gameobj.c

   1 #include "gameobj.h"
   2 #include <stddef.h>
   3 #include <assert.h>
   4
   5 gameobj objs[OBJ_MAX];
   6 uint8_t obj_slot_used[OBJ_MAX];
   7 uint8_t obj_count;
   8 // return -1 on error or gameobj slot id.
   9 int gameobj_alloc(void) {
  10         if(obj_count >= OBJ_MAX) return -1;
  11         // fast path: try next slot
  12         size_t i = obj_count;
  13         if(!obj_slot_used[i]) {
  14                 return_slot:
  15                 obj_slot_used[i] = 1;
  16                 obj_count++;
  17                 return i;
  18         }
  19
  20         for (i = 0; i < OBJ_MAX; i++) {
  21                 if(!obj_slot_used[i]) goto return_slot;
  22         }
  23         return -1;
  24 }
  25
  26 void gameobj_free(int id) {
  27         assert(obj_slot_used[id] == 1);
  28         obj_slot_used[id] = 0;
  29         obj_count--;
  30 }
  31
  32 extern uint32_t tickcounter;
  33 void gameobj_start_anim(int obj_id, enum animation_id aid) {
  34         if(obj_id == -1) return;
  35         objs[obj_id].animid = aid;
  36         objs[obj_id].anim_curr = ANIM_STEP_INIT;
  37         size_t tick_frames = objs[obj_id].objtype == OBJ_BIG_EXPLOSION ? 8 : 4;
  38         objs[obj_id].anim_frame = tickcounter % tick_frames;
  39 }
  40
  41 void gameobj_init(int id, vec2f *pos, vec2f* vel,
  42                   enum sprite_index spritemap_id,
  43                   enum animation_id animid, enum objtype objtype) {
  44         if(id == -1) return;
  45         struct gameobj *o = &objs[id];
  46         o->pos = *pos;
  47         o->vel = *vel;
  48         o->spritemap_id = spritemap_id;
  49         o->objtype = objtype;
  50         gameobj_start_anim(id, animid);
  51 }
  52
  53 void gameobj_init_bulletdata(int id, int steps) {
  54         if(id == -1) return;
  55         struct gameobj *o = &objs[id];
  56         o->objspecific.bullet.step_curr = 0;
  57         o->objspecific.bullet.step_max = steps;
  58 }