source: nagslang/screens/area.py @ 385:51deb78cae52

Last change on this file since 385:51deb78cae52 was 385:51deb78cae52, checked in by Stefano Rivera <stefano@…>, 7 years ago

Use a result object to get new drawables back to the area

File size: 9.8 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.enemies import DeadEnemy
12from nagslang.events import (
13    ScreenChange, DoorEvent, FireEvent, EnemyDeathEvent, ClawEvent)
14from nagslang.level import Level
15from nagslang.screens.base import Screen
16from nagslang.game_object import Bullet, ClawAttack
17from nagslang.sound import sound
18
19
20class ControlKeys(object):
21    direction_keys = {
22        (0, 1): set([pygame.locals.K_UP, pygame.locals.K_w]),
23        (0, -1): set([pygame.locals.K_DOWN, pygame.locals.K_s]),
24        (-1, 0): set([pygame.locals.K_LEFT, pygame.locals.K_a]),
25        (1, 0): set([pygame.locals.K_RIGHT, pygame.locals.K_d]),
26    }
27
28    attack_keys = set([pygame.locals.K_z, pygame.locals.K_LCTRL])
29
30    command_keys = {
31        pygame.locals.K_c: CMD_TOGGLE_FORM,
32        pygame.locals.K_SPACE: CMD_ACTION,
33    }
34
35    def __init__(self):
36        self.keys_down = set()
37
38    def key_down(self, key):
39        self.keys_down.add(key)
40
41    def key_up(self, key):
42        self.keys_down.discard(key)
43
44    def handle_event(self, ev):
45        if ev.type == pygame.locals.KEYDOWN:
46            self.key_down(ev.key)
47        elif ev.type == pygame.locals.KEYUP:
48            self.key_up(ev.key)
49
50    def get_direction(self):
51        dx, dy = 0, 0
52        for (tx, ty), keys in self.direction_keys.iteritems():
53            if self.keys_down & keys:
54                dx += tx
55                dy += ty
56        return (dx, dy)
57
58    def is_attacking(self):
59        return bool(self.keys_down & self.attack_keys)
60
61    def get_command_key(self, key):
62        return self.command_keys.get(key, None)
63
64
65class Drawables(object):
66    def __init__(self):
67        self._drawables = {}
68
69    def add(self, drawable):
70        self._drawables.setdefault(drawable.zorder, []).append(drawable)
71
72    def remove(self, drawable):
73        self._drawables[drawable.zorder].remove(drawable)
74
75    def get_drawables(self):
76        for zorder in sorted(self._drawables):
77            for drawable in self._drawables[zorder]:
78                yield drawable
79
80    __iter__ = get_drawables
81
82
83class AreaScreen(Screen):
84
85    def setup(self):
86        self._disable_render = False  # Avoid redrawing on scene changes
87        self.keys = ControlKeys()
88        self._level = Level(self.name, self.world)
89        self._level.load(self.space)
90        self._drawables = Drawables()
91        self.add_walls()
92        self._add_collision_handlers()
93        self.add_protagonist()
94        self.add_game_objects()
95        sound.play_music("POL-cyber-factory-short.ogg")
96
97    def teardown(self):
98        sound.stop()
99
100    @classmethod
101    def list_areas(self):
102        return Level.list_levels()
103
104    def _player_collision_pre_solve_handler(self, space, arbiter):
105        gobj = arbiter.shapes[1].physicser.game_object
106        result = gobj.collide_with_protagonist(self.protagonist)
107        # The collision handler must return `True` or `False`. We don't want to
108        # accidentally reject collisions from handlers that return `None`, so
109        # we explicitly check for `False` and treate everything else as `True`.
110        return result is not False
111
112    def _claw_attack_collision_pre_solve_handler(self, space, arbiter):
113        claw = arbiter.shapes[0].physicser.game_object
114        gobj = arbiter.shapes[1].physicser.game_object
115        result = gobj.collide_with_claw_attack(claw)
116        return result is not False
117
118    def _furniture_collision_pre_solve_handler(self, space, arbiter):
119        furniture = arbiter.shapes[0].physicser.game_object
120        gobj = arbiter.shapes[1].physicser.game_object
121        result = gobj.collide_with_furniture(furniture)
122        return result is not False
123
124    def _add_collision_handlers(self):
125        for collision_type in CALLBACK_COLLIDERS:
126            self.space.add_collision_handler(
127                COLLISION_TYPE_PLAYER, collision_type,
128                pre_solve=self._player_collision_pre_solve_handler)
129            self.space.add_collision_handler(
130                COLLISION_TYPE_FURNITURE, collision_type,
131                pre_solve=self._furniture_collision_pre_solve_handler)
132            self.space.add_collision_handler(
133                COLLISION_TYPE_WEREWOLF_ATTACK, collision_type,
134                pre_solve=self._claw_attack_collision_pre_solve_handler)
135
136    def add_walls(self):
137        self.walls = []
138        body = pymunk.Body()
139        body.position = (0, 0)
140        walls = self._level.get_walls()
141        for wall in walls:
142            if len(wall) < 2:
143                # Don't try to add a useless wall
144                continue
145            corners = wall
146            corner = corners[-1]
147            for next_corner in corners:
148                wall = pymunk.Segment(body, corner, next_corner, 5)
149                wall.collision_type = COLLISION_TYPE_WALL
150                wall.elasticity = 1.0
151                self.walls.append(wall)
152                corner = next_corner
153        self.space.add(*self.walls)
154
155    def add_game_objects(self):
156        for drawable in self._level.drawables:
157            self._drawables.add(drawable)
158
159    def add_protagonist(self):
160        self.protagonist = self.world.protagonist
161        self.protagonist.change_space(self.space)
162        self._drawables.add(self.protagonist)
163
164    def handle_event(self, ev):
165        if ev.type == pygame.locals.KEYDOWN:
166            if ev.key == pygame.locals.K_ESCAPE:
167                ScreenChange.post('menu')
168            cmd_key = self.keys.get_command_key(ev.key)
169            if cmd_key is not None:
170                self.protagonist.handle_keypress(cmd_key)
171        elif DoorEvent.matches(ev):
172            self.protagonist.set_position(ev.dest_pos)
173            if ev.destination != self.name:
174                # Go to anther screen
175                self._disable_render = True
176                self.world.rooms += 1
177                self.world.level = (ev.destination, ev.dest_pos)
178                ScreenChange.post(ev.destination)
179                return
180            # else we're teleporting within the screen, and just the
181            # position change is enough
182        elif FireEvent.matches(ev):
183            bullet = Bullet(self.space, ev.source, ev.impulse, ev.damage,
184                            ev.bullet_type, ev.source_collision_type)
185            self._drawables.add(bullet)
186        elif EnemyDeathEvent.matches(ev):
187            self.world.kills += 1
188            dead_enemy = DeadEnemy(self.space, self.world, ev.position,
189                                   ev.enemy_type)
190            self._drawables.add(dead_enemy)
191        elif ClawEvent.matches(ev):
192            claw_attack = ClawAttack(self.space, ev.source, ev.vector,
193                                     ev.damage)
194            self._drawables.add(claw_attack)
195        self.keys.handle_event(ev)
196
197    def _calc_viewport(self, level_surface, display_surface):
198        level_size = level_surface.get_size()
199        display_size = display_surface.get_size()
200        protagnist_pos = self.protagonist.physicser.get_render_position(
201            level_surface)
202        x_wide = display_size[0] // 2
203        y_wide = display_size[1] // 2
204        if display_size[0] > level_size[0]:
205            x = -(display_size[0] - level_size[0]) // 2
206        elif protagnist_pos[0] < x_wide:
207            x = 0
208        elif protagnist_pos[0] > level_size[0] - x_wide:
209            x = level_size[0] - display_size[0]
210        else:
211            x = protagnist_pos[0] - x_wide
212        if display_size[1] > level_size[1]:
213            y = -(display_size[1] - level_size[1]) // 2
214        elif protagnist_pos[1] < y_wide:
215            y = 0
216        elif protagnist_pos[1] > level_size[1] - y_wide:
217            y = level_size[1] - display_size[1]
218        else:
219            y = protagnist_pos[1] - y_wide
220        return pygame.rect.Rect(x, y, display_size[0], display_size[1])
221
222    def render(self, surface):
223        if self._disable_render:
224            return
225        background = self._level.get_background()
226        mysurface = background.copy()
227        for drawable in self._drawables:
228            drawable.render(mysurface)
229        render_rect = self._calc_viewport(mysurface, surface)
230        surface.blit(mysurface, (0, 0), render_rect)
231        for overlay in self._level.overlay_drawables:
232            if overlay.is_visible():
233                overlay.render(surface, render_rect.topleft)
234        self.render_health_bar(surface)
235
236    def tick_protagonist(self):
237        dx, dy = self.keys.get_direction()
238        self.protagonist.set_direction(dx, dy)
239        if self.keys.is_attacking():
240            self.protagonist.handle_attack_key_down()
241
242    def tick(self, seconds):
243        super(AreaScreen, self).tick(seconds)
244        self.tick_protagonist()
245        for drawable in self._drawables:
246            result = drawable.update(seconds)
247            if result is not None:
248                for new_drawable in result.add:
249                    self._drawables.add(new_drawable)
250                for old_drawable in result.remove:
251                    self._drawables.remove(old_drawable)
252
253    def render_health_bar(self, surface, damage_experienced=None):
254        bar_surface = pygame.Surface((110, 50)).convert(surface)
255        if damage_experienced:
256            health_box_colour = pygame.color.THECOLORS['red']
257        else:
258            health_box_colour = pygame.color.THECOLORS['white']
259        bar_surface.fill(health_box_colour)
260        if self.protagonist.in_human_form():
261            health_colour = pygame.color.THECOLORS['red']
262        else:
263            health_colour = pygame.color.THECOLORS['violetred3']
264        rect = pygame.Rect(5, 5, self.protagonist.get_health_level(), 40)
265        pygame.draw.rect(bar_surface, health_colour, rect, 0)
266        bar_surface.set_alpha(192)
267        y_pos = surface.get_height() - 20 - bar_surface.get_height()
268        surface.blit(bar_surface, (20, y_pos))
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