Reimplement cut stock game gibbing feature

docs/CHANGELOG.md

@@ -47,6 +47,8 @@ Version 1.9.0 (not released yet)
 - Add `server_password` command
 - Add `$DF CTF Flag Return Time` option in dedicated server config
 - Add mod name to main menu
+- Add `gore_level` command
+- Add gibbing when enemies die from explosives (gore level 2)
 
 [@is-this-c](https://github.com/is-this-c)
 - Support `©` in TrueType fonts

game_patch/multi/server.cpp

@@ -407,6 +407,18 @@ FunHook<float(rf::Entity*, float, int, int, int)> entity_damage_hook{
             }
         }
 
+        // should entity gib?
+        if (damaged_ep->life < -100.0f && damage_type == 3 &&   // explosive
+            damaged_ep->material == 3 &&                        // flesh
+            rf::game_get_gore_level() >= 2 &&
+            !(damaged_ep->entity_flags & 0x2000000) &&          // custom_corpse (used by snakes and sea creature)
+            !(damaged_ep->entity_flags & 0x1) &&                // dying
+            !(damaged_ep->entity_flags & 0x1000) &&             // in_water
+            !(damaged_ep->entity_flags & 0x2000))               // eye_under_water
+        {
+            damaged_ep->entity_flags |= 0x80;
+        }
+
         float real_damage = entity_damage_hook.call_target(damaged_ep, damage, killer_handle, damage_type, killer_uid);
 
         if (rf::is_server && is_pvp_damage && real_damage > 0.0f) {

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 +203,85 @@ CodeInjection entity_process_pre_hide_riot_shield_injection{
     },
 };
 
+// avoids gibbing if gore level is too low or if this specific corpse shouldn't gib
+CodeInjection corpse_damage_patch{
+    0x00417C6A,
+    [](auto& regs) {
+        rf::Corpse* cp = regs.esi;
+
+        if (rf::game_get_gore_level() < 2 ||
+            cp->corpse_flags & 0x400 ||         // drools_slime (used by snakes)
+            cp->corpse_flags & 0x4)             // custom_state_anim (used by sea creature)
+        {
+            regs.eip = 0x00417C97;
+        }
+    }
+};
+
+FunHook<void(int)> entity_blood_throw_gibs_hook{
+    0x0042E3C0, [](int handle) {
+        rf::Object* objp = rf::obj_from_handle(handle);
+
+        if (!objp) {
+            return;
+        }
+
+        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);
+    }
+};
+
+ConsoleCommand2 gore_level_cmd{
+    "gore_level",
+    [](std::optional<int> gore_setting) {
+        if (gore_setting) {
+            if (*gore_setting >= 0 && *gore_setting <= 2) {
+                rf::game_set_gore_level(*gore_setting);
+                rf::console::print("Set gore level to {}", rf::game_get_gore_level());
+            }
+            else {
+                rf::console::print("Invalid gore level specified. Allowed range is 0 (minimal) to 2 (maximum).");
+            }
+        }
+        else {
+            rf::console::print("Gore level is {}", rf::game_get_gore_level());
+        }
+
+
+    },
+    "Set gore level.",
+    "gore_level [level]"
+};
+
 void entity_do_patch()
 {
     // Fix player being stuck to ground when jumping, especially when FPS is greater than 200
@@ -252,4 +333,11 @@ 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
+    corpse_damage_patch.install();
+	entity_blood_throw_gibs_hook.install();
+
+    // Commands
+    gore_level_cmd.register_cmd();
 }

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<>

game_patch/rf/player/player.h

@@ -173,4 +173,6 @@ namespace rf
     static auto& player_do_frame = addr_as_ref<void(Player*)>(0x004A2700);
     static auto& player_make_weapon_current_selection = addr_as_ref<void(Player *player, int weapon_type)>(0x004A4980);
     static auto& player_start_death_fade = addr_as_ref<void(Player *pp, float time_sec, void (*callback)(Player *))>(0x004A73E0);
+    static auto& game_get_gore_level = addr_as_ref<int()>(0x00436A20);
+    static auto& game_set_gore_level = addr_as_ref<int(int gore_setting)>(0x00436A10);
 }

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