synergine2/synergine2_cocos2d/gui.py

# coding: utf-8
import typing
import weakref
from math import floor

import pyglet
from pyglet.window import key
from pyglet.window import mouse

import cocos
from cocos import collision_model
from cocos import euclid
from cocos.layer import ScrollableLayer
from synergine2.config import Config
from synergine2.log import SynergineLogger
from synergine2.terminals import Terminal
from synergine2.terminals import TerminalPackage
from synergine2_cocos2d.actions import MoveTo
from synergine2_cocos2d.actor import Actor
from synergine2_cocos2d.animation import Animate
from synergine2_cocos2d.animation import ANIMATION_WALK
from synergine2_cocos2d.exception import InteractionNotFound
from synergine2_cocos2d.exception import OuterWorldPosition
from synergine2_cocos2d.gl import draw_rectangle
from synergine2_cocos2d.gl import rectangle_positions_type
from synergine2_cocos2d.interaction import InteractionManager
from synergine2_cocos2d.layer import LayerManager
from synergine2_cocos2d.middleware import MapMiddleware
from synergine2_cocos2d.middleware import TMXMiddleware
from synergine2_cocos2d.user_action import UserAction
from synergine2_xyz.move import FinishMoveEvent
from synergine2_xyz.move import StartMoveEvent
from synergine2_xyz.utils import get_angle
from synergine2_xyz.xyz import XYZSubjectMixin


class GridManager(object):
    def __init__(
        self,
        cell_width: int,
        cell_height: int,
        world_width: int,
        world_height: int,
    ) -> None:
        self.cell_width = cell_width
        self.cell_height = cell_height
        self.world_width = world_width
        self.world_height = world_height

    def get_grid_position(self, pixel_position: typing.Tuple[int, int]) -> typing.Tuple[int, int]:
        pixel_x, pixel_y = pixel_position

        cell_x = int(floor(pixel_x / self.cell_width))
        cell_y = int(floor(pixel_y / self.cell_height))

        if cell_x > self.world_width or cell_y > self.world_height or cell_x < 0 or cell_y < 0:
            raise OuterWorldPosition('Position "{}" is outer world ({}x{})'.format(
                (cell_x, cell_y),
                self.world_width,
                self.world_height,
            ))

        return cell_x, cell_y

    def get_pixel_position_of_grid_position(self, grid_position: typing.Tuple[int, int]) -> typing.Tuple[int, int]:
        return grid_position[0] * self.cell_width + (self.cell_width // 2),\
               grid_position[1] * self.cell_height + (self.cell_height // 2)

    def get_rectangle_positions(
        self,
        grid_position: typing.Tuple[int, int],
    ) -> rectangle_positions_type:
        """
        A<---D
        |    |
        B--->C
        :param grid_position:grid position to exploit
        :return: grid pixel corners positions
        """
        grid_x, grid_y = grid_position

        a = grid_x * self.cell_width, grid_y * self.cell_height + self.cell_height
        b = grid_x * self.cell_width, grid_y * self.cell_height
        c = grid_x * self.cell_width + self.cell_width, grid_y * self.cell_height
        d = grid_x * self.cell_width + self.cell_width, grid_y * self.cell_height + self.cell_height

        return a, d, c, b


class MinMaxRect(cocos.cocosnode.CocosNode):
    def __init__(self, layer_manager: LayerManager):
        super(MinMaxRect, self).__init__()
        self.layer_manager = layer_manager
        self.color3 = (20, 20, 20)
        self.color3f = (0, 0, 0, 0.2)
        self.vertexes = [(0.0, 0.0), (0.0, 0.0), (0.0, 0.0), (0.0, 0.0)]
        self.visible = False

    def adjust_from_w_minmax(self, wminx, wmaxx, wminy, wmaxy):
        # asumes world to screen preserves order
        sminx, sminy = self.layer_manager.scrolling_manager.world_to_screen(wminx, wminy)
        smaxx, smaxy = self.layer_manager.scrolling_manager.world_to_screen(wmaxx, wmaxy)
        self.vertexes = [(sminx, sminy), (sminx, smaxy), (smaxx, smaxy), (smaxx, sminy)]

    def draw(self):
        if not self.visible:
            return

        draw_rectangle(
            self.vertexes,
            self.color3,
            self.color3f,
        )

    def set_vertexes_from_minmax(self, minx, maxx, miny, maxy):
        self.vertexes = [(minx, miny), (minx, maxy), (maxx, maxy), (maxx, miny)]


class EditLayer(cocos.layer.Layer):
    is_event_handler = True

    def __init__(
        self,
        config: Config,
        logger: SynergineLogger,
        layer_manager: LayerManager,
        grid_manager: GridManager,
        worldview,
        bindings=None,
        fastness=None,
        autoscroll_border=10,
        autoscroll_fastness=None,
        wheel_multiplier=None,
        zoom_min=None,
        zoom_max=None,
        zoom_fastness=None,
        mod_modify_selection=None,
        mod_restricted_mov=None,
    ):
        # TODO: Clean init params
        super(EditLayer, self).__init__()

        self.config = config
        self.logger = logger
        self.layer_manager = layer_manager
        self.grid_manager = grid_manager

        self.bindings = bindings
        buttons = {}
        modifiers = {}
        for k in bindings:
            buttons[bindings[k]] = 0
            modifiers[bindings[k]] = 0
        self.buttons = buttons
        self.modifiers = modifiers

        self.fastness = fastness
        self.autoscroll_border = autoscroll_border
        self.autoscroll_fastness = autoscroll_fastness
        self.wheel_multiplier = wheel_multiplier
        self.zoom_min = zoom_min
        self.zoom_max = zoom_max
        self.zoom_fastness = zoom_fastness
        self.mod_modify_selection = mod_modify_selection
        self.mod_restricted_mov = mod_restricted_mov

        self.weak_scroller = weakref.ref(self.layer_manager.scrolling_manager)
        self.weak_worldview = weakref.ref(worldview)
        self.wwidth = worldview.width
        self.wheight = worldview.height

        self.autoscrolling = False
        self.drag_selecting = False
        self.drag_moving = False
        self.restricted_mov = False
        self.wheel = 0
        self.dragging = False
        self.keyscrolling = False
        self.keyscrolling_descriptor = (0, 0)
        self.wdrag_start_point = (0, 0)
        self.elastic_box = None  # type: MinMaxRect
        self.elastic_box_wminmax = 0, 0, 0, 0
        self.selection = {}
        self.screen_mouse = (0, 0)
        self.world_mouse = (0, 0)
        self.sleft = None
        self.sright = None
        self.sbottom = None
        self.s_top = None
        self.user_action_pending = None  # UserAction

        # opers that change cshape must ensure it goes to False,
        # selection opers must ensure it goes to True
        self.selection_in_collman = True
        # TODO: Hardcoded here, should be obtained from level properties or calc
        # from available actors or current actors in worldview
        gsize = 32 * 1.25
        self.collision_manager = collision_model.CollisionManagerGrid(
            -gsize,
            self.wwidth + gsize,
            -gsize,
            self.wheight + gsize,
            gsize,
            gsize,
        )

        self.schedule(self.update)
        self.selectable_actors = []

    def set_selectable(self, actor: Actor) -> None:
        self.selectable_actors.append(actor)
        self.collision_manager.add(actor)

    def unset_selectable(self, actor: Actor) -> None:
        self.selectable_actors.remove(actor)
        self.collision_manager.remove_tricky(actor)

    def draw(self, *args, **kwargs) -> None:
        self.draw_update_cshapes()
        self.draw_selection()
        self.draw_interactions()

    def draw_update_cshapes(self) -> None:
        for actor in self.selectable_actors:
            if actor.need_update_cshape:
                if self.collision_manager.knows(actor):
                    self.collision_manager.remove_tricky(actor)
                    actor.update_cshape()
                    self.collision_manager.add(actor)

    def draw_selection(self) -> None:
        for actor, cshape in self.selection.items():
            grid_position = self.grid_manager.get_grid_position(actor.position)
            rect_positions = self.grid_manager.get_rectangle_positions(grid_position)

            draw_rectangle(
                self.layer_manager.scrolling_manager.world_to_screen_positions(rect_positions),
                (0, 81, 211),
            )

    def draw_interactions(self) -> None:
        if self.user_action_pending:
            try:
                interaction = self.layer_manager.interaction_manager.get_for_user_action(self.user_action_pending)
                interaction.draw_pending()
            except InteractionNotFound:
                pass

    def on_enter(self):
        super(EditLayer, self).on_enter()
        scene = self.get_ancestor(cocos.scene.Scene)
        if self.elastic_box is None:
            self.elastic_box = MinMaxRect(self.layer_manager)
            scene.add(self.elastic_box, z=10)

    def update(self, dt):
        mx = self.buttons['right'] - self.buttons['left']
        my = self.buttons['up'] - self.buttons['down']
        dz = self.buttons['zoomin'] - self.buttons['zoomout']

        # scroll
        if self.autoscrolling:
            self.update_autoscroll(dt)
        else:
            # care for keyscrolling
            new_keyscrolling = ((len(self.selection) == 0) and
                                (mx != 0 or my != 0))
            new_keyscrolling_descriptor = (mx, my)
            if ((new_keyscrolling != self.keyscrolling) or
                (new_keyscrolling_descriptor != self.keyscrolling_descriptor)):
                self.keyscrolling = new_keyscrolling
                self.keyscrolling_descriptor = new_keyscrolling_descriptor
                fastness = 1.0
                if mx != 0 and my != 0:
                    fastness *= 0.707106  # 1/sqrt(2)
                self.autoscrolling_sdelta = (0.5 * fastness * mx, 0.5 * fastness * my)
            if self.keyscrolling:
                self.update_autoscroll(dt)

        # selection move
        if self.drag_moving:
            # update positions
            wx, wy = self.world_mouse
            dx = wx - self.wdrag_start_point[0]
            dy = wy - self.wdrag_start_point[1]
            if self.restricted_mov:
                if abs(dy) > abs(dx):
                    dx = 0
                else:
                    dy = 0
            dpos = euclid.Vector2(dx, dy)
            for actor in self.selection:
                old_pos = self.selection[actor].center
                new_pos = old_pos + dpos

                try:
                    grid_pos = self.grid_manager.get_grid_position(new_pos)
                    grid_pixel_pos = self.grid_manager.get_pixel_position_of_grid_position(grid_pos)
                    actor.update_position(grid_pixel_pos)
                except OuterWorldPosition:
                    # don't update position
                    pass

        scroller = self.weak_scroller()

        # zoom
        zoom_change = (dz != 0 or self.wheel != 0)
        if zoom_change:
            if self.mouse_into_world():
                wzoom_center = self.world_mouse
                szoom_center = self.screen_mouse
            else:
                # decay to scroller unadorned
                wzoom_center = None
            if self.wheel != 0:
                dt_dz = 0.01666666 * self.wheel
                self.wheel = 0
            else:
                dt_dz = dt * dz
            zoom = scroller.scale + dt_dz * self.zoom_fastness
            if zoom < self.zoom_min:
                zoom = self.zoom_min
            elif zoom > self.zoom_max:
                zoom = self.zoom_max
            scroller.scale = zoom
            if wzoom_center is not None:
                # postprocess toward 'world point under mouse the same before
                # and after zoom' ; other restrictions may prevent fully comply
                wx1, wy1 = self.layer_manager.scrolling_manager.screen_to_world(*szoom_center)
                fx = scroller.restricted_fx + (wzoom_center[0] - wx1)
                fy = scroller.restricted_fy + (wzoom_center[1] - wy1)
                scroller.set_focus(fx, fy)

    def update_mouse_position(self, sx, sy):
        self.screen_mouse = sx, sy
        self.world_mouse = self.layer_manager.scrolling_manager.screen_to_world(sx, sy)
        # handle autoscroll
        border = self.autoscroll_border
        if border is not None:
            # sleft and companions includes the border
            scroller = self.weak_scroller()
            self.update_view_bounds()
            sdx = 0.0
            if sx < self.sleft:
                sdx = sx - self.sleft
            elif sx > self.sright:
                sdx = sx - self.sright
            sdy = 0.0
            if sy < self.sbottom:
                sdy = sy - self.sbottom
            elif sy > self.s_top:
                sdy = sy - self.s_top
            self.autoscrolling = sdx != 0.0 or sdy != 0.0
            if self.autoscrolling:
                self.autoscrolling_sdelta = (sdx / border, sdy / border)

    def update_autoscroll(self, dt):
        fraction_sdx, fraction_sdy = self.autoscrolling_sdelta
        scroller = self.weak_scroller()
        worldview = self.weak_worldview()
        f = self.autoscroll_fastness
        wdx = (fraction_sdx * f * dt) / scroller.scale / worldview.scale
        wdy = (fraction_sdy * f * dt) / scroller.scale / worldview.scale
        # ask scroller to try scroll (wdx, wdy)
        fx = scroller.restricted_fx + wdx
        fy = scroller.restricted_fy + wdy
        scroller.set_focus(fx, fy)
        self.world_mouse = self.layer_manager.scrolling_manager.screen_to_world(*self.screen_mouse)
        self.adjust_elastic_box()
        # self.update_view_bounds()

    def update_view_bounds(self):
        scroller = self.weak_scroller()
        scx, scy = self.layer_manager.scrolling_manager.world_to_screen(
            scroller.restricted_fx,
            scroller.restricted_fy,
        )
        hw = scroller.view_w / 2.0
        hh = scroller.view_h / 2.0
        border = self.autoscroll_border
        self.sleft = scx - hw + border
        self.sright = scx + hw - border
        self.sbottom = scy - hh + border
        self.s_top = scy + hh - border

    def mouse_into_world(self):
        worldview = self.weak_worldview()
        # TODO: allow lower limits != 0 ?
        return ((0 <= self.world_mouse[0] <= worldview.width) and
               (0 <= self.world_mouse[1] <= worldview.height))

    def on_key_press(self, k, m):
        binds = self.bindings

        # TODO: Clarify code
        # Actions available if actor selected
        if self.selection:
            if k == key.M:
                self.user_action_pending = UserAction.ORDER_MOVE

        if k in binds:
            self.buttons[binds[k]] = 1
            self.modifiers[binds[k]] = 1
            return True
        return False

    def on_key_release(self, k, m):
        binds = self.bindings
        if k in binds:
            self.buttons[binds[k]] = 0
            self.modifiers[binds[k]] = 0
            return True
        return False

    def on_mouse_motion(self, sx, sy, dx, dy):
        self.update_mouse_position(sx, sy)

    def on_mouse_leave(self, sx, sy):
        self.autoscrolling = False

    def on_mouse_press(self, x, y, buttons, modifiers):
        rx, ry = self.layer_manager.scrolling_manager.screen_to_world(x, y)
        self.logger.info(
            'GUI click: x: {}, y: {}, rx: {}, ry: {} ({}|{})'.format(x, y, rx, ry, buttons, modifiers)
        )

        if mouse.LEFT:
            # Non action pending case
            if not self.user_action_pending:
                actor = self.single_actor_from_mouse()
                if actor:
                    self.selection.clear()
                    self.selection_add(actor)
            # Action pending case
            else:
                try:
                    interaction = self.layer_manager.interaction_manager.get_for_user_action(self.user_action_pending)
                    interaction.execute()
                except InteractionNotFound:
                    pass

        if mouse.RIGHT:
            if self.user_action_pending:
                self.user_action_pending = None

    def on_mouse_release(self, sx, sy, button, modifiers):
        # should we handle here mod_restricted_mov ?
        wx, wy = self.layer_manager.scrolling_manager.screen_to_world(sx, sy)
        modify_selection = modifiers & self.mod_modify_selection
        if self.dragging:
            # ignore all buttons except left button
            if button != mouse.LEFT:
                return
            if self.drag_selecting:
                self.end_drag_selection(wx, wy, modify_selection)
            elif self.drag_moving:
                self.end_drag_move(wx, wy)
            self.dragging = False
        else:
            if button == mouse.LEFT:
                self.end_click_selection(wx, wy, modify_selection)

    def end_click_selection(self, wx, wy, modify_selection):
        under_mouse_unique = self.single_actor_from_mouse()
        if modify_selection:
            # toggle selected status for unique
            if under_mouse_unique in self.selection:
                self.selection_remove(under_mouse_unique)
            elif under_mouse_unique is not None:
                self.selection_add(under_mouse_unique)
        else:
            # new_selected becomes the current selected
            self.selection.clear()
            self.user_action_pending = None
            if under_mouse_unique is not None:
                self.selection_add(under_mouse_unique)

    def selection_add(self, actor):
        self.selection[actor] = actor.cshape.copy()

    def selection_remove(self, actor):
        del self.selection[actor]

    def end_drag_selection(self, wx, wy, modify_selection):
        new_selection = self.collision_manager.objs_into_box(*self.elastic_box_wminmax)
        if not modify_selection:
            # new_selected becomes the current selected
            self.selection.clear()
        for actor in new_selection:
            self.selection_add(actor)

        self.elastic_box.visible = False
        self.drag_selecting = False

    def on_mouse_drag(self, sx, sy, dx, dy, buttons, modifiers):
        # TODO: inhibir esta llamada si estamos fuera de la client area / viewport
        self.update_mouse_position(sx, sy)
        if not buttons & mouse.LEFT:
            # ignore except for left-btn-drag
            return

        if not self.dragging:
            print("begin drag")
            self.begin_drag()
            return

        if self.drag_selecting:
            # update elastic box
            self.adjust_elastic_box()
        elif self.drag_moving:
            self.restricted_mov = (modifiers & self.mod_restricted_mov)

    def adjust_elastic_box(self):
        # when elastic_box visible this method needs to be called any time
        # world_mouse changes or screen_to_world results changes (scroll, etc)
        wx0, wy0 = self.wdrag_start_point
        wx1, wy1 = self.world_mouse
        wminx = min(wx0, wx1)
        wmaxx = max(wx0, wx1)
        wminy = min(wy0, wy1)
        wmaxy = max(wy0, wy1)
        self.elastic_box_wminmax = wminx, wmaxx, wminy, wmaxy
        self.elastic_box.adjust_from_w_minmax(*self.elastic_box_wminmax)

    def begin_drag(self):
        self.dragging = True
        self.wdrag_start_point = self.world_mouse
        under_mouse_unique = self.single_actor_from_mouse()
        if under_mouse_unique is None:
            # begin drag selection
            self.drag_selecting = True
            self.adjust_elastic_box()
            self.elastic_box.visible = True
            print("begin drag selection: drag_selecting, drag_moving",
                  self.drag_selecting, self.drag_moving)

        else:
            # want drag move
            if under_mouse_unique in self.selection:
                # want to move current selection
                pass
            else:
                # change selection before moving
                self.selection.clear()
                self.selection_add(under_mouse_unique)
            self.begin_drag_move()

    def begin_drag_move(self):
        # begin drag move
        self.drag_moving = True

        # how-to update collman: remove/add vs clear/add all
        # when total number of actors is low anyone will be fine,
        # with high numbers, most probably we move only a small fraction
        # For simplicity I choose remove/add, albeit a hybrid aproach
        # can be implemented later
        self.set_selection_in_collman(False)
#        print "begin drag: drag_selecting, drag_moving", self.drag_selecting, self.drag_moving

    def end_drag_move(self, wx, wy):
        self.set_selection_in_collman(True)
        for actor in self.selection:
            self.selection[actor] = actor.cshape.copy()

        self.drag_moving = False

    def single_actor_from_mouse(self):
        under_mouse = self.collision_manager.objs_touching_point(*self.world_mouse)
        if len(under_mouse) == 0:
            return None
        # return the one with the center most near to mouse, if tie then
        # an arbitrary in the tie
        nearest = None
        near_d = None
        p = euclid.Vector2(*self.world_mouse)
        for actor in under_mouse:
            d = (actor.cshape.center - p).magnitude_squared()
            if nearest is None or (d < near_d):
                nearest = actor
                near_d = d
        return nearest

    def set_selection_in_collman(self, bool_value):
        if self.selection_in_collman == bool_value:
            return
        self.selection_in_collman = bool_value
        if bool_value:
            for actor in self.selection:
                self.collision_manager.add(actor)
        else:
            for actor in self.selection:
                self.collision_manager.remove_tricky(actor)

    def on_mouse_scroll(self, x, y, scroll_x, scroll_y):
        # TODO: check if mouse over scroller viewport?
        self.wheel += scroll_y * self.wheel_multiplier


class MainLayer(ScrollableLayer):
    is_event_handler = True

    def __init__(
        self,
        layer_manager: LayerManager,
        grid_manager: GridManager,
        width: int,
        height: int,
        scroll_step: int=100,
    ) -> None:
        super().__init__()
        self.layer_manager = layer_manager
        self.scroll_step = scroll_step
        self.grid_manager = grid_manager

        self.width = width
        self.height = height
        self.px_width = width
        self.px_height = height


class SubjectMapper(object):
    def __init__(
        self,
        actor_class: typing.Type[Actor],
    ) -> None:
        self.actor_class = actor_class

    def append(
        self,
        subject: XYZSubjectMixin,
        layer_manager: LayerManager,
    ) -> None:
        actor = self.actor_class(subject)
        pixel_position = layer_manager.grid_manager.get_pixel_position_of_grid_position(
            (subject.position[0], subject.position[1]),
        )
        actor.update_position(euclid.Vector2(*pixel_position))

        # TODO: Selectable nature must be configurable
        layer_manager.add_subject(actor)
        layer_manager.set_selectable(actor)


class SubjectMapperFactory(object):
    def __init__(self) -> None:
        self.mapping = {}  # type: typing.Dict[typing.Type[XYZSubjectMixin], SubjectMapper]

    def register_mapper(self, subject_class: typing.Type[XYZSubjectMixin], mapper: SubjectMapper) -> None:
        if subject_class not in self.mapping:
            self.mapping[subject_class] = mapper
        else:
            raise ValueError('subject_class already register with "{}"'.format(str(self.mapping[subject_class])))

    def get_subject_mapper(self, subject: XYZSubjectMixin) -> SubjectMapper:
        for subject_class, mapper in self.mapping.items():
            if isinstance(subject, subject_class):
                return mapper
        raise KeyError('No mapper for subject "{}"'.format(str(subject)))


class Gui(object):
    def __init__(
            self,
            config: Config,
            logger: SynergineLogger,
            terminal: Terminal,
            read_queue_interval: float= 1/60.0,
    ):
        self.config = config
        self.logger = logger
        self._read_queue_interval = read_queue_interval
        self.terminal = terminal
        self.cycle_duration = self.config.resolve('core.cycle_duration')

        cocos.director.director.init(
            width=640,
            height=480,
            vsync=True,
            resizable=True,
        )

        self.interaction_manager = InteractionManager(
            config=self.config,
            logger=self.logger,
            terminal=self.terminal,
        )
        self.layer_manager = LayerManager(
            self.config,
            self.logger,
            middleware=self.get_layer_middleware(),
            interaction_manager=self.interaction_manager,
        )
        self.layer_manager.init()
        self.layer_manager.center()

        # Enable blending
        pyglet.gl.glEnable(pyglet.gl.GL_BLEND)
        pyglet.gl.glBlendFunc(pyglet.gl.GL_SRC_ALPHA, pyglet.gl.GL_ONE_MINUS_SRC_ALPHA)

        # Enable transparency
        pyglet.gl.glEnable(pyglet.gl.GL_ALPHA_TEST)
        pyglet.gl.glAlphaFunc(pyglet.gl.GL_GREATER, .1)

        self.subject_mapper_factory = SubjectMapperFactory()

    def get_layer_middleware(self) -> MapMiddleware:
        raise NotImplementedError()

    def run(self):
        self.before_run()
        pyglet.clock.schedule_interval(
            lambda *_, **__: self.terminal.read(),
            self._read_queue_interval,
        )
        cocos.director.director.run(self.get_main_scene())

    def before_run(self) -> None:
        pass

    def get_main_scene(self) -> cocos.cocosnode.CocosNode:
        raise NotImplementedError()

    def before_received(self, package: TerminalPackage):
        pass

    def after_received(self, package: TerminalPackage):
        pass


class TMXGui(Gui):
    def __init__(
        self,
        config: Config,
        logger: SynergineLogger,
        terminal: Terminal,
        read_queue_interval: float = 1 / 60.0,
        map_dir_path: str=None,
    ):
        assert map_dir_path
        self.map_dir_path = map_dir_path
        super(TMXGui, self).__init__(
            config,
            logger,
            terminal,
            read_queue_interval,
        )

        self.terminal.register_event_handler(
            FinishMoveEvent,
            self.set_subject_position,
        )

        self.terminal.register_event_handler(
            StartMoveEvent,
            self.start_move_subject,
        )

        # configs
        self.move_duration_ref = float(self.config.resolve('game.move.walk_ref_time'))

    def get_layer_middleware(self) -> MapMiddleware:
        return TMXMiddleware(
            self.config,
            self.logger,
            self.map_dir_path,
        )

    def get_main_scene(self) -> cocos.cocosnode.CocosNode:
        return self.layer_manager.main_scene

    def before_received(self, package: TerminalPackage):
        super().before_received(package)
        if package.subjects:  # They are new subjects in the simulation
            for subject in package.subjects:
                self.append_subject(subject)

    def append_subject(self, subject: XYZSubjectMixin) -> None:
        subject_mapper = self.subject_mapper_factory.get_subject_mapper(subject)
        subject_mapper.append(subject, self.layer_manager)

    def set_subject_position(self, event: FinishMoveEvent):
        actor = self.layer_manager.subject_layer.subjects_index[event.subject_id]
        new_world_position = self.layer_manager.grid_manager.get_pixel_position_of_grid_position(event.to_position)

        actor.set_position(*new_world_position)

    def start_move_subject(self, event: StartMoveEvent):
        actor = self.layer_manager.subject_layer.subjects_index[event.subject_id]
        new_world_position = self.layer_manager.grid_manager.get_pixel_position_of_grid_position(event.to_position)

        move_action = MoveTo(new_world_position, self.move_duration_ref)
        actor.do(move_action)
        actor.do(Animate(ANIMATION_WALK, duration=self.move_duration_ref, cycle_duration=2))
        actor.rotation = get_angle(event.from_position, event.to_position)