source: nagslang/screens/area.py @ 391:866cdc74b26a

Last change on this file since 391:866cdc74b26a was 391:866cdc74b26a, checked in by Stefano Rivera <stefano@…>, 7 years ago

Use Result to handle enemy death (but keep the event for accounting purposes)

File size: 9.6 KB
Line 
1"""Display a game area."""
2
3import pygame
4import pymunk
5import pymunk.pygame_util
6
7from nagslang.constants import (
8    COLLISION_TYPE_WALL, COLLISION_TYPE_PLAYER, CALLBACK_COLLIDERS,
9    COLLISION_TYPE_FURNITURE, COLLISION_TYPE_WEREWOLF_ATTACK,
10    CMD_TOGGLE_FORM, CMD_ACTION)
11from nagslang.events import (
12    ScreenChange, DoorEvent, EnemyDeathEvent, FireEvent, ClawEvent)
13from nagslang.level import Level
14from nagslang.screens.base import Screen
15from nagslang.game_object import Bullet, ClawAttack
16from nagslang.sound import sound
17
18
19class ControlKeys(object):
20    direction_keys = {
21        (0, 1): set([pygame.locals.K_UP, pygame.locals.K_w]),
22        (0, -1): set([pygame.locals.K_DOWN, pygame.locals.K_s]),
23        (-1, 0): set([pygame.locals.K_LEFT, pygame.locals.K_a]),
24        (1, 0): set([pygame.locals.K_RIGHT, pygame.locals.K_d]),
25    }
26
27    attack_keys = set([pygame.locals.K_z, pygame.locals.K_LCTRL])
28
29    command_keys = {
30        pygame.locals.K_c: CMD_TOGGLE_FORM,
31        pygame.locals.K_SPACE: CMD_ACTION,
32    }
33
34    def __init__(self):
35        self.keys_down = set()
36
37    def key_down(self, key):
38        self.keys_down.add(key)
39
40    def key_up(self, key):
41        self.keys_down.discard(key)
42
43    def handle_event(self, ev):
44        if ev.type == pygame.locals.KEYDOWN:
45            self.key_down(ev.key)
46        elif ev.type == pygame.locals.KEYUP:
47            self.key_up(ev.key)
48
49    def get_direction(self):
50        dx, dy = 0, 0
51        for (tx, ty), keys in self.direction_keys.iteritems():
52            if self.keys_down & keys:
53                dx += tx
54                dy += ty
55        return (dx, dy)
56
57    def is_attacking(self):
58        return bool(self.keys_down & self.attack_keys)
59
60    def get_command_key(self, key):
61        return self.command_keys.get(key, None)
62
63
64class Drawables(object):
65    def __init__(self):
66        self._drawables = {}
67
68    def add(self, drawable):
69        self._drawables.setdefault(drawable.zorder, []).append(drawable)
70
71    def remove(self, drawable):
72        self._drawables[drawable.zorder].remove(drawable)
73
74    def get_drawables(self):
75        for zorder in sorted(self._drawables):
76            for drawable in self._drawables[zorder]:
77                yield drawable
78
79    __iter__ = get_drawables
80
81
82class AreaScreen(Screen):
83
84    def setup(self):
85        self._disable_render = False  # Avoid redrawing on scene changes
86        self.keys = ControlKeys()
87        self._level = Level(self.name, self.world)
88        self._level.load(self.space)
89        self._drawables = Drawables()
90        self.add_walls()
91        self._add_collision_handlers()
92        self.add_protagonist()
93        self.add_game_objects()
94        sound.play_music("POL-cyber-factory-short.ogg")
95
96    def teardown(self):
97        sound.stop()
98
99    @classmethod
100    def list_areas(self):
101        return Level.list_levels()
102
103    def _player_collision_pre_solve_handler(self, space, arbiter):
104        gobj = arbiter.shapes[1].physicser.game_object
105        result = gobj.collide_with_protagonist(self.protagonist)
106        # The collision handler must return `True` or `False`. We don't want to
107        # accidentally reject collisions from handlers that return `None`, so
108        # we explicitly check for `False` and treate everything else as `True`.
109        return result is not False
110
111    def _claw_attack_collision_pre_solve_handler(self, space, arbiter):
112        claw = arbiter.shapes[0].physicser.game_object
113        gobj = arbiter.shapes[1].physicser.game_object
114        result = gobj.collide_with_claw_attack(claw)
115        return result is not False
116
117    def _furniture_collision_pre_solve_handler(self, space, arbiter):
118        furniture = arbiter.shapes[0].physicser.game_object
119        gobj = arbiter.shapes[1].physicser.game_object
120        result = gobj.collide_with_furniture(furniture)
121        return result is not False
122
123    def _add_collision_handlers(self):
124        for collision_type in CALLBACK_COLLIDERS:
125            self.space.add_collision_handler(
126                COLLISION_TYPE_PLAYER, collision_type,
127                pre_solve=self._player_collision_pre_solve_handler)
128            self.space.add_collision_handler(
129                COLLISION_TYPE_FURNITURE, collision_type,
130                pre_solve=self._furniture_collision_pre_solve_handler)
131            self.space.add_collision_handler(
132                COLLISION_TYPE_WEREWOLF_ATTACK, collision_type,
133                pre_solve=self._claw_attack_collision_pre_solve_handler)
134
135    def add_walls(self):
136        self.walls = []
137        body = pymunk.Body()
138        body.position = (0, 0)
139        walls = self._level.get_walls()
140        for wall in walls:
141            if len(wall) < 2:
142                # Don't try to add a useless wall
143                continue
144            corners = wall
145            corner = corners[-1]
146            for next_corner in corners:
147                wall = pymunk.Segment(body, corner, next_corner, 5)
148                wall.collision_type = COLLISION_TYPE_WALL
149                wall.elasticity = 1.0
150                self.walls.append(wall)
151                corner = next_corner
152        self.space.add(*self.walls)
153
154    def add_game_objects(self):
155        for drawable in self._level.drawables:
156            self._drawables.add(drawable)
157
158    def add_protagonist(self):
159        self.protagonist = self.world.protagonist
160        self.protagonist.change_space(self.space)
161        self._drawables.add(self.protagonist)
162
163    def handle_event(self, ev):
164        if ev.type == pygame.locals.KEYDOWN:
165            if ev.key == pygame.locals.K_ESCAPE:
166                ScreenChange.post('menu')
167            cmd_key = self.keys.get_command_key(ev.key)
168            if cmd_key is not None:
169                self.protagonist.handle_keypress(cmd_key)
170        elif DoorEvent.matches(ev):
171            self.protagonist.set_position(ev.dest_pos)
172            if ev.destination != self.name:
173                # Go to anther screen
174                self._disable_render = True
175                self.world.rooms += 1
176                self.world.level = (ev.destination, ev.dest_pos)
177                ScreenChange.post(ev.destination)
178                return
179            # else we're teleporting within the screen, and just the
180            # position change is enough
181        elif FireEvent.matches(ev):
182            bullet = Bullet(self.space, ev.source, ev.impulse, ev.damage,
183                            ev.bullet_type, ev.source_collision_type)
184            self._drawables.add(bullet)
185        elif EnemyDeathEvent.matches(ev):
186            self.world.kills += 1
187        elif ClawEvent.matches(ev):
188            claw_attack = ClawAttack(self.space, ev.source, ev.vector,
189                                     ev.damage)
190            self._drawables.add(claw_attack)
191        self.keys.handle_event(ev)
192
193    def _calc_viewport(self, level_surface, display_surface):
194        level_size = level_surface.get_size()
195        display_size = display_surface.get_size()
196        protagnist_pos = self.protagonist.physicser.get_render_position(
197            level_surface)
198        x_wide = display_size[0] // 2
199        y_wide = display_size[1] // 2
200        if display_size[0] > level_size[0]:
201            x = -(display_size[0] - level_size[0]) // 2
202        elif protagnist_pos[0] < x_wide:
203            x = 0
204        elif protagnist_pos[0] > level_size[0] - x_wide:
205            x = level_size[0] - display_size[0]
206        else:
207            x = protagnist_pos[0] - x_wide
208        if display_size[1] > level_size[1]:
209            y = -(display_size[1] - level_size[1]) // 2
210        elif protagnist_pos[1] < y_wide:
211            y = 0
212        elif protagnist_pos[1] > level_size[1] - y_wide:
213            y = level_size[1] - display_size[1]
214        else:
215            y = protagnist_pos[1] - y_wide
216        return pygame.rect.Rect(x, y, display_size[0], display_size[1])
217
218    def render(self, surface):
219        if self._disable_render:
220            return
221        background = self._level.get_background()
222        mysurface = background.copy()
223        for drawable in self._drawables:
224            drawable.render(mysurface)
225        render_rect = self._calc_viewport(mysurface, surface)
226        surface.blit(mysurface, (0, 0), render_rect)
227        for overlay in self._level.overlay_drawables:
228            if overlay.is_visible():
229                overlay.render(surface, render_rect.topleft)
230        self.render_health_bar(surface)
231
232    def tick_protagonist(self):
233        dx, dy = self.keys.get_direction()
234        self.protagonist.set_direction(dx, dy)
235        if self.keys.is_attacking():
236            self.protagonist.handle_attack_key_down()
237
238    def tick(self, seconds):
239        super(AreaScreen, self).tick(seconds)
240        self.tick_protagonist()
241        for drawable in self._drawables:
242            result = drawable.update(seconds)
243            if result is not None:
244                for new_drawable in result.add:
245                    self._drawables.add(new_drawable)
246                for old_drawable in result.remove:
247                    self._drawables.remove(old_drawable)
248
249    def render_health_bar(self, surface, damage_experienced=None):
250        bar_surface = pygame.Surface((110, 50)).convert(surface)
251        if damage_experienced:
252            health_box_colour = pygame.color.THECOLORS['red']
253        else:
254            health_box_colour = pygame.color.THECOLORS['white']
255        bar_surface.fill(health_box_colour)
256        if self.protagonist.in_human_form():
257            health_colour = pygame.color.THECOLORS['red']
258        else:
259            health_colour = pygame.color.THECOLORS['violetred3']
260        rect = pygame.Rect(5, 5, self.protagonist.get_health_level(), 40)
261        pygame.draw.rect(bar_surface, health_colour, rect, 0)
262        bar_surface.set_alpha(192)
263        y_pos = surface.get_height() - 20 - bar_surface.get_height()
264        surface.blit(bar_surface, (20, y_pos))
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