Footsteps for enemies/teammates in MP

docs/CHANGELOG.md

@@ -51,6 +51,7 @@ Version 1.3.0 (Bakeapple): Not yet released
 [@nickalreadyinuse](https://github.com/nickalreadyinuse)
 - Optimize network performance for `af_obj_update` packets and bot decommission logic
 - Sync animation state for crouched players in first person spectate view
+- Implement enemy and teammate footstep audio for weapons other than pistol in multiplayer. Enabled by default with server permission, `cl_footsteps` to toggle.
 
 Version 1.2.2 (Willow): Released Jan-04-2026
 --------------------------------

game_patch/misc/alpine_settings.h

@@ -148,6 +148,7 @@ struct AlpineGameSettings
     bool always_clamp_official_lightmaps = false;
     bool static_bomb_code = false;
     bool entity_pain_sounds = true;
+    bool footsteps = true;
     static constexpr int min_gib_chunk_count = 7;
     static constexpr int max_gib_chunk_count = 100;
     int gib_chunk_count = 14;

game_patch/multi/alpine_packets.cpp

@@ -21,6 +21,7 @@
 #include "../sound/sound.h"
 #include "../misc/alpine_settings.h"
 #include "../object/object.h"
+#include "../object/object_private.h"
 
 void af_send_packet(rf::Player* player, const void* data, int len, bool is_reliable)
 {
@@ -1253,6 +1254,8 @@ static void build_af_server_info_packet(af_server_info_packet& pkt)
         af |= af_server_info_flags::SIF_LOCATION_PINGING;
     if (g_alpine_server_config_active_rules.spawn_delay.enabled)
         af |= af_server_info_flags::SIF_DELAYED_SPAWNS;
+    if (g_alpine_server_config.allow_footsteps)
+        af |= af_server_info_flags::SIF_ALLOW_FOOTSTEPS;
     if (g_alpine_server_config.signal_cfg_changed) {
         af |= af_server_info_flags::SIF_SERVER_CFG_CHANGED;
         for (rf::Player& player : SinglyLinkedList{rf::player_list}) {
@@ -1423,13 +1426,17 @@ static void af_process_server_info_packet(const void* data, size_t len, const rf
     server_info.gaussian_spread = (pkt.af_flags & af_server_info_flags::SIF_GAUSSIAN_SPREAD) != 0;
     server_info.location_pinging = (pkt.af_flags & af_server_info_flags::SIF_LOCATION_PINGING) != 0;
     server_info.delayed_spawns = (pkt.af_flags & af_server_info_flags::SIF_DELAYED_SPAWNS) != 0;
+    server_info.allow_footsteps = (pkt.af_flags & af_server_info_flags::SIF_ALLOW_FOOTSTEPS) != 0;
 
     if ((pkt.af_flags & af_server_info_flags::SIF_SERVER_CFG_CHANGED) != 0) {
         g_remote_server_cfg_popup.set_cfg_changed();
     }
 
     server_info.semi_auto_cooldown = static_cast<int>(pkt.semi_auto_cooldown);
 
+    // Update footstep activation based on new server permissions
+    evaluate_footsteps();
+
     //xlog::warn("af_server_info processed - gt {}, cooldown {}", pkt.game_type, server_info.semi_auto_cooldown.value());
 }
 

game_patch/multi/alpine_packets.h

@@ -183,6 +183,7 @@ enum af_server_info_flags : uint32_t {
     SIF_LOCATION_PINGING = 1u << 10,
     SIF_DELAYED_SPAWNS = 1u << 11,
     SIF_SERVER_CFG_CHANGED = 1u << 12,
+    SIF_ALLOW_FOOTSTEPS = 1u << 13,
 };
 
 // Subset of `rf::NetGameFlags`.

game_patch/multi/dedi_cfg.cpp

@@ -1077,6 +1077,10 @@ static void apply_known_key_in_order(AlpineServerConfig& cfg, const std::string&
         if (auto v = node.value<bool>())
             cfg.allow_unlimited_fps = *v;
     }
+    else if (key == "allow_footsteps") {
+        if (auto v = node.value<bool>())
+            cfg.allow_footsteps = *v;
+    }
     else if (key == "use_sp_damage_calculation") {
         if (auto v = node.value<bool>())
             cfg.use_sp_damage_calculation = *v;
@@ -1858,6 +1862,7 @@ void print_alpine_dedicated_server_config_info(std::string& output, bool verbose
     std::format_to(iter, "  Allow lightmap only mode:              {}\n", cfg.allow_lightmaps_only);
     std::format_to(iter, "  Allow disable muzzle flash:            {}\n", cfg.allow_disable_muzzle_flash);
     std::format_to(iter, "  Allow disable 240 FPS cap:             {}\n", cfg.allow_unlimited_fps);
+    std::format_to(iter, "  Allow footsteps:                       {}\n", cfg.allow_footsteps);
     std::format_to(iter, "  SP-style damage calculation:           {}\n", cfg.use_sp_damage_calculation);
     std::format_to(iter, "  Exclude bots from player count:        {}\n", cfg.exclude_bots_from_player_count);
 

game_patch/multi/kill.cpp

@@ -18,6 +18,7 @@
 #include "server_internal.h"
 #include "alpine_packets.h"
 #include "../misc/player.h"
+#include "../object/object_private.h"
 
 bool kill_messages = true;
 
@@ -353,6 +354,9 @@ FunHook<void()> multi_level_init_hook{
             reset_gungame_notifications();
             weapon_manager.initialize_score_to_weapon_map();
         }
+
+        // Re-evaluate footstep state when level loads
+        evaluate_footsteps();
     },
 };
 

game_patch/multi/multi.h

@@ -100,6 +100,7 @@ struct AlpineFactionServerInfo
     bool delayed_spawns = false;
     int koth_score_limit = 0;
     int dc_score_limit = 0;
+    bool allow_footsteps = false;
 };
 
 enum class AlpineRestrictVerdict : uint8_t

game_patch/multi/network.cpp

@@ -45,6 +45,7 @@
 #include "../misc/player.h"
 #include "../misc/alpine_settings.h"
 #include "../object/object.h"
+#include "../object/object_private.h"
 #include "../os/console.h"
 #include "../purefaction/pf.h"
 #include "../sound/sound.h"
@@ -1318,6 +1319,9 @@ CallHook<int(const rf::NetAddr*, std::byte*, size_t)> send_join_accept_packet_ho
         if (server_delayed_spawns()) {
             ext_data.flags |= AlpineFactionJoinAcceptPacketExt::Flags::delayed_spawns;
         }
+        if (server_allow_footsteps()) {
+            ext_data.flags |= AlpineFactionJoinAcceptPacketExt::Flags::allow_footsteps;
+        }
         auto [buf, new_len] = extend_packet_bytes(data, len, &ext_data, sizeof(ext_data));
         //auto [new_data, new_len] = extend_packet_fixed(data, len, ext_data);
         return send_join_accept_packet_hook.call_target(addr, buf.get(), new_len);
@@ -1350,6 +1354,7 @@ CodeInjection process_join_accept_injection{
             server_info.gaussian_spread = !!(ext_data.flags & AlpineFactionJoinAcceptPacketExt::Flags::gaussian_spread);
             server_info.location_pinging = !!(ext_data.flags & AlpineFactionJoinAcceptPacketExt::Flags::location_pinging);
             server_info.delayed_spawns = !!(ext_data.flags & AlpineFactionJoinAcceptPacketExt::Flags::delayed_spawns);
+            server_info.allow_footsteps = !!(ext_data.flags & AlpineFactionJoinAcceptPacketExt::Flags::allow_footsteps);
 
             constexpr float default_fov = 90.0f;
             if (!!(ext_data.flags & AlpineFactionJoinAcceptPacketExt::Flags::max_fov) && ext_data.max_fov >= default_fov) {
@@ -1359,6 +1364,9 @@ CodeInjection process_join_accept_injection{
                 server_info.semi_auto_cooldown = ext_data.semi_auto_cooldown;
             }
             g_af_server_info = std::optional{server_info};
+
+            // Update footstep activation based on server permissions
+            evaluate_footsteps();
         }
         else {
             g_af_server_info.reset();
@@ -1949,6 +1957,9 @@ FunHook<void()> multi_stop_hook{
                 static_cast<PlayerAdditionalData*>(rf::local_player);
             *player_add_data = PlayerAdditionalData{};
         }
+
+        // Re-evaluate footstep state when leaving multiplayer
+        evaluate_footsteps();
         multi_stop_hook.call_target();
     },
 };

game_patch/multi/network.h

@@ -114,6 +114,7 @@ struct AlpineFactionJoinAcceptPacketExt
         gaussian_spread     = 1u << 9,
         location_pinging    = 1u << 10,
         delayed_spawns      = 1u << 11,
+        allow_footsteps     = 1u << 12,
     } flags = Flags::none;
 
     float max_fov;

game_patch/multi/server.cpp

@@ -3223,6 +3223,11 @@ bool server_gaussian_spread()
     return g_alpine_server_config.gaussian_spread;
 }
 
+bool server_allow_footsteps()
+{
+    return g_alpine_server_config.allow_footsteps;
+}
+
 std::tuple<bool, int, bool, bool> server_features_require_alpine_client()
 {
     bool requires_alpine = false; // alpine required to spawn

game_patch/multi/server.h

@@ -28,6 +28,7 @@ bool server_allow_disable_muzzle_flash();
 bool server_apply_click_limiter();
 bool server_allow_unlimited_fps();
 bool server_gaussian_spread();
+bool server_allow_footsteps();
 std::tuple<bool, int, bool, bool> server_features_require_alpine_client();
 void server_reliable_socket_ready(rf::Player* player);
 bool server_weapon_items_give_full_ammo();

game_patch/multi/server_internal.h

@@ -679,6 +679,7 @@ struct AlpineServerConfig
     bool allow_disable_screenshake = true;
     bool allow_disable_muzzle_flash = true;
     bool allow_unlimited_fps = false;
+    bool allow_footsteps = true;
     bool use_sp_damage_calculation = false;
     bool exclude_bots_from_player_count = false;
     AlpineRestrictConfig alpine_restricted_config;

game_patch/object/entity.cpp

@@ -2,6 +2,8 @@
 #include <patch_common/FunHook.h>
 #include <patch_common/CallHook.h>
 #include <patch_common/AsmWriter.h>
+#include <cstring>
+#include <unordered_set>
 #include <xlog/xlog.h>
 #include "../misc/achievements.h"
 #include "../misc/alpine_settings.h"
@@ -17,6 +19,11 @@
 #include "../rf/os/frametime.h"
 #include "../rf/os/os.h"
 #include "../rf/sound/sound.h"
+#include "../rf/object.h"
+#include "../rf/vmesh.h"
+#include "../rf/character.h"
+#include "../rf/math/vector.h"
+#include "../multi/multi.h"
 
 rf::Timestamp g_player_jump_timestamp;
 
@@ -437,6 +444,117 @@ void apply_entity_sim_distance() {
     rf::entity_sim_distance = g_alpine_game_config.entity_sim_distance;
 }
 
+// Fix for footstep audio bug in multiplayer where remote players' footsteps
+// only play when they have a pistol equipped. Only pistol walk/run animations
+// have footstep triggers defined in entity.tbl; other weapons lack them.
+// We hook the animation update function (0x0051bce3) to inject trigger values
+// into skeletons that have empty trigger names, using VMVF time range data.
+
+bool g_footsteps_active = false;
+
+// Footstep trigger positions as percentages of animation duration
+static constexpr float footstep_walk_left_pct = 0.15f;
+static constexpr float footstep_walk_right_pct = 0.55f;
+static constexpr float footstep_run_left_pct = 0.12f;
+static constexpr float footstep_run_right_pct = 0.52f;
+
+CodeInjection footstep_trigger_fixup_injection{
+    0x0051bce3,
+    [](auto& regs) {
+        if (!g_footsteps_active) return;
+
+        uint32_t* anims_array = reinterpret_cast<uint32_t*>(static_cast<int32_t>(regs.edx));
+        int anim_index = static_cast<int32_t>(regs.ebp);
+        rf::Skeleton* skeleton = reinterpret_cast<rf::Skeleton*>(anims_array[anim_index]);
+        if (!skeleton) return;
+
+        // Only inject if trigger names are empty (no existing footstep data)
+        if (skeleton->triggers[0].name[0] != '\0') return;
+
+        const char* name = skeleton->mvf_filename;
+        if (!name || name[0] == '\0') return;
+
+        bool is_walk = std::strstr(name, "walk") != nullptr;
+        bool is_run = !is_walk && std::strstr(name, "run") != nullptr;
+        if (!is_walk && !is_run) return;
+
+        if (!skeleton->animation_data) return;
+
+        uint8_t* data = static_cast<uint8_t*>(skeleton->animation_data);
+        if (data[0] != 'V' || data[1] != 'M' || data[2] != 'V' || data[3] != 'F') return;
+
+        int start_time = *reinterpret_cast<int*>(data + 0x10);
+        int end_time = *reinterpret_cast<int*>(data + 0x14);
+        int duration = end_time - start_time;
+        if (duration <= 0) return;
+
+        float left_pct = is_walk ? footstep_walk_left_pct : footstep_run_left_pct;
+        float right_pct = is_walk ? footstep_walk_right_pct : footstep_run_right_pct;
+
+        int left_trigger = start_time + static_cast<int>(duration * left_pct);
+        int right_trigger = start_time + static_cast<int>(duration * right_pct);
+
+        std::strncpy(skeleton->triggers[0].name, "footstep_left", 15);
+        skeleton->triggers[0].name[15] = '\0';
+        skeleton->triggers[0].value = left_trigger;
+
+        std::strncpy(skeleton->triggers[1].name, "footstep_right", 15);
+        skeleton->triggers[1].name[15] = '\0';
+        skeleton->triggers[1].value = right_trigger;
+
+        static std::unordered_set<std::string> logged_injected;
+        if (logged_injected.insert(name).second) {
+            xlog::info("Footstep fix: {} injected left={} right={} (start={} end={} dur={} type={})",
+                name, left_trigger, right_trigger, start_time, end_time, duration,
+                is_walk ? "walk" : "run");
+        }
+    }
+};
+
+void evaluate_footsteps()
+{
+    // Check both client preference and server permission
+    bool client_wants_fix = g_alpine_game_config.footsteps;
+    bool server_allows_fix = false;
+
+    // Determine server permission:
+    // - Single-player: always allowed
+    // - Server (hosting): always allowed
+    // - Client on Alpine Faction server: check server permission
+    // - Client on legacy server: NOT allowed (compatibility)
+    if (!rf::is_multi) {
+        server_allows_fix = true;
+    }
+    else if (rf::is_server) {
+        server_allows_fix = true;
+    }
+    else {
+        // Client: only allow if Alpine Faction server permits it
+        const auto& server_info = get_af_server_info();
+        if (server_info.has_value()) {
+            server_allows_fix = server_info->allow_footsteps;
+        }
+    }
+
+    g_footsteps_active = client_wants_fix && server_allows_fix;
+
+    xlog::info("Footstep fix: client_wants={}, server_allows={}, active={}",
+        client_wants_fix, server_allows_fix, g_footsteps_active);
+}
+
+ConsoleCommand2 cl_footsteps_cmd{
+    "cl_footsteps",
+    []() {
+        g_alpine_game_config.footsteps = !g_alpine_game_config.footsteps;
+        evaluate_footsteps();
+        rf::console::print("Footsteps: {} (active: {})",
+            g_alpine_game_config.footsteps ? "enabled" : "disabled",
+            g_footsteps_active ? "yes" : "no");
+    },
+    "Toggle footstep trigger injection for all weapons",
+    "cl_footsteps",
+};
+
 FunHook<void(rf::Entity*, float)> entity_maybe_play_pain_sound_hook{
     0x004196F0, [](rf::Entity* ep, float percent_damage) {
         if (g_alpine_game_config.entity_pain_sounds) {
@@ -512,11 +630,16 @@ void entity_do_patch()
 	// Restore cut stock game feature for entities and corpses exploding into chunks
 	entity_blood_throw_gibs_hook.install();
 
+    // Footstep fix: inject trigger frames on-the-fly when animations have empty triggers
+    evaluate_footsteps();
+    footstep_trigger_fixup_injection.install();
+
     // Commands
     sp_exposuredamage_cmd.register_cmd();
     cl_gorelevel_cmd.register_cmd();
     cl_gibchunks_cmd.register_cmd();
     cl_gibvelocityscale_cmd.register_cmd();
     cl_giblifetimems_cmd.register_cmd();
     cl_painsounds_cmd.register_cmd();
+    cl_footsteps_cmd.register_cmd();
 }

game_patch/object/object_private.h

@@ -13,3 +13,7 @@ void entity_do_patch();
 void item_do_patch();
 void particle_do_patch();
 void obj_light_apply_patch();
+
+// Footstep fix state (controlled by client config AND server permission)
+extern bool g_footsteps_active;
+void evaluate_footsteps();