Sorcery in C

void equipItem(uint16_t id, uint8_t slot, Stack stack, EContext context) {
  extern Item items[0x8000];
  int eqType = (id >> 13) - 2;
  uint16_t* oldId = (*context)->moreData.playerData.equipped + eqType;
  uint32_t* playerAttrs = (*context)->eh.attrs;
  uint32_t* oldAttrBoosts = items[*oldId].data.equipmentData.attrs;
  uint32_t* newAttrBoosts = items[id].data.equipmentData.attrs;
  int i;
  for (i = 0; i < 4; ++i) {
    playerAttrs[i] += newAttrBoosts[i] - oldAttrBoosts[i];
  }
  uint64_t* playerHM = (uint64_t*) *context;
  uint64_t* oldHM = (uint64_t*) (oldAttrBoosts + 4);
  uint64_t* newHM = (uint64_t*) (newAttrBoosts + 4);
  for (i = 0; i < 2; ++i) {
    playerHM[i] += newHM[i] - oldHM[i];
  }
  uint16_t t = *oldId;
  *oldId = (*context)->moreData.playerData.items[slot].id;
  (*context)->moreData.playerData.items[slot].id = t;
}