game.c

   1 #include <SDL2/SDL.h>
   2
   3 #include <assert.h>
   4 #include <stdbool.h>
   5 #include <math.h>
   6
   7 #include "game.h"
   8
   9 #define SPEED      (0.000006 * TICK_DELAY)
  10 #define ROTATE     (0.000006 * TICK_DELAY)
  11 #define BULL_SPEED (0.0008   * TICK_DELAY)
  12
  13 Player g_player[MAX_PLAYERS];
  14 Bullet g_bullet[MAX_BULLETS];
  15
  16 static bool svmode;
  17
  18 void g_player_set(unsigned int id, bool live, float x, float y, float r, float vx, float vy, float vr, int shoot) {
  19         assert(id < MAX_PLAYERS);
  20         g_player[id] = (Player) {
  21                 .updated = true,
  22                 .live    = live,
  23                 .x       = x,
  24                 .y       = y,
  25                 .r       = r,
  26                 .vx      = vx,
  27                 .vy      = vy,
  28                 .vr      = vr,
  29         };
  30 }
  31
  32 void g_bullet_set(unsigned int id, unsigned int owner, bool live, float x, float y, float vx, float vy, int tick) {
  33         assert(id < MAX_BULLETS);
  34         assert(owner < MAX_PLAYERS);
  35         g_bullet[id] = (Bullet) {
  36                 .live  = live,
  37                 .owner = owner,
  38                 .x     = x,
  39                 .y     = y,
  40                 .vx    = vx,
  41                 .vy    = vy,
  42                 .tick  = tick,
  43         };
  44 }
  45
  46 static int freebullet() {
  47         for(int i = 0; i < MAX_BULLETS; i++)
  48                 if(!g_bullet[i].live)
  49                         return i;
  50         return -1;
  51 }
  52
  53 static void moveplayer(int id, float speed) {
  54         g_player[id].vx += speed * cos(g_player[id].r * 2 * M_PI);
  55         g_player[id].vy += speed * sin(g_player[id].r * 2 * M_PI);
  56 }
  57
  58 static void roteplayer(int id, float speed) {
  59         g_player[id].vr += speed;
  60 }
  61
  62 static void fireplayer(int id) {
  63         int j = freebullet();
  64         if(j < 0)
  65                 return;
  66
  67         if(g_player[id].shoot < PLAYER_SHOOT)
  68                 return;
  69
  70         g_player[id].shoot = 0;
  71
  72         if(svmode) {
  73                 float vx = BULL_SPEED * cos(g_player[id].r * 2 * M_PI);
  74                 float vy = BULL_SPEED * sin(g_player[id].r * 2 * M_PI);
  75                 g_bullet_set(j, id, true, g_player[id].x, g_player[id].y, vx, vy, 0);
  76         }
  77 }
  78
  79 static void checkspacebound(float * a) {
  80         float x = *a;
  81         if(x < -1)
  82                 x = fabs(x);
  83         else if(x > 1)
  84                 x = -x;
  85         *a = x;
  86 }
  87
  88 static bool collide(float x1, float y1, float r1, float x2, float y2, float r2) {
  89         float l = sqrtf(powf(x1 - x2, 2) + powf(y1 - y2, 2));
  90         return ((l - r1 - r2) <= 0);
  91 }
  92
  93 void g_player_does(unsigned int id, DoesBits code) {
  94         assert(id < MAX_PLAYERS);
  95
  96         if(code.up)
  97                 moveplayer(id, SPEED);
  98         if(code.down)
  99                 moveplayer(id, -SPEED);
 100         if(code.left)
 101                 roteplayer(id, -ROTATE);
 102         if(code.right)
 103                 roteplayer(id, ROTATE);
 104         if(code.fire)
 105                 fireplayer(id);
 106 }
 107
 108 void g_update() {
 109         for(int i = 0; i < MAX_PLAYERS; i++) {
 110                 if(g_player[i].live) {
 111                         g_player[i].updated = true;
 112                         g_player[i].x += g_player[i].vx;
 113                         g_player[i].y += g_player[i].vy;
 114                         g_player[i].r += g_player[i].vr;
 115                         checkspacebound(&g_player[i].x);
 116                         checkspacebound(&g_player[i].y);
 117
 118                         ++g_player[i].shoot;
 119                         if(g_player[i].shoot > PLAYER_SHOOT)
 120                                 g_player[i].shoot = PLAYER_SHOOT;
 121                 }
 122         }
 123
 124         for(int i = 0; i < MAX_BULLETS; i++) {
 125                 if(g_bullet[i].live) {
 126                         g_bullet[i].updated = true;
 127                         g_bullet[i].tick += 1;
 128                         g_bullet[i].x += g_bullet[i].vx;
 129                         g_bullet[i].y += g_bullet[i].vy;
 130
 131                         checkspacebound(&g_bullet[i].x);
 132                         checkspacebound(&g_bullet[i].y);
 133
 134                         for(int j = 0; j < MAX_PLAYERS; j++)
 135                                 if(g_player[j].live)
 136                                         if(collide(g_bullet[i].x, g_bullet[i].y, 0.0001, g_player[j].x, g_player[j].y, PLAYER_SIZE))
 137                                                 if(j != g_bullet[i].owner)
 138                                                         g_player[j].live = false;
 139
 140                         if(g_bullet[i].tick > BULLET_TIME)
 141                                 g_bullet[i].live = false;
 142                 }
 143         }
 144 }
 145
 146 void g_init(bool server_mode) {
 147         svmode = server_mode;
 148         // TODO memset & co
 149 }