source: nagslang/enemies.py@ 393:8d961e05b7b6

Last change on this file since 393:8d961e05b7b6 was 393:8d961e05b7b6, checked in by Stefano Rivera <stefano@…>, 8 years ago

Use Result to handle firing

File size: 10.3 KB
Line 
1import math
2import random
3
4import pymunk
5import pymunk.pygame_util
6from pymunk.vec2d import Vec2d
7
8from nagslang import render
9from nagslang.constants import (COLLISION_TYPE_ENEMY, COLLISION_TYPE_FURNITURE,
10 ACID_SPEED, ACID_DAMAGE, ZORDER_MID)
11from nagslang.events import EnemyDeathEvent
12from nagslang.game_object import (GameObject, SingleShapePhysicser, Result,
13 Bullet, make_body)
14from nagslang.mutators import FLIP_H
15from nagslang.resources import resources
16from nagslang.utils import vec_with_length
17
18
19def get_editable_enemies():
20 classes = []
21 for cls_name, cls in globals().iteritems():
22 if isinstance(cls, type) and issubclass(cls, Enemy):
23 if hasattr(cls, 'requires'):
24 classes.append((cls_name, cls))
25 return classes
26
27
28def get_alien_image(enemy_type, suffix, *transforms):
29 image_name = 'alien_%s_%s.png' % (enemy_type, suffix)
30 return resources.get_image('creatures', image_name, transforms=transforms)
31
32
33class Enemy(GameObject):
34 """A base class for mobile enemies"""
35 zorder = ZORDER_MID
36 enemy_type = None # Which set of images to use
37 enemy_damage = None
38 health = None
39 impulse_factor = None
40
41 def __init__(self, space, world, position):
42 super(Enemy, self).__init__(
43 self.make_physics(space, position), self.make_renderer())
44 self.world = world
45 self.angle = 0
46
47 def make_physics(self, space, position):
48 raise NotImplementedError
49
50 def make_renderer(self):
51 return render.FacingSelectionRenderer({
52 'left': render.TimedAnimatedRenderer(
53 [get_alien_image(self.enemy_type, '1'),
54 get_alien_image(self.enemy_type, '2')], 3),
55 'right': render.TimedAnimatedRenderer(
56 [get_alien_image(self.enemy_type, '1', FLIP_H),
57 get_alien_image(self.enemy_type, '2', FLIP_H)], 3),
58 })
59
60 def attack(self):
61 raise NotImplementedError
62
63 @classmethod
64 def requires(cls):
65 return [("name", "string"), ("position", "coordinates")]
66
67 def hit(self, weapon):
68 self.lose_health(weapon.damage)
69
70 def lose_health(self, amount):
71 self.health -= amount
72 if self.health <= 0:
73 EnemyDeathEvent.post()
74 self.physicser.remove_from_space()
75
76 def set_direction(self, dx, dy):
77 vec = vec_with_length((dx, dy), self.impulse_factor)
78 self.angle = vec.angle
79 self.physicser.apply_impulse(vec)
80
81 def collide_with_protagonist(self, protagonist):
82 if self.enemy_damage is not None:
83 protagonist.lose_health(self.enemy_damage)
84
85 def collide_with_claw_attack(self, claw_attack):
86 self.lose_health(claw_attack.damage)
87
88 def ranged_attack(self, range_, speed, damage, type_, reload_time,
89 result=None):
90 if result is None:
91 result = Result()
92
93 pos = self.physicser.position
94 target = self.world.protagonist.get_shape().body.position
95
96 r = self.get_space().segment_query(pos, target)
97 for collision in r:
98 shape = collision.shape
99 if (shape in (self.get_shape(), self.world.protagonist.get_shape())
100 or shape.sensor):
101 continue
102 return result
103
104 if not self.check_timer('reload_time'):
105 self.start_timer('reload_time', reload_time)
106 vec = Vec2d((target.x - pos.x, target.y - pos.y))
107 if vec.length < range_:
108 vec.length = speed
109 result.add += (Bullet(self.get_space(), pos, vec, damage,
110 type_, COLLISION_TYPE_ENEMY),)
111 return result
112
113 def greedy_move(self, target):
114 """Simple greedy path finder"""
115 def _calc_step(tp, pp):
116 if (tp < pp):
117 step = max(-1, tp - pp)
118 elif (tp > pp):
119 step = min(1, tp - pp)
120 if abs(step) < 0.5:
121 step = 0
122 return step
123 x_step = _calc_step(target[0], self.physicser.position[0])
124 y_step = _calc_step(target[1], self.physicser.position[1])
125 return (x_step, y_step)
126
127 def random_move(self):
128 """Random move"""
129 x_step = random.choice([-1, 0, 1])
130 y_step = random.choice([-1, 0, 1])
131 return x_step, y_step
132
133 def update(self, dt):
134 super(Enemy, self).update(dt)
135 result = Result()
136 if self.health <= 0:
137 result.remove += (self,)
138 result.add += (DeadEnemy(self.get_space(), self.world,
139 self.physicser.position,
140 self.enemy_type),)
141 return result
142
143
144class DeadEnemy(GameObject):
145 def __init__(self, space, world, position, enemy_type='A'):
146 body = make_body(10, 10000, position, damping=0.5)
147 self.shape = pymunk.Poly(
148 body, [(-20, -20), (20, -20), (20, 20), (-20, 20)])
149 self.shape.friction = 0.5
150 self.shape.collision_type = COLLISION_TYPE_FURNITURE
151 super(DeadEnemy, self).__init__(
152 SingleShapePhysicser(space, self.shape),
153 render.ImageRenderer(resources.get_image(
154 'creatures', 'alien_%s_dead.png' % enemy_type)),
155 )
156
157 @classmethod
158 def requires(cls):
159 return [("name", "string"), ("position", "coordinates")]
160
161
162class PatrollingAlien(Enemy):
163 is_moving = True # Always walking.
164 enemy_type = 'A'
165 health = 42
166 enemy_damage = 15
167 impulse_factor = 50
168
169 def __init__(self, space, world, position, end_position):
170 # An enemy that patrols between the two points
171 super(PatrollingAlien, self).__init__(space, world, position)
172 self._start_pos = position
173 self._end_pos = end_position
174 self._direction = 'away'
175
176 def make_physics(self, space, position):
177 body = make_body(10, pymunk.inf, position, 0.8)
178 shape = pymunk.Circle(body, 30)
179 shape.elasticity = 1.0
180 shape.friction = 0.05
181 shape.collision_type = COLLISION_TYPE_ENEMY
182 return SingleShapePhysicser(space, shape)
183
184 def get_render_angle(self):
185 # No image rotation when rendering, please.
186 return 0
187
188 def get_facing_direction(self):
189 # Enemies can face left or right.
190 if - math.pi / 2 < self.angle <= math.pi / 2:
191 return 'right'
192 else:
193 return 'left'
194
195 def _switch_direction(self):
196 if self._direction == 'away':
197 self._direction = 'towards'
198 else:
199 self._direction = 'away'
200
201 def update(self, dt):
202 # Calculate the step every frame
203 if self._direction == 'away':
204 target = self._end_pos
205 else:
206 target = self._start_pos
207 x_step, y_step = self.greedy_move(target)
208 if abs(x_step) < 1 and abs(y_step) < 1:
209 self._switch_direction()
210 self.set_direction(x_step, y_step)
211 result = self.ranged_attack(300, ACID_SPEED, ACID_DAMAGE, 'acid', 0.2)
212 return result.merge(super(PatrollingAlien, self).update(dt))
213
214 @classmethod
215 def requires(cls):
216 return [("name", "string"), ("position", "coordinates"),
217 ("end_position", "coordinates")]
218
219
220class ChargingAlien(Enemy):
221 # Simplistic charging of the protagonist
222 is_moving = False
223 enemy_type = 'B'
224 health = 42
225 enemy_damage = 20
226 impulse_factor = 300
227
228 def __init__(self, space, world, position, attack_range=100):
229 super(ChargingAlien, self).__init__(space, world, position)
230 self._range = attack_range
231
232 def make_physics(self, space, position):
233 body = make_body(100, pymunk.inf, position, 0.8)
234 shape = pymunk.Circle(body, 30)
235 shape.elasticity = 1.0
236 shape.friction = 0.05
237 shape.collision_type = COLLISION_TYPE_ENEMY
238 return SingleShapePhysicser(space, shape)
239
240 def get_render_angle(self):
241 # No image rotation when rendering, please.
242 return 0
243
244 def get_facing_direction(self):
245 # Enemies can face left or right.
246 if - math.pi / 2 < self.angle <= math.pi / 2:
247 return 'right'
248 else:
249 return 'left'
250
251 def _calc_movement(self):
252 pos = self.physicser.position
253 target = self.world.protagonist.get_shape().body.position
254 if pos.get_distance(target) > self._range:
255 # stop
256 self.is_moving = False
257 return 0, 0
258 self.is_moving = True
259 dx, dy = self.greedy_move(target)
260 return dx, dy
261
262 def update(self, dt):
263 # Calculate the step every frame
264 # Distance to the protagonist
265 result = self.ranged_attack(300, ACID_SPEED, ACID_DAMAGE, 'acid', 0.2)
266 dx, dy = self._calc_movement()
267 self.set_direction(dx, dy)
268 return result.merge(super(ChargingAlien, self).update(dt))
269
270 @classmethod
271 def requires(cls):
272 return [("name", "string"), ("position", "coordinates"),
273 ("attack_range", "distance")]
274
275
276class RunAndGunAlien(ChargingAlien):
277 # Simplistic shooter
278 # Move until we're in range, and then randomly
279 impulse_factor = 90
280 is_moving = True
281
282 def __init__(self, space, world, position, attack_range=100):
283 super(RunAndGunAlien, self).__init__(space, world, position,
284 attack_range)
285 self.count = 0
286 self._old_move = (0, 0)
287
288 def make_physics(self, space, position):
289 body = make_body(10, pymunk.inf, position, 0.8)
290 shape = pymunk.Circle(body, 30)
291 shape.elasticity = 1.0
292 shape.friction = 0.05
293 shape.collision_type = COLLISION_TYPE_ENEMY
294 return SingleShapePhysicser(space, shape)
295
296 def _calc_movement(self):
297 pos = self.physicser.position
298 target = self.world.protagonist.get_shape().body.position
299 if pos.get_distance(target) < self._range:
300 if self.count > 10:
301 self._old_move = self.random_move()
302 self.count = 0
303 return self._old_move
304 else:
305 return self.greedy_move(target)
306
307 def update(self, dt):
308 self.count += 1
309 return super(RunAndGunAlien, self).update(dt)
310
311 @classmethod
312 def requires(cls):
313 return [("name", "string"), ("position", "coordinates"),
314 ("attack_range", "distance")]
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