From 1fa3b61163b233f6c8c6b86dfa196fb798a6f094 Mon Sep 17 00:00:00 2001
From: salmonik <salmonik@tuta.io>
Date: Wed, 4 Nov 2026 12:39:45 +0100
Subject: ESP: classify NPC damage immunity/armour/vulnerability

- Resolve server m_takedamage (DAMAGE_NO/DAMAGE_EVENTS_ONLY = immune).
- Classify gunship/strider/dropship as ARMORED (OnTakeDamage only accepts
  DMG_BLAST; only the RPG passes), and headcrab/antlion/manhack as VULN
  (gravity gun / physics impact).
- ESP draws ARMORED/VULN/IMMUNE tags above the name (new "Damage tags"
  toggle, [esp] dmg).
- Aimbot, silent aim, triggerbot and melee skip immune targets and armoured
  targets unless the active weapon is the RPG.
---
 src/server.cpp | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

(limited to 'src/server.cpp')

diff --git a/src/server.cpp b/src/server.cpp
index c2864c8..e9fd921 100644
--- a/src/server.cpp
+++ b/src/server.cpp
@@ -51,6 +51,7 @@ static int g_srv_followtarget = -1;
 static int g_srv_spawnflags = -1;
 static int g_srv_hacked = -1;
 static int g_srv_npcstate = -1;
+static int g_srv_takedamage = -1;
 static bool g_srv_ready = false;
 static bool g_srv_checked = false;
 
@@ -141,15 +142,17 @@ bool resolve_server_netvars() {
   g_srv_spawnflags = datamap_offset("m_spawnflags", FIELD_INTEGER, 0x4);
   g_srv_hacked = datamap_offset("m_bHackedByAlyx", FIELD_BOOLEAN);
   g_srv_npcstate = datamap_offset("m_NPCState", FIELD_INTEGER);
+  g_srv_takedamage = datamap_offset("m_takedamage", FIELD_INTEGER);
   g_srv_ready = g_srv_health > 0;
   if (g_srv_ready) {
     logf("server datamap (%s): health=%d maxhealth=%d lifeste=%d "
          "modelindex=%d absvel=%d vel=%d activeweapon=%d relationship=%d "
-         "followtarget=%d spawnflags=%d hacked=%d npcstate=%d",
+         "followtarget=%d spawnflags=%d hacked=%d npcstate=%d "
+         "takedamage=%d",
          g_server.path.c_str(), g_srv_health, g_srv_maxhealth, g_srv_lifestate,
          g_srv_modelindex, g_srv_absvelocity, g_srv_velocity,
          g_srv_activeweapon, g_srv_relationship, g_srv_followtarget,
-         g_srv_spawnflags, g_srv_hacked, g_srv_npcstate);
+         g_srv_spawnflags, g_srv_hacked, g_srv_npcstate, g_srv_takedamage);
     fail_logged = false;
   } else if (!fail_logged) {
     fail_logged = true;
@@ -268,6 +271,18 @@ int server_npc_state(int idx) {
   return *(int *)((uintptr_t)base + g_srv_npcstate);
 }
 
+// TAKEDAMAGE: 0 = DAMAGE_NO, 1 = DAMAGE_EVENTS_ONLY, 2 = DAMAGE_YES,
+// 3 = DAMAGE_AIM. 0/1 cannot be damaged at all.
+int server_npc_takedamage(int idx) {
+  if (!g_srv_ready || g_srv_takedamage < 0)
+    return -1;
+  void *base = nullptr;
+  server_entity_health(idx, nullptr, nullptr, &base);
+  if (!base)
+    return -1;
+  return *(int *)((uintptr_t)base + g_srv_takedamage);
+}
+
 bool server_npc_has_follow_target(int idx) {
   if (!g_srv_ready || g_srv_followtarget < 0)
     return false;
-- 
cgit v1.2.3