Added a new hook: HOOK_ENCOUNTER

Added procedure and macros for unsigned integer comparison to lib.math.h.

artifacts/scripting/headers/lib.math.h

@@ -5,6 +5,17 @@
   Numbers...
 */
 
+#define above(a, b)        (unsigned_comp(a, b) > 0)
+#define above_equal(a, b)  (unsigned_comp(a, b) >= 0)
+#define below(a, b)        (unsigned_comp(a, b) < 0)
+#define below_equal(a, b)  (unsigned_comp(a, b) <= 0)
+
+procedure unsigned_comp(variable a, variable b) begin
+   if (a bwxor b) then return 0;
+   if (b == 0) then return 1;
+   return 1 if (a / b) else -1;
+end
+
 #define MAX(x, y)    ((x > y) * x + (x <= y) * y)
 #define MIN(x, y)    ((x < y) * x + (x >= y) * y)
 #define in_range(x, from, to)    (x >= from and x <= to)

artifacts/scripting/headers/sfall.h

@@ -65,6 +65,7 @@
 #define HOOK_STDPROCEDURE     (40)
 #define HOOK_STDPROCEDURE_END (41)
 #define HOOK_TARGETOBJECT     (42)
+#define HOOK_ENCOUNTER        (43)
 
 //Valid arguments to list_begin
 #define LIST_CRITTERS    (0)

artifacts/scripting/hookscripts.txt

@@ -669,3 +669,17 @@ int     arg2 - 1 when the target object is valid to attack, 0 otherwise
 Obj     arg3 - the target object
 
 mixed   ret1 - overrides the target object, or pass -1 to prevent the player from attacking the object
+
+-------------------------------------------
+
+HOOK_ENCOUNTER (hs_encounter.int)
+
+Runs whenever a random encounter occurs (except the Horrigan meeting and scripted encounters), or when the player enters a local map from the world map.
+You can override the map for loading or the encounter.
+
+int     arg1 - event type: 0 - when a random encounter occurs, 1 - when the player enters from the world map
+int     arg2 - the map ID that the encounter will load (see MAPS.h or Maps.txt)
+int     arg3 - 1 when the encounter occurs is a special encounter, 0 otherwise
+
+int     ret1 - overrides the map ID, or pass -1 to cancel the encounter and continue traveling (only for event type 0)
+int     ret2 - pass 1 to cancel the encounter and load the specified map from the ret1 (only for event type 0)

sfall/FalloutEngine/VariableOffsets.h

@@ -60,6 +60,7 @@
 #define FO_VAR_edit_win                   0x57060C
 #define FO_VAR_Educated                   0x57082C
 #define FO_VAR_elevation                  0x631D2C
+#define FO_VAR_EncounterMapID             0x672E4C
 #define FO_VAR_Experience_                0x6681B4
 #define FO_VAR_fade_steps                 0x6642D0
 #define FO_VAR_fallout_game_time          0x51C720
@@ -158,6 +159,8 @@
 #define FO_VAR_obj_seen_check             0x6610BC
 #define FO_VAR_objectTable                0x639DA0
 #define FO_VAR_objItemOutlineState        0x519798
+#define FO_VAR_old_world_xpos             0x672E5C
+#define FO_VAR_old_world_ypos             0x672E60
 #define FO_VAR_optionRect                 0x58ECC0
 #define FO_VAR_optionsButtonDown          0x59D400
 #define FO_VAR_optionsButtonDown1         0x570518

sfall/Modules/HookScripts.cpp

@@ -93,6 +93,7 @@ static HooksInjectInfo injectHooks[] = {
 	{HOOK_STDPROCEDURE,     Inject_ScriptProcedureHook,  false},
 	{HOOK_STDPROCEDURE_END, Inject_ScriptProcedureHook2, false},
 	{HOOK_TARGETOBJECT,     Inject_TargetObjectHook,     false},
+	{HOOK_ENCOUNTER,        Inject_EncounterHook,        false},
 };
 
 bool HookScripts::injectAllHooks;

sfall/Modules/HookScripts.h

@@ -69,6 +69,7 @@ enum HookType
 	HOOK_STDPROCEDURE     = 40,
 	HOOK_STDPROCEDURE_END = 41,
 	HOOK_TARGETOBJECT     = 42,
+	HOOK_ENCOUNTER        = 43,
 	HOOK_COUNT
 };
 

sfall/Modules/HookScripts/MiscHs.cpp

@@ -525,6 +525,98 @@ end:
 	}
 }
 
+// hook does not work for scripted encounters and meeting Horrigan
+static long __fastcall EncounterHook_Script(long encounterMapID, long eventType, long encType) {
+	BeginHook();
+	argCount = 3;
+
+	args[0] = eventType; // 1 - enter local map from the world map
+	args[1] = encounterMapID;
+	args[2] = (encType == 3); // 1 - special random encounter (not verified)
+
+	RunHookScript(HOOK_ENCOUNTER);
+
+	if (cRet) {
+		encounterMapID = rets[0];
+		if (encounterMapID < -1) encounterMapID = -1;
+		if (eventType == 0 && cRet > 1 && encounterMapID != -1 && rets[1] == 1) { // 1 - cancel the encounter and load the specified map
+			encounterMapID = -encounterMapID - 2; // map number in negative value
+		}
+		if (encounterMapID < 0) {
+			// set the coordinates of the last encounter
+			*(DWORD*)FO_VAR_old_world_xpos = fo::var::world_xpos;
+			*(DWORD*)FO_VAR_old_world_ypos = fo::var::world_ypos;
+		}
+	}
+	EndHook();
+	return encounterMapID;
+}
+
+static void __declspec(naked) wmWorldMap_hook() {
+	__asm {
+		mov  ebx, eax; // keep map id
+		mov  edx, 1;
+		mov  ecx, eax;
+		push 0;
+		call EncounterHook_Script;
+		test eax, eax;
+		cmovl eax, ebx; // restore map if map < 0
+		jmp  fo::funcoffs::map_load_idx_; // eax - map id
+	}
+}
+
+static void __declspec(naked) wmRndEncounterOccurred_hook() {
+	static long hkEncounterMapID = -1;
+	__asm {
+		cmp  hkEncounterMapID, -1;
+		jnz  blinkIcon;
+		test edx, edx;
+		jz   hookRun;
+		jmp  fo::funcoffs::wmInterfaceRefresh_;
+hookRun: /////////////////////////////////
+		push edx;
+		push ecx;
+		push ecx; // encType
+		xor  edx, edx;
+		mov  ecx, dword ptr ds:[FO_VAR_EncounterMapID];
+		call EncounterHook_Script;
+		pop  ecx;
+		pop  edx;
+		mov  dword ptr ds:[FO_VAR_EncounterMapID], eax;
+		cmp  eax, -1;
+		je   cancelEnc;
+		jl   clearEnc;
+		jmp  fo::funcoffs::wmInterfaceRefresh_;
+clearEnc: /////////////////////////////////
+		mov  dword ptr ds:[FO_VAR_EncounterMapID], -1;
+		neg  eax;
+		sub  eax, 2; // recover correct map number from negative value
+		mov  hkEncounterMapID, eax;
+		dec  edx;
+blinkIcon:
+		cmp  edx, 6; // counter of blinking
+		je   break;
+		jmp  fo::funcoffs::wmInterfaceRefresh_;
+break:
+		mov  eax, hkEncounterMapID;
+		cmp  ds:[FO_VAR_Move_on_Car], 1;
+		jne  noCar;
+		mov  edx, FO_VAR_carCurrentArea;
+		call fo::funcoffs::wmMatchAreaContainingMapIdx_;
+		mov  eax, hkEncounterMapID;
+noCar:
+		call fo::funcoffs::map_load_idx_;
+		xor  eax, eax;
+		//mov  ds:[0x672E48], eax; // _wmUnkVar00
+		mov  hkEncounterMapID, -1;
+cancelEnc:
+		inc  eax; // 0 - continue movement, 1 - interrupt
+		add  esp, 4;
+		mov  ebx, 0x4C0BC7;
+		jmp  ebx;
+	}
+}
+
 void Inject_BarterPriceHook() {
 	HookCalls(BarterPriceHook, {
 		0x474D4C, // barter_attempt_transaction_ (offers button)
@@ -587,6 +679,11 @@ void Inject_UseSkillOnHook() {
 	SafeWriteBatch<DWORD>((DWORD)&sourceSkillOn, {0x4AB0EF, 0x4AB5C0, 0x4ABAF2}); // fix for time
 }
 
+void Inject_EncounterHook() {
+	HookCall(0x4C02AF, wmWorldMap_hook);
+	HookCall(0x4C095C, wmRndEncounterOccurred_hook);
+}
+
 void InitMiscHookScripts() {
 	LoadHookScript("hs_barterprice", HOOK_BARTERPRICE);
 	LoadHookScript("hs_useskillon", HOOK_USESKILLON);
@@ -598,6 +695,7 @@ void InitMiscHookScripts() {
 	LoadHookScript("hs_setglobalvar", HOOK_SETGLOBALVAR);
 	LoadHookScript("hs_resttimer", HOOK_RESTTIMER);
 	LoadHookScript("hs_explosivetimer", HOOK_EXPLOSIVETIMER);
+	LoadHookScript("hs_encounter", HOOK_ENCOUNTER);
 }
 
 }

sfall/Modules/HookScripts/MiscHs.h

@@ -15,4 +15,5 @@ namespace sfall
 	void Inject_SetGlobalVarHook();
 	void Inject_RestTimerHook();
 	void Inject_ExplosiveTimerHook();
+	void Inject_EncounterHook();
 }