refactor use item handler

src/procedures.c

@@ -542,6 +542,80 @@ void handlePlayerAction (PlayerData *player, int action, short x, short y, short
 
 }
 
+void handlePlayerUseItem (PlayerData *player, short x, short y, short z, uint8_t face) {
+
+  // Check interaction with containers when not sneaking
+  if (!(player->flags & 0x04)) {
+    uint8_t target = getBlockAt(x, y, z);
+    if (target == B_crafting_table) {
+      sc_openScreen(player->client_fd, 12, "Crafting", 8);
+      return 0;
+    } else if (target == B_furnace) {
+      sc_openScreen(player->client_fd, 14, "Furnace", 7);
+      return 0;
+    } else if (target == B_composter) {
+      // Check if the player is holding anything
+      uint8_t *count = &player->inventory_count[player->hotbar];
+      if (*count == 0) return 0;
+      // Check if the item is a valid compost item
+      uint16_t item = player->inventory_items[player->hotbar];
+      uint32_t compost_chance = isCompostItem(item);
+      if (compost_chance != 0) {
+        // Take away composted item
+        if ((*count -= 1) == 0) item = 0;
+        sc_setContainerSlot(player->client_fd, 0, serverSlotToClientSlot(0, player->hotbar), *count, item);
+        // Test compost chance and give bone meal on success
+        if (fast_rand() < compost_chance) {
+          givePlayerItem(player, I_bone_meal, 1);
+        }
+        return 0;
+      }
+    }
+  }
+
+  switch (face) {
+    case 0: y -= 1; break;
+    case 1: y += 1; break;
+    case 2: z -= 1; break;
+    case 3: z += 1; break;
+    case 4: x -= 1; break;
+    case 5: x += 1; break;
+    default: break;
+  }
+
+  uint16_t *item = &player->inventory_items[player->hotbar];
+  uint8_t *count = &player->inventory_count[player->hotbar];
+  uint8_t block = I_to_B(*item);
+
+  // if the selected item doesn't correspond to a block, exit
+  if (block == 0) return 0;
+  // if the selected slot doesn't hold any items, exit
+  if (*count == 0) return 0;
+
+  // check if the block's placement conditions are met
+  if (
+    !( // player is not in the way
+      !isPassableBlock(block) &&
+      x == player->x &&
+      (y == player->y || y == player->y + 1) &&
+      z == player->z
+    ) &&
+    isReplaceableBlock(getBlockAt(x, y, z)) &&
+    (!isColumnBlock(block) || getBlockAt(x, y - 1, z) != B_air)
+  ) {
+    // decrease item amount in selected slot
+    *count -= 1;
+    // clear item id in slot if amount is zero
+    if (*count == 0) *item = 0;
+    // apply server-side block change
+    makeBlockChange(x, y, z, block);
+  }
+
+  // sync hotbar contents to player
+  sc_setContainerSlot(player->client_fd, 0, serverSlotToClientSlot(0, player->hotbar), *count, *item);
+
+}
+
 void spawnMob (uint8_t type, short x, uint8_t y, short z, uint8_t health) {
 
   for (int i = 0; i < MAX_MOBS; i ++) {