Added new HOOK_SNEAK (from Mr.Stalin)

artifacts/example_mods/Sneak/gl_sneak.ssl

@@ -0,0 +1,46 @@
+/*
+   Example implementation of the algorithm of how the game engine checks the Sneak skill
+*/
+
+#include "..\headers\define.h"
+#include "..\headers\command.h"
+#include "..\headers\sfall\sfall.h"
+
+procedure start;
+
+procedure start begin
+   if game_loaded then begin
+      register_hook(HOOK_SNEAK);
+   end else begin
+      variable sneakIsSuccess, time, level;
+
+      level := critter_skill_level(dude_obj, SKILL_SNEAK);
+      if (roll_vs_skill(dude_obj, SKILL_SNEAK, 0) < ROLL_SUCCESS) then begin
+         sneakIsSuccess := false;
+         time := ONE_GAME_MINUTE;
+         if (level <= 250) then
+            if (level <= 200) then
+               if (level <= 170) then
+                  if (level <= 135) then
+                     if (level <= 100) then
+                        if (level > 80) then
+                           time := 400;          // 40 secs
+                     else
+                        time := 300;             // 30 secs
+                  else
+                     time := 200;                // 20 secs
+               else
+                  time := 150;                   // 15 secs
+            else
+               time := 120;                      // 12 secs
+         else
+            time := 100;                         // 10 secs for skill level > 250
+      end
+      else begin
+         sneakIsSuccess := true;
+         time := ONE_GAME_MINUTE;
+      end
+      set_sfall_return(sneakIsSuccess);
+      set_sfall_return(time);
+   end
+end

artifacts/scripting/headers/sfall.h

@@ -60,6 +60,7 @@
 #define HOOK_ONEXPLOSION      (36)
 #define HOOK_SUBCOMBATDAMAGE  (37)
 #define HOOK_SETLIGHTING      (38)
+#define HOOK_SNEAK            (39)
 
 //Valid arguments to list_begin
 #define LIST_CRITTERS    (0)

artifacts/scripting/hookscripts.txt

@@ -617,3 +617,17 @@ int     arg3 - the light radius, or -1 when setting the light level for a map
 
 int     ret1 - overrides the light intensity. Intensity range is from 0 to 65536
 int     ret2 - overrides the light radius. Radius range is from 0 to 8 (works only for the object)
+
+-------------------------------------------
+
+HOOK_SNEAK (hs_sneak.int)
+
+Runs when the Sneak skill is activated, or when the game rolls another Sneak check after the duration for the current one is over.
+You can override the result of a random Sneak check or the duration time for the current result.
+
+int     arg1 - Sneak check result: 1 - success, 0 - failure
+int     arg2 - the duration in ticks for the current Sneak check (time is based on the Sneak skill level)
+Critter arg3 - the critter (usually dude_obj)
+
+int     ret1 - overrides the Sneak check result
+int     ret2 - overrides the duration time for the current result

sfall/Modules/HookScripts.cpp

@@ -83,6 +83,7 @@ static HooksInjectInfo injectHooks[] = {
 	{HOOK_ONEXPLOSION,      Inject_OnExplosionHook,      false},
 	{HOOK_SUBCOMBATDAMAGE,  Inject_SubCombatDamageHook,  false}, // replace the code logic
 	{HOOK_SETLIGHTING,      Inject_SetLightingHook,      false},
+	{HOOK_SNEAK,            Inject_SneakCheckHook,       false},
 };
 
 bool HookScripts::injectAllHooks;

sfall/Modules/HookScripts.h

@@ -65,6 +65,7 @@ enum HookType
 	HOOK_ONEXPLOSION      = 36,
 	HOOK_SUBCOMBATDAMAGE  = 37,
 	HOOK_SETLIGHTING      = 38,
+	HOOK_SNEAK            = 39,
 	HOOK_COUNT
 };
 

sfall/Modules/HookScripts/MiscHs.cpp

@@ -225,6 +225,32 @@ defaultHandler:
 	}
 }
 
+static void __declspec(naked) SneakCheckHook() {
+	__asm {
+		HookBegin;
+		mov esi, ds:[FO_VAR_sneak_working];
+		mov args[0], esi; // 1 = successful sneak
+		mov args[4], eax; // timer
+		mov args[8], edx; // critter
+		pushadc;
+	}
+
+	argCount = 3;
+	RunHookScript(HOOK_SNEAK);
+
+	__asm {
+		popadc;
+		cmp  cRet, 1;
+		jb   skip;
+		mov  esi, rets[0];
+		mov  ds:[FO_VAR_sneak_working], esi;
+		cmova eax, rets[4]; // override timer
+skip:
+		HookEnd;
+		jmp  fo::funcoffs::queue_add_;
+	}
+}
+
 static long __stdcall PerceptionRangeHook_Script(int type) {
 	long result;
 	__asm {
@@ -513,6 +539,10 @@ void Inject_StealCheckHook() {
 	HookCalls(StealCheckHook, { 0x4749A2, 0x474A69 });
 }
 
+void Inject_SneakCheckHook() {
+	HookCall(0x42E3D9, SneakCheckHook);
+}
+
 void Inject_WithinPerceptionHook() {
 	HookCalls(PerceptionRangeHook, {
 		0x429157,
@@ -558,6 +588,7 @@ void InitMiscHookScripts() {
 	LoadHookScript("hs_useskillon", HOOK_USESKILLON);
 	LoadHookScript("hs_useskill", HOOK_USESKILL);
 	LoadHookScript("hs_steal", HOOK_STEAL);
+	LoadHookScript("hs_sneak", HOOK_SNEAK);
 	LoadHookScript("hs_withinperception", HOOK_WITHINPERCEPTION);
 	LoadHookScript("hs_cartravel", HOOK_CARTRAVEL);
 	LoadHookScript("hs_setglobalvar", HOOK_SETGLOBALVAR);

sfall/Modules/HookScripts/MiscHs.h

@@ -9,6 +9,7 @@ namespace sfall
 	void Inject_UseSkillOnHook();
 	void Inject_UseSkillHook();
 	void Inject_StealCheckHook();
+	void Inject_SneakCheckHook();
 	void Inject_WithinPerceptionHook();
 	void Inject_CarTravelHook();
 	void Inject_SetGlobalVarHook();