Better Examples

.gitignore

@@ -1,7 +1,7 @@
 out
 debian/tmp
 .vscode
-build
+build*
 CMakeLists.txt.user
 *.autosave
 AppImageBuilder.yml

example-mod/.gitignore

@@ -1 +0,0 @@
-build

example-mods/README.md

@@ -1,7 +1,8 @@
-# Example Mod
+# Example Mods
 This is an example of a mod that cane be built using the modding SDK.
 
-This specific mod adds even more items and blocks to the Creative Inventory. It was originally by [@Bigjango13](https://github.com/bigjango13).
+* **Expanded Creative Mod**: This specific mod adds even more items and blocks to the Creative Inventory. It was originally by [@Bigjango13](https://github.com/bigjango13).
+* **Chat Commands Mod**: This specific mod makes an chat message starting with a ``/`` handled by the MCPI API.
 
 ## The SDK
 The modding SDK is a collection of exported CMake targets that allows anyone to create their own MCPI mod!

example-mods/chat-commands/.gitignore

@@ -0,0 +1,14 @@
+out
+debian/tmp
+.vscode
+build*
+CMakeLists.txt.user
+*.autosave
+AppImageBuilder.yml
+appimage-builder-cache
+appimage-build
+AppDir
+*.zsync
+*.AppImage
+core*
+qemu_*

example-mods/chat-commands/CMakeLists.txt

@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.16.0)
+
+# Build For ARM
+set(CMAKE_C_COMPILER arm-linux-gnueabihf-gcc)
+set(CMAKE_CXX_COMPILER arm-linux-gnueabihf-g++)
+
+# Start Project
+project(chat-commands)
+
+# Include SDK
+include("$ENV{HOME}/.minecraft-pi/sdk/lib/minecraft-pi-reborn-client/sdk/sdk.cmake")
+
+# Build
+add_library(chat-commands SHARED chat-commands.cpp)
+target_link_libraries(chat-commands mods-headers reborn-patch symbols chat misc)

example-mods/chat-commands/chat-commands.cpp

@@ -0,0 +1,25 @@
+// Headers
+
+#include <libreborn/libreborn.h>
+#include <symbols/minecraft.h>
+#include <mods/chat/chat.h>
+#include <mods/misc/misc.h>
+
+// The Actual Mod
+HOOK(chat_handle_packet_send, void, (unsigned char *minecraft, unsigned char *packet)) {
+    // Get Message
+    char *message = *(char **) (packet + ChatPacket_message_property_offset);
+    if (message[0] == '/') {
+        // API Command
+        unsigned char *gui = minecraft + Minecraft_gui_property_offset;
+        std::string out = chat_send_api_command(minecraft, &message[1]);
+        if (out.length() > 0 && out[out.length() - 1] == '\n') {
+            out[out.length() - 1] = '\0';
+        }
+        misc_add_message(gui, out.c_str());
+    } else {
+        // Call Original Method
+        ensure_chat_handle_packet_send();
+        (*real_chat_handle_packet_send)(minecraft, packet);
+    }
+}

example-mods/expanded-creative/.gitignore

@@ -0,0 +1,14 @@
+out
+debian/tmp
+.vscode
+build*
+CMakeLists.txt.user
+*.autosave
+AppImageBuilder.yml
+appimage-builder-cache
+appimage-build
+AppDir
+*.zsync
+*.AppImage
+core*
+qemu_*

mods/include/mods/chat/chat.h

@@ -2,6 +2,12 @@
 
 #include <libreborn/libreborn.h>
 
+#ifdef __cplusplus
+#include <string>
+// Send API Command
+std::string chat_send_api_command(unsigned char *minecraft, char *str);
+#endif
+
 #ifdef __cplusplus
 extern "C" {
 #endif
@@ -13,6 +19,7 @@ unsigned int chat_get_counter();
 
 // Override using the HOOK() macro to provide customized chat behavior.
 void chat_send_message(unsigned char *server_side_network_handler, char *username, char *message);
+void chat_handle_packet_send(unsigned char *minecraft, unsigned char *packet);
 
 #ifdef __cplusplus
 }

mods/include/mods/misc/misc.h

@@ -10,6 +10,9 @@ void misc_run_on_tick(misc_update_function_t function);
 
 void Level_saveLevelData_injection(unsigned char *level);
 
+// Use this instead of directly calling Gui::addMessage(), it has proper logging!
+void misc_add_message(unsigned char *gui, const char *text);
+
 #ifdef __cplusplus
 }
 #endif

mods/src/chat/chat.cpp

@@ -29,22 +29,25 @@ int _chat_enabled = 0;
 #define MAX_CHAT_MESSAGE_LENGTH 512
 
 // Send API Command
-#ifndef MCPI_SERVER_MODE
+std::string chat_send_api_command(unsigned char *minecraft, char *str) {
-static void send_api_command(unsigned char *minecraft, char *str) {
     struct ConnectedClient client;
     client.sock = -1;
     client.str = "";
     client.time = 0;
     unsigned char *command_server = *(unsigned char **) (minecraft + Minecraft_command_server_property_offset);
     if (command_server != NULL) {
-        (*CommandServer_parse)(command_server, client, str);
+        return (*CommandServer_parse)(command_server, client, str);
+    } else {
+        return "";
     }
 }
+
+#ifndef MCPI_SERVER_MODE
 // Send API Chat Command
 static void send_api_chat_command(unsigned char *minecraft, char *str) {
     char *command = NULL;
     safe_asprintf(&command, "chat.post(%s)\n", str);
-    send_api_command(minecraft, command);
+    chat_send_api_command(minecraft, command);
     free(command);
 }
 #endif
@@ -57,24 +60,28 @@ void chat_send_message(unsigned char *server_side_network_handler, char *usernam
     (*ServerSideNetworkHandler_displayGameMessage)(server_side_network_handler, std::string(full_message));
     free(full_message);
 }
+// Handle Chat packet Send
+void chat_handle_packet_send(unsigned char *minecraft, unsigned char *packet) {
+    unsigned char *rak_net_instance = *(unsigned char **) (minecraft + Minecraft_rak_net_instance_property_offset);
+    unsigned char *rak_net_instance_vtable = *(unsigned char **) rak_net_instance;
+    RakNetInstance_isServer_t RakNetInstance_isServer = *(RakNetInstance_isServer_t *) (rak_net_instance_vtable + RakNetInstance_isServer_vtable_offset);
+    if ((*RakNetInstance_isServer)(rak_net_instance)) {
+        // Hosting Multiplayer
+        char *message = *(char **) (packet + ChatPacket_message_property_offset);
+        unsigned char *server_side_network_handler = *(unsigned char **) (minecraft + Minecraft_network_handler_property_offset);
+        chat_send_message(server_side_network_handler, *default_username, message);
+    } else {
+        // Client
+        RakNetInstance_send_t RakNetInstance_send = *(RakNetInstance_send_t *) (rak_net_instance_vtable + RakNetInstance_send_vtable_offset);
+        (*RakNetInstance_send)(rak_net_instance, packet);
+    }
+}
 
 // Manually Send (And Loopback) ChatPacket
 static void CommandServer_parse_CommandServer_dispatchPacket_injection(unsigned char *command_server, unsigned char *packet) {
     unsigned char *minecraft = *(unsigned char **) (command_server + CommandServer_minecraft_property_offset);
     if (minecraft != NULL) {
-        unsigned char *rak_net_instance = *(unsigned char **) (minecraft + Minecraft_rak_net_instance_property_offset);
+        chat_handle_packet_send(minecraft, packet);
-        unsigned char *rak_net_instance_vtable = *(unsigned char **) rak_net_instance;
-        RakNetInstance_isServer_t RakNetInstance_isServer = *(RakNetInstance_isServer_t *) (rak_net_instance_vtable + RakNetInstance_isServer_vtable_offset);
-        if ((*RakNetInstance_isServer)(rak_net_instance)) {
-            // Hosting Multiplayer
-            char *message = *(char **) (packet + ChatPacket_message_property_offset);
-            unsigned char *server_side_network_handler = *(unsigned char **) (minecraft + Minecraft_network_handler_property_offset);
-            chat_send_message(server_side_network_handler, *default_username, message);
-        } else {
-            // Client
-            RakNetInstance_send_t RakNetInstance_send = *(RakNetInstance_send_t *) (rak_net_instance_vtable + RakNetInstance_send_vtable_offset);
-            (*RakNetInstance_send)(rak_net_instance, packet);
-        }
     }
 }
 

mods/src/misc/logging.cpp

@@ -35,6 +35,9 @@ static void Gui_addMessage_injection(unsigned char *gui, std::string const& text
     // Free
     free(new_message);
 }
+void misc_add_message(unsigned char *gui, const char *text) {
+    Gui_addMessage_injection(gui, text);
+}
 
 // Print Progress Reports
 static int last_progress = -1;