From aa027ec549e147b6edbf1251d909f62ca89a994b Mon Sep 17 00:00:00 2001
From: iProgramInCpp <iprogramincpp@gmail.com>
Date: Fri, 4 Aug 2023 09:54:39 +0300
Subject: [PATCH] * Improve the inventory. Prepare for survival mode inventory.

---
 source/GUI/Gui.cpp                            |   2 +-
 .../GUI/Screen/IngameBlockSelectionScreen.cpp | 101 +++---
 .../GUI/Screen/IngameBlockSelectionScreen.hpp |   5 +
 source/Inventory.cpp                          | 322 ++++++++----------
 source/Inventory.hpp                          |  30 +-
 source/Network/ClientSideNetworkHandler.cpp   |   2 +-
 source/Network/ServerSideNetworkHandler.cpp   |   2 +-
 source/World/Entity/Player.cpp                |   3 +
 source/World/Item/ItemInstance.cpp            |   6 +
 source/World/Item/ItemInstance.hpp            |   1 +
 source/World/LevelData.cpp                    |   6 +-
 source/World/Renderer/ItemRenderer.cpp        | 119 ++++---
 12 files changed, 290 insertions(+), 309 deletions(-)

diff --git a/source/GUI/Gui.cpp b/source/GUI/Gui.cpp
index fbad417..edc0aa2 100644
--- a/source/GUI/Gui.cpp
+++ b/source/GUI/Gui.cpp
@@ -315,7 +315,7 @@ void Gui::tick()
 
 void Gui::renderSlot(int slot, int x, int y, float f)
 {
-	int itemID = m_pMinecraft->m_pLocalPlayer->m_pInventory->getSelectionSlotItemId(slot);
+	int itemID = m_pMinecraft->m_pLocalPlayer->m_pInventory->getQuickSlotItemId(slot);
 	if (itemID < 0)
 		return;
 
diff --git a/source/GUI/Screen/IngameBlockSelectionScreen.cpp b/source/GUI/Screen/IngameBlockSelectionScreen.cpp
index 552ea2d..b8960de 100644
--- a/source/GUI/Screen/IngameBlockSelectionScreen.cpp
+++ b/source/GUI/Screen/IngameBlockSelectionScreen.cpp
@@ -9,16 +9,27 @@
 #include "IngameBlockSelectionScreen.hpp"
 #include "ItemRenderer.hpp"
 
-#define C_SLOTS_HEIGHT ((C_MAX_INVENTORY_ITEMS + 8) / 9)
-
 std::string g_sNotAvailableInDemoVersion = "Not available in the demo version";
 
+Inventory* IngameBlockSelectionScreen::getInventory()
+{
+	return m_pMinecraft->m_pLocalPlayer->m_pInventory;
+}
+
+int IngameBlockSelectionScreen::getBottomY()
+{
+	// -1 for some reason, -2 to make it align between top of screen and top of hotbar instead
+	return (m_height - 22 * (getSlotsHeight() - 2)) / 2;
+}
+
 int IngameBlockSelectionScreen::getSelectedSlot(int x, int y)
 {
-	int bottom = m_height - 151;
+	int slotsHeight = getSlotsHeight();
+	int bottom = m_height - getBottomY();
+	int top = bottom - slotsHeight * 22;
 	int left = m_width / 2 - 87;
 
-	if (y < bottom)
+	if (y < top)
 		return -1;
 	if (x < left)
 		return -1;
@@ -27,7 +38,7 @@ int IngameBlockSelectionScreen::getSelectedSlot(int x, int y)
 	if (idx > 8)
 		return -1;
 
-	return idx + 36 - 9 * ((y - bottom) / 22);
+	return idx + 9 * slotsHeight - 9 * ((y - top) / 22);
 }
 
 int IngameBlockSelectionScreen::getSlotPosX(int x)
@@ -37,27 +48,28 @@ int IngameBlockSelectionScreen::getSlotPosX(int x)
 
 int IngameBlockSelectionScreen::getSlotPosY(int y)
 {
-	return m_height - 63 - 22 * y;
+	return m_height - getBottomY() - 22 * y;
+}
+
+int IngameBlockSelectionScreen::getSlotsHeight()
+{
+	return (getInventory()->getNumSlots() + 8) / 9;
 }
 
 bool IngameBlockSelectionScreen::isAllowed(int slot)
 {
-	if (slot < 0 || slot > C_MAX_INVENTORY_ITEMS-1)
-		return false;
-
-#ifdef DEMO
-	return slot > 17;
-#endif
-	return true;
+	return slot >= 0 && slot < getInventory()->getNumSlots();
 }
 
 void IngameBlockSelectionScreen::init()
 {
-	Inventory* pInv = m_pMinecraft->m_pLocalPlayer->m_pInventory;
+	Inventory* pInv = getInventory();
 
-	for (int i = 9; i < C_MAX_HOTBAR_ITEMS + C_MAX_INVENTORY_ITEMS; i++)
+	int nItems = pInv->getNumItems();
+
+	for (int i = 0; i < nItems; i++)
 	{
-		if (pInv->getSelectionSlotItemId(i) == pInv->getSelectedItemId())
+		if (pInv->getItem(i)->m_itemID == pInv->getSelectedItemId())
 		{
 			m_selectedSlot = i - 9;
 			break;
@@ -65,17 +77,16 @@ void IngameBlockSelectionScreen::init()
 	}
 
 	if (!isAllowed(m_selectedSlot))
-		m_selectedSlot = 27;
+		m_selectedSlot = 0;
 }
 
 void IngameBlockSelectionScreen::renderSlot(int index, int x, int y, float f)
 {
-	int item = m_pMinecraft->m_pLocalPlayer->m_pInventory->getSelectionSlotItemId(index);
-	if (item < 0)
+	ItemInstance* pItem = getInventory()->getItem(index);
+	if (!pItem)
 		return;
 
-	ItemInstance inst(item, 2, 0);
-	ItemRenderer::renderGuiItem(m_pMinecraft->m_pFont, m_pMinecraft->m_pTextures, &inst, x, y, item);
+	ItemRenderer::renderGuiItem(m_pMinecraft->m_pFont, m_pMinecraft->m_pTextures, pItem, x, y, pItem != nullptr);
 }
 
 void IngameBlockSelectionScreen::renderSlots()
@@ -83,13 +94,13 @@ void IngameBlockSelectionScreen::renderSlots()
 	glColor4f(1.0f, 1.0f, 1.0f, 1.0f);
 	m_pMinecraft->m_pTextures->loadAndBindTexture("gui/gui.png");
 
-	for (int y = 0; y != -22 * C_SLOTS_HEIGHT; y -= 22)
-		blit(m_width / 2 - 182 / 2, m_height - 66 + y, 0, 0, 182, 22, 0, 0);
+	for (int y = 0; y != -22 * getSlotsHeight(); y -= 22)
+		blit(m_width / 2 - 182 / 2, m_height - 3 - getBottomY() + y, 0, 0, 182, 22, 0, 0);
 
 	if (m_selectedSlot >= 0)
-		blit(m_width / 2 - 92 + 20 * (m_selectedSlot % 9), m_height - 67 - 22 * (m_selectedSlot / 9), 0, 22, 24, 22, 0, 0);
+		blit(m_width / 2 - 92 + 20 * (m_selectedSlot % 9), m_height - 4 - getBottomY() - 22 * (m_selectedSlot / 9), 0, 22, 24, 22, 0, 0);
 
-	for (int y = 0, index = 9; y < C_SLOTS_HEIGHT; y++)
+	for (int y = 0, index = 0; y < getSlotsHeight(); y++)
 	{
 		int posY = getSlotPosY(y);
 		for (int x = 0; x < 9; x++)
@@ -151,44 +162,10 @@ void IngameBlockSelectionScreen::mouseReleased(int x, int y, int type)
 
 void IngameBlockSelectionScreen::selectSlotAndClose()
 {
-	Inventory* pInv = m_pMinecraft->m_pLocalPlayer->m_pInventory;
-	int item = pInv->getSelectionSlotItemId(m_selectedSlot + 9);
-	int idx = 0;
-
-	// @TODO: Fix gotos
-#ifdef ENH_ENABLE_9TH_SLOT
-#define MAX_ITEMS (C_MAX_HOTBAR_ITEMS - 1)
-#else
-#define MAX_ITEMS (C_MAX_HOTBAR_ITEMS - 2)
-#endif
-
-	if (item == pInv->getSelectionSlotItemId(0))
-	{
-	label_4:
-		if (!idx)
-			goto label_5;
-	}
-	else while (++idx != MAX_ITEMS)
-	{
-		if (item == pInv->getSelectionSlotItemId(idx))
-			goto label_4;
-	}
-
-	while (true)
-	{
-		int item = pInv->getSelectionSlotItemId(idx - 1);
-		pInv->setSelectionSlotItemId(idx, item);
-
-		if (idx == 1)
-			break;
-
-		--idx;
-	}
-label_5:
-	pInv->setSelectionSlotItemId(0, item);
-	pInv->selectSlot(0);
+	Inventory* pInv = getInventory();
+	
+	pInv->selectItem(m_selectedSlot);
 
 	m_pMinecraft->m_pSoundEngine->play("random.click");
-
 	m_pMinecraft->setScreen(nullptr);
 }
diff --git a/source/GUI/Screen/IngameBlockSelectionScreen.hpp b/source/GUI/Screen/IngameBlockSelectionScreen.hpp
index 5e8613b..c1cc70a 100644
--- a/source/GUI/Screen/IngameBlockSelectionScreen.hpp
+++ b/source/GUI/Screen/IngameBlockSelectionScreen.hpp
@@ -10,12 +10,17 @@
 
 #include "Screen.hpp"
 
+class Inventory;
+
 class IngameBlockSelectionScreen : public Screen
 {
 public:
+	Inventory* getInventory();
+	int getBottomY();
 	int getSelectedSlot(int x, int y);
 	int getSlotPosX(int x);
 	int getSlotPosY(int y);
+	int getSlotsHeight();
 	bool isAllowed(int slot);
 	void renderSlots();
 	void renderDemoOverlay();
diff --git a/source/Inventory.cpp b/source/Inventory.cpp
index 96aa305..bb081e7 100644
--- a/source/Inventory.cpp
+++ b/source/Inventory.cpp
@@ -1,85 +1,6 @@
 #include "Inventory.hpp"
 #include "Item.hpp"
 
-#ifdef DEMO
-
-static void MoveItemToSlot(int* pItems, int item, int index)
-{
-	if (index < 0 || index >= C_MAX_INVENTORY_ITEMS)
-		return;
-
-	if (pItems[index] == item)
-		return;
-
-	// search for the item, if it doesn't exist, return
-
-	int i = 0;
-	for (; i < C_MAX_INVENTORY_ITEMS; i++)
-	{
-		if (pItems[i] == item)
-			break;
-	}
-
-	if (i == C_MAX_INVENTORY_ITEMS)
-		return;
-
-	// swap the slot where our `item` was, and the slot at the index
-	int oldItem = pItems[index];
-	pItems[index] = pItems[i];
-	pItems[i] = oldItem;
-
-#ifndef ORIGINAL_CODE
-	if (item > 0)
-#endif
-	printf("adding item: %s to %d\n", Tile::tiles[item]->getDescriptionId().c_str(), index);
-}
-
-static void ShuffleInventoryForDemo(int* pHotbar, int* pItems)
-{
-	pHotbar[0] = Tile::wood->m_ID;
-	pHotbar[1] = Tile::stoneBrick->m_ID;
-	pHotbar[2] = Tile::sandStone->m_ID;
-	pHotbar[3] = Tile::dirt->m_ID;
-	pHotbar[4] = Tile::redBrick->m_ID;
-	pHotbar[5] = Tile::rock->m_ID;
-	pHotbar[6] = Tile::torch->m_ID;
-	pHotbar[7] = Tile::ladder->m_ID;
-#ifdef ENH_ENABLE_9TH_SLOT
-	pHotbar[8] = Tile::rose->m_ID;
-#endif
-
-	MoveItemToSlot(pItems, pHotbar[0], 27);
-	MoveItemToSlot(pItems, pHotbar[1], 28);
-	MoveItemToSlot(pItems, pHotbar[2], 29);
-	MoveItemToSlot(pItems, pHotbar[3], 30);
-	MoveItemToSlot(pItems, pHotbar[4], 31);
-	MoveItemToSlot(pItems, pHotbar[5], 32);
-	MoveItemToSlot(pItems, pHotbar[6], 33);
-	MoveItemToSlot(pItems, pHotbar[7], 34);
-	MoveItemToSlot(pItems, Tile::flower->m_ID, 35);
-	MoveItemToSlot(pItems, Tile::cloth_10->m_ID, 18);
-	MoveItemToSlot(pItems, Tile::cloth_20->m_ID, 19);
-	MoveItemToSlot(pItems, Tile::cloth_30->m_ID, 20);
-	MoveItemToSlot(pItems, Tile::cloth_40->m_ID, 21);
-	MoveItemToSlot(pItems, Tile::cloth_50->m_ID, 22);
-	MoveItemToSlot(pItems, Tile::cloth_60->m_ID, 23);
-	MoveItemToSlot(pItems, Tile::cloth_70->m_ID, 24);
-	MoveItemToSlot(pItems, Tile::sand->m_ID, 25);
-	MoveItemToSlot(pItems, Tile::glass->m_ID, 26);
-	MoveItemToSlot(pItems, Tile::mushroom1->m_ID, 1);
-	MoveItemToSlot(pItems, Tile::obsidian->m_ID, 8);
-
-#ifndef ORIGINAL_CODE
-	// @NOTE: For Testing
-	//pHotbar[1] = Item::camera->m_itemID;
-	//pHotbar[2] = Tile::tnt->m_ID;
-	//pHotbar[3] = Tile::water->m_ID;
-	//pHotbar[4] = Tile::lava->m_ID;
-#endif
-}
-
-#endif
-
 Inventory::Inventory(Player* pPlayer)
 {
 	m_pPlayer = pPlayer;
@@ -87,116 +8,175 @@ Inventory::Inventory(Player* pPlayer)
 
 	for (int i = 0; i < C_MAX_HOTBAR_ITEMS; i++)
 		m_hotbar[i] = -1;
-	for (int i = 0; i < C_MAX_INVENTORY_ITEMS; i++)
-		m_items[i] = -1;
-
-	// @NOTE: This layout of the hotbar and inventory can be seen in the following video,
-	// titled "Minecraft - Pocket Edition on Xperia Play".
-	// https://www.youtube.com/watch?v=jO-y5wzmK4E
-
-	m_hotbar[0]  = Tile::wood->m_ID;
-	m_hotbar[1]  = Tile::cloth_10->m_ID;
-	m_hotbar[2]  = Tile::cloth_20->m_ID;
-	m_hotbar[3]  = Tile::cloth_30->m_ID;
-	m_hotbar[4]  = Tile::cloth_40->m_ID;
-	m_hotbar[5]  = Tile::cloth_50->m_ID;
-	m_hotbar[6]  = Tile::cloth_60->m_ID;
-	m_hotbar[7]  = Tile::ladder->m_ID;
-
-	// slot 8 missing. I assume that's the "..." button
-
-	m_items[0] = Tile::rock->m_ID;
-	m_items[1] = Tile::stoneBrick->m_ID;
-	m_items[2] = Tile::sandStone->m_ID;
-	m_items[3] = Tile::wood->m_ID;
-	m_items[4] = Tile::treeTrunk->m_ID;
-	m_items[5] = Tile::goldBlock->m_ID;
-	m_items[6] = Tile::ironBlock->m_ID;
-	m_items[7] = Tile::emeraldBlock->m_ID;
-	m_items[8] = Tile::redBrick->m_ID;
-	m_items[9] = Tile::leaves->m_ID;
-	m_items[10] = Tile::cloth_10->m_ID;
-	m_items[11] = Tile::cloth_20->m_ID;
-	m_items[12] = Tile::cloth_30->m_ID;
-	m_items[13] = Tile::cloth_40->m_ID;
-	m_items[14] = Tile::cloth_50->m_ID;
-	m_items[15] = Tile::cloth_60->m_ID;
-	m_items[16] = Tile::cloth_70->m_ID;
-	m_items[17] = Tile::glass->m_ID;
-	m_items[18] = Tile::cloth_01->m_ID;
-	m_items[19] = Tile::cloth_11->m_ID;
-	m_items[20] = Tile::cloth_21->m_ID;
-	m_items[21] = Tile::cloth_31->m_ID;
-	m_items[22] = Tile::cloth_41->m_ID;
-	m_items[23] = Tile::stairs_wood->m_ID;
-	m_items[24] = Tile::stairs_stone->m_ID;
-	m_items[25] = Tile::stoneSlabHalf->m_ID;
-	m_items[26] = Tile::sand->m_ID;
-	m_items[27] = Tile::ladder->m_ID;
-	m_items[28] = Tile::torch->m_ID;
-	m_items[29] = Tile::flower->m_ID;
-	m_items[30] = Tile::rose->m_ID;
-	m_items[31] = Tile::mushroom1->m_ID;
-	m_items[32] = Tile::mushroom2->m_ID;
-	m_items[33] = Tile::reeds->m_ID;
-	m_items[34] = Tile::obsidian->m_ID;
-	m_items[35] = Tile::dirt->m_ID;
-
-#ifdef DEMO
-	ShuffleInventoryForDemo(m_hotbar, m_items);
-#endif
-
-#ifdef ENH_EXTRA_ITEMS_IN_INV
-	// populate the 5th row now with items that might be of interest
-	m_items[36] = Tile::tnt->m_ID;
-	m_items[37] = Item::camera->m_itemID;
-	m_items[38] = Item::door_wood->m_itemID;
-	m_items[39] = Tile::gravel->m_ID;
-	m_items[40] = Tile::cloth->m_ID;
-	m_items[41] = Tile::mossStone->m_ID;
-	m_items[42] = Tile::bookshelf->m_ID;
-	m_items[43] = Tile::sponge->m_ID;
-	m_items[44] = Tile::sapling->m_ID;
-#endif
 }
 
-#ifdef ENH_ENABLE_9TH_SLOT
-#define HOTBAR_DIFF 0
-#else
-#define HOTBAR_DIFF 1
-#endif
-
-int Inventory::getSelectionSize()
+void Inventory::prepareCreativeInventory()
 {
-	return C_MAX_HOTBAR_ITEMS;
+	m_bIsSurvival = false;
+
+	m_items.clear();
+
+	// add some items
+	addCreativeItem(Tile::rock->m_ID);
+	addCreativeItem(Tile::stoneBrick->m_ID);
+	addCreativeItem(Tile::sandStone->m_ID);
+	addCreativeItem(Tile::wood->m_ID);
+	addCreativeItem(Tile::treeTrunk->m_ID);
+	addCreativeItem(Tile::goldBlock->m_ID);
+	addCreativeItem(Tile::ironBlock->m_ID);
+	addCreativeItem(Tile::emeraldBlock->m_ID);
+	addCreativeItem(Tile::redBrick->m_ID);
+	addCreativeItem(Tile::leaves->m_ID);
+	addCreativeItem(Tile::cloth_10->m_ID);
+	addCreativeItem(Tile::cloth_20->m_ID);
+	addCreativeItem(Tile::cloth_30->m_ID);
+	addCreativeItem(Tile::cloth_40->m_ID);
+	addCreativeItem(Tile::cloth_50->m_ID);
+	addCreativeItem(Tile::cloth_60->m_ID);
+	addCreativeItem(Tile::cloth_70->m_ID);
+	addCreativeItem(Tile::glass->m_ID);
+	addCreativeItem(Tile::cloth_01->m_ID);
+	addCreativeItem(Tile::cloth_11->m_ID);
+	addCreativeItem(Tile::cloth_21->m_ID);
+	addCreativeItem(Tile::cloth_31->m_ID);
+	addCreativeItem(Tile::cloth_41->m_ID);
+	addCreativeItem(Tile::stairs_wood->m_ID);
+	addCreativeItem(Tile::stairs_stone->m_ID);
+	addCreativeItem(Tile::stoneSlabHalf->m_ID);
+	addCreativeItem(Tile::sand->m_ID);
+	addCreativeItem(Tile::ladder->m_ID);
+	addCreativeItem(Tile::torch->m_ID);
+	addCreativeItem(Tile::flower->m_ID);
+	addCreativeItem(Tile::rose->m_ID);
+	addCreativeItem(Tile::mushroom1->m_ID);
+	addCreativeItem(Tile::mushroom2->m_ID);
+	addCreativeItem(Tile::reeds->m_ID);
+	addCreativeItem(Tile::obsidian->m_ID);
+	addCreativeItem(Tile::dirt->m_ID);
+	addCreativeItem(Tile::tnt->m_ID);
+	addCreativeItem(Tile::gravel->m_ID);
+	addCreativeItem(Tile::cloth->m_ID);
+	addCreativeItem(Tile::mossStone->m_ID);
+	addCreativeItem(Tile::bookshelf->m_ID);
+	addCreativeItem(Tile::sponge->m_ID);
+	addCreativeItem(Tile::sapling->m_ID);
+	addCreativeItem(Tile::water->m_ID);
+	addCreativeItem(Tile::lava->m_ID);
+	addCreativeItem(Tile::fire->m_ID);
+	addCreativeItem(Item::camera->m_itemID);
+	addCreativeItem(Item::door_wood->m_itemID);
+	addCreativeItem(Item::door_iron->m_itemID);
+
+	for (int i = C_MAX_HOTBAR_ITEMS - 1; i >= 0; i--)
+		selectItem(i);
 }
 
-int Inventory::getSelectionSlotItemId(int slot)
+void Inventory::prepareSurvivalInventory()
 {
-	if (slot >= 0 && slot < C_MAX_HOTBAR_ITEMS - HOTBAR_DIFF)
-		return m_hotbar[slot];
+	m_bIsSurvival = true;
+	m_items.clear();
+}
 
-	if (slot > C_MAX_HOTBAR_ITEMS + C_MAX_INVENTORY_ITEMS - 1 || slot < 0)
+int Inventory::getNumSlots()
+{
+	if (m_bIsSurvival)
+		return C_NUM_SURVIVAL_SLOTS;
+
+	return getNumItems();
+}
+
+int Inventory::getNumItems()
+{
+	return int(m_items.size());
+}
+
+void Inventory::addCreativeItem(int itemID, int auxValue)
+{
+	m_items.emplace_back(ItemInstance(itemID, 1, auxValue));
+}
+
+ItemInstance* Inventory::getItem(int slotNo)
+{
+	if (slotNo < 0 || slotNo >= int(m_items.size()))
+		return nullptr;
+
+	return &m_items[slotNo];
+}
+
+int Inventory::getQuickSlotItemId(int slotNo)
+{
+	if (slotNo < 0 || slotNo >= C_MAX_HOTBAR_ITEMS)
+		return -1;
+	
+	int idx = m_hotbar[slotNo];
+	ItemInstance* pInst = getItem(idx);
+	if (!pInst)
 		return -1;
 
-	return m_items[slot - C_MAX_HOTBAR_ITEMS];
-}
-
-void Inventory::setSelectionSlotItemId(int slotNo, int item)
-{
-	if (slotNo >= 0 && slotNo < C_MAX_HOTBAR_ITEMS - HOTBAR_DIFF)
-		m_hotbar[slotNo] = item;
+	return pInst->m_itemID;
 }
 
 int Inventory::getSelectedItemId()
 {
-	return getSelectionSlotItemId(m_SelectedHotbarSlot);
+	return getQuickSlotItemId(m_SelectedHotbarSlot);
+}
+
+void Inventory::selectItem(int slotNo)
+{
+	if (slotNo < 0 || slotNo >= getNumItems())
+		return;
+
+	// look for it in the hotbar
+	for (int i = 0; i < C_MAX_HOTBAR_ITEMS; i++)
+	{
+		if (m_hotbar[i] == slotNo)
+		{
+			m_SelectedHotbarSlot = i;
+			return;
+		}
+	}
+
+	for (int i = C_MAX_HOTBAR_ITEMS - 2; i >= 0; i--)
+		m_hotbar[i + 1] = m_hotbar[i];
+
+	m_hotbar[0] = slotNo;
+	m_SelectedHotbarSlot = 0;
 }
 
 void Inventory::selectSlot(int slotNo)
 {
-	if (slotNo < 0 || slotNo >= C_MAX_HOTBAR_ITEMS - HOTBAR_DIFF)
+	if (slotNo < 0 || slotNo >= C_MAX_HOTBAR_ITEMS)
 		return;
 
 	m_SelectedHotbarSlot = slotNo;
 }
+
+void Inventory::setQuickSlotIndexByItemId(int slotNo, int itemID)
+{
+	if (slotNo < 0 || slotNo >= C_MAX_HOTBAR_ITEMS)
+		return;
+
+	// TODO: survival mode handling
+	for (int i = 0; i < getNumItems(); i++)
+	{
+		if (m_items[i].m_itemID == itemID)
+		{
+			m_hotbar[slotNo] = i;
+			return;
+		}
+	}
+
+	m_hotbar[slotNo] = -1;
+}
+
+void Inventory::selectItemById(int itemID)
+{
+	for (int i = 0; i < getNumItems(); i++)
+	{
+		if (m_items[i].m_itemID != itemID)
+			continue;
+
+		selectItem(i);
+		return;
+	}
+}
diff --git a/source/Inventory.hpp b/source/Inventory.hpp
index c0b1759..50322f3 100644
--- a/source/Inventory.hpp
+++ b/source/Inventory.hpp
@@ -1,33 +1,41 @@
 #pragma once
 
 #include "Player.hpp"
+#include "ItemInstance.hpp"
 
 class Player; // in case we're included from Player.hpp
 
 #define C_MAX_HOTBAR_ITEMS (9)
 
-#ifdef ENH_EXTRA_ITEMS_IN_INV
-#define C_MAX_INVENTORY_ITEMS (36+9)
-#else
-#define C_MAX_INVENTORY_ITEMS (36)
-#endif
+#define C_NUM_SURVIVAL_SLOTS (36)
 
 class Inventory
 {
 public:
 	Inventory(Player*);
+	void prepareCreativeInventory();
+	void prepareSurvivalInventory();
 
-	int getSelectionSize();
-	int getSelectionSlotItemId(int slotNo);
+	int getNumSlots();
+	int getNumItems();
+
+	void addCreativeItem(int itemID, int auxValue = 0);
+
+	ItemInstance* getItem(int slotNo);
+	int getQuickSlotItemId(int slotNo);
 	int getSelectedItemId();
+	void selectItem(int slotNo); // selects an item by slot number and puts it in the quick slots if needed
 	void selectSlot(int slotNo);
-	void setSelectionSlotItemId(int slotNo, int item);
+
+	void setQuickSlotIndexByItemId(int slotNo, int itemID);
+	void selectItemById(int itemID);
 
 public:
-	int m_SelectedHotbarSlot;
-	Player* m_pPlayer;
+	int m_SelectedHotbarSlot = 0;
+	Player* m_pPlayer = nullptr;
+	bool m_bIsSurvival = false;
 
 	int m_hotbar[C_MAX_HOTBAR_ITEMS];
-	int m_items [C_MAX_INVENTORY_ITEMS];
+	std::vector<ItemInstance> m_items;
 };
 
diff --git a/source/Network/ClientSideNetworkHandler.cpp b/source/Network/ClientSideNetworkHandler.cpp
index 9ceff72..2dcfc89 100644
--- a/source/Network/ClientSideNetworkHandler.cpp
+++ b/source/Network/ClientSideNetworkHandler.cpp
@@ -335,7 +335,7 @@ void ClientSideNetworkHandler::handle(const RakNet::RakNetGUID& rakGuid, PlayerE
 		return;
 	}
 
-	pPlayer->m_pInventory->setSelectionSlotItemId(0, pPlayerEquipmentPkt->m_itemID);
+	pPlayer->m_pInventory->selectItemById(pPlayerEquipmentPkt->m_itemID);
 	pPlayer->m_pInventory->selectSlot(0);
 }
 
diff --git a/source/Network/ServerSideNetworkHandler.cpp b/source/Network/ServerSideNetworkHandler.cpp
index 52d8351..8ca16e0 100644
--- a/source/Network/ServerSideNetworkHandler.cpp
+++ b/source/Network/ServerSideNetworkHandler.cpp
@@ -200,7 +200,7 @@ void ServerSideNetworkHandler::handle(const RakNet::RakNetGUID& guid, PlayerEqui
 		return;
 	}
 
-	pPlayer->m_pInventory->setSelectionSlotItemId(0, packet->m_itemID);
+	pPlayer->m_pInventory->selectItemById(packet->m_itemID);
 	pPlayer->m_pInventory->selectSlot(0);
 
 	redistributePacket(packet, guid);
diff --git a/source/World/Entity/Player.cpp b/source/World/Entity/Player.cpp
index 38dff19..38d7b58 100644
--- a/source/World/Entity/Player.cpp
+++ b/source/World/Entity/Player.cpp
@@ -15,6 +15,9 @@ Player::Player(Level* pLevel) : Mob(pLevel)
 
 	m_pInventory = new Inventory(this);
 
+	// @TODO: GameMode::prepareInventory
+	m_pInventory->prepareCreativeInventory();
+
 	field_84 = 1.62f;
 
 	Pos pos = m_pLevel->getSharedSpawnPos();
diff --git a/source/World/Item/ItemInstance.cpp b/source/World/Item/ItemInstance.cpp
index d9073a3..b24c720 100644
--- a/source/World/Item/ItemInstance.cpp
+++ b/source/World/Item/ItemInstance.cpp
@@ -14,10 +14,16 @@ void ItemInstance::init(int itemID, int amount, int auxValue)
 {
 	m_itemID = itemID;
 	m_amount = amount;
+	m_auxValue = auxValue;
 
 	//@BUG? Not using the auxValue.  This is problematic in the case of wool and dyes.
 }
 
+ItemInstance::ItemInstance()
+{
+	init(0, 0, 0);
+}
+
 ItemInstance::ItemInstance(Item* pItem)
 {
 	init(pItem->m_itemID, 1, 0);
diff --git a/source/World/Item/ItemInstance.hpp b/source/World/Item/ItemInstance.hpp
index 92295c5..1a1aba0 100644
--- a/source/World/Item/ItemInstance.hpp
+++ b/source/World/Item/ItemInstance.hpp
@@ -20,6 +20,7 @@ class Player;
 class ItemInstance
 {
 public:
+	ItemInstance();
 	ItemInstance(Item*);
 	ItemInstance(Item*, int amount);
 	ItemInstance(Item*, int amount, int auxValue);
diff --git a/source/World/LevelData.cpp b/source/World/LevelData.cpp
index 7725d50..573ed81 100644
--- a/source/World/LevelData.cpp
+++ b/source/World/LevelData.cpp
@@ -70,8 +70,9 @@ void PlayerData::loadPlayer(Player* player)
 	// @NOTE: Why are we updating m_pos, field_3C and field_98 above if we do this?
 	player->setPos(m_pos.x, m_pos.y, m_pos.z);
 
+	// TODO: survival mode stuff
 	for (int i = 0; i < C_MAX_HOTBAR_ITEMS; i++)
-		player->m_pInventory->setSelectionSlotItemId(i, m_hotbar[i]);
+		player->m_pInventory->setQuickSlotIndexByItemId(i, m_hotbar[i]);
 }
 
 void PlayerData::savePlayer(Player* player)
@@ -85,6 +86,7 @@ void PlayerData::savePlayer(Player* player)
 	field_26 = player->field_BC;
 	field_28 = player->field_7C;
 
+	// TODO: survival mode stuff
 	for (int i = 0; i < C_MAX_HOTBAR_ITEMS; i++)
-		m_hotbar[i] = player->m_pInventory->getSelectionSlotItemId(i);
+		m_hotbar[i] = player->m_pInventory->getQuickSlotItemId(i);
 }
diff --git a/source/World/Renderer/ItemRenderer.cpp b/source/World/Renderer/ItemRenderer.cpp
index aaee605..ce8f06f 100644
--- a/source/World/Renderer/ItemRenderer.cpp
+++ b/source/World/Renderer/ItemRenderer.cpp
@@ -165,87 +165,86 @@ void ItemRenderer::renderGuiItem(Font* font, Textures* textures, ItemInstance* i
 		return;
 
 	int itemID = instance->m_itemID;
-	if (b)
-	{
-		// @BUG: This is one of the reasons you can't actually hold items in early Minecraft.
-		// There's an attempt to index `Tile::tiles` out of bounds, which of course fails, and likely crashes the game. :(
-		// If only they'd placed the g_ItemFrames[itemID] check before the TileRenderer::canRender check...
+	if (!b)
+		return;
+
+	// @BUG: This is one of the reasons you can't actually hold items in early Minecraft.
+	// There's an attempt to index `Tile::tiles` out of bounds, which of course fails, and likely crashes the game. :(
+	// If only they'd placed the g_ItemFrames[itemID] check before the TileRenderer::canRender check...
 #ifdef ORIGINAL_CODE
 #define COND_PRE
 #else
 #define COND_PRE (0 <= itemID && itemID < C_MAX_TILES) && 
 #endif
 
-		bool bCanRenderAsIs = false;
+	bool bCanRenderAsIs = false;
 
 #ifdef ENH_3D_INVENTORY_TILES
-		// We don't need to care about g_ItemFrames at all since blocks will get 3D rendered and 2D props will use the terrain.png as the texture.
-		if (COND_PRE(TileRenderer::canRender(Tile::tiles[itemID]->getRenderShape())))
-		{
-			bCanRenderAsIs = true;
-		}
+	// We don't need to care about g_ItemFrames at all since blocks will get 3D rendered and 2D props will use the terrain.png as the texture.
+	if (COND_PRE(TileRenderer::canRender(Tile::tiles[itemID]->getRenderShape())))
+	{
+		bCanRenderAsIs = true;
+	}
 #else
-		if (COND_PRE(TileRenderer::canRender(Tile::tiles[itemID]->getRenderShape()) || g_ItemFrames[itemID] != 0))
-		{
-			bCanRenderAsIs = true;
-		}
+	if (COND_PRE(TileRenderer::canRender(Tile::tiles[itemID]->getRenderShape()) || g_ItemFrames[itemID] != 0))
+	{
+		bCanRenderAsIs = true;
+	}
 #endif
-		
-
-		if (itemID < C_MAX_TILES && bCanRenderAsIs)
-		{
+	
+	if (itemID < C_MAX_TILES && bCanRenderAsIs)
+	{
 #ifndef ENH_3D_INVENTORY_TILES
-			textures->loadAndBindTexture(C_BLOCKS_NAME);
+		textures->loadAndBindTexture(C_BLOCKS_NAME);
 
-			float texU = float(g_ItemFrames[instance->m_itemID] % 10) * 48.0f;
-			float texV = float(g_ItemFrames[instance->m_itemID] / 10) * 48.0f;
+		float texU = float(g_ItemFrames[instance->m_itemID] % 10) * 48.0f;
+		float texV = float(g_ItemFrames[instance->m_itemID] / 10) * 48.0f;
 
-			Tesselator& t = Tesselator::instance;
-			// @NOTE: These do nothing, due to a previous t.voidBeginAndEndCalls call.
-			t.begin();
-			t.vertexUV(float(x +  0), float(y + 16), 0.0f,  texU          / 512.0f, (texV + 48.0f) / 512.0f);
-			t.vertexUV(float(x + 16), float(y + 16), 0.0f, (texU + 48.0f) / 512.0f, (texV + 48.0f) / 512.0f);
-			t.vertexUV(float(x + 16), float(y +  0), 0.0f, (texU + 48.0f) / 512.0f,  texV          / 512.0f);
-			t.vertexUV(float(x +  0), float(y +  0), 0.0f,  texU          / 512.0f,  texV          / 512.0f);
-			t.draw();
+		Tesselator& t = Tesselator::instance;
+		// @NOTE: These do nothing, due to a previous t.voidBeginAndEndCalls call.
+		t.begin();
+		t.vertexUV(float(x +  0), float(y + 16), 0.0f,  texU          / 512.0f, (texV + 48.0f) / 512.0f);
+		t.vertexUV(float(x + 16), float(y + 16), 0.0f, (texU + 48.0f) / 512.0f, (texV + 48.0f) / 512.0f);
+		t.vertexUV(float(x + 16), float(y +  0), 0.0f, (texU + 48.0f) / 512.0f,  texV          / 512.0f);
+		t.vertexUV(float(x +  0), float(y +  0), 0.0f,  texU          / 512.0f,  texV          / 512.0f);
+		t.draw();
 #else
-			textures->loadAndBindTexture(C_TERRAIN_NAME);
+		textures->loadAndBindTexture(C_TERRAIN_NAME);
 
-			//glDisable(GL_BLEND);
-			//glEnable(GL_DEPTH_TEST);
+		//glDisable(GL_BLEND);
+		//glEnable(GL_DEPTH_TEST);
 
-			glPushMatrix();
+		glPushMatrix();
 
-			// scale, rotate, and translate the tile onto the correct screen coordinate
-			glTranslatef((GLfloat)x + 8, (GLfloat)y + 8, -8);
-			glScalef(10, 10, 10);
-			glRotatef(210.0f, 1.0f, 0.0f, 0.0f);
-			glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
+		// scale, rotate, and translate the tile onto the correct screen coordinate
+		glTranslatef((GLfloat)x + 8, (GLfloat)y + 8, -8);
+		glScalef(10, 10, 10);
+		glRotatef(210.0f, 1.0f, 0.0f, 0.0f);
+		glRotatef(45.0f, 0.0f, 1.0f, 0.0f);
 
-			#ifdef ENH_SHADE_HELD_TILES
-			#	define PARM_HACK , 1
-			#else
-			#	define PARM_HACK
-			#endif
-			tileRenderer->renderTile(Tile::tiles[itemID], instance->m_auxValue PARM_HACK);
-			#undef PARM_HACK
+		#ifdef ENH_SHADE_HELD_TILES
+		#	define PARM_HACK , 1
+		#else
+		#	define PARM_HACK
+		#endif
+		tileRenderer->renderTile(Tile::tiles[itemID], instance->m_auxValue PARM_HACK);
+		#undef PARM_HACK
 
-			glPopMatrix();
+		glPopMatrix();
 
-			//glDisable(GL_DEPTH_TEST);
-			//glEnable(GL_BLEND);
+		//glDisable(GL_DEPTH_TEST);
+		//glEnable(GL_BLEND);
 #endif
-		}
-		else if (instance->getIcon() >= 0)
-		{
-			// @BUG: The last bound texture will be the texture that ALL items will take. This is because begin and end calls
-			// have been void'ed by a  t.voidBeginAndEndCalls call in Gui::render.
-			if (instance->m_itemID <= 255)
-				textures->loadAndBindTexture(C_TERRAIN_NAME);
-			else
-				textures->loadAndBindTexture(C_ITEMS_NAME);
+	}
+	else if (instance->getIcon() >= 0)
+	{
+		// @BUG: The last bound texture will be the texture that ALL items will take. This is because begin and end calls
+		// have been void'ed by a  t.voidBeginAndEndCalls call in Gui::render.
+		if (instance->m_itemID <= 255)
+			textures->loadAndBindTexture(C_TERRAIN_NAME);
+		else
+			textures->loadAndBindTexture(C_ITEMS_NAME);
 
-			blit(x, y, 16 * (instance->getIcon() % 16), 16 * (instance->getIcon() / 16), 16, 16);
-		}
+		blit(x, y, 16 * (instance->getIcon() % 16), 16 * (instance->getIcon() / 16), 16, 16);
 	}
 }