Added a fixed implementation of the tile_num_beyond_ function

Removed the code of multihex critter self-hit fix from BugFixes.cpp.
(now fixed properly with the aforementioned implementation)

artifacts/ddraw.ini

@@ -15,7 +15,7 @@ UseCommandLine=0
 ;If DataLoadOrderPatch is enabled, the data load order is:
 ;master_patches > critter_patches > PatchFileXX > patchXXX.dat > critter_dat > f2_res_patches > f2_res_dat > master_dat
 ;Paths to folders and Fallout .dat files are supported. The available range for PatchFile option names is from 0 to 99
-;The greater numbers take precedence over lesser numbers
+;Larger numbers take precedence over smaller numbers (same as patchXXX.dat)
 ;PatchFile0=mods\RP_data
 
 ;Path to the folder in which the game will automatically search and load custom files (by *.dat mask, including folders)

sfall/FalloutEngine/Functions_def.h

@@ -54,6 +54,7 @@ WRAP_WATCOM_FFUNC3(long, register_object_play_sfx, fo::GameObject*, object, cons
 WRAP_WATCOM_FFUNC3(long, scr_get_local_var, long, sid, long, varId, long*, value)
 WRAP_WATCOM_FFUNC3(long, scr_set_local_var, long, sid, long, varId, long, value)
 WRAP_WATCOM_FFUNC6(long, text_object_create, fo::GameObject*, object, const char*, text, long, font, long, colorText, long, colorOutline, fo::BoundRect*, rect)
+WRAP_WATCOM_FFUNC3(long, tile_coord, long, tile, long*, outX, long*, outY) // the fourth argument of the function is not used
 WRAP_WATCOM_FFUNC3(long, tile_num_in_direction, long, tile, long, rotation, long, distance)
 WRAP_WATCOM_FFUNC8(void, trans_cscale, void*, fromBuff, long, width, long, height, long, fromPitch, void*, toBuff, long, toWidth, long, toHeight, long, toPitch)
 WRAP_WATCOM_FFUNC3(void, win_clip, fo::Window*, window, fo::RectList**, rects, void*, buffer)
@@ -268,6 +269,7 @@ WRAP_WATCOM_FUNC1(void, stat_pc_add_experience, long, amount) // Adds experience
 WRAP_WATCOM_FUNC1(long, text_font, long, fontNum)
 WRAP_WATCOM_FUNC2(long, tile_dist, long, scrTile, long, dstTile)
 WRAP_WATCOM_FUNC2(long, tile_dir, long, scrTile, long, dstTile)
+WRAP_WATCOM_FUNC1(long, tile_on_edge, long, tile)
 WRAP_WATCOM_FUNC0(void, tile_refresh_display) // Redraws the whole screen
 WRAP_WATCOM_FUNC2(void, tile_refresh_rect, fo::BoundRect*, boundRect, long, elevation) // Redraws the given rectangle on screen
 WRAP_WATCOM_FUNC1(long, trait_level, long, traitID)

sfall/Game/inventory.cpp

@@ -110,7 +110,7 @@ static void __declspec(naked) adjust_fid_hack() {
 }
 
 void Inventory::init() {
-	// Replace functions
+	// Replace adjust_fid_ function
 	sf::MakeJump(fo::funcoffs::adjust_fid_, adjust_fid_hack); // 0x4716E8
 }
 

sfall/Game/skills.cpp

@@ -50,7 +50,7 @@ static void __declspec(naked) trait_adjust_skill_hack() {
 }
 
 void Skills::init() {
-	// Replace functions
+	// Replace trait_adjust_skill_ function
 	sf::MakeJump(fo::funcoffs::trait_adjust_skill_, trait_adjust_skill_hack); // 0x4B40FC
 }
 

sfall/Game/stats.cpp

@@ -120,7 +120,7 @@ static void __declspec(naked) trait_adjust_stat_hack() {
 }
 
 void Stats::init() {
-	// Replace functions
+	// Replace trait_adjust_stat_ function
 	sf::MakeJump(fo::funcoffs::trait_adjust_stat_, trait_adjust_stat_hack); // 0x4B3C7C
 
 	// Fix the carry weight penalty of the Small Frame trait not being applied to bonus Strength points

sfall/Game/tilemap.cpp

@@ -0,0 +1,162 @@
+/*
+ *    sfall
+ *    Copyright (C) 2008-2021  The sfall team
+ *
+ */
+
+#include "..\main.h"
+#include "..\FalloutEngine\Fallout2.h"
+
+#include "tilemap.h"
+
+namespace game
+{
+
+namespace sf = sfall;
+
+static std::vector<int> buildLineTiles;
+
+static bool TileExists(long tile) {
+	return (std::find(buildLineTiles.cbegin(), buildLineTiles.cend(), tile) != buildLineTiles.cend());
+}
+
+// Fixed and improved implementation of tile_num_beyond_ engine function
+// compared to the original implementation, this function gets the hex (tile) from the constructed line more correctly
+long __fastcall Tilemap::tile_num_beyond(long sourceTile, long targetTile, long maxRange) {
+	if (maxRange <= 0 || sourceTile == targetTile) return sourceTile;
+
+	maxRange++;
+
+	if (buildLineTiles.empty()) {
+		buildLineTiles.reserve(50);
+	} else {
+		buildLineTiles.clear();
+	}
+
+	long currentRange = fo::func::tile_dist(sourceTile, targetTile);
+	//fo::func::debug_printf("\ntile_dist: %d", currentRange);
+
+	long lastTile = targetTile;
+	long source_X, source_Y, target_X, target_Y;
+
+	fo::func::tile_coord(sourceTile, &source_X, &source_Y);
+	fo::func::tile_coord(targetTile, &target_X, &target_Y);
+
+	// set the point to the center of the hexagon
+	source_X += 16;
+	source_Y += 8;
+	target_X += 16;
+	target_Y += 8;
+
+	long diffX = target_X - source_X;
+	long addToX = -1;
+	if (diffX >= 0) addToX = (diffX > 0);
+
+	long diffY = target_Y - source_Y;
+	long addToY = -1;
+	if (diffY >= 0) addToY = (diffY > 0);
+
+	long diffX_x2 = 2 * std::abs(diffX);
+	long diffY_x2 = 2 * std::abs(diffY);
+
+	long direction = (source_X != target_X) ? fo::func::tile_dir(sourceTile, targetTile) : -1;
+	//fo::func::debug_printf("\ntile_dir: %d", direction);
+	switch (direction) {
+		case 0:
+			target_X += 8;
+			target_Y -= 4;
+			break;
+		case 1:
+			target_X += 15;
+			break;
+		case 2:
+			target_X += 8;
+			target_Y += 4;
+			break;
+		case 3:
+			target_X -= 8;
+			target_Y += 4;
+			break;
+		case 4:
+			target_X -= 15;
+			break;
+		case 5:
+			target_X -= 8;
+			target_Y -= 4;
+			break;
+	}
+	long step = 0;
+
+	if (diffX_x2 > diffY_x2) {
+		long stepY = diffY_x2 - (diffX_x2 >> 1);
+		while (true) {
+			if (!(++step % 2)) {
+				long tile = fo::func::tile_num(target_X, target_Y);
+				//fo::func::debug_printf("\ntile_num: %d [x:%d y:%d]", tile, target_X, target_Y);
+				if (tile != lastTile) {
+					if (!TileExists(tile)) {
+						if (++currentRange >= maxRange || fo::func::tile_on_edge(tile)) return tile;
+						buildLineTiles.push_back(tile);
+					}
+					lastTile = tile;
+				}
+			}
+			if (stepY >= 0) {
+				stepY -= diffX_x2;
+				target_Y += addToY;
+			}
+			stepY += diffY_x2;
+			target_X += addToX;
+
+			// Example of an algorithm constructing a straight line from point A to B
+			// source: x = 784(800), y = 278(286)
+			// target: x = 640(656), y = 314(322) - the target is located to the left and below
+			// 0. x = 800, y = 286, stepY = -72
+			// 1. x = 799, y = 286, stepY = -72+72=0
+			// 2. x = 798, y = 287, stepY = 0-288+72=-216
+			// 3. x = 797, y = 287, stepY = -216+72=-144
+			// 4. x = 796, y = 287, stepY = -144+72=-72
+			// 5. x = 795, y = 287, stepY = -72+72=0
+			// 6. x = 794, y = 288, stepY = 0-288+72=-216
+		}
+	} else {
+		long stepX = diffX_x2 - (diffY_x2 >> 1);
+		while (true) {
+			if (!(++step % 2)) {
+				long tile = fo::func::tile_num(target_X, target_Y);
+				//fo::func::debug_printf("\ntile_num: %d [x:%d y:%d]", tile, target_X, target_Y);
+				if (tile != lastTile) {
+					if (!TileExists(tile)) {
+						if (++currentRange >= maxRange || fo::func::tile_on_edge(tile)) return tile;
+						buildLineTiles.push_back(tile);
+					}
+					lastTile = tile;
+				}
+			}
+			if (stepX >= 0) {
+				stepX -= diffY_x2;
+				target_X += addToX;
+			}
+			stepX += diffX_x2;
+			target_Y += addToY;
+		}
+	}
+}
+
+static void __declspec(naked) tile_num_beyond_hack() {
+	__asm {
+		//push ecx;
+		push ebx;
+		mov  ecx, eax;
+		call Tilemap::tile_num_beyond;
+		pop ecx;
+		retn;
+	}
+}
+
+void Tilemap::init() {
+	// Replace tile_num_beyond_ function
+	sf::MakeJump(fo::funcoffs::tile_num_beyond_ + 1, tile_num_beyond_hack); // 0x4B1B84
+}
+
+}

sfall/Game/tilemap.h

@@ -0,0 +1,19 @@
+/*
+ *    sfall
+ *    Copyright (C) 2008-2021  The sfall team
+ *
+ */
+
+#pragma once
+
+namespace game
+{
+
+class Tilemap {
+public:
+	static void init();
+
+	static long __fastcall tile_num_beyond(long sourceTile, long targetTile, long maxRange);
+};
+
+}

sfall/Modules/AI.cpp

@@ -47,18 +47,19 @@ fo::GameObject* AI::CheckShootAndFriendlyInLineOfFire(fo::GameObject* object, lo
 		}
 		// continue checking the line of fire from object tile to targetTile
 		fo::GameObject* obj = object; // for ignoring the object (multihex) when building the path
-		fo::func::make_straight_path_func(object, objTile, targetTile, 0, (DWORD*)&obj, 32, (void*)fo::funcoffs::obj_shoot_blocking_at_);
-		if (!CheckShootAndFriendlyInLineOfFire(obj, targetTile, team)) return nullptr;
+		fo::func::make_straight_path_func(object, objTile, targetTile, 0, (DWORD*)&obj, 0x20, (void*)fo::funcoffs::obj_shoot_blocking_at_);
+
+		object = CheckShootAndFriendlyInLineOfFire(obj, targetTile, team);
 	}
-	return object;
+	return object; // friendly critter, any object or null
 }
 
 // Returns the friendly critter in the line of fire
 fo::GameObject* AI::CheckFriendlyFire(fo::GameObject* target, fo::GameObject* attacker) {
 	fo::GameObject* object = nullptr;
-	fo::func::make_straight_path_func(attacker, attacker->tile, target->tile, 0, (DWORD*)&object, 32, (void*)fo::funcoffs::obj_shoot_blocking_at_);
+	fo::func::make_straight_path_func(attacker, attacker->tile, target->tile, 0, (DWORD*)&object, 0x20, (void*)fo::funcoffs::obj_shoot_blocking_at_);
 	object = CheckShootAndFriendlyInLineOfFire(object, target->tile, attacker->critter.teamNum);
-	return (object && object->IsCritter()) ? object : nullptr; // 0 if there are no friendly critters
+	return (object && object->IsCritter()) ? object : nullptr; // 0 - if there are no friendly critters
 }
 
 bool AI::AttackInRange(fo::GameObject* source, fo::GameObject* weapon, long distance) {

sfall/Modules/BugFixes.cpp

@@ -1004,28 +1004,6 @@ runToObject:
 	}
 }
 
-static void __declspec(naked) MultiHexAIMissHitFix() {
-	__asm {
-		mov  ecx, ebx;                      // distance weaponRange
-		call fo::funcoffs::tile_num_beyond_;
-		mov  ebx, [esi];                    // ctd.source
-		test [ebx + flags + 1], 0x08;       // is source multihex?
-		jnz  checkTile;
-		retn;
-checkTile:
-		mov  edx, [ebx + tile];             // source tile
-		call fo::funcoffs::tile_dist_;      // eax - tile form tile_num_beyond_
-		cmp  eax, 1;                        // if distance is less than or equal to 1, this is a self-hit
-		jle  fix;
-		retn;
-fix:	// get correct tile beyond
-		mov  eax, [ebx + tile];             // source tile
-		mov  edx, [ebx + rotation];         // source rotation
-		mov  ebx, ecx;                      // distance weaponRange
-		jmp  fo::funcoffs::tile_num_in_direction_; // return new tile for missed projectile
-	}
-}
-
 // checks if an attacked object is a critter before attempting dodge animation
 static void __declspec(naked) action_melee_hack() {
 	__asm {
@@ -3180,15 +3158,6 @@ void BugFixes::init()
 		dlogr(" Done", DL_INIT);
 	//}
 
-	// Fix for multihex critters hitting themselves when they miss an attack with ranged weapons
-	// Note: in fact, the bug is in tile_num_beyond_ and related functions. In case of a more comprehensive fix to them, this fix
-	// will need to be removed
-	//if (GetConfigInt("Misc", "MultiHexSelfHitFix", 1)) {
-		dlog("Applying multihex critter self-hit fix.", DL_INIT);
-		HookCalls(MultiHexAIMissHitFix, {0x423B44, 0x42315D});
-		dlogr(" Done", DL_INIT);
-	//}
-
 	//if (GetConfigInt("Misc", "DodgyDoorsFix", 1)) {
 		dlog("Applying Dodgy Door Fix.", DL_INIT);
 		MakeJump(0x4113D6, action_melee_hack);

sfall/ReplacementFuncs.h

@@ -11,3 +11,4 @@
 #include "Game\render.h"
 #include "Game\skills.h"
 #include "Game\stats.h"
+#include "Game\tilemap.h"

sfall/ddraw.vcxproj

@@ -297,6 +297,7 @@
     <ClInclude Include="Game\render.h" />
     <ClInclude Include="Game\skills.h" />
     <ClInclude Include="Game\stats.h" />
+    <ClInclude Include="Game\tilemap.h" />
     <ClInclude Include="IniReader.h" />
     <ClInclude Include="Modules\CritterPoison.h" />
     <ClInclude Include="Modules\CritterStats.h" />
@@ -406,6 +407,7 @@
     <ClCompile Include="Game\render.cpp" />
     <ClCompile Include="Game\skills.cpp" />
     <ClCompile Include="Game\stats.cpp" />
+    <ClCompile Include="Game\tilemap.cpp" />
     <ClCompile Include="IniReader.cpp" />
     <ClCompile Include="Modules\CritterPoison.cpp" />
     <ClCompile Include="Modules\CritterStats.cpp" />

sfall/ddraw.vcxproj.filters

@@ -339,6 +339,9 @@
       <Filter>Modules\Scripting\Handlers</Filter>
     </ClInclude>
     <ClInclude Include="IniReader.h" />
+    <ClInclude Include="Game\tilemap.h">
+      <Filter>Game</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="main.cpp" />
@@ -628,6 +631,9 @@
       <Filter>Modules\Scripting\Handlers</Filter>
     </ClCompile>
     <ClCompile Include="IniReader.cpp" />
+    <ClCompile Include="Game\tilemap.cpp">
+      <Filter>Game</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="version.rc" />

sfall/main.cpp

@@ -20,10 +20,6 @@
 
 #include <psapi.h>
 
-#include <algorithm>
-#include <stdio.h>
-#include <memory>
-
 #include "FalloutEngine\Fallout2.h"
 #include "ModuleManager.h"
 #include "Modules\Module.h"
@@ -108,6 +104,7 @@ void InitReplacementHacks() {
 	game::Render::init();
 	game::Skills::init();
 	game::Stats::init();
+	game::Tilemap::init();
 }
 
 static void InitModules() {