Add properties to CharacterBody for more move_and_slide options

2 files changed, 309 insertions, 104 deletions

diff --git a/scene/2d/physics_body_2d.cpp b/scene/2d/physics_body_2d.cpp
index 9235a2290e..2d3feb30a1 100644
--- a/scene/2d/physics_body_2d.cpp
+++ b/scene/2d/physics_body_2d.cpp
@@ -69,7 +69,6 @@ Ref<KinematicCollision2D> PhysicsBody2D::_move(const Vector2 &p_motion, bool p_i
 		}
 
 		motion_cache->result = result;
-
 		return motion_cache;
 	}
 
@@ -1046,139 +1045,240 @@ void RigidBody2D::_reload_physics_characteristics() {
 
 //////////////////////////
 
-//so, if you pass 45 as limit, avoid numerical precision errors when angle is 45.
+// So, if you pass 45 as limit, avoid numerical precision errors when angle is 45.
 #define FLOOR_ANGLE_THRESHOLD 0.01
 
 void CharacterBody2D::move_and_slide() {
-	Vector2 body_velocity_normal = linear_velocity.normalized();
-	bool was_on_floor = on_floor;
-
-	// Hack in order to work with calling from _process as well as from _physics_process; calling from thread is risky
+	// Hack in order to work with calling from _process as well as from _physics_process; calling from thread is risky.
 	float delta = Engine::get_singleton()->is_in_physics_frame() ? get_physics_process_delta_time() : get_process_delta_time();
 
-	Vector2 current_floor_velocity = floor_velocity;
-
-	if ((on_floor || on_wall) && on_floor_body.is_valid()) {
-		//this approach makes sure there is less delay between the actual body velocity and the one we saved
-		PhysicsDirectBodyState2D *bs = PhysicsServer2D::get_singleton()->body_get_direct_state(on_floor_body);
-		if (bs) {
-			Transform2D gt = get_global_transform();
-			Vector2 local_position = gt.elements[2] - bs->get_transform().elements[2];
-			current_floor_velocity = bs->get_velocity_at_local_position(local_position);
+	Vector2 current_platform_velocity = platform_velocity;
+
+	if ((on_floor || on_wall) && platform_rid.is_valid()) {
+		bool excluded = (exclude_body_layers & platform_layer) != 0;
+		if (!excluded) {
+			// This approach makes sure there is less delay between the actual body velocity and the one we saved.
+			PhysicsDirectBodyState2D *bs = PhysicsServer2D::get_singleton()->body_get_direct_state(platform_rid);
+			if (bs) {
+				Transform2D gt = get_global_transform();
+				Vector2 local_position = gt.elements[2] - bs->get_transform().elements[2];
+				current_platform_velocity = bs->get_velocity_at_local_position(local_position);
+			}
+		} else {
+			current_platform_velocity = Vector2();
 		}
 	}
 
 	motion_results.clear();
+
+	bool was_on_floor = on_floor;
 	on_floor = false;
 	on_ceiling = false;
 	on_wall = false;
-	floor_normal = Vector2();
-	floor_velocity = Vector2();
 
-	if (current_floor_velocity != Vector2() && on_floor_body.is_valid()) {
+	if (!current_platform_velocity.is_equal_approx(Vector2())) {
 		PhysicsServer2D::MotionResult floor_result;
 		Set<RID> exclude;
-		exclude.insert(on_floor_body);
-		if (move_and_collide(current_floor_velocity * delta, infinite_inertia, floor_result, true, false, false, false, exclude)) {
+		exclude.insert(platform_rid);
+		if (move_and_collide(current_platform_velocity * delta, infinite_inertia, floor_result, true, false, false, false, exclude)) {
 			motion_results.push_back(floor_result);
 			_set_collision_direction(floor_result);
 		}
 	}
 
-	on_floor_body = RID();
 	Vector2 motion = linear_velocity * delta;
+	Vector2 motion_slide_up = motion.slide(up_direction);
+
+	Vector2 prev_platform_velocity = current_platform_velocity;
+	Vector2 prev_floor_normal = floor_normal;
+	RID prev_platform_rid = platform_rid;
+	int prev_platform_layer = platform_layer;
+
+	platform_rid = RID();
+	floor_normal = Vector2();
+	platform_velocity = Vector2();
 
 	// No sliding on first attempt to keep floor motion stable when possible,
-	// when stop on slope is enabled.
-	bool sliding_enabled = !stop_on_slope;
+	// When stop on slope is enabled or when there is no up direction.
+	bool sliding_enabled = !stop_on_slope || up_direction == Vector2();
+	// Constant speed can be applied only the first time sliding is enabled.
+	bool can_apply_constant_speed = sliding_enabled;
+	bool first_slide = true;
+	bool vel_dir_facing_up = linear_velocity.dot(up_direction) > 0;
+	Vector2 last_travel;
 
 	for (int iteration = 0; iteration < max_slides; ++iteration) {
 		PhysicsServer2D::MotionResult result;
 		bool found_collision = false;
 
+		Vector2 prev_position = get_global_transform().elements[2];
+
 		for (int i = 0; i < 2; ++i) {
 			bool collided;
-			if (i == 0) { //collide
+			if (i == 0) { // Collide.
 				collided = move_and_collide(motion, infinite_inertia, result, margin, true, false, !sliding_enabled);
-				if (!collided) {
-					motion = Vector2(); //clear because no collision happened and motion completed
-				}
-			} else { //separate raycasts (if any)
+			} else { // Separate raycasts (if any).
 				collided = separate_raycast_shapes(result);
 				if (collided) {
-					result.remainder = motion; //keep
+					result.remainder = motion; // Keep.
 					result.motion = Vector2();
 				}
 			}
 
 			if (collided) {
 				found_collision = true;
-
 				motion_results.push_back(result);
 				_set_collision_direction(result);
 
-				if (on_floor && stop_on_slope) {
-					if ((body_velocity_normal + up_direction).length() < 0.01) {
-						Transform2D gt = get_global_transform();
-						if (result.motion.length() > margin) {
-							gt.elements[2] -= result.motion.slide(up_direction);
-						} else {
+				if (on_floor && stop_on_slope && (linear_velocity.normalized() + up_direction).length() < 0.01) {
+					Transform2D gt = get_global_transform();
+					if (result.motion.length() > margin) {
+						gt.elements[2] -= result.motion.slide(up_direction);
+					} else {
+						gt.elements[2] -= result.motion;
+					}
+					set_global_transform(gt);
+					linear_velocity = Vector2();
+					motion = Vector2();
+					break;
+				}
+
+				if (result.remainder.is_equal_approx(Vector2())) {
+					motion = Vector2();
+					break;
+				}
+
+				// Move on floor only checks.
+				if (move_on_floor_only && on_wall && motion_slide_up.dot(result.collision_normal) <= 0) {
+					// Avoid to move forward on a wall if move_on_floor_only is true.
+					if (was_on_floor && !is_on_floor_only() && !vel_dir_facing_up) {
+						// If the movement is large the body can be prevented from reaching the walls.
+						if (result.motion.length() <= margin) {
+							// Cancels the motion.
+							Transform2D gt = get_global_transform();
 							gt.elements[2] -= result.motion;
+							set_global_transform(gt);
 						}
-						set_global_transform(gt);
+						on_floor = true;
+						platform_rid = prev_platform_rid;
+						platform_layer = prev_platform_layer;
+
+						platform_velocity = prev_platform_velocity;
+						floor_normal = prev_floor_normal;
 						linear_velocity = Vector2();
-						return;
+						motion = Vector2();
+						break;
+					}
+					// Prevents the body from being able to climb a slope when it moves forward against the wall.
+					else if (!is_on_floor_only()) {
+						motion = up_direction * up_direction.dot(result.remainder);
+						motion = motion.slide(result.collision_normal);
+					} else {
+						motion = result.remainder;
 					}
 				}
-
-				if (sliding_enabled || !on_floor) {
-					motion = result.remainder.slide(result.collision_normal);
-					linear_velocity = linear_velocity.slide(result.collision_normal);
-				} else {
+				// Constant Speed when the slope is upward.
+				else if (constant_speed_on_floor && is_on_floor_only() && can_apply_constant_speed && was_on_floor && motion.dot(result.collision_normal) < 0) {
+					can_apply_constant_speed = false;
+					Vector2 motion_slide_norm = result.remainder.slide(result.collision_normal).normalized();
+					if (!motion_slide_norm.is_equal_approx(Vector2())) {
+						motion = motion_slide_norm * (motion_slide_up.length() - result.motion.slide(up_direction).length() - last_travel.slide(up_direction).length());
+					}
+				}
+				// Regular sliding, the last part of the test handle the case when you don't want to slide on the ceiling.
+				else if ((sliding_enabled || !on_floor) && (!on_ceiling || slide_on_ceiling || !vel_dir_facing_up)) {
+					Vector2 slide_motion = result.remainder.slide(result.collision_normal);
+					if (slide_motion.dot(linear_velocity) > 0.0) {
+						motion = slide_motion;
+					} else {
+						motion = Vector2();
+					}
+					if (slide_on_ceiling && on_ceiling) {
+						// Apply slide only in the direction of the input motion, otherwise just stop to avoid jittering when moving against a wall.
+						if (vel_dir_facing_up) {
+							linear_velocity = linear_velocity.slide(result.collision_normal);
+						} else {
+							// Avoid acceleration in slope when falling.
+							linear_velocity = up_direction * up_direction.dot(linear_velocity);
+						}
+					}
+				}
+				// No sliding on first attempt to keep floor motion stable when possible.
+				else {
 					motion = result.remainder;
+					if (on_ceiling && !slide_on_ceiling && vel_dir_facing_up) {
+						linear_velocity = linear_velocity.slide(up_direction);
+						motion = motion.slide(up_direction);
+					}
 				}
-			}
 
-			sliding_enabled = true;
+				last_travel = result.motion;
+			}
+			// When you move forward in a downward slope you don’t collide because you will be in the air.
+			// This test ensures that constant speed is applied, only if the player is still on the ground after the snap is applied.
+			else if (i == 0 && constant_speed_on_floor && first_slide && _on_floor_if_snapped(was_on_floor, vel_dir_facing_up)) {
+				can_apply_constant_speed = false;
+				sliding_enabled = true;
+				Transform2D gt = get_global_transform();
+				gt.elements[2] = prev_position;
+				set_global_transform(gt);
+
+				Vector2 motion_slide_norm = motion.slide(prev_floor_normal).normalized();
+				if (!motion_slide_norm.is_equal_approx(Vector2())) {
+					motion = motion_slide_norm * (motion_slide_up.length());
+					found_collision = true;
+				}
+			}
 		}
+		can_apply_constant_speed = !can_apply_constant_speed && !sliding_enabled;
+		sliding_enabled = true;
+		first_slide = false;
 
-		if (!found_collision || motion == Vector2()) {
+		if (!found_collision || motion.is_equal_approx(Vector2())) {
 			break;
 		}
 	}
 
+	_snap_on_floor(was_on_floor, vel_dir_facing_up);
+
 	if (!on_floor && !on_wall) {
 		// Add last platform velocity when just left a moving platform.
-		linear_velocity += current_floor_velocity;
+		linear_velocity += current_platform_velocity;
 	}
 
-	if (!was_on_floor || snap == Vector2()) {
+	// Reset the gravity accumulation when touching the ground.
+	if (on_floor && !vel_dir_facing_up) {
+		linear_velocity = linear_velocity.slide(up_direction);
+	}
+}
+
+void CharacterBody2D::_snap_on_floor(bool was_on_floor, bool vel_dir_facing_up) {
+	if (Math::is_equal_approx(floor_snap_length, 0) || up_direction == Vector2() || on_floor || !was_on_floor || vel_dir_facing_up) {
 		return;
 	}
 
-	// Apply snap.
 	Transform2D gt = get_global_transform();
 	PhysicsServer2D::MotionResult result;
-	if (move_and_collide(snap, infinite_inertia, result, margin, false, true, false)) {
+	if (move_and_collide(up_direction * -floor_snap_length, infinite_inertia, result, margin, false, true, false)) {
 		bool apply = true;
-		if (up_direction != Vector2()) {
-			if (Math::acos(result.collision_normal.dot(up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) {
-				on_floor = true;
-				floor_normal = result.collision_normal;
-				on_floor_body = result.collider;
-				floor_velocity = result.collider_velocity;
-				if (stop_on_slope) {
-					// move and collide may stray the object a bit because of pre un-stucking,
-					// so only ensure that motion happens on floor direction in this case.
-					if (result.motion.length() > margin) {
-						result.motion = up_direction * up_direction.dot(result.motion);
-					} else {
-						result.motion = Vector2();
-					}
+		float collision_angle = Math::acos(result.collision_normal.dot(up_direction));
+		if (collision_angle <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) {
+			on_floor = true;
+			floor_normal = result.collision_normal;
+			platform_velocity = result.collider_velocity;
+			_set_platform_data(result);
+
+			if (stop_on_slope) {
+				// move and collide may stray the object a bit because of pre un-stucking,
+				// so only ensure that motion happens on floor direction in this case.
+				if (result.motion.length() > margin) {
+					result.motion = up_direction * up_direction.dot(result.motion);
+				} else {
+					result.motion = Vector2();
 				}
-			} else {
-				apply = false;
 			}
+		} else {
+			apply = false;
 		}
 
 		if (apply) {
@@ -1188,23 +1288,46 @@ void CharacterBody2D::move_and_slide() {
 	}
 }
 
+bool CharacterBody2D::_on_floor_if_snapped(bool was_on_floor, bool vel_dir_facing_up) {
+	if (Math::is_equal_approx(floor_snap_length, 0) || up_direction == Vector2() || on_floor || !was_on_floor || vel_dir_facing_up) {
+		return false;
+	}
+
+	PhysicsServer2D::MotionResult result;
+	if (move_and_collide(up_direction * -floor_snap_length, infinite_inertia, result, margin, false, true, false)) {
+		if (Math::acos(result.collision_normal.dot(up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) {
+			return true;
+		}
+	}
+
+	return false;
+}
+
 void CharacterBody2D::_set_collision_direction(const PhysicsServer2D::MotionResult &p_result) {
 	if (up_direction == Vector2()) {
-		//all is a wall
-		on_wall = true;
+		return;
+	}
+
+	if (Math::acos(p_result.collision_normal.dot(up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) { //floor
+		on_floor = true;
+		floor_normal = p_result.collision_normal;
+		platform_velocity = p_result.collider_velocity;
+		_set_platform_data(p_result);
+	} else if (Math::acos(p_result.collision_normal.dot(-up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) { //ceiling
+		on_ceiling = true;
 	} else {
-		if (Math::acos(p_result.collision_normal.dot(up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) { //floor
-			on_floor = true;
-			floor_normal = p_result.collision_normal;
-			on_floor_body = p_result.collider;
-			floor_velocity = p_result.collider_velocity;
-		} else if (Math::acos(p_result.collision_normal.dot(-up_direction)) <= floor_max_angle + FLOOR_ANGLE_THRESHOLD) { //ceiling
-			on_ceiling = true;
-		} else {
-			on_wall = true;
-			on_floor_body = p_result.collider;
-			floor_velocity = p_result.collider_velocity;
-		}
+		on_wall = true;
+		platform_velocity = p_result.collider_velocity;
+		_set_platform_data(p_result);
+	}
+}
+
+void CharacterBody2D::_set_platform_data(const PhysicsServer2D::MotionResult &p_result) {
+	platform_rid = p_result.collider;
+	platform_layer = 0;
+	CollisionObject2D *collision_object = Object::cast_to<CollisionObject2D>(ObjectDB::get_instance(p_result.collider_id));
+	if (collision_object) {
+		platform_layer = collision_object->get_collision_layer();
 	}
 }
 
@@ -1256,20 +1379,32 @@ bool CharacterBody2D::is_on_floor() const {
 	return on_floor;
 }
 
+bool CharacterBody2D::is_on_floor_only() const {
+	return on_floor && !on_wall && !on_ceiling;
+}
+
 bool CharacterBody2D::is_on_wall() const {
 	return on_wall;
 }
 
+bool CharacterBody2D::is_on_wall_only() const {
+	return on_wall && !on_floor && !on_ceiling;
+}
+
 bool CharacterBody2D::is_on_ceiling() const {
 	return on_ceiling;
 }
 
+bool CharacterBody2D::is_on_ceiling_only() const {
+	return on_ceiling && !on_floor && !on_wall;
+}
+
 Vector2 CharacterBody2D::get_floor_normal() const {
 	return floor_normal;
 }
 
-Vector2 CharacterBody2D::get_floor_velocity() const {
-	return floor_velocity;
+Vector2 CharacterBody2D::get_platform_velocity() const {
+	return platform_velocity;
 }
 
 int CharacterBody2D::get_slide_count() const {
@@ -1319,6 +1454,35 @@ void CharacterBody2D::set_infinite_inertia_enabled(bool p_enabled) {
 	infinite_inertia = p_enabled;
 }
 
+bool CharacterBody2D::is_constant_speed_on_floor_enabled() const {
+	return constant_speed_on_floor;
+}
+void CharacterBody2D::set_constant_speed_on_floor_enabled(bool p_enabled) {
+	constant_speed_on_floor = p_enabled;
+}
+
+bool CharacterBody2D::is_move_on_floor_only_enabled() const {
+	return move_on_floor_only;
+}
+void CharacterBody2D::set_move_on_floor_only_enabled(bool p_enabled) {
+	move_on_floor_only = p_enabled;
+}
+
+bool CharacterBody2D::is_slide_on_ceiling_enabled() const {
+	return slide_on_ceiling;
+}
+void CharacterBody2D::set_slide_on_ceiling_enabled(bool p_enabled) {
+	slide_on_ceiling = p_enabled;
+}
+
+uint32_t CharacterBody2D::get_exclude_body_layers() const {
+	return exclude_body_layers;
+}
+
+void CharacterBody2D::set_exclude_body_layers(uint32_t p_exclude_layers) {
+	exclude_body_layers = p_exclude_layers;
+}
+
 int CharacterBody2D::get_max_slides() const {
 	return max_slides;
 }
@@ -1336,12 +1500,13 @@ void CharacterBody2D::set_floor_max_angle(real_t p_radians) {
 	floor_max_angle = p_radians;
 }
 
-const Vector2 &CharacterBody2D::get_snap() const {
-	return snap;
+real_t CharacterBody2D::get_floor_snap_length() {
+	return floor_snap_length;
 }
 
-void CharacterBody2D::set_snap(const Vector2 &p_snap) {
-	snap = p_snap;
+void CharacterBody2D::set_floor_snap_length(real_t p_floor_snap_length) {
+	ERR_FAIL_COND(p_floor_snap_length < 0);
+	floor_snap_length = p_floor_snap_length;
 }
 
 const Vector2 &CharacterBody2D::get_up_direction() const {
@@ -1357,11 +1522,11 @@ void CharacterBody2D::_notification(int p_what) {
 		case NOTIFICATION_ENTER_TREE: {
 			// Reset move_and_slide() data.
 			on_floor = false;
-			on_floor_body = RID();
+			platform_rid = RID();
 			on_ceiling = false;
 			on_wall = false;
 			motion_results.clear();
-			floor_velocity = Vector2();
+			platform_velocity = Vector2();
 		} break;
 	}
 }
@@ -1377,31 +1542,48 @@ void CharacterBody2D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("is_stop_on_slope_enabled"), &CharacterBody2D::is_stop_on_slope_enabled);
 	ClassDB::bind_method(D_METHOD("set_stop_on_slope_enabled", "enabled"), &CharacterBody2D::set_stop_on_slope_enabled);
 	ClassDB::bind_method(D_METHOD("is_infinite_inertia_enabled"), &CharacterBody2D::is_infinite_inertia_enabled);
+	ClassDB::bind_method(D_METHOD("set_constant_speed_on_floor_enabled", "enabled"), &CharacterBody2D::set_constant_speed_on_floor_enabled);
+	ClassDB::bind_method(D_METHOD("is_constant_speed_on_floor_enabled"), &CharacterBody2D::is_constant_speed_on_floor_enabled);
+	ClassDB::bind_method(D_METHOD("set_move_on_floor_only_enabled", "enabled"), &CharacterBody2D::set_move_on_floor_only_enabled);
+	ClassDB::bind_method(D_METHOD("is_move_on_floor_only_enabled"), &CharacterBody2D::is_move_on_floor_only_enabled);
+	ClassDB::bind_method(D_METHOD("set_slide_on_ceiling_enabled", "enabled"), &CharacterBody2D::set_slide_on_ceiling_enabled);
+	ClassDB::bind_method(D_METHOD("is_slide_on_ceiling_enabled"), &CharacterBody2D::is_slide_on_ceiling_enabled);
+
+	ClassDB::bind_method(D_METHOD("set_exclude_body_layers", "exclude_layer"), &CharacterBody2D::set_exclude_body_layers);
+	ClassDB::bind_method(D_METHOD("get_exclude_body_layers"), &CharacterBody2D::get_exclude_body_layers);
+
 	ClassDB::bind_method(D_METHOD("set_infinite_inertia_enabled", "enabled"), &CharacterBody2D::set_infinite_inertia_enabled);
 	ClassDB::bind_method(D_METHOD("get_max_slides"), &CharacterBody2D::get_max_slides);
 	ClassDB::bind_method(D_METHOD("set_max_slides", "max_slides"), &CharacterBody2D::set_max_slides);
 	ClassDB::bind_method(D_METHOD("get_floor_max_angle"), &CharacterBody2D::get_floor_max_angle);
 	ClassDB::bind_method(D_METHOD("set_floor_max_angle", "radians"), &CharacterBody2D::set_floor_max_angle);
-	ClassDB::bind_method(D_METHOD("get_snap"), &CharacterBody2D::get_snap);
-	ClassDB::bind_method(D_METHOD("set_snap", "snap"), &CharacterBody2D::set_snap);
+	ClassDB::bind_method(D_METHOD("get_floor_snap_length"), &CharacterBody2D::get_floor_snap_length);
+	ClassDB::bind_method(D_METHOD("set_floor_snap_length", "floor_snap_length"), &CharacterBody2D::set_floor_snap_length);
 	ClassDB::bind_method(D_METHOD("get_up_direction"), &CharacterBody2D::get_up_direction);
 	ClassDB::bind_method(D_METHOD("set_up_direction", "up_direction"), &CharacterBody2D::set_up_direction);
 
 	ClassDB::bind_method(D_METHOD("is_on_floor"), &CharacterBody2D::is_on_floor);
+	ClassDB::bind_method(D_METHOD("is_on_floor_only"), &CharacterBody2D::is_on_floor_only);
 	ClassDB::bind_method(D_METHOD("is_on_ceiling"), &CharacterBody2D::is_on_ceiling);
+	ClassDB::bind_method(D_METHOD("is_on_ceiling_only"), &CharacterBody2D::is_on_ceiling_only);
 	ClassDB::bind_method(D_METHOD("is_on_wall"), &CharacterBody2D::is_on_wall);
+	ClassDB::bind_method(D_METHOD("is_on_wall_only"), &CharacterBody2D::is_on_wall_only);
 	ClassDB::bind_method(D_METHOD("get_floor_normal"), &CharacterBody2D::get_floor_normal);
-	ClassDB::bind_method(D_METHOD("get_floor_velocity"), &CharacterBody2D::get_floor_velocity);
+	ClassDB::bind_method(D_METHOD("get_platform_velocity"), &CharacterBody2D::get_platform_velocity);
 	ClassDB::bind_method(D_METHOD("get_slide_count"), &CharacterBody2D::get_slide_count);
 	ClassDB::bind_method(D_METHOD("get_slide_collision", "slide_idx"), &CharacterBody2D::_get_slide_collision);
 
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "linear_velocity"), "set_linear_velocity", "get_linear_velocity");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "stop_on_slope"), "set_stop_on_slope_enabled", "is_stop_on_slope_enabled");
 	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "infinite_inertia"), "set_infinite_inertia_enabled", "is_infinite_inertia_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "constant_speed_on_floor"), "set_constant_speed_on_floor_enabled", "is_constant_speed_on_floor_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "move_on_floor_only"), "set_move_on_floor_only_enabled", "is_move_on_floor_only_enabled");
+	ADD_PROPERTY(PropertyInfo(Variant::BOOL, "slide_on_ceiling"), "set_slide_on_ceiling_enabled", "is_slide_on_ceiling_enabled");
 	ADD_PROPERTY(PropertyInfo(Variant::INT, "max_slides", PROPERTY_HINT_RANGE, "1,8,1,or_greater"), "set_max_slides", "get_max_slides");
-	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_max_angle", PROPERTY_HINT_RANGE, "0,180,0.1"), "set_floor_max_angle", "get_floor_max_angle");
-	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "snap"), "set_snap", "get_snap");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_max_angle", PROPERTY_HINT_RANGE, "0,180,0.1,radians"), "set_floor_max_angle", "get_floor_max_angle");
+	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "floor_snap_length", PROPERTY_HINT_RANGE, "0,1000,0.1"), "set_floor_snap_length", "get_floor_snap_length");
 	ADD_PROPERTY(PropertyInfo(Variant::VECTOR2, "up_direction"), "set_up_direction", "get_up_direction");
+	ADD_PROPERTY(PropertyInfo(Variant::INT, "exclude_body_layers", PROPERTY_HINT_LAYERS_2D_PHYSICS), "set_exclude_body_layers", "get_exclude_body_layers");
 
 	ADD_PROPERTY(PropertyInfo(Variant::FLOAT, "collision/safe_margin", PROPERTY_HINT_RANGE, "0.001,256,0.001"), "set_safe_margin", "get_safe_margin");
 }
diff --git a/scene/2d/physics_body_2d.h b/scene/2d/physics_body_2d.h
index c20372fe75..00948b4344 100644
--- a/scene/2d/physics_body_2d.h
+++ b/scene/2d/physics_body_2d.h
@@ -273,16 +273,20 @@ private:
 
 	bool stop_on_slope = false;
 	bool infinite_inertia = true;
+	bool constant_speed_on_floor = false;
+	bool move_on_floor_only = true;
+	bool slide_on_ceiling = true;
 	int max_slides = 4;
+	int platform_layer;
 	real_t floor_max_angle = Math::deg2rad((real_t)45.0);
-	Vector2 snap;
+	float floor_snap_length = 0;
 	Vector2 up_direction = Vector2(0.0, -1.0);
-
+	uint32_t exclude_body_layers = 0;
 	Vector2 linear_velocity;
 
 	Vector2 floor_normal;
-	Vector2 floor_velocity;
-	RID on_floor_body;
+	Vector2 platform_velocity;
+	RID platform_rid;
 	bool on_floor = false;
 	bool on_ceiling = false;
 	bool on_wall = false;
@@ -290,10 +294,6 @@ private:
 	Vector<PhysicsServer2D::MotionResult> motion_results;
 	Vector<Ref<KinematicCollision2D>> slide_colliders;
 
-	Ref<KinematicCollision2D> _get_slide_collision(int p_bounce);
-
-	void _set_collision_direction(const PhysicsServer2D::MotionResult &p_result);
-
 	bool separate_raycast_shapes(PhysicsServer2D::MotionResult &r_result);
 
 	void set_safe_margin(real_t p_margin);
@@ -305,17 +305,37 @@ private:
 	bool is_infinite_inertia_enabled() const;
 	void set_infinite_inertia_enabled(bool p_enabled);
 
+	bool is_constant_speed_on_floor_enabled() const;
+	void set_constant_speed_on_floor_enabled(bool p_enabled);
+
+	bool is_move_on_floor_only_enabled() const;
+	void set_move_on_floor_only_enabled(bool p_enabled);
+
+	bool is_slide_on_ceiling_enabled() const;
+	void set_slide_on_ceiling_enabled(bool p_enabled);
+
 	int get_max_slides() const;
 	void set_max_slides(int p_max_slides);
 
+	real_t get_move_max_angle() const;
+	void set_move_max_angle(real_t p_radians);
+
 	real_t get_floor_max_angle() const;
 	void set_floor_max_angle(real_t p_radians);
 
-	const Vector2 &get_snap() const;
-	void set_snap(const Vector2 &p_snap);
+	real_t get_floor_snap_length();
+	void set_floor_snap_length(real_t p_floor_snap_length);
 
+	uint32_t get_exclude_body_layers() const;
+	void set_exclude_body_layers(const uint32_t p_exclude_layer);
+
+	Ref<KinematicCollision2D> _get_slide_collision(int p_bounce);
 	const Vector2 &get_up_direction() const;
+	bool _on_floor_if_snapped(bool was_on_floor, bool vel_dir_facing_up);
 	void set_up_direction(const Vector2 &p_up_direction);
+	void _set_collision_direction(const PhysicsServer2D::MotionResult &p_result);
+	void _set_platform_data(const PhysicsServer2D::MotionResult &p_result);
+	void _snap_on_floor(bool was_on_floor, bool vel_dir_facing_up);
 
 protected:
 	void _notification(int p_what);
@@ -328,10 +348,13 @@ public:
 	void set_linear_velocity(const Vector2 &p_velocity);
 
 	bool is_on_floor() const;
+	bool is_on_floor_only() const;
 	bool is_on_wall() const;
+	bool is_on_wall_only() const;
 	bool is_on_ceiling() const;
+	bool is_on_ceiling_only() const;
 	Vector2 get_floor_normal() const;
-	Vector2 get_floor_velocity() const;
+	Vector2 get_platform_velocity() const;
 
 	int get_slide_count() const;
 	PhysicsServer2D::MotionResult get_slide_collision(int p_bounce) const;