From 06af8c821fded2ee9601febe35b79faa81801604 Mon Sep 17 00:00:00 2001
From: TheBrokenRail <connor24nolan@live.com>
Date: Sat, 25 Feb 2023 00:26:45 -0500
Subject: [PATCH] Add Cave Generation

---
 launcher/src/client/available-feature-flags |  1 +
 mods/src/misc/misc.c                        | 22 +++++++++++++++++++++
 mods/src/server/server.cpp                  |  8 +++++++-
 symbols/include/symbols/minecraft.h         | 19 ++++++++++++++++++
 4 files changed, 49 insertions(+), 1 deletion(-)

diff --git a/launcher/src/client/available-feature-flags b/launcher/src/client/available-feature-flags
index 4b473043a..e98763877 100644
--- a/launcher/src/client/available-feature-flags
+++ b/launcher/src/client/available-feature-flags
@@ -45,3 +45,4 @@ TRUE Improved Classic Title Screen
 FALSE Disable Speed Bridging
 FALSE Disable Creative Mode Mining Delay
 FALSE Add Biome Colors To Grass
+TRUE Generate Caves
diff --git a/mods/src/misc/misc.c b/mods/src/misc/misc.c
index 43e80d58b..1bc8d6a90 100644
--- a/mods/src/misc/misc.c
+++ b/mods/src/misc/misc.c
@@ -373,6 +373,23 @@ static int32_t TallGrass_getColor_injection(unsigned char *tile, unsigned char *
     }
 }
 
+// Generate Caves
+static void RandomLevelSource_buildSurface_injection(unsigned char *random_level_source, int32_t chunk_x, int32_t chunk_y, unsigned char *chunk_data, unsigned char **biomes) {
+    // Call Original Method
+    (*RandomLevelSource_buildSurface)(random_level_source, chunk_x, chunk_y, chunk_data, biomes);
+
+    // Get Level
+    unsigned char *level = *(unsigned char **) (random_level_source + RandomLevelSource_level_property_offset);
+
+    // Get Cave Feature
+    unsigned char *cave_feature = random_level_source + RandomLevelSource_cave_feature_property_offset;
+    unsigned char *cave_feature_vtable = *(unsigned char **) cave_feature;
+
+    // Generate
+    LargeFeature_apply_t LargeCaveFeature_apply = *(LargeFeature_apply_t *) (cave_feature_vtable + LargeFeature_apply_vtable_offset);
+    (*LargeCaveFeature_apply)(cave_feature, random_level_source, level, chunk_x, chunk_y, chunk_data, 0);
+}
+
 // Init
 static void nop() {
 }
@@ -484,6 +501,11 @@ void init_misc() {
         patch_address((void *) TallGrass_getColor_vtable_addr, (void *) TallGrass_getColor_injection);
     }
 
+    // Generate Caves
+    if (feature_has("Generate Caves", server_auto)) {
+        overwrite_calls((void *) RandomLevelSource_buildSurface, (void *) RandomLevelSource_buildSurface_injection);
+    }
+
     // Init C++ And Logging
     _init_misc_cpp();
     _init_misc_logging();
diff --git a/mods/src/server/server.cpp b/mods/src/server/server.cpp
index 1508b8c52..532950eb1 100644
--- a/mods/src/server/server.cpp
+++ b/mods/src/server/server.cpp
@@ -60,7 +60,8 @@ static ServerProperties &get_server_properties() {
 #define DEFAULT_WORLD_NAME "world"
 #define DEFAULT_MAX_PLAYERS "4"
 #define DEFAULT_WHITELIST "false"
-#define DEFAULT_DEATH_MESSAGES "false"
+#define DEFAULT_DEATH_MESSAGES "true"
+#define DEFAULT_GENERATE_CAVES "true"
 
 // Get World Name
 static std::string get_world_name() {
@@ -487,6 +488,9 @@ static const char *get_features() {
         if (get_server_properties().get_bool("death-messages", DEFAULT_DEATH_MESSAGES)) {
             features += "Implement Death Messages|";
         }
+        if (get_server_properties().get_bool("generate-caves", DEFAULT_GENERATE_CAVES)) {
+            features += "Generate Caves|";
+        }
     }
     return features.c_str();
 }
@@ -536,6 +540,8 @@ static void server_init() {
         properties_file_output << "whitelist=" DEFAULT_WHITELIST "\n";
         properties_file_output << "# Enable Death Messages\n";
         properties_file_output << "death-messages=" DEFAULT_DEATH_MESSAGES "\n";
+        properties_file_output << "# Generate Caves\n";
+        properties_file_output << "generate-caves=" DEFAULT_GENERATE_CAVES "\n";
         properties_file_output.close();
         // Re-Open File
         properties_file = std::ifstream(file);
diff --git a/symbols/include/symbols/minecraft.h b/symbols/include/symbols/minecraft.h
index 31ea41f5e..b611ed54b 100644
--- a/symbols/include/symbols/minecraft.h
+++ b/symbols/include/symbols/minecraft.h
@@ -74,6 +74,8 @@ static unsigned char *Options_Option_ANAGLYPH = (unsigned char *) 0x136c08; // O
 
 static bool *Minecraft_useAmbientOcclusion = (bool *) 0x136b90;
 
+static bool *HeavyTile_instaFall = (bool *) 0x180cc0;
+
 // Structures
 
 struct AABB {
@@ -883,6 +885,23 @@ static WorkbenchScreen_t WorkbenchScreen = (WorkbenchScreen_t) 0x301cc;
 static uint32_t Biome_color_property_offset = 0x2c; // int32_t
 static uint32_t Biome_leaf_color_property_offset = 0x34; // int32_t
 
+// LargeFeature
+
+typedef void (*LargeFeature_apply_t)(unsigned char *large_feature, unsigned char *chunk_source, unsigned char *level, int32_t chunk_x, int32_t chunk_y, unsigned char *chunk_data, int32_t unused);
+static uint32_t LargeFeature_apply_vtable_offset = 0x8;
+
+// RandomLevelSource
+
+typedef void (*RandomLevelSource_postProcess_t)(unsigned char *random_level_source, unsigned char *chunk_source, int32_t chunk_x, int32_t chunk_y);
+static RandomLevelSource_postProcess_t RandomLevelSource_postProcess = (RandomLevelSource_postProcess_t) 0xb2238;
+static void *RandomLevelSource_postProcess_vtable_addr = (void *) 0x1105ac;
+
+typedef void (*RandomLevelSource_buildSurface_t)(unsigned char *random_level_source, int32_t chunk_x, int32_t chunk_y, unsigned char *chunk_data, unsigned char **biomes);
+static RandomLevelSource_buildSurface_t RandomLevelSource_buildSurface = (RandomLevelSource_buildSurface_t) 0xb32ec;
+
+static uint32_t RandomLevelSource_cave_feature_property_offset = 0x8; // LargeCaveFeature
+static uint32_t RandomLevelSource_level_property_offset = 0x72c8; // Level *
+
 // Method That Require C++ Types
 #ifdef __cplusplus