/
enemy.c
295 lines (266 loc) · 6.03 KB
/
enemy.c
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
#include <SDL2/SDL.h>
#include "globals.h"
#include "enemy.h"
#include "bullet.h"
#include "defense.h"
void enemy_init()
{
int x, y;
for (y = 0; y < 5; y++)
{
for (x = 0; x < 11; x++)
{
if (y == 0)
{
enemy[x][y].surf[0] = enemysurf1a;
enemy[x][y].surf[1] = enemysurf1b;
}
else if (y == 1 || y == 2)
{
enemy[x][y].surf[0] = enemysurf2a;
enemy[x][y].surf[1] = enemysurf2b;
}
else
{
enemy[x][y].surf[0] = enemysurf3a;
enemy[x][y].surf[1] = enemysurf3b;
}
enemy[x][y].rect.w = enemy[x][y].surf[0]->w * gScale;
enemy[x][y].rect.h = enemy[x][y].surf[0]->h * gScale;
}
}
command.rect.w = command.surf[0]->w * gScale;
command.rect.h = command.surf[0]->h * gScale;
gDifficulty = .5f;
enemy_reset();
}
void enemy_reset()
{
int x, y;
enemy_direction = 1;
enemy_total = 55;
enemy_animation_time = 750;
for (y = 0; y < 5; y++)
{
for (x = 0; x < 11; x++)
{
enemy[x][y].alive = 1;
enemy[x][y].death_time = 0;
enemy[x][y].x = 32 * gScale * x;
enemy[x][y].y = 32 * gScale * y + (64 * gScale);
// Center enemies, correct offset since images are different sizes
if (y == 0)
enemy[x][y].x += 2 * gScale;
if (y == 1 || y == 2)
enemy[x][y].x += 1;
}
}
command.x = SCREEN_WIDTH;
command.y = 64 * gScale;
command.rect.x = (int)command.x;
command.rect.y = (int)command.y;
command.alive = 0;
command_spawned = 0;
command.death_time = 0;
}
void enemy_logic(unsigned long dt)
{
int x, y;
int move_down = 0;
double rate;
enemy_speed = getEnemySpeed();
if (enemy[0][0].x < 0 || enemy[0][0].x + (11*32*gScale) > SCREEN_WIDTH)
{
enemy_direction *= -1;
move_down = 1;
}
for (y = 0; y < 5; y++)
{
for (x = 0; x < 11; x++)
{
enemy[x][y].x += enemy_speed * enemy_direction * dt;
if (move_down)
{
// prevents enemies getting stuck on side then disappearing
enemy[x][y].x += enemy_speed * enemy_direction * dt;
enemy[x][y].y += 16 * gScale;
}
enemy[x][y].rect.x = (int)enemy[x][y].x;
enemy[x][y].rect.y = (int)enemy[x][y].y;
// spawn bullets with an equal fire rate throughout level
// since enemies decrease, higher chance of a given alive enemy
// shooting as enemies are shot down and levels passed
rate = 100000.0 * ((float)enemy_total+1.0)/55.0 * (1.0/gDifficulty);
if (enemy[x][y].alive && rand() % (int)rate < 2*dt)
{
bullet_fire(enemy[x][y].rect.x + enemy[x][y].rect.w/2 - gScale, enemy[x][y].rect.y + enemy[x][y].rect.h - 1, 0);
}
}
}
// Command ship spawn algorithm
// Random chance to spawn after enemies move two rows down
if (!command_spawned && (rand() % 40000 < 2*dt) && enemy[0][0].rect.y > 160)
{
command_spawned = 1;
command.alive = 1;
command_speed = (rand() % 3) + 1;
command_points = command_speed * 100;
Mix_FadeInChannel(-1, gCommandEntrance, -1, 2000);
}
// force command ship to spawn if it gets close to end of wave
else if (!command_spawned && enemy_total < 8)
{
command_spawned = 1;
command.alive = 1;
command_speed = (rand() % 3) + 1;
command_points = command_speed * 100;
Mix_FadeInChannel(-1, gCommandEntrance, -1, 2000);
}
if (command.alive)
{
command.x -= .02f * gScale * command_speed * dt;
command.rect.x = (int)command.x;
if (command.rect.x + command.rect.w < 0)
{
command.alive = 0;
Mix_HaltChannel(-1);
Mix_PlayChannel(-1, gCommandExit, 0);
}
}
// reset level if all enemies were killed
if (enemy_total == 0)
{
SDL_Delay(2000);
gDifficulty *= 2.0f;
enemy_reset();
bullet_reset();
defense_reset();
}
}
void enemy_render()
{
int x, y;
for (y = 0; y < 5; y++)
{
for (x = 0; x < 11; x++)
{
if (enemy[x][y].alive)
{
if (SDL_GetTicks() % (enemy_animation_time*2) < enemy_animation_time)
{
SDL_BlitScaled(enemy[x][y].surf[0], NULL, gScreen, &enemy[x][y].rect);
}
else
{
SDL_BlitScaled(enemy[x][y].surf[1], NULL, gScreen, &enemy[x][y].rect);
}
}
else if (SDL_GetTicks() - enemy[x][y].death_time < 300)
{
SDL_BlitScaled(enemyexplosionsurf, NULL, gScreen, &enemy[x][y].rect);
}
}
}
if (command.alive)
{
SDL_BlitScaled(command.surf[0], NULL, gScreen, &command.rect);
}
else if (SDL_GetTicks() - command.death_time < 300)
{
SDL_BlitScaled(command.surf[1], NULL, gScreen, &command.rect);
}
}
float getEnemySpeed()
{
float speed = .1f;
switch(enemy_total)
{
case 55:
case 54:
case 53:
case 52:
case 51:
case 50:
case 49:
case 48:
case 47:
case 46:
speed = .0025f;
enemy_animation_time = 700;
break;
case 45:
case 44:
case 43:
case 42:
case 41:
case 40:
case 39:
case 38:
speed = .005f;
enemy_animation_time = 650;
break;
case 37:
case 36:
case 35:
case 34:
case 33:
case 32:
case 31:
speed = .01f;
enemy_animation_time = 600;
break;
case 30:
case 29:
case 28:
case 27:
case 26:
case 25:
case 24:
case 23:
speed = .0175f;
enemy_animation_time = 500;
break;
case 22:
case 21:
case 20:
case 19:
case 18:
case 17:
speed = .025f;
enemy_animation_time = 400;
break;
case 16:
case 15:
case 14:
case 13:
case 12:
speed = .035f;
break;
case 11:
case 10:
case 9:
case 8:
speed = .0475f;
enemy_animation_time = 300;
break;
case 7:
case 6:
case 5:
case 4:
speed = .0625f;
enemy_animation_time = 200;
break;
case 3:
case 2:
speed = .075f;
enemy_animation_time = 100;
break;
case 1:
speed = .1f;
enemy_animation_time = 50;
break;
default:
break;
}
return speed * gScale * gDifficulty;
}