implement basic crafting

src/crafting.c

@@ -0,0 +1,84 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "globals.h"
+#include "registries.h"
+#include "crafting.h"
+
+void getCraftingOutput (PlayerData *player, uint8_t *count, uint16_t *item) {
+
+  uint8_t i, filled = 0, first = 10;
+  for (i = 0; i < 9; i ++) {
+    if (player->craft_items[i]) {
+      filled ++;
+      if (first == 10) first = i;
+    }
+  }
+
+  uint8_t first_col = first % 3, first_row = first / 3;
+
+  switch (filled) {
+
+    case 0:
+      *item = 0;
+      *count = 0;
+      return;
+
+    case 1:
+      switch (player->craft_items[first]) {
+        case I_oak_log:
+          *item = I_oak_planks;
+          *count = 4;
+          return;
+        case I_oak_planks:
+          *item = 715; // oak_button
+          *count = 1;
+          return;
+
+        default: break;
+      }
+      break;
+
+    case 2:
+      switch (player->craft_items[first]) {
+        case I_oak_planks:
+          if (first_col != 2 && player->craft_items[first + 1] == I_oak_planks) {
+            *item = 731; // oak_pressure_plate
+            *count = 1;
+            return;
+          } else if (first_row != 2 && player->craft_items[first + 3] == I_oak_planks) {
+            *item = I_stick;
+            *count = 4;
+            return;
+          }
+          break;
+
+        default: break;
+      }
+
+    case 4:
+      switch (player->craft_items[first]) {
+        case I_oak_planks:
+          if (
+            first_col != 2 && first_row != 2 &&
+            player->craft_items[first + 1] == I_oak_planks &&
+            player->craft_items[first + 3] == I_oak_planks &&
+            player->craft_items[first + 4] == I_oak_planks
+          ) {
+            *item = 320; // crafting_table
+            *count = 1;
+            return;
+          }
+          break;
+
+        default: break;
+      }
+
+    default: break;
+
+  }
+
+  *count = 0;
+  *item = 0;
+
+}

src/crafting.h

@@ -0,0 +1,10 @@
+#ifndef CRAFTING_H
+#define CRAFTING_H
+
+#include <stdlib.h>
+
+#include "globals.h"
+
+void getCraftingOutput (PlayerData *player, uint8_t *count, uint16_t *item);
+
+#endif

src/globals.h

@@ -2,6 +2,7 @@
 #define H_GLOBALS
 
 #include <stdint.h>
+#include <unistd.h>
 
 #define true 1
 #define false 0
@@ -41,6 +42,7 @@ typedef struct {
   int8_t pitch;
   uint8_t hotbar;
   uint16_t inventory_items[41];
+  uint16_t craft_items[9];
   uint8_t inventory_count[41];
 } PlayerData;
 

src/packets.c

@@ -10,6 +10,7 @@
 #include "varnum.h"
 #include "registries.h"
 #include "worldgen.h"
+#include "crafting.h"
 
 // C->S Handshake
 int cs_handshake (int client_fd) {
@@ -432,6 +433,7 @@ int cs_useItemOn (int client_fd) {
 
 }
 
+// C->S Click Container
 int cs_clickContainer (int client_fd) {
 
   int window_id = readVarInt(client_fd);
@@ -446,18 +448,19 @@ int cs_clickContainer (int client_fd) {
   PlayerData *player;
   if (getPlayerData(client_fd, &player)) return 1;
 
-  uint8_t slot, count;
+  uint8_t slot, count, craft = false;
   uint16_t item;
   int tmp;
 
   for (int i = 0; i < changes_count; i ++) {
 
     slot = clientSlotToServerSlot(readUint16(client_fd));
+    if (slot > 40) craft = true;
 
     if (!readByte(client_fd)) { // no item?
       if (slot != 255) {
         player->inventory_items[slot] = 0;
-        player->inventory_count[slot] = 0;
+        if (slot <= 40) player->inventory_count[slot] = 0;
       }
       continue;
     }
@@ -471,13 +474,18 @@ int cs_clickContainer (int client_fd) {
     tmp = readVarInt(client_fd);
     recv(client_fd, recv_buffer, tmp, MSG_WAITALL);
 
-    if (item <= 255 && count > 0) {
+    if (count > 0) {
       player->inventory_items[slot] = item;
-      player->inventory_count[slot] = count;
+      if (slot <= 40) player->inventory_count[slot] = count;
     }
 
   }
 
+  if (craft) {
+    getCraftingOutput(player, &count, &item);
+    sc_setContainerSlot(client_fd, window_id, 0, count, item);
+  }
+
   return 0;
 
 }

src/tools.c

@@ -186,6 +186,14 @@ uint8_t clientSlotToServerSlot (uint8_t slot) {
   if (slot >= 9 && slot <= 35) return slot;
   if (slot == 45) return 40;
   if (slot >= 5 && slot <= 8) return 4 - (slot - 5) + 36;
+
+  // map inventory crafting slots to player data crafting grid (semi-hack)
+  // this abuses the fact that the buffers are adjacent in player data
+  if (slot == 1) return 41;
+  if (slot == 2) return 42;
+  if (slot == 3) return 44;
+  if (slot == 4) return 45;
+
   return 255;
 }