[Experimental] Fix LOS through thin/small props (#962)

* Add plugin `l4d_fix_prop_los`

* Add compiled `l4d_fix_prop_los`

* Add `l4d_fix_prop_los` to generalfixes

* Fix missing definition

Author: jensewe

addons/sourcemod/gamedata/l4d_fix_prop_los.txt

@@ -0,0 +1,46 @@
+"Games"
+{
+	"#default"
+	{
+		"Functions"
+		{
+			"l4d_fix_prop_los::CBaseProp::CalculateBlockLOS"
+			{
+				"signature"		"CBaseProp::CalculateBlockLOS"
+				"callconv"		"thiscall"
+				"return"		"void"
+				"this"			"entity"
+			}
+		}
+	}
+
+	"left4dead"
+	{
+		"Signatures"
+		{
+			"CBaseProp::CalculateBlockLOS"
+			{
+				"library"		"server"
+				"linux"			"@_ZN9CBaseProp17CalculateBlockLOSEv"
+				"windows"		"\x83\xEC\x0C\x53\x55\x8B\xE9\x8B\x85\x2A\x2A\x2A\x2A\x8B"
+								// 83 EC 0C 53 55 8B E9 8B 85 ? ? ? ? 8B
+			}
+		}
+	}
+
+	"left4dead2"
+	{
+		"Signatures"
+		{
+			"CBaseProp::CalculateBlockLOS"
+			{
+				"library"		"server"
+				"linux"			"@_ZN9CBaseProp17CalculateBlockLOSEv"
+				"windows"		"\x55\x8B\xEC\x83\xEC\x10\x53\x8B\xD9\x8B\x83\x2A\x2A\x2A\x2A\x8B"
+								// 55 8B EC 83 EC 10 53 8B D9 8B 83 ? ? ? ? 8B
+								// Search string "ai_addon_thrownprojectile"
+								// Called inside
+			}
+		}
+	}
+}

addons/sourcemod/plugins/fixes/l4d_fix_prop_los.smx

@@ -0,0 +1,49 @@
+#pragma semicolon 1
+#pragma newdecls required
+
+#include <sourcemod>
+#include <dhooks>
+
+#define PLUGIN_VERSION "1.0"
+
+public Plugin myinfo = 
+{
+	name = "[L4D & 2] Fix Prop LOS",
+	author = "Forgetest",
+	description = "Fix thin/small 'prop_*' entity not blocking LOS.",
+	version = PLUGIN_VERSION,
+	url = "https://github.com/Target5150/MoYu_Server_Stupid_Plugins",
+}
+
+methodmap GameDataWrapper < GameData {
+	public GameDataWrapper(const char[] file) {
+		GameData gd = new GameData(file);
+		if (!gd) SetFailState("Missing gamedata \"%s\"", file);
+		return view_as<GameDataWrapper>(gd);
+	}
+	public DynamicDetour CreateDetourOrFail(
+			const char[] name,
+			DHookCallback preHook = INVALID_FUNCTION,
+			DHookCallback postHook = INVALID_FUNCTION) {
+		DynamicDetour hSetup = DynamicDetour.FromConf(this, name);
+		if (!hSetup)
+			SetFailState("Missing detour setup \"%s\"", name);
+		if (preHook != INVALID_FUNCTION && !hSetup.Enable(Hook_Pre, preHook))
+			SetFailState("Failed to pre-detour \"%s\"", name);
+		if (postHook != INVALID_FUNCTION && !hSetup.Enable(Hook_Post, postHook))
+			SetFailState("Failed to post-detour \"%s\"", name);
+		return hSetup;
+	}
+}
+
+public void OnPluginStart()
+{
+	GameDataWrapper gd = new GameDataWrapper("l4d_fix_prop_los");
+	delete gd.CreateDetourOrFail("l4d_fix_prop_los::CBaseProp::CalculateBlockLOS", DTR_CalculateBlockLOS);
+	delete gd;
+}
+
+MRESReturn DTR_CalculateBlockLOS(int entity)
+{
+	return MRES_Supercede;
+}

addons/sourcemod/scripting/l4d_fix_prop_los.sp

@@ -71,6 +71,7 @@ sm plugins load fixes/l4d2_fix_rocket_pull.smx
 sm plugins load optional/l4d_return_thrown_items.smx
 sm plugins load fixes/l4d_prop_touching_rules.smx
 sm plugins load fixes/l4d2_fix_tank_rock_handoff.smx
+sm plugins load fixes/l4d_fix_prop_los.smx
 
 // Anti-Cheat.
 sm plugins load optional/l4d2_block_autoaim.smx // Sort of a cheat..?