Reimplement cut stock game gibbing feature

common/include/common/config/GameConfig.h

@@ -60,6 +60,7 @@ struct GameConfig
     CfgVar<bool> mesh_static_lighting = true;
     CfgVar<bool> glares = true;
     CfgVar<bool> show_enemy_bullets = true;
+    CfgVar<bool> gibs = false;
 
     static constexpr float min_fov = 75.0f;
     static constexpr float max_fov = 160.0f;

common/src/config/GameConfig.cpp

@@ -171,6 +171,7 @@ bool GameConfig::visit_vars(T&& visitor, bool is_save)
     result &= visitor(dash_faction_key, "Swap Assault Rifle Controls", swap_assault_rifle_controls);
     result &= visitor(dash_faction_key, "Swap Grenade Controls", swap_grenade_controls);
     result &= visitor(dash_faction_key, "Glares", glares);
+    result &= visitor(dash_faction_key, "Gibs", gibs);
     result &= visitor(dash_faction_key, "Linear Pitch", linear_pitch);
     result &= visitor(dash_faction_key, "Show Enemy Bullets", show_enemy_bullets);
     result &= visitor(dash_faction_key, "Keep Launcher Open", keep_launcher_open);

docs/CHANGELOG.md

@@ -45,6 +45,7 @@ Version 1.9.0 (not released yet)
 - Properly handle WM_PAINT in dedicated server, may improve performance (DF bug)
 - Fix crash when `verify_level` command is run without a level being loaded
 - Fix cockpit not rendering for any jeeps after the first one entered each level load
+- Add gibbing when enemies die from explosives (enable with `gibs` command)
 
 Version 1.8.0 (released 2022-09-17)
 -----------------------------------

game_patch/object/entity.cpp

@@ -3,8 +3,10 @@
 #include <patch_common/CallHook.h>
 #include <patch_common/AsmWriter.h>
 #include <xlog/xlog.h>
+#include "../os/console.h"
 #include "../rf/entity.h"
 #include "../rf/corpse.h"
+#include "../rf/multi.h"
 #include "../rf/weapon.h"
 #include "../rf/player/player.h"
 #include "../rf/particle_emitter.h"
@@ -201,6 +203,104 @@ CodeInjection entity_process_pre_hide_riot_shield_injection{
     },
 };
 
+// initialize new AiInfo field used in `entity_damage` to store if on death, the last damage dealt was explosive
+CodeInjection ai_init_ai_info_injection{
+    0x00403022,
+    [](auto& regs) {
+        rf::AiInfo* aip = regs.esi;
+        if (aip) {
+            aip->explosive_last_damage = false;
+        }
+    }
+};
+
+bool consider_gibs() {
+    return g_game_config.gibs && !rf::is_multi;
+}
+
+FunHook<void(int)> entity_blood_throw_gibs_hook{
+    0x0042E3C0, [](int handle) {
+        if (!consider_gibs()) {
+            return;
+        }
+
+        rf::Object* objp = rf::obj_from_handle(handle);
+
+        if (!objp) {
+            return; // invalid object
+        }
+
+        int explode_vclip_index = rf::vclip_lookup("bloodsplat");
+        int chunk_explode_vclip_index = rf::vclip_lookup("bloodsplat");
+        float explode_vclip_radius = 1.0f;
+        const char* debris_filename = "df_meatchunks0.V3D";
+
+        static const int debris_max_lifetime = 7000; // ms
+        static const float debris_velocity = 8.5f;
+        static const float damage_scale = 1.0f;
+        static rf::String cust_snd_set = "gib bounce";
+
+        if (objp->type == rf::OT_ENTITY) { // use overrides from associated entity.tbl class if present
+            rf::Entity* ep = static_cast<rf::Entity*>(objp);
+
+            explode_vclip_index = (ep->info->explode_vclip_index > 0)
+				? ep->info->explode_vclip_index : explode_vclip_index;
+
+            explode_vclip_radius = (ep->info->explode_vclip_radius > 0.0f)
+				? ep->info->explode_vclip_radius : explode_vclip_radius;
+
+            debris_filename = (!ep->info->debris_filename.empty())
+                ? ep->info->debris_filename.c_str() : debris_filename;
+        }
+        else if (objp->type != rf::OT_CORPSE) { // do not gib anything except entities and corpses
+            return;
+        }
+
+        rf::game_do_explosion(
+            explode_vclip_index, objp->room, 0, &objp->pos, explode_vclip_radius, damage_scale, 0);
+
+        rf::debris_spawn_from_object(
+            objp, debris_filename, chunk_explode_vclip_index, debris_max_lifetime, debris_velocity, &cust_snd_set);
+    }
+};
+
+CodeInjection entity_damage_explosive_death_injection{
+    0x0041A413,
+    [](auto& regs) {        
+        rf::Entity* ep = regs.esi;
+        int damage_type = regs.ebp;
+        ep->ai.explosive_last_damage = (damage_type == 3); // explosive damage
+        if (consider_gibs() && ep) {
+            // using body temp > 90 (from entity.tbl class) as the determining factor for if an entity should gib
+            // in stock game, this includes only humanoid enemies and reeper/baby reeper
+            // in mods, this lets the mod author control which of their mod's entities gib
+            if (ep->ai.explosive_last_damage && ep->info->body_temp >= 90.0f) {
+                ep->death_anim_index = -1; // no death anim needed if entity is gibbing
+            }
+        }
+    }
+};
+
+CodeInjection entity_dying_frame_explode_injection{
+    0x0041EE4C,
+    [](auto& regs) {
+        rf::Entity* ep = regs.esi;
+        if (consider_gibs() && ep && ep->ai.explosive_last_damage && ep->info->body_temp >= 90.0f) {
+            regs.eip = 0x0041EE55;
+        }
+    },
+};
+
+ConsoleCommand2 gibs_cmd{
+    "gibs",
+    []() {
+        g_game_config.gibs = !g_game_config.gibs;
+        g_game_config.save();
+        rf::console::print("Gibs are {}.", g_game_config.gibs ? "enabled" : "disabled");
+    },
+    "Make enemies and corpses explode into chunks from explosives (single player only)",
+};
+
 void entity_do_patch()
 {
     // Fix player being stuck to ground when jumping, especially when FPS is greater than 200
@@ -252,4 +352,13 @@ void entity_do_patch()
 
     // Hide riot shield third person model if entity is hidden (e.g. in cutscenes)
     entity_process_pre_hide_riot_shield_injection.install();
+
+	// Restore cut stock game feature for entities and corpses exploding into chunks
+    ai_init_ai_info_injection.install();
+	entity_blood_throw_gibs_hook.install();
+    entity_damage_explosive_death_injection.install();
+    entity_dying_frame_explode_injection.install();
+
+    // Commands
+    gibs_cmd.register_cmd();
 }

game_patch/rf/ai.h

@@ -212,6 +212,9 @@ namespace rf
         float movement_radius;
         float movement_height;
         bool use_custom_attack_range;
+#ifdef DASH_FACTION
+        bool explosive_last_damage;
+#endif
         float custom_attack_range;
         int ai_flags;
     };

game_patch/rf/entity.h

@@ -425,6 +425,9 @@ namespace rf
     static auto& entity_turn_weapon_on = addr_as_ref<void __cdecl(int entity_handle, int weapon_type, bool alt_fire)>(0x0041A870);
     static auto& entity_turn_weapon_off = addr_as_ref<void __cdecl(int entity_handle, int weapon_type)>(0x0041AE70);
     static auto& entity_restore_mesh = addr_as_ref<void(Entity *ep, const char *mesh_name)>(0x0042C570);
+    static auto& game_do_explosion = addr_as_ref<void(int vclip, GRoom* src_room, const Vector3* src_pos,
+        const Vector3* pos, float radius, float damage_scale, const Vector3* dir)>(0x00436490);
+    static auto& vclip_lookup = addr_as_ref<int(const char*)>(0x004C1D00);
 
     static auto& entity_list = addr_as_ref<Entity>(0x005CB060);
     static auto& local_player_entity = addr_as_ref<Entity*>(0x005CB054);

game_patch/rf/object.h

@@ -134,6 +134,9 @@ namespace rf
     static auto& obj_light_calculate = addr_as_ref<void()>(0x0048B0E0);
 
     static auto& object_list = addr_as_ref<Object>(0x0073D880);
+
+    static auto& debris_spawn_from_object = addr_as_ref<void(Object* objp, const char* debris_v3d_filename,
+        int explode_index, int max_lifetime_ms, float velocity, rf::String* cust_snd_set)>(0x004133C0);
 }
 
 template<>

resources/CMakeLists.txt

@@ -44,6 +44,7 @@ add_packfile(dashfaction.vpp
     images/bullet_icon_powercell_1.tga
     images/bullet_icon_rocket_1.tga
     images/bullet_icon_shotgun_1.tga
+    images/df_gore1.tga
     images/enviro0_1.tga
     images/enviro10_1.tga
     images/enviro20_1.tga
@@ -87,6 +88,7 @@ add_packfile(dashfaction.vpp
     meshes/Vat1.v3m
     meshes/coffeesmokedtbl2.v3m
     meshes/coffeesmokedtblAlt.v3m
+    meshes/df_meatchunks0.v3m
 
     standard_vs:${CMAKE_BINARY_DIR}/shaders/standard_vs.bin
     character_vs:${CMAKE_BINARY_DIR}/shaders/character_vs.bin

resources/licensing-info.txt

@@ -27,6 +27,7 @@ Chris "Goober" Parsons:
 * HUD textures for the big mode
 * symbol glyphs in ttf fonts
 * launcher header
+* texture and mesh for gibs
 
 natalie <[email protected]>:
 * code contributions