key[3], key[4]),
+							to_restore_handle_modes[i]);
 				}
 
 				undo_redo->add_do_method(this, "_clear_selection_for_anim", animation);
@@ -1328,8 +1359,8 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				// 7-reselect
 
 				for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-					float oldpos = animation->track_get_key_time(E->get().first, E->get().second);
-					float newpos = editor->snap_time(oldpos + moving_selection_offset.x);
+					real_t oldpos = animation->track_get_key_time(E->get().first, E->get().second);
+					real_t newpos = editor->snap_time(oldpos + moving_selection_offset.x);
 
 					undo_redo->add_do_method(this, "_select_at_anim", animation, E->get().first, newpos);
 					undo_redo->add_undo_method(this, "_select_at_anim", animation, E->get().first, oldpos);
@@ -1356,12 +1387,16 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 			select_single_attempt = IntPair(-1, -1);
 		}
 
-		float y = (get_size().height / 2 - mm->get_position().y) * v_zoom + v_scroll;
+		float y = (get_size().height / 2.0 - mm->get_position().y) * v_zoom + v_scroll;
 		float x = editor->snap_time(((mm->get_position().x - limit) / timeline->get_zoom_scale()) + timeline->get_value());
 
 		if (!read_only) {
 			moving_selection_offset = Vector2(x - animation->track_get_key_time(moving_selection_from_track, moving_selection_from_key), y - animation->bezier_track_get_key_value(moving_selection_from_track, moving_selection_from_key));
 		}
+
+		additional_moving_handle_lefts.clear();
+		additional_moving_handle_rights.clear();
+
 		update();
 	}
 
@@ -1380,8 +1415,8 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 		update();
 	}
 
-	if (moving_handle != 0 && mm.is_valid()) {
-		float y = (get_size().height / 2 - mm->get_position().y) * v_zoom + v_scroll;
+	if ((moving_handle == 1 || moving_handle == -1) && mm.is_valid()) {
+		float y = (get_size().height / 2.0 - mm->get_position().y) * v_zoom + v_scroll;
 		float x = editor->snap_time((mm->get_position().x - timeline->get_name_limit()) / timeline->get_zoom_scale()) + timeline->get_value();
 
 		Vector2 key_pos = Vector2(animation->track_get_key_time(selected_track, moving_handle_key), animation->bezier_track_get_key_value(selected_track, moving_handle_key));
@@ -1394,8 +1429,10 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 		if (moving_handle == -1) {
 			moving_handle_left = moving_handle_value;
 
-			if (animation->bezier_track_get_key_handle_mode(moving_handle_track, moving_handle_key) == Animation::HANDLE_MODE_BALANCED) {
-				double ratio = timeline->get_zoom_scale() * v_zoom;
+			Animation::HandleMode handle_mode = animation->bezier_track_get_key_handle_mode(moving_handle_track, moving_handle_key);
+
+			if (handle_mode == Animation::HANDLE_MODE_BALANCED) {
+				real_t ratio = timeline->get_zoom_scale() * v_zoom;
 				Transform2D xform;
 				xform.set_scale(Vector2(1.0, 1.0 / ratio));
 
@@ -1403,12 +1440,16 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				Vector2 vec_in = xform.xform(moving_handle_left);
 
 				moving_handle_right = xform.affine_inverse().xform(-vec_in.normalized() * vec_out.length());
+			} else if (handle_mode == Animation::HANDLE_MODE_MIRRORED) {
+				moving_handle_right = -moving_handle_left;
 			}
 		} else if (moving_handle == 1) {
 			moving_handle_right = moving_handle_value;
 
-			if (animation->bezier_track_get_key_handle_mode(moving_handle_track, moving_handle_key) == Animation::HANDLE_MODE_BALANCED) {
-				double ratio = timeline->get_zoom_scale() * v_zoom;
+			Animation::HandleMode handle_mode = animation->bezier_track_get_key_handle_mode(moving_handle_track, moving_handle_key);
+
+			if (handle_mode == Animation::HANDLE_MODE_BALANCED) {
+				real_t ratio = timeline->get_zoom_scale() * v_zoom;
 				Transform2D xform;
 				xform.set_scale(Vector2(1.0, 1.0 / ratio));
 
@@ -1416,26 +1457,26 @@ void AnimationBezierTrackEdit::gui_input(const Ref<InputEvent> &p_event) {
 				Vector2 vec_out = xform.xform(moving_handle_right);
 
 				moving_handle_left = xform.affine_inverse().xform(-vec_out.normalized() * vec_in.length());
+			} else if (handle_mode == Animation::HANDLE_MODE_MIRRORED) {
+				moving_handle_left = -moving_handle_right;
 			}
 		}
 		update();
 	}
 
-	bool is_finishing_key_handle_drag = moving_handle != 0 && mb.is_valid() && !mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT;
-	if (is_finishing_key_handle_drag) {
+	if ((moving_handle == -1 || moving_handle == 1) && mb.is_valid() && !mb->is_pressed() && mb->get_button_index() == MouseButton::LEFT) {
 		if (!read_only) {
 			undo_redo->create_action(TTR("Move Bezier Points"));
 			if (moving_handle == -1) {
-				double ratio = timeline->get_zoom_scale() * v_zoom;
+				real_t ratio = timeline->get_zoom_scale() * v_zoom;
 				undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_in_handle", moving_handle_track, moving_handle_key, moving_handle_left, ratio);
 				undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_in_handle", moving_handle_track, moving_handle_key, animation->bezier_track_get_key_in_handle(moving_handle_track, moving_handle_key), ratio);
 			} else if (moving_handle == 1) {
-				double ratio = timeline->get_zoom_scale() * v_zoom;
+				real_t ratio = timeline->get_zoom_scale() * v_zoom;
 				undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_out_handle", moving_handle_track, moving_handle_key, moving_handle_right, ratio);
 				undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_out_handle", moving_handle_track, moving_handle_key, animation->bezier_track_get_key_out_handle(moving_handle_track, moving_handle_key), ratio);
 			}
 			undo_redo->commit_action();
-
 			moving_handle = 0;
 			update();
 		}
@@ -1469,7 +1510,7 @@ void AnimationBezierTrackEdit::_zoom_callback(Vector2 p_scroll_vec, Vector2 p_or
 			timeline->get_zoom()->set_value(timeline->get_zoom()->get_value() * 1.05);
 		}
 	}
-	v_scroll = v_scroll + (p_origin.y - get_size().y / 2) * (v_zoom - v_zoom_orig);
+	v_scroll = v_scroll + (p_origin.y - get_size().y / 2.0) * (v_zoom - v_zoom_orig);
 	update();
 }
 
@@ -1478,20 +1519,19 @@ void AnimationBezierTrackEdit::_menu_selected(int p_index) {
 		case MENU_KEY_INSERT: {
 			if (animation->get_track_count() > 0) {
 				Array new_point;
-				new_point.resize(6);
+				new_point.resize(5);
 
-				float h = (get_size().height / 2 - menu_insert_key.y) * v_zoom + v_scroll;
+				float h = (get_size().height / 2.0 - menu_insert_key.y) * v_zoom + v_scroll;
 
 				new_point[0] = h;
 				new_point[1] = -0.25;
 				new_point[2] = 0;
 				new_point[3] = 0.25;
 				new_point[4] = 0;
-				new_point[5] = Animation::HANDLE_MODE_BALANCED;
 
 				int limit = timeline->get_name_limit();
 
-				float time = ((menu_insert_key.x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
+				real_t time = ((menu_insert_key.x - limit) / timeline->get_zoom_scale()) + timeline->get_value();
 
 				while (animation->track_find_key(selected_track, time, true) != -1) {
 					time += 0.001;
@@ -1501,8 +1541,8 @@ void AnimationBezierTrackEdit::_menu_selected(int p_index) {
 				undo_redo->add_do_method(animation.ptr(), "track_insert_key", selected_track, time, new_point);
 				undo_redo->add_undo_method(animation.ptr(), "track_remove_key_at_time", selected_track, time);
 				undo_redo->commit_action();
+				update();
 			}
-
 		} break;
 		case MENU_KEY_DUPLICATE: {
 			duplicate_selection();
@@ -1513,9 +1553,21 @@ void AnimationBezierTrackEdit::_menu_selected(int p_index) {
 		case MENU_KEY_SET_HANDLE_FREE: {
 			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_FREE);
 		} break;
+		case MENU_KEY_SET_HANDLE_LINEAR: {
+			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_LINEAR);
+		} break;
 		case MENU_KEY_SET_HANDLE_BALANCED: {
 			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_BALANCED);
 		} break;
+		case MENU_KEY_SET_HANDLE_MIRRORED: {
+			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_MIRRORED);
+		} break;
+		case MENU_KEY_SET_HANDLE_AUTO_BALANCED: {
+			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_BALANCED, true);
+		} break;
+		case MENU_KEY_SET_HANDLE_AUTO_MIRRORED: {
+			_change_selected_keys_handle_mode(Animation::HANDLE_MODE_MIRRORED, true);
+		} break;
 	}
 }
 
@@ -1524,9 +1576,9 @@ void AnimationBezierTrackEdit::duplicate_selection() {
 		return;
 	}
 
-	float top_time = 1e10;
+	real_t top_time = 1e10;
 	for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-		float t = animation->track_get_key_time(E->get().first, E->get().second);
+		real_t t = animation->track_get_key_time(E->get().first, E->get().second);
 		if (t < top_time) {
 			top_time = t;
 		}
@@ -1534,17 +1586,17 @@ void AnimationBezierTrackEdit::duplicate_selection() {
 
 	undo_redo->create_action(TTR("Anim Duplicate Keys"));
 
-	List<Pair<int, float>> new_selection_values;
+	List<Pair<int, real_t>> new_selection_values;
 
 	for (SelectionSet::Element *E = selection.back(); E; E = E->prev()) {
-		float t = animation->track_get_key_time(E->get().first, E->get().second);
-		float dst_time = t + (timeline->get_play_position() - top_time);
+		real_t t = animation->track_get_key_time(E->get().first, E->get().second);
+		real_t dst_time = t + (timeline->get_play_position() - top_time);
 		int existing_idx = animation->track_find_key(E->get().first, dst_time, true);
 
 		undo_redo->add_do_method(animation.ptr(), "track_insert_key", E->get().first, dst_time, animation->track_get_key_value(E->get().first, E->get().second), animation->track_get_key_transition(E->get().first, E->get().second));
 		undo_redo->add_undo_method(animation.ptr(), "track_remove_key_at_time", E->get().first, dst_time);
 
-		Pair<int, float> p;
+		Pair<int, real_t> p;
 		p.first = E->get().first;
 		p.second = dst_time;
 		new_selection_values.push_back(p);
@@ -1559,9 +1611,9 @@ void AnimationBezierTrackEdit::duplicate_selection() {
 	//reselect duplicated
 
 	selection.clear();
-	for (const Pair<int, float> &E : new_selection_values) {
+	for (const Pair<int, real_t> &E : new_selection_values) {
 		int track = E.first;
-		float time = E.second;
+		real_t time = E.second;
 
 		int existing_idx = animation->track_find_key(track, time, true);
 
@@ -1591,18 +1643,24 @@ void AnimationBezierTrackEdit::delete_selection() {
 	}
 }
 
+void AnimationBezierTrackEdit::_bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle, const Animation::HandleMode p_handle_mode) {
+	ERR_FAIL_COND(animation.is_null());
+	int idx = animation->bezier_track_insert_key(p_track, p_time, p_value, p_in_handle, p_out_handle);
+	animation->bezier_track_set_key_handle_mode(p_track, idx, p_handle_mode);
+}
+
 void AnimationBezierTrackEdit::_bind_methods() {
-	ClassDB::bind_method("_clear_selection", &AnimationBezierTrackEdit::_clear_selection);
-	ClassDB::bind_method("_clear_selection_for_anim", &AnimationBezierTrackEdit::_clear_selection_for_anim);
-	ClassDB::bind_method("_select_at_anim", &AnimationBezierTrackEdit::_select_at_anim);
-	ClassDB::bind_method("_update_hidden_tracks_after", &AnimationBezierTrackEdit::_update_hidden_tracks_after);
-	ClassDB::bind_method("_update_locked_tracks_after", &AnimationBezierTrackEdit::_update_locked_tracks_after);
+	ClassDB::bind_method(D_METHOD("_clear_selection"), &AnimationBezierTrackEdit::_clear_selection);
+	ClassDB::bind_method(D_METHOD("_clear_selection_for_anim"), &AnimationBezierTrackEdit::_clear_selection_for_anim);
+	ClassDB::bind_method(D_METHOD("_select_at_anim"), &AnimationBezierTrackEdit::_select_at_anim);
+	ClassDB::bind_method(D_METHOD("_update_hidden_tracks_after"), &AnimationBezierTrackEdit::_update_hidden_tracks_after);
+	ClassDB::bind_method(D_METHOD("_update_locked_tracks_after"), &AnimationBezierTrackEdit::_update_locked_tracks_after);
+	ClassDB::bind_method(D_METHOD("_bezier_track_insert_key"), &AnimationBezierTrackEdit::_bezier_track_insert_key);
 
 	ADD_SIGNAL(MethodInfo("timeline_changed", PropertyInfo(Variant::FLOAT, "position"), PropertyInfo(Variant::BOOL, "drag")));
 	ADD_SIGNAL(MethodInfo("remove_request", PropertyInfo(Variant::INT, "track")));
 	ADD_SIGNAL(MethodInfo("insert_key", PropertyInfo(Variant::FLOAT, "offset")));
-	ADD_SIGNAL(MethodInfo("select_key", PropertyInfo(Variant::INT, "track"), PropertyInfo(Variant::INT, "index"), PropertyInfo(Variant::BOOL, "single")));
-	ADD_SIGNAL(MethodInfo("deselect_key", PropertyInfo(Variant::INT, "track"), PropertyInfo(Variant::INT, "index")));
+	ADD_SIGNAL(MethodInfo("select_key", PropertyInfo(Variant::INT, "index"), PropertyInfo(Variant::BOOL, "single"), PropertyInfo(Variant::INT, "track")));
 	ADD_SIGNAL(MethodInfo("clear_selection"));
 	ADD_SIGNAL(MethodInfo("close_request"));
 
diff --git a/editor/animation_bezier_editor.h b/editor/animation_bezier_editor.h
index 3e94b4fa84..beb7a5e9c6 100644
--- a/editor/animation_bezier_editor.h
+++ b/editor/animation_bezier_editor.h
@@ -32,7 +32,7 @@
 #define ANIMATION_BEZIER_EDITOR_H
 
 #include "animation_track_editor.h"
-#include "core/templates/rb_set.h"
+#include "core/templates/hashfuncs.h"
 
 class EditorUndoRedoManager;
 class ViewPanner;
@@ -45,14 +45,18 @@ class AnimationBezierTrackEdit : public Control {
 		MENU_KEY_DUPLICATE,
 		MENU_KEY_DELETE,
 		MENU_KEY_SET_HANDLE_FREE,
+		MENU_KEY_SET_HANDLE_LINEAR,
 		MENU_KEY_SET_HANDLE_BALANCED,
+		MENU_KEY_SET_HANDLE_MIRRORED,
+		MENU_KEY_SET_HANDLE_AUTO_BALANCED,
+		MENU_KEY_SET_HANDLE_AUTO_MIRRORED,
 	};
 
 	AnimationTimelineEdit *timeline = nullptr;
 	Ref<EditorUndoRedoManager> undo_redo;
 	Node *root = nullptr;
 	Control *play_position = nullptr; //separate control used to draw so updates for only position changed are much faster
-	float play_position_pos = 0;
+	real_t play_position_pos = 0;
 
 	Ref<Animation> animation;
 	bool read_only = false;
@@ -112,25 +116,37 @@ class AnimationBezierTrackEdit : public Control {
 	Vector2 box_selection_from;
 	Vector2 box_selection_to;
 
-	int moving_handle = 0; //0 no move -1 or +1 out
+	int moving_handle = 0; //0 no move -1 or +1 out, 2 both (drawing only)
 	int moving_handle_key = 0;
 	int moving_handle_track = 0;
 	Vector2 moving_handle_left;
 	Vector2 moving_handle_right;
 	int moving_handle_mode = 0; // value from Animation::HandleMode
 
+	struct PairHasher {
+		static _FORCE_INLINE_ uint32_t hash(const Pair<int, int> &p_value) {
+			int32_t hash = 23;
+			hash = hash * 31 * hash_one_uint64(p_value.first);
+			hash = hash * 31 * hash_one_uint64(p_value.second);
+			return hash;
+		}
+	};
+
+	HashMap<Pair<int, int>, Vector2, PairHasher> additional_moving_handle_lefts;
+	HashMap<Pair<int, int>, Vector2, PairHasher> additional_moving_handle_rights;
+
 	void _clear_selection();
 	void _clear_selection_for_anim(const Ref<Animation> &p_anim);
-	void _select_at_anim(const Ref<Animation> &p_anim, int p_track, float p_pos);
-	void _change_selected_keys_handle_mode(Animation::HandleMode p_mode);
+	void _select_at_anim(const Ref<Animation> &p_anim, int p_track, real_t p_pos);
+	void _change_selected_keys_handle_mode(Animation::HandleMode p_mode, bool p_auto = false);
 
 	Vector2 menu_insert_key;
 
 	struct AnimMoveRestore {
 		int track = 0;
-		float time = 0;
+		double time = 0;
 		Variant key;
-		float transition = 0;
+		real_t transition = 0;
 	};
 
 	AnimationTrackEditor *editor = nullptr;
@@ -145,7 +161,7 @@ class AnimationBezierTrackEdit : public Control {
 
 	Vector<EditPoint> edit_points;
 
-	struct SelectionCompare {
+	struct PairCompare {
 		bool operator()(const IntPair &lh, const IntPair &rh) {
 			if (lh.first == rh.first) {
 				return lh.second < rh.second;
@@ -155,7 +171,7 @@ class AnimationBezierTrackEdit : public Control {
 		}
 	};
 
-	typedef RBSet<IntPair, SelectionCompare> SelectionSet;
+	typedef RBSet<IntPair, PairCompare> SelectionSet;
 
 	SelectionSet selection;
 
@@ -187,12 +203,14 @@ public:
 	void set_root(Node *p_root);
 	void set_filtered(bool p_filtered);
 
-	void set_play_position(float p_pos);
+	void set_play_position(real_t p_pos);
 	void update_play_position();
 
 	void duplicate_selection();
 	void delete_selection();
 
+	void _bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle, const Animation::HandleMode p_handle_mode);
+
 	AnimationBezierTrackEdit();
 };
 
diff --git a/editor/animation_track_editor.cpp b/editor/animation_track_editor.cpp
index d95fe64a09..7fa7b45f85 100644
--- a/editor/animation_track_editor.cpp
+++ b/editor/animation_track_editor.cpp
@@ -65,12 +65,12 @@ public:
 	}
 
 	static void _bind_methods() {
-		ClassDB::bind_method("_update_obj", &AnimationTrackKeyEdit::_update_obj);
-		ClassDB::bind_method("_key_ofs_changed", &AnimationTrackKeyEdit::_key_ofs_changed);
-		ClassDB::bind_method("_hide_script_from_inspector", &AnimationTrackKeyEdit::_hide_script_from_inspector);
-		ClassDB::bind_method("get_root_path", &AnimationTrackKeyEdit::get_root_path);
-		ClassDB::bind_method("_dont_undo_redo", &AnimationTrackKeyEdit::_dont_undo_redo);
-		ClassDB::bind_method("_read_only", &AnimationTrackKeyEdit::_read_only);
+		ClassDB::bind_method(D_METHOD("_update_obj"), &AnimationTrackKeyEdit::_update_obj);
+		ClassDB::bind_method(D_METHOD("_key_ofs_changed"), &AnimationTrackKeyEdit::_key_ofs_changed);
+		ClassDB::bind_method(D_METHOD("_hide_script_from_inspector"), &AnimationTrackKeyEdit::_hide_script_from_inspector);
+		ClassDB::bind_method(D_METHOD("get_root_path"), &AnimationTrackKeyEdit::get_root_path);
+		ClassDB::bind_method(D_METHOD("_dont_undo_redo"), &AnimationTrackKeyEdit::_dont_undo_redo);
+		ClassDB::bind_method(D_METHOD("_read_only"), &AnimationTrackKeyEdit::_read_only);
 	}
 
 	void _fix_node_path(Variant &value) {
@@ -351,8 +351,8 @@ public:
 					setting = true;
 					undo_redo->create_action(TTR("Anim Change Keyframe Value"), UndoRedo::MERGE_ENDS);
 					int prev = animation->bezier_track_get_key_handle_mode(track, key);
-					undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_handle_mode", track, key, value);
-					undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_handle_mode", track, key, prev);
+					undo_redo->add_do_method(this, "_bezier_track_set_key_handle_mode", animation.ptr(), track, key, value);
+					undo_redo->add_undo_method(this, "_bezier_track_set_key_handle_mode", animation.ptr(), track, key, prev);
 					undo_redo->add_do_method(this, "_update_obj", animation);
 					undo_redo->add_undo_method(this, "_update_obj", animation);
 					undo_redo->commit_action();
@@ -637,10 +637,16 @@ public:
 
 			} break;
 			case Animation::TYPE_BEZIER: {
+				Animation::HandleMode hm = animation->bezier_track_get_key_handle_mode(track, key);
 				p_list->push_back(PropertyInfo(Variant::FLOAT, PNAME("value")));
-				p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("in_handle")));
-				p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("out_handle")));
-				p_list->push_back(PropertyInfo(Variant::INT, PNAME("handle_mode"), PROPERTY_HINT_ENUM, "Free,Balanced"));
+				if (hm == Animation::HANDLE_MODE_LINEAR) {
+					p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("in_handle"), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_READ_ONLY));
+					p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("out_handle"), PROPERTY_HINT_NONE, "", PROPERTY_USAGE_DEFAULT | PROPERTY_USAGE_READ_ONLY));
+				} else {
+					p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("in_handle")));
+					p_list->push_back(PropertyInfo(Variant::VECTOR2, PNAME("out_handle")));
+				}
+				p_list->push_back(PropertyInfo(Variant::INT, PNAME("handle_mode"), PROPERTY_HINT_ENUM, "Free,Linear,Balanced,Mirrored"));
 
 			} break;
 			case Animation::TYPE_AUDIO: {
@@ -726,12 +732,12 @@ public:
 	}
 
 	static void _bind_methods() {
-		ClassDB::bind_method("_update_obj", &AnimationMultiTrackKeyEdit::_update_obj);
-		ClassDB::bind_method("_key_ofs_changed", &AnimationMultiTrackKeyEdit::_key_ofs_changed);
-		ClassDB::bind_method("_hide_script_from_inspector", &AnimationMultiTrackKeyEdit::_hide_script_from_inspector);
-		ClassDB::bind_method("get_root_path", &AnimationMultiTrackKeyEdit::get_root_path);
-		ClassDB::bind_method("_dont_undo_redo", &AnimationMultiTrackKeyEdit::_dont_undo_redo);
-		ClassDB::bind_method("_read_only", &AnimationMultiTrackKeyEdit::_read_only);
+		ClassDB::bind_method(D_METHOD("_update_obj"), &AnimationMultiTrackKeyEdit::_update_obj);
+		ClassDB::bind_method(D_METHOD("_key_ofs_changed"), &AnimationMultiTrackKeyEdit::_key_ofs_changed);
+		ClassDB::bind_method(D_METHOD("_hide_script_from_inspector"), &AnimationMultiTrackKeyEdit::_hide_script_from_inspector);
+		ClassDB::bind_method(D_METHOD("get_root_path"), &AnimationMultiTrackKeyEdit::get_root_path);
+		ClassDB::bind_method(D_METHOD("_dont_undo_redo"), &AnimationMultiTrackKeyEdit::_dont_undo_redo);
+		ClassDB::bind_method(D_METHOD("_read_only"), &AnimationMultiTrackKeyEdit::_read_only);
 	}
 
 	void _fix_node_path(Variant &value, NodePath &base) {
@@ -972,8 +978,8 @@ public:
 								undo_redo->create_action(TTR("Anim Multi Change Keyframe Value"), UndoRedo::MERGE_ENDS);
 							}
 							Vector2 prev = animation->bezier_track_get_key_in_handle(track, key);
-							undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_in_handle", track, key, value);
-							undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_in_handle", track, key, prev);
+							undo_redo->add_do_method(this, "_bezier_track_set_key_in_handle", track, key, value);
+							undo_redo->add_undo_method(this, "_bezier_track_set_key_in_handle", track, key, prev);
 							update_obj = true;
 						} else if (name == "out_handle") {
 							const Variant &value = p_value;
@@ -983,8 +989,8 @@ public:
 								undo_redo->create_action(TTR("Anim Multi Change Keyframe Value"), UndoRedo::MERGE_ENDS);
 							}
 							Vector2 prev = animation->bezier_track_get_key_out_handle(track, key);
-							undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_out_handle", track, key, value);
-							undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_out_handle", track, key, prev);
+							undo_redo->add_do_method(this, "_bezier_track_set_key_out_handle", track, key, value);
+							undo_redo->add_undo_method(this, "_bezier_track_set_key_out_handle", track, key, prev);
 							update_obj = true;
 						} else if (name == "handle_mode") {
 							const Variant &value = p_value;
@@ -994,8 +1000,8 @@ public:
 								undo_redo->create_action(TTR("Anim Multi Change Keyframe Value"), UndoRedo::MERGE_ENDS);
 							}
 							int prev = animation->bezier_track_get_key_handle_mode(track, key);
-							undo_redo->add_do_method(animation.ptr(), "bezier_track_set_key_handle_mode", track, key, value);
-							undo_redo->add_undo_method(animation.ptr(), "bezier_track_set_key_handle_mode", track, key, prev);
+							undo_redo->add_do_method(this, "_bezier_track_set_key_handle_mode", animation.ptr(), track, key, value);
+							undo_redo->add_undo_method(this, "_bezier_track_set_key_handle_mode", animation.ptr(), track, key, prev);
 							update_obj = true;
 						}
 					} break;
@@ -1326,7 +1332,7 @@ public:
 					p_list->push_back(PropertyInfo(Variant::FLOAT, "value"));
 					p_list->push_back(PropertyInfo(Variant::VECTOR2, "in_handle"));
 					p_list->push_back(PropertyInfo(Variant::VECTOR2, "out_handle"));
-					p_list->push_back(PropertyInfo(Variant::INT, "handle_mode", PROPERTY_HINT_ENUM, "Free,Balanced"));
+					p_list->push_back(PropertyInfo(Variant::INT, "handle_mode", PROPERTY_HINT_ENUM, "Free,Linear,Balanced,Mirrored"));
 				} break;
 				case Animation::TYPE_AUDIO: {
 					p_list->push_back(PropertyInfo(Variant::OBJECT, "stream", PROPERTY_HINT_RESOURCE_TYPE, "AudioStream"));
@@ -2726,9 +2732,15 @@ String AnimationTrackEdit::get_tooltip(const Point2 &p_pos) const {
 						case Animation::HANDLE_MODE_FREE: {
 							text += TTR("Handle mode: Free\n");
 						} break;
+						case Animation::HANDLE_MODE_LINEAR: {
+							text += TTR("Handle mode: Linear\n");
+						} break;
 						case Animation::HANDLE_MODE_BALANCED: {
 							text += TTR("Handle mode: Balanced\n");
 						} break;
+						case Animation::HANDLE_MODE_MIRRORED: {
+							text += TTR("Handle mode: Mirrored\n");
+						} break;
 					}
 				} break;
 				case Animation::TYPE_AUDIO: {
@@ -3259,7 +3271,6 @@ void AnimationTrackEdit::_bind_methods() {
 	ADD_SIGNAL(MethodInfo("insert_key", PropertyInfo(Variant::FLOAT, "offset")));
 	ADD_SIGNAL(MethodInfo("select_key", PropertyInfo(Variant::INT, "index"), PropertyInfo(Variant::BOOL, "single")));
 	ADD_SIGNAL(MethodInfo("deselect_key", PropertyInfo(Variant::INT, "index")));
-	ADD_SIGNAL(MethodInfo("bezier_edit"));
 
 	ADD_SIGNAL(MethodInfo("move_selection_begin"));
 	ADD_SIGNAL(MethodInfo("move_selection", PropertyInfo(Variant::FLOAT, "offset")));
@@ -3422,7 +3433,8 @@ void AnimationTrackEditor::set_animation(const Ref<Animation> &p_anim, bool p_re
 		track_edits[_get_track_selected()]->release_focus();
 	}
 	if (animation.is_valid()) {
-		animation->disconnect("changed", callable_mp(this, &AnimationTrackEditor::_animation_changed));
+		animation->disconnect("tracks_changed", callable_mp(this, &AnimationTrackEditor::_animation_changed));
+		animation->disconnect("changed", callable_mp(this, &AnimationTrackEditor::_sync_animation_change));
 		_clear_selection();
 	}
 	animation = p_anim;
@@ -3433,7 +3445,8 @@ void AnimationTrackEditor::set_animation(const Ref<Animation> &p_anim, bool p_re
 	_update_tracks();
 
 	if (animation.is_valid()) {
-		animation->connect("changed", callable_mp(this, &AnimationTrackEditor::_animation_changed));
+		animation->connect("tracks_changed", callable_mp(this, &AnimationTrackEditor::_animation_changed), CONNECT_DEFERRED);
+		animation->connect("changed", callable_mp(this, &AnimationTrackEditor::_sync_animation_change), CONNECT_DEFERRED);
 
 		hscroll->show();
 		edit->set_disabled(read_only);
@@ -4348,13 +4361,12 @@ AnimationTrackEditor::TrackIndices AnimationTrackEditor::_confirm_insert(InsertD
 		} break;
 		case Animation::TYPE_BEZIER: {
 			Array array;
-			array.resize(6);
+			array.resize(5);
 			array[0] = p_id.value;
 			array[1] = -0.25;
 			array[2] = 0;
 			array[3] = 0.25;
 			array[4] = 0;
-			array[5] = Animation::HANDLE_MODE_BALANCED;
 			value = array;
 			bezier_edit_icon->set_disabled(false);
 
@@ -4617,11 +4629,19 @@ void AnimationTrackEditor::_update_tracks() {
 	}
 }
 
+void AnimationTrackEditor::_sync_animation_change() {
+	bezier_edit->update();
+}
+
 void AnimationTrackEditor::_animation_changed() {
 	if (animation_changing_awaiting_update) {
 		return; // All will be updated, don't bother with anything.
 	}
 
+	if (key_edit) {
+		_update_key_edit();
+	}
+
 	if (key_edit && key_edit->setting) {
 		// If editing a key, just update the edited track, makes refresh less costly.
 		if (key_edit->track < track_edits.size()) {
@@ -5081,13 +5101,12 @@ void AnimationTrackEditor::_insert_key_from_track(float p_ofs, int p_track) {
 			Variant value;
 			_find_hint_for_track(p_track, bp, &value);
 			Array arr;
-			arr.resize(6);
+			arr.resize(5);
 			arr[0] = value;
 			arr[1] = -0.25;
 			arr[2] = 0;
 			arr[3] = 0.25;
 			arr[4] = 0;
-			arr[5] = 0;
 
 			undo_redo->create_action(TTR("Add Track Key"));
 			undo_redo->add_do_method(animation.ptr(), "track_insert_key", p_track, p_ofs, arr);
@@ -5566,6 +5585,13 @@ void AnimationTrackEditor::_bezier_edit(int p_for_track) {
 	// Search everything within the track and curve - edit it.
 }
 
+void AnimationTrackEditor::_bezier_track_set_key_handle_mode(Animation *p_anim, int p_track, int p_index, Animation::HandleMode p_mode, Animation::HandleSetMode p_set_mode) {
+	if (!p_anim) {
+		return;
+	}
+	p_anim->bezier_track_set_key_handle_mode(p_track, p_index, p_mode, p_set_mode);
+}
+
 void AnimationTrackEditor::_anim_duplicate_keys(bool transpose) {
 	// Duplicait!
 	if (selection.size() && animation.is_valid() && (!transpose || (_get_track_selected() >= 0 && _get_track_selected() < animation->get_track_count()))) {
@@ -6416,15 +6442,17 @@ void AnimationTrackEditor::_select_all_tracks_for_copy() {
 }
 
 void AnimationTrackEditor::_bind_methods() {
-	ClassDB::bind_method("_animation_update", &AnimationTrackEditor::_animation_update);
-	ClassDB::bind_method("_track_grab_focus", &AnimationTrackEditor::_track_grab_focus);
-	ClassDB::bind_method("_update_tracks", &AnimationTrackEditor::_update_tracks);
-	ClassDB::bind_method("_clear_selection_for_anim", &AnimationTrackEditor::_clear_selection_for_anim);
-	ClassDB::bind_method("_select_at_anim", &AnimationTrackEditor::_select_at_anim);
-
-	ClassDB::bind_method("_key_selected", &AnimationTrackEditor::_key_selected); // Still used by some connect_compat.
-	ClassDB::bind_method("_key_deselected", &AnimationTrackEditor::_key_deselected); // Still used by some connect_compat.
-	ClassDB::bind_method("_clear_selection", &AnimationTrackEditor::_clear_selection); // Still used by some connect_compat.
+	ClassDB::bind_method(D_METHOD("_animation_update"), &AnimationTrackEditor::_animation_update);
+	ClassDB::bind_method(D_METHOD("_track_grab_focus"), &AnimationTrackEditor::_track_grab_focus);
+	ClassDB::bind_method(D_METHOD("_update_tracks"), &AnimationTrackEditor::_update_tracks);
+	ClassDB::bind_method(D_METHOD("_clear_selection_for_anim"), &AnimationTrackEditor::_clear_selection_for_anim);
+	ClassDB::bind_method(D_METHOD("_select_at_anim"), &AnimationTrackEditor::_select_at_anim);
+
+	ClassDB::bind_method(D_METHOD("_key_selected"), &AnimationTrackEditor::_key_selected); // Still used by some connect_compat.
+	ClassDB::bind_method(D_METHOD("_key_deselected"), &AnimationTrackEditor::_key_deselected); // Still used by some connect_compat.
+	ClassDB::bind_method(D_METHOD("_clear_selection"), &AnimationTrackEditor::_clear_selection); // Still used by some connect_compat.
+
+	ClassDB::bind_method(D_METHOD("_bezier_track_set_key_handle_mode", "animation", "track_idx", "key_idx", "key_handle_mode", "key_handle_set_mode"), &AnimationTrackEditor::_bezier_track_set_key_handle_mode, DEFVAL(Animation::HANDLE_SET_MODE_NONE));
 
 	ADD_SIGNAL(MethodInfo("timeline_changed", PropertyInfo(Variant::FLOAT, "position"), PropertyInfo(Variant::BOOL, "drag"), PropertyInfo(Variant::BOOL, "timeline_only")));
 	ADD_SIGNAL(MethodInfo("keying_changed"));
diff --git a/editor/animation_track_editor.h b/editor/animation_track_editor.h
index 5ebf25899f..9cf3269fd0 100644
--- a/editor/animation_track_editor.h
+++ b/editor/animation_track_editor.h
@@ -324,8 +324,9 @@ class AnimationTrackEditor : public VBoxContainer {
 	Vector<AnimationTrackEditGroup *> groups;
 
 	bool animation_changing_awaiting_update = false;
-	void _animation_update();
+	void _animation_update(); // Updated by AnimationTrackEditor(this)
 	int _get_track_selected();
+	void _sync_animation_change();
 	void _animation_changed();
 	void _update_tracks();
 
@@ -449,6 +450,7 @@ class AnimationTrackEditor : public VBoxContainer {
 	void _toggle_bezier_edit();
 	void _cancel_bezier_edit();
 	void _bezier_edit(int p_for_track);
+	void _bezier_track_set_key_handle_mode(Animation *p_anim, int p_track, int p_index, Animation::HandleMode p_mode, Animation::HandleSetMode p_set_mode = Animation::HANDLE_SET_MODE_NONE);
 
 	////////////// edit menu stuff
 
diff --git a/editor/icons/BezierHandlesBalanced.svg b/editor/icons/BezierHandlesBalanced.svg
index 911029e431..b1778b1a5e 100644
--- a/editor/icons/BezierHandlesBalanced.svg
+++ b/editor/icons/BezierHandlesBalanced.svg
@@ -1 +1 @@
-<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.2881355-6.847458 6.5762712-8.1355935c5.0847459.9491522 5.9661009 8.1355925 5.9661009 8.1355925" fill="none" stroke="#5fb2ff" stroke-miterlimit="4.9" stroke-width="1.7"/><ellipse cx="1.898304" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><path d="m7.4559186 5.1473018-4.7355323 1.5541798" fill="none" stroke="#5fb2ff" stroke-width=".618"/><path d="m10.790357 4.2063094-2.5009748.9433136" fill="none" stroke="#5fb2ff" stroke-width=".614897"/><g fill="#e0e0e0"><ellipse cx="8.271187" cy="4.779661" rx="1.267586" ry="1.199789"/><path d="m1.7157324 5.8754878a1.2675855 1.1997888 0 0 0 -1.26757806 1.1992188 1.2675855 1.1997888 0 0 0 1.26757806 1.1992187 1.2675855 1.1997888 0 0 0 1.2675781-1.1992187 1.2675855 1.1997888 0 0 0 -1.2675781-1.1992188zm.00195.4238282a.84677333.80148375 0 0 1 .8476593.8007812.84677333.80148375 0 0 1 -.8476562.8007812.84677333.80148375 0 0 1 -.84765616-.8007812.84677333.80148375 0 0 1 .84765616-.8007812z"/><path d="m11.909414 2.4642073a1.2836218 1.231838 0 0 0 -1.283614 1.2312528 1.2836218 1.231838 0 0 0 1.283614 1.2312527 1.2836218 1.231838 0 0 0 1.283614-1.2312527 1.2836218 1.231838 0 0 0 -1.283614-1.2312528zm.002.4351497a.85748593.82289328 0 0 1 .858383.8221719.85748593.82289328 0 0 1 -.85838.822172.85748593.82289328 0 0 1 -.858379-.822172.85748593.82289328 0 0 1 .858379-.8221719z"/></g></svg>
+<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.2881355-6.847458 6.5762712-8.1355935c5.0847459.9491522 5.9661009 8.1355925 5.9661009 8.1355925" fill="none" stroke="#87b1d7" stroke-miterlimit="4.9" stroke-width=".5"/><path d="m2.4962504 7.6963851 10.1811806-3.7166314" fill="none" stroke="#61b2ff" stroke-width="1.5"/><g fill="#e0e0e0"><ellipse cx="1.898304" cy="13.491526" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" rx="1.267586" ry="1.199789"/><ellipse cx="8.338983" cy="5.491526" rx="1.267586" ry="1.199789"/><path d="m1.6910776 6.7273a1.2675855 1.1997888 0 0 0 -1.26757808 1.1992188 1.2675855 1.1997888 0 0 0 1.26757808 1.1992187 1.2675855 1.1997888 0 0 0 1.2675781-1.1992187 1.2675855 1.1997888 0 0 0 -1.2675781-1.1992188zm.00195.4238282a.84677333.80148375 0 0 1 .8476593.8007812.84677333.80148375 0 0 1 -.8476562.8007812.84677333.80148375 0 0 1 -.84765618-.8007812.84677333.80148375 0 0 1 .84765618-.8007812z"/><path d="m13.40948 2.2963899a1.2836218 1.231838 0 0 0 -1.283614 1.2312528 1.2836218 1.231838 0 0 0 1.283614 1.2312526 1.2836218 1.231838 0 0 0 1.283614-1.2312526 1.2836218 1.231838 0 0 0 -1.283614-1.2312528zm.002.4351497a.85748593.82289328 0 0 1 .858383.8221719.85748593.82289328 0 0 1 -.85838.8221719.85748593.82289328 0 0 1 -.858379-.8221719.85748593.82289328 0 0 1 .858379-.8221719z"/></g></svg>
diff --git a/editor/icons/BezierHandlesFree.svg b/editor/icons/BezierHandlesFree.svg
index 6e91288c79..c7bff530ae 100644
--- a/editor/icons/BezierHandlesFree.svg
+++ b/editor/icons/BezierHandlesFree.svg
@@ -1 +1 @@
-<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.2881355-6.847458 6.5762712-8.1355935c5.0847459.9491522 5.9661009 8.1355925 5.9661009 8.1355925" fill="none" stroke="#5fb2ff" stroke-miterlimit="4.9" stroke-width="1.7"/><ellipse cx="1.898304" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><path d="m7.6850253 4.7560401-3.776127.6607599" fill="none" stroke="#5fb2ff" stroke-width=".805138"/><path d="m11.695505 2.3941651-2.999121 2.2935078" fill="none" stroke="#5fb2ff" stroke-width=".730798"/><g fill="#e0e0e0"><ellipse cx="8.271187" cy="4.779661" rx="1.267586" ry="1.199789"/><path d="m2.4961199 4.3976698a1.1997888 1.2675855 80.074672 0 0 -1.0419038 1.3997559 1.1997888 1.2675855 80.074672 0 0 1.4553094.9627848 1.1997888 1.2675855 80.074672 0 0 1.0419037-1.3997558 1.1997888 1.2675855 80.074672 0 0 -1.4553093-.9627849zm.074974.4171488a.80148375.84677333 80.074672 0 1 .9729986.6426896.80148375.84677333 80.074672 0 1 -.6969432.934902.80148375.84677333 80.074672 0 1 -.9729958-.6426902.80148375.84677333 80.074672 0 1 .6969432-.934902z"/><path d="m11.838896.64428913a1.231838 1.2836218 52.593897 0 0 -.271701 1.75779027 1.231838 1.2836218 52.593897 0 0 1.767576.1983008 1.231838 1.2836218 52.593897 0 0 .271701-1.75779027 1.231838 1.2836218 52.593897 0 0 -1.767576-.1983008zm.265925.3444462a.82289328.85748593 52.593897 0 1 1.181294.13165847.82289328.85748593 52.593897 0 1 -.182417 1.1745241.82289328.85748593 52.593897 0 1 -1.181291-.1316609.82289328.85748593 52.593897 0 1 .182417-1.17452347z"/></g></svg>
+<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.3064631-5.1979735 6.5945988-6.486109c5.0847463.9491522 5.9477733 6.486108 5.9477733 6.486108" fill="none" stroke="#87b1d7" stroke-miterlimit="4.9" stroke-width=".5"/><path d="m2.3554991 8.5165019 6.0018116-1.3754919 2.0717113-4.6377276" fill="none" stroke="#61b3ff" stroke-width="1.5"/><g fill="#e0e0e0"><ellipse cx="1.898304" cy="13.491526" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" rx="1.267586" ry="1.199789"/><ellipse cx="8.35731" cy="7.14101" rx="1.267586" ry="1.199789"/><path d="m1.3048251 7.4400522a1.1997888 1.2675855 80.074672 0 0 -1.04190379 1.3997559 1.1997888 1.2675855 80.074672 0 0 1.45530939.9627848 1.1997888 1.2675855 80.074672 0 0 1.0419037-1.3997558 1.1997888 1.2675855 80.074672 0 0 -1.4553093-.9627849zm.074974.4171488a.80148375.84677333 80.074672 0 1 .9729986.6426896.80148375.84677333 80.074672 0 1 -.6969432.934902.80148375.84677333 80.074672 0 1 -.97299579-.6426902.80148375.84677333 80.074672 0 1 .69694319-.934902z"/><path d="m10.024463.73592688a1.231838 1.2836218 52.593897 0 0 -.2717015 1.75779042 1.231838 1.2836218 52.593897 0 0 1.7675765.1983008 1.231838 1.2836218 52.593897 0 0 .271701-1.75779042 1.231838 1.2836218 52.593897 0 0 -1.767576-.1983008zm.265925.34444622a.82289328.85748593 52.593897 0 1 1.181294.1316585.82289328.85748593 52.593897 0 1 -.182417 1.1745242.82289328.85748593 52.593897 0 1 -1.181291-.1316609.82289328.85748593 52.593897 0 1 .182417-1.1745236z"/></g></svg>
diff --git a/editor/icons/BezierHandlesLinear.svg b/editor/icons/BezierHandlesLinear.svg
new file mode 100644
index 0000000000..2667779dcb
--- /dev/null
+++ b/editor/icons/BezierHandlesLinear.svg
@@ -0,0 +1 @@
+<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m8.2711868 4.7796612-6.3728828 8.7118648z" fill="none" stroke="#87b1d7" stroke-miterlimit="4.9" stroke-width=".5"/><ellipse cx="1.898304" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><path d="m14.237288 13.491526-5.9661012-8.7118648" fill="none" stroke="#87b1d7" stroke-miterlimit="4.9" stroke-width=".5"/><path d="m5.6316733 8.3879317 2.6395135-3.6082705 2.4416832 3.5654122" fill="none" stroke="#61b2ff" stroke-width="1.5"/><g fill="#e0e0e0"><ellipse cx="14.237288" cy="13.491526" rx="1.267586" ry="1.199789"/><ellipse cx="8.271187" cy="4.779661" rx="1.267586" ry="1.199789"/><path d="m5.0847454 7.9363749a1.2675855 1.1997888 0 0 0 -1.2675781 1.1992188 1.2675855 1.1997888 0 0 0 1.2675781 1.1992183 1.2675855 1.1997888 0 0 0 1.2675781-1.1992183 1.2675855 1.1997888 0 0 0 -1.2675781-1.1992188zm.00195.4238282a.84677333.80148375 0 0 1 .8476593.8007812.84677333.80148375 0 0 1 -.8476562.8007812.84677333.80148375 0 0 1 -.8476562-.8007812.84677333.80148375 0 0 1 .8476562-.8007812z"/><path d="m11.254237 7.9043407a1.2836218 1.231838 0 0 0 -1.2836135 1.2312528 1.2836218 1.231838 0 0 0 1.2836135 1.2312525 1.2836218 1.231838 0 0 0 1.283614-1.2312525 1.2836218 1.231838 0 0 0 -1.283614-1.2312528zm.002.4351497a.85748593.82289328 0 0 1 .858383.8221719.85748593.82289328 0 0 1 -.85838.822172.85748593.82289328 0 0 1 -.858379-.822172.85748593.82289328 0 0 1 .858379-.8221719z"/></g></svg>
diff --git a/editor/icons/BezierHandlesMirror.svg b/editor/icons/BezierHandlesMirror.svg
index 9180e31921..07817f7247 100644
--- a/editor/icons/BezierHandlesMirror.svg
+++ b/editor/icons/BezierHandlesMirror.svg
@@ -1 +1 @@
-<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.2881355-6.847458 6.5762712-8.1355935c5.0847459.9491522 5.9661009 8.1355925 5.9661009 8.1355925" fill="none" stroke="#5fb2ff" stroke-miterlimit="4.9" stroke-width="1.7"/><ellipse cx="1.898304" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><path d="m8.2033896 4.6779662h-3.8335021" fill="none" stroke="#5fb2ff" stroke-width=".805138"/><path d="m11.931789 4.6440679h-3.7283994" fill="none" stroke="#5fb2ff" stroke-width=".716709"/><g fill="#e0e0e0"><ellipse cx="8.271187" cy="4.779661" rx="1.267586" ry="1.199789"/><path d="m3.1539157 3.4305762a1.2675855 1.1997888 0 0 0 -1.2675781 1.1992188 1.2675855 1.1997888 0 0 0 1.2675781 1.1992187 1.2675855 1.1997888 0 0 0 1.2675781-1.1992187 1.2675855 1.1997888 0 0 0 -1.2675781-1.1992188zm.00195.4238282a.84677333.80148375 0 0 1 .8476593.8007812.84677333.80148375 0 0 1 -.8476562.8007812.84677333.80148375 0 0 1 -.8476562-.8007812.84677333.80148375 0 0 1 .8476562-.8007812z"/><path d="m13.093969 3.3750567a1.2675855 1.1997888 0 0 0 -1.267578 1.1992188 1.2675855 1.1997888 0 0 0 1.267578 1.1992187 1.2675855 1.1997888 0 0 0 1.267578-1.1992187 1.2675855 1.1997888 0 0 0 -1.267578-1.1992188zm.002.4238282a.84677333.80148375 0 0 1 .847659.8007812.84677333.80148375 0 0 1 -.847656.8007812.84677333.80148375 0 0 1 -.847656-.8007812.84677333.80148375 0 0 1 .847656-.8007812z"/></g></svg>
+<svg height="16" viewBox="0 0 16 16" width="16" xmlns="http://www.w3.org/2000/svg"><path d="m1.7627119 13.627119s1.2881355-6.847458 6.5762712-8.1355935c5.0847459.9491522 5.9661009 8.1355925 5.9661009 8.1355925" fill="none" stroke="#87b1d7" stroke-miterlimit="4.9" stroke-width=".5"/><ellipse cx="1.898304" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><ellipse cx="14.237288" cy="13.491526" fill="#e0e0e0" rx="1.267586" ry="1.199789"/><path d="m8.3389831 5.4915255-5.8519685.0395137" fill="none" stroke="#5fb2ff" stroke-width="1.5"/><path d="m13.814033 5.4419288-5.4750499.0156984" fill="none" stroke="#5fb2ff" stroke-width="1.5"/><g fill="#e0e0e0"><ellipse cx="8.40678" cy="5.593221" rx="1.267586" ry="1.199789"/><path d="m1.6400247 4.2441355a1.2675855 1.1997888 0 0 0 -1.26757814 1.1992188 1.2675855 1.1997888 0 0 0 1.26757814 1.1992187 1.2675855 1.1997888 0 0 0 1.2675781-1.1992187 1.2675855 1.1997888 0 0 0 -1.2675781-1.1992188zm.00195.4238282a.84677333.80148375 0 0 1 .8476593.8007812.84677333.80148375 0 0 1 -.8476562.8007812.84677333.80148375 0 0 1 -.84765624-.8007812.84677333.80148375 0 0 1 .84765624-.8007812z"/><path d="m14.659116 4.188616a1.2675855 1.1997888 0 0 0 -1.267578 1.1992188 1.2675855 1.1997888 0 0 0 1.267578 1.1992187 1.2675855 1.1997888 0 0 0 1.267578-1.1992187 1.2675855 1.1997888 0 0 0 -1.267578-1.1992188zm.002.4238282a.84677333.80148375 0 0 1 .847659.8007812.84677333.80148375 0 0 1 -.847656.8007812.84677333.80148375 0 0 1 -.847656-.8007812.84677333.80148375 0 0 1 .847656-.8007812z"/></g></svg>
diff --git a/scene/resources/animation.cpp b/scene/resources/animation.cpp
index 0782f779b5..da59c4dbd1 100644
--- a/scene/resources/animation.cpp
+++ b/scene/resources/animation.cpp
@@ -313,29 +313,37 @@ bool Animation::_set(const StringName &p_name, const Variant &p_value) {
 				Dictionary d = p_value;
 				ERR_FAIL_COND_V(!d.has("times"), false);
 				ERR_FAIL_COND_V(!d.has("points"), false);
-
 				Vector<real_t> times = d["times"];
 				Vector<real_t> values = d["points"];
+#ifdef TOOLS_ENABLED
+				ERR_FAIL_COND_V(!d.has("handle_modes"), false);
+				Vector<int> handle_modes = d["handle_modes"];
+#endif // TOOLS_ENABLED
 
-				ERR_FAIL_COND_V(times.size() * 6 != values.size(), false);
+				ERR_FAIL_COND_V(times.size() * 5 != values.size(), false);
 
 				if (times.size()) {
 					int valcount = times.size();
 
 					const real_t *rt = times.ptr();
 					const real_t *rv = values.ptr();
+#ifdef TOOLS_ENABLED
+					const int *rh = handle_modes.ptr();
+#endif // TOOLS_ENABLED
 
 					bt->values.resize(valcount);
 
 					for (int i = 0; i < valcount; i++) {
 						bt->values.write[i].time = rt[i];
 						bt->values.write[i].transition = 0; //unused in bezier
-						bt->values.write[i].value.value = rv[i * 6 + 0];
-						bt->values.write[i].value.in_handle.x = rv[i * 6 + 1];
-						bt->values.write[i].value.in_handle.y = rv[i * 6 + 2];
-						bt->values.write[i].value.out_handle.x = rv[i * 6 + 3];
-						bt->values.write[i].value.out_handle.y = rv[i * 6 + 4];
-						bt->values.write[i].value.handle_mode = static_cast<HandleMode>((int)rv[i * 6 + 5]);
+						bt->values.write[i].value.value = rv[i * 5 + 0];
+						bt->values.write[i].value.in_handle.x = rv[i * 5 + 1];
+						bt->values.write[i].value.in_handle.y = rv[i * 5 + 2];
+						bt->values.write[i].value.out_handle.x = rv[i * 5 + 3];
+						bt->values.write[i].value.out_handle.y = rv[i * 5 + 4];
+#ifdef TOOLS_ENABLED
+						bt->values.write[i].value.handle_mode = static_cast<HandleMode>(rh[i]);
+#endif // TOOLS_ENABLED
 					}
 				}
 
@@ -699,28 +707,39 @@ bool Animation::_get(const StringName &p_name, Variant &r_ret) const {
 				int kk = bt->values.size();
 
 				key_times.resize(kk);
-				key_points.resize(kk * 6);
+				key_points.resize(kk * 5);
 
 				real_t *wti = key_times.ptrw();
 				real_t *wpo = key_points.ptrw();
 
+#ifdef TOOLS_ENABLED
+				Vector<int> handle_modes;
+				handle_modes.resize(kk);
+				int *whm = handle_modes.ptrw();
+#endif // TOOLS_ENABLED
+
 				int idx = 0;
 
 				const TKey<BezierKey> *vls = bt->values.ptr();
 
 				for (int i = 0; i < kk; i++) {
 					wti[idx] = vls[i].time;
-					wpo[idx * 6 + 0] = vls[i].value.value;
-					wpo[idx * 6 + 1] = vls[i].value.in_handle.x;
-					wpo[idx * 6 + 2] = vls[i].value.in_handle.y;
-					wpo[idx * 6 + 3] = vls[i].value.out_handle.x;
-					wpo[idx * 6 + 4] = vls[i].value.out_handle.y;
-					wpo[idx * 6 + 5] = (double)vls[i].value.handle_mode;
+					wpo[idx * 5 + 0] = vls[i].value.value;
+					wpo[idx * 5 + 1] = vls[i].value.in_handle.x;
+					wpo[idx * 5 + 2] = vls[i].value.in_handle.y;
+					wpo[idx * 5 + 3] = vls[i].value.out_handle.x;
+					wpo[idx * 5 + 4] = vls[i].value.out_handle.y;
+#ifdef TOOLS_ENABLED
+					whm[idx] = static_cast<int>(vls[i].value.handle_mode);
+#endif // TOOLS_ENABLED
 					idx++;
 				}
 
 				d["times"] = key_times;
 				d["points"] = key_points;
+#ifdef TOOLS_ENABLED
+				d["handle_modes"] = handle_modes;
+#endif // TOOLS_ENABLED
 
 				r_ret = d;
 
@@ -1626,7 +1645,7 @@ int Animation::track_insert_key(int p_track, double p_time, const Variant &p_key
 			BezierTrack *bt = static_cast<BezierTrack *>(t);
 
 			Array arr = p_key;
-			ERR_FAIL_COND_V(arr.size() != 6, -1);
+			ERR_FAIL_COND_V(arr.size() != 5, -1);
 
 			TKey<BezierKey> k;
 			k.time = p_time;
@@ -1635,9 +1654,16 @@ int Animation::track_insert_key(int p_track, double p_time, const Variant &p_key
 			k.value.in_handle.y = arr[2];
 			k.value.out_handle.x = arr[3];
 			k.value.out_handle.y = arr[4];
-			k.value.handle_mode = static_cast<HandleMode>((int)arr[5]);
 			ret = _insert(p_time, bt->values, k);
 
+			Vector<int> key_neighborhood;
+			key_neighborhood.push_back(ret);
+			if (ret > 0) {
+				key_neighborhood.push_back(ret - 1);
+			}
+			if (ret < track_get_key_count(p_track) - 1) {
+				key_neighborhood.push_back(ret + 1);
+			}
 		} break;
 		case TYPE_AUDIO: {
 			AudioTrack *at = static_cast<AudioTrack *>(t);
@@ -1776,13 +1802,12 @@ Variant Animation::track_get_key_value(int p_track, int p_key_idx) const {
 			ERR_FAIL_INDEX_V(p_key_idx, bt->values.size(), Variant());
 
 			Array arr;
-			arr.resize(6);
+			arr.resize(5);
 			arr[0] = bt->values[p_key_idx].value.value;
 			arr[1] = bt->values[p_key_idx].value.in_handle.x;
 			arr[2] = bt->values[p_key_idx].value.in_handle.y;
 			arr[3] = bt->values[p_key_idx].value.out_handle.x;
 			arr[4] = bt->values[p_key_idx].value.out_handle.y;
-			arr[5] = (double)bt->values[p_key_idx].value.handle_mode;
 			return arr;
 
 		} break;
@@ -2151,14 +2176,13 @@ void Animation::track_set_key_value(int p_track, int p_key_idx, const Variant &p
 			ERR_FAIL_INDEX(p_key_idx, bt->values.size());
 
 			Array arr = p_value;
-			ERR_FAIL_COND(arr.size() != 6);
+			ERR_FAIL_COND(arr.size() != 5);
 
 			bt->values.write[p_key_idx].value.value = arr[0];
 			bt->values.write[p_key_idx].value.in_handle.x = arr[1];
 			bt->values.write[p_key_idx].value.in_handle.y = arr[2];
 			bt->values.write[p_key_idx].value.out_handle.x = arr[3];
 			bt->values.write[p_key_idx].value.out_handle.y = arr[4];
-			bt->values.write[p_key_idx].value.handle_mode = static_cast<HandleMode>((int)arr[5]);
 
 		} break;
 		case TYPE_AUDIO: {
@@ -3347,7 +3371,7 @@ StringName Animation::method_track_get_name(int p_track, int p_key_idx) const {
 	return pm->methods[p_key_idx].method;
 }
 
-int Animation::bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle, const HandleMode p_handle_mode) {
+int Animation::bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle) {
 	ERR_FAIL_INDEX_V(p_track, tracks.size(), -1);
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND_V(t->type != TYPE_BEZIER, -1);
@@ -3365,7 +3389,6 @@ int Animation::bezier_track_insert_key(int p_track, double p_time, real_t p_valu
 	if (k.value.out_handle.x < 0) {
 		k.value.out_handle.x = 0;
 	}
-	k.value.handle_mode = p_handle_mode;
 
 	int key = _insert(p_time, bt->values, k);
 
@@ -3374,30 +3397,6 @@ int Animation::bezier_track_insert_key(int p_track, double p_time, real_t p_valu
 	return key;
 }
 
-void Animation::bezier_track_set_key_handle_mode(int p_track, int p_index, HandleMode p_mode, double p_balanced_value_time_ratio) {
-	ERR_FAIL_INDEX(p_track, tracks.size());
-	Track *t = tracks[p_track];
-	ERR_FAIL_COND(t->type != TYPE_BEZIER);
-
-	BezierTrack *bt = static_cast<BezierTrack *>(t);
-
-	ERR_FAIL_INDEX(p_index, bt->values.size());
-
-	bt->values.write[p_index].value.handle_mode = p_mode;
-
-	if (p_mode == HANDLE_MODE_BALANCED) {
-		Transform2D xform;
-		xform.set_scale(Vector2(1.0, 1.0 / p_balanced_value_time_ratio));
-
-		Vector2 vec_in = xform.xform(bt->values[p_index].value.in_handle);
-		Vector2 vec_out = xform.xform(bt->values[p_index].value.out_handle);
-
-		bt->values.write[p_index].value.in_handle = xform.affine_inverse().xform(-vec_out.normalized() * vec_in.length());
-	}
-
-	emit_changed();
-}
-
 void Animation::bezier_track_set_key_value(int p_track, int p_index, real_t p_value) {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	Track *t = tracks[p_track];
@@ -3408,10 +3407,11 @@ void Animation::bezier_track_set_key_value(int p_track, int p_index, real_t p_va
 	ERR_FAIL_INDEX(p_index, bt->values.size());
 
 	bt->values.write[p_index].value.value = p_value;
+
 	emit_changed();
 }
 
-void Animation::bezier_track_set_key_in_handle(int p_track, int p_index, const Vector2 &p_handle, double p_balanced_value_time_ratio) {
+void Animation::bezier_track_set_key_in_handle(int p_track, int p_index, const Vector2 &p_handle, real_t p_balanced_value_time_ratio) {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND(t->type != TYPE_BEZIER);
@@ -3426,7 +3426,11 @@ void Animation::bezier_track_set_key_in_handle(int p_track, int p_index, const V
 	}
 	bt->values.write[p_index].value.in_handle = in_handle;
 
-	if (bt->values[p_index].value.handle_mode == HANDLE_MODE_BALANCED) {
+#ifdef TOOLS_ENABLED
+	if (bt->values[p_index].value.handle_mode == HANDLE_MODE_LINEAR) {
+		bt->values.write[p_index].value.in_handle = Vector2();
+		bt->values.write[p_index].value.out_handle = Vector2();
+	} else if (bt->values[p_index].value.handle_mode == HANDLE_MODE_BALANCED) {
 		Transform2D xform;
 		xform.set_scale(Vector2(1.0, 1.0 / p_balanced_value_time_ratio));
 
@@ -3434,12 +3438,15 @@ void Animation::bezier_track_set_key_in_handle(int p_track, int p_index, const V
 		Vector2 vec_in = xform.xform(in_handle);
 
 		bt->values.write[p_index].value.out_handle = xform.affine_inverse().xform(-vec_in.normalized() * vec_out.length());
+	} else if (bt->values[p_index].value.handle_mode == HANDLE_MODE_MIRRORED) {
+		bt->values.write[p_index].value.out_handle = -in_handle;
 	}
+#endif // TOOLS_ENABLED
 
 	emit_changed();
 }
 
-void Animation::bezier_track_set_key_out_handle(int p_track, int p_index, const Vector2 &p_handle, double p_balanced_value_time_ratio) {
+void Animation::bezier_track_set_key_out_handle(int p_track, int p_index, const Vector2 &p_handle, real_t p_balanced_value_time_ratio) {
 	ERR_FAIL_INDEX(p_track, tracks.size());
 	Track *t = tracks[p_track];
 	ERR_FAIL_COND(t->type != TYPE_BEZIER);
@@ -3454,7 +3461,11 @@ void Animation::bezier_track_set_key_out_handle(int p_track, int p_index, const
 	}
 	bt->values.write[p_index].value.out_handle = out_handle;
 
-	if (bt->values[p_index].value.handle_mode == HANDLE_MODE_BALANCED) {
+#ifdef TOOLS_ENABLED
+	if (bt->values[p_index].value.handle_mode == HANDLE_MODE_LINEAR) {
+		bt->values.write[p_index].value.in_handle = Vector2();
+		bt->values.write[p_index].value.out_handle = Vector2();
+	} else if (bt->values[p_index].value.handle_mode == HANDLE_MODE_BALANCED) {
 		Transform2D xform;
 		xform.set_scale(Vector2(1.0, 1.0 / p_balanced_value_time_ratio));
 
@@ -3462,7 +3473,10 @@ void Animation::bezier_track_set_key_out_handle(int p_track, int p_index, const
 		Vector2 vec_out = xform.xform(out_handle);
 
 		bt->values.write[p_index].value.in_handle = xform.affine_inverse().xform(-vec_out.normalized() * vec_in.length());
+	} else if (bt->values[p_index].value.handle_mode == HANDLE_MODE_MIRRORED) {
+		bt->values.write[p_index].value.in_handle = -out_handle;
 	}
+#endif // TOOLS_ENABLED
 
 	emit_changed();
 }
@@ -3479,18 +3493,6 @@ real_t Animation::bezier_track_get_key_value(int p_track, int p_index) const {
 	return bt->values[p_index].value.value;
 }
 
-int Animation::bezier_track_get_key_handle_mode(int p_track, int p_index) const {
-	ERR_FAIL_INDEX_V(p_track, tracks.size(), 0);
-	Track *t = tracks[p_track];
-	ERR_FAIL_COND_V(t->type != TYPE_BEZIER, 0);
-
-	BezierTrack *bt = static_cast<BezierTrack *>(t);
-
-	ERR_FAIL_INDEX_V(p_index, bt->values.size(), 0);
-
-	return bt->values[p_index].value.handle_mode;
-}
-
 Vector2 Animation::bezier_track_get_key_in_handle(int p_track, int p_index) const {
 	ERR_FAIL_INDEX_V(p_track, tracks.size(), Vector2());
 	Track *t = tracks[p_track];
@@ -3515,6 +3517,109 @@ Vector2 Animation::bezier_track_get_key_out_handle(int p_track, int p_index) con
 	return bt->values[p_index].value.out_handle;
 }
 
+#ifdef TOOLS_ENABLED
+void Animation::bezier_track_set_key_handle_mode(int p_track, int p_index, HandleMode p_mode, HandleSetMode p_set_mode) {
+	ERR_FAIL_INDEX(p_track, tracks.size());
+	Track *t = tracks[p_track];
+	ERR_FAIL_COND(t->type != TYPE_BEZIER);
+
+	BezierTrack *bt = static_cast<BezierTrack *>(t);
+
+	ERR_FAIL_INDEX(p_index, bt->values.size());
+
+	bt->values.write[p_index].value.handle_mode = p_mode;
+
+	switch (p_mode) {
+		case HANDLE_MODE_LINEAR: {
+			bt->values.write[p_index].value.in_handle = Vector2(0, 0);
+			bt->values.write[p_index].value.out_handle = Vector2(0, 0);
+		} break;
+		case HANDLE_MODE_BALANCED:
+		case HANDLE_MODE_MIRRORED: {
+			int prev_key = MAX(0, p_index - 1);
+			int next_key = MIN(bt->values.size() - 1, p_index + 1);
+			if (prev_key == next_key) {
+				break; // Exists only one key.
+			}
+			real_t in_handle_x = 0;
+			real_t in_handle_y = 0;
+			real_t out_handle_x = 0;
+			real_t out_handle_y = 0;
+			if (p_mode == HANDLE_MODE_BALANCED) {
+				// Note:
+				// If p_set_mode == HANDLE_SET_MODE_NONE, I don't know if it should change the Tangent implicitly.
+				// At the least, we need to avoid corrupting the handles when loading animation from the resource.
+				// However, changes made by the Inspector do not go through the BezierEditor,
+				// so if you change from Free to Balanced or Mirrored in Inspector, there is no guarantee that
+				// it is Balanced or Mirrored until there is a handle operation.
+				if (p_set_mode == HANDLE_SET_MODE_RESET) {
+					real_t handle_length = 1.0 / 3.0;
+					in_handle_x = (bt->values[prev_key].time - bt->values[p_index].time) * handle_length;
+					in_handle_y = 0;
+					out_handle_x = (bt->values[next_key].time - bt->values[p_index].time) * handle_length;
+					out_handle_y = 0;
+					bt->values.write[p_index].value.in_handle = Vector2(in_handle_x, in_handle_y);
+					bt->values.write[p_index].value.out_handle = Vector2(out_handle_x, out_handle_y);
+				} else if (p_set_mode == HANDLE_SET_MODE_AUTO) {
+					real_t handle_length = 1.0 / 6.0;
+					real_t tangent = (bt->values[next_key].value.value - bt->values[prev_key].value.value) / (bt->values[next_key].time - bt->values[prev_key].time);
+					in_handle_x = (bt->values[prev_key].time - bt->values[p_index].time) * handle_length;
+					in_handle_y = in_handle_x * tangent;
+					out_handle_x = (bt->values[next_key].time - bt->values[p_index].time) * handle_length;
+					out_handle_y = out_handle_x * tangent;
+					bt->values.write[p_index].value.in_handle = Vector2(in_handle_x, in_handle_y);
+					bt->values.write[p_index].value.out_handle = Vector2(out_handle_x, out_handle_y);
+				}
+			} else {
+				real_t handle_length = 1.0 / 4.0;
+				real_t prev_interval = Math::abs(bt->values[p_index].time - bt->values[prev_key].time);
+				real_t next_interval = Math::abs(bt->values[p_index].time - bt->values[next_key].time);
+				real_t min_time = 0;
+				if (Math::is_zero_approx(prev_interval)) {
+					min_time = next_interval;
+				} else if (Math::is_zero_approx(next_interval)) {
+					min_time = prev_interval;
+				} else {
+					min_time = MIN(prev_interval, next_interval);
+				}
+				if (p_set_mode == HANDLE_SET_MODE_RESET) {
+					in_handle_x = -min_time * handle_length;
+					in_handle_y = 0;
+					out_handle_x = min_time * handle_length;
+					out_handle_y = 0;
+					bt->values.write[p_index].value.in_handle = Vector2(in_handle_x, in_handle_y);
+					bt->values.write[p_index].value.out_handle = Vector2(out_handle_x, out_handle_y);
+				} else if (p_set_mode == HANDLE_SET_MODE_AUTO) {
+					real_t tangent = (bt->values[next_key].value.value - bt->values[prev_key].value.value) / min_time;
+					in_handle_x = -min_time * handle_length;
+					in_handle_y = in_handle_x * tangent;
+					out_handle_x = min_time * handle_length;
+					out_handle_y = out_handle_x * tangent;
+					bt->values.write[p_index].value.in_handle = Vector2(in_handle_x, in_handle_y);
+					bt->values.write[p_index].value.out_handle = Vector2(out_handle_x, out_handle_y);
+				}
+			}
+		} break;
+		default: {
+		} break;
+	}
+
+	emit_changed();
+}
+
+Animation::HandleMode Animation::bezier_track_get_key_handle_mode(int p_track, int p_index) const {
+	ERR_FAIL_INDEX_V(p_track, tracks.size(), HANDLE_MODE_FREE);
+	Track *t = tracks[p_track];
+	ERR_FAIL_COND_V(t->type != TYPE_BEZIER, HANDLE_MODE_FREE);
+
+	BezierTrack *bt = static_cast<BezierTrack *>(t);
+
+	ERR_FAIL_INDEX_V(p_index, bt->values.size(), HANDLE_MODE_FREE);
+
+	return bt->values[p_index].value.handle_mode;
+}
+#endif // TOOLS_ENABLED
+
 real_t Animation::bezier_track_interpolate(int p_track, double p_time) const {
 	//this uses a different interpolation scheme
 	ERR_FAIL_INDEX_V(p_track, tracks.size(), 0);
@@ -3911,7 +4016,7 @@ void Animation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("method_track_get_name", "track_idx", "key_idx"), &Animation::method_track_get_name);
 	ClassDB::bind_method(D_METHOD("method_track_get_params", "track_idx", "key_idx"), &Animation::method_track_get_params);
 
-	ClassDB::bind_method(D_METHOD("bezier_track_insert_key", "track_idx", "time", "value", "in_handle", "out_handle", "handle_mode"), &Animation::bezier_track_insert_key, DEFVAL(Vector2()), DEFVAL(Vector2()), DEFVAL(Animation::HandleMode::HANDLE_MODE_BALANCED));
+	ClassDB::bind_method(D_METHOD("bezier_track_insert_key", "track_idx", "time", "value", "in_handle", "out_handle"), &Animation::bezier_track_insert_key, DEFVAL(Vector2()), DEFVAL(Vector2()));
 
 	ClassDB::bind_method(D_METHOD("bezier_track_set_key_value", "track_idx", "key_idx", "value"), &Animation::bezier_track_set_key_value);
 	ClassDB::bind_method(D_METHOD("bezier_track_set_key_in_handle", "track_idx", "key_idx", "in_handle", "balanced_value_time_ratio"), &Animation::bezier_track_set_key_in_handle, DEFVAL(1.0));
@@ -3931,9 +4036,6 @@ void Animation::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("audio_track_get_key_start_offset", "track_idx", "key_idx"), &Animation::audio_track_get_key_start_offset);
 	ClassDB::bind_method(D_METHOD("audio_track_get_key_end_offset", "track_idx", "key_idx"), &Animation::audio_track_get_key_end_offset);
 
-	ClassDB::bind_method(D_METHOD("bezier_track_set_key_handle_mode", "track_idx", "key_idx", "key_handle_mode", "balanced_value_time_ratio"), &Animation::bezier_track_set_key_handle_mode, DEFVAL(1.0));
-	ClassDB::bind_method(D_METHOD("bezier_track_get_key_handle_mode", "track_idx", "key_idx"), &Animation::bezier_track_get_key_handle_mode);
-
 	ClassDB::bind_method(D_METHOD("animation_track_insert_key", "track_idx", "time", "animation"), &Animation::animation_track_insert_key);
 	ClassDB::bind_method(D_METHOD("animation_track_set_key_animation", "track_idx", "key_idx", "animation"), &Animation::animation_track_set_key_animation);
 	ClassDB::bind_method(D_METHOD("animation_track_get_key_animation", "track_idx", "key_idx"), &Animation::animation_track_get_key_animation);
@@ -3981,9 +4083,6 @@ void Animation::_bind_methods() {
 	BIND_ENUM_CONSTANT(LOOP_NONE);
 	BIND_ENUM_CONSTANT(LOOP_LINEAR);
 	BIND_ENUM_CONSTANT(LOOP_PINGPONG);
-
-	BIND_ENUM_CONSTANT(HANDLE_MODE_FREE);
-	BIND_ENUM_CONSTANT(HANDLE_MODE_BALANCED);
 }
 
 void Animation::clear() {
diff --git a/scene/resources/animation.h b/scene/resources/animation.h
index 367134b94c..5e88980397 100644
--- a/scene/resources/animation.h
+++ b/scene/resources/animation.h
@@ -73,10 +73,19 @@ public:
 		LOOP_PINGPONG,
 	};
 
+#ifdef TOOLS_ENABLED
 	enum HandleMode {
 		HANDLE_MODE_FREE,
+		HANDLE_MODE_LINEAR,
 		HANDLE_MODE_BALANCED,
+		HANDLE_MODE_MIRRORED,
 	};
+	enum HandleSetMode {
+		HANDLE_SET_MODE_NONE,
+		HANDLE_SET_MODE_RESET,
+		HANDLE_SET_MODE_AUTO,
+	};
+#endif // TOOLS_ENABLED
 
 private:
 	struct Track {
@@ -166,8 +175,10 @@ private:
 	struct BezierKey {
 		Vector2 in_handle; //relative (x always <0)
 		Vector2 out_handle; //relative (x always >0)
-		HandleMode handle_mode = HANDLE_MODE_BALANCED;
 		real_t value = 0.0;
+#ifdef TOOLS_ENABLED
+		HandleMode handle_mode = HANDLE_MODE_FREE;
+#endif // TOOLS_ENABLED
 	};
 
 	struct BezierTrack : public Track {
@@ -429,15 +440,17 @@ public:
 	void track_set_interpolation_type(int p_track, InterpolationType p_interp);
 	InterpolationType track_get_interpolation_type(int p_track) const;
 
-	int bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle, const HandleMode p_handle_mode = HandleMode::HANDLE_MODE_BALANCED);
-	void bezier_track_set_key_handle_mode(int p_track, int p_index, HandleMode p_mode, double p_balanced_value_time_ratio = 1.0);
+	int bezier_track_insert_key(int p_track, double p_time, real_t p_value, const Vector2 &p_in_handle, const Vector2 &p_out_handle);
 	void bezier_track_set_key_value(int p_track, int p_index, real_t p_value);
-	void bezier_track_set_key_in_handle(int p_track, int p_index, const Vector2 &p_handle, double p_balanced_value_time_ratio = 1.0);
-	void bezier_track_set_key_out_handle(int p_track, int p_index, const Vector2 &p_handle, double p_balanced_value_time_ratio = 1.0);
+	void bezier_track_set_key_in_handle(int p_track, int p_index, const Vector2 &p_handle, real_t p_balanced_value_time_ratio = 1.0);
+	void bezier_track_set_key_out_handle(int p_track, int p_index, const Vector2 &p_handle, real_t p_balanced_value_time_ratio = 1.0);
 	real_t bezier_track_get_key_value(int p_track, int p_index) const;
-	int bezier_track_get_key_handle_mode(int p_track, int p_index) const;
 	Vector2 bezier_track_get_key_in_handle(int p_track, int p_index) const;
 	Vector2 bezier_track_get_key_out_handle(int p_track, int p_index) const;
+#ifdef TOOLS_ENABLED
+	void bezier_track_set_key_handle_mode(int p_track, int p_index, HandleMode p_mode, HandleSetMode p_set_mode = HANDLE_SET_MODE_NONE);
+	HandleMode bezier_track_get_key_handle_mode(int p_track, int p_index) const;
+#endif // TOOLS_ENABLED
 
 	real_t bezier_track_interpolate(int p_track, double p_time) const;
 
@@ -490,7 +503,10 @@ public:
 VARIANT_ENUM_CAST(Animation::TrackType);
 VARIANT_ENUM_CAST(Animation::InterpolationType);
 VARIANT_ENUM_CAST(Animation::UpdateMode);
-VARIANT_ENUM_CAST(Animation::HandleMode);
 VARIANT_ENUM_CAST(Animation::LoopMode);
+#ifdef TOOLS_ENABLED
+VARIANT_ENUM_CAST(Animation::HandleMode);
+VARIANT_ENUM_CAST(Animation::HandleSetMode);
+#endif // TOOLS_ENABLED
 
 #endif // ANIMATION_H