Fix number of tool uses being off by 1..32767 (#11110)

13 files changed, 137 insertions, 49 deletions

diff --git a/src/client/content_cao.cpp b/src/client/content_cao.cpp
index 1e79d00c9..5c8465b22 100644
--- a/src/client/content_cao.cpp
+++ b/src/client/content_cao.cpp
@@ -1870,7 +1870,8 @@ bool GenericCAO::directReportPunch(v3f dir, const ItemStack *punchitem,
 			m_armor_groups,
 			toolcap,
 			punchitem,
-			time_from_last_punch);
+			time_from_last_punch,
+			punchitem->wear);
 
 	if(result.did_punch && result.damage != 0)
 	{
diff --git a/src/client/game.cpp b/src/client/game.cpp
index 57951dc95..7f0aff49c 100644
--- a/src/client/game.cpp
+++ b/src/client/game.cpp
@@ -3619,7 +3619,8 @@ void Game::handleDigging(const PointedThing &pointed, const v3s16 &nodepos,
 	// cheat detection.
 	// Get digging parameters
 	DigParams params = getDigParams(nodedef_manager->get(n).groups,
-			&selected_item.getToolCapabilities(itemdef_manager));
+			&selected_item.getToolCapabilities(itemdef_manager),
+			selected_item.wear);
 
 	// If can't dig, try hand
 	if (!params.diggable) {
diff --git a/src/network/serverpackethandler.cpp b/src/network/serverpackethandler.cpp
index d4bef3ca2..c1ddb5005 100644
--- a/src/network/serverpackethandler.cpp
+++ b/src/network/serverpackethandler.cpp
@@ -1119,8 +1119,8 @@ void Server::handleCommand_Interact(NetworkPacket *pkt)
 		float time_from_last_punch =
 			playersao->resetTimeFromLastPunch();
 
-		u16 wear = pointed_object->punch(dir, &toolcap, playersao,
-				time_from_last_punch);
+		u32 wear = pointed_object->punch(dir, &toolcap, playersao,
+				time_from_last_punch, tool_item.wear);
 
 		// Callback may have changed item, so get it again
 		playersao->getWieldedItem(&selected_item);
@@ -1173,7 +1173,8 @@ void Server::handleCommand_Interact(NetworkPacket *pkt)
 
 			// Get diggability and expected digging time
 			DigParams params = getDigParams(m_nodedef->get(n).groups,
-					&selected_item.getToolCapabilities(m_itemdef));
+					&selected_item.getToolCapabilities(m_itemdef),
+					selected_item.wear);
 			// If can't dig, try hand
 			if (!params.diggable) {
 				params = getDigParams(m_nodedef->get(n).groups,
diff --git a/src/script/lua_api/l_object.cpp b/src/script/lua_api/l_object.cpp
index b7185f7ec..072b13d80 100644
--- a/src/script/lua_api/l_object.cpp
+++ b/src/script/lua_api/l_object.cpp
@@ -174,7 +174,7 @@ int ObjectRef::l_punch(lua_State *L)
 	v3f dir = readParam<v3f>(L, 5, sao->getBasePosition() - puncher->getBasePosition());
 	dir.normalize();
 
-	u16 wear = sao->punch(dir, &toolcap, puncher, time_from_last_punch);
+	u32 wear = sao->punch(dir, &toolcap, puncher, time_from_last_punch);
 	lua_pushnumber(L, wear);
 
 	return 1;
diff --git a/src/script/lua_api/l_util.cpp b/src/script/lua_api/l_util.cpp
index 2405cd90d..53319ccfd 100644
--- a/src/script/lua_api/l_util.cpp
+++ b/src/script/lua_api/l_util.cpp
@@ -160,28 +160,33 @@ int ModApiUtil::l_write_json(lua_State *L)
 	return 1;
 }
 
-// get_dig_params(groups, tool_capabilities)
+// get_dig_params(groups, tool_capabilities[, wear])
 int ModApiUtil::l_get_dig_params(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
 	ItemGroupList groups;
 	read_groups(L, 1, groups);
 	ToolCapabilities tp = read_tool_capabilities(L, 2);
-	push_dig_params(L, getDigParams(groups, &tp));
+	if (lua_isnoneornil(L, 3)) {
+		push_dig_params(L, getDigParams(groups, &tp));
+	} else {
+		u16 wear = readParam<int>(L, 3);
+		push_dig_params(L, getDigParams(groups, &tp, wear));
+	}
 	return 1;
 }
 
-// get_hit_params(groups, tool_capabilities[, time_from_last_punch])
+// get_hit_params(groups, tool_capabilities[, time_from_last_punch, [, wear]])
 int ModApiUtil::l_get_hit_params(lua_State *L)
 {
 	NO_MAP_LOCK_REQUIRED;
 	std::unordered_map<std::string, int> groups;
 	read_groups(L, 1, groups);
 	ToolCapabilities tp = read_tool_capabilities(L, 2);
-	if(lua_isnoneornil(L, 3))
-		push_hit_params(L, getHitParams(groups, &tp));
-	else
-		push_hit_params(L, getHitParams(groups, &tp, readParam<float>(L, 3)));
+	float time_from_last_punch = readParam<float>(L, 3, 1000000);
+	int wear = readParam<int>(L, 4, 0);
+	push_hit_params(L, getHitParams(groups, &tp,
+		time_from_last_punch, wear));
 	return 1;
 }
 
diff --git a/src/script/lua_api/l_util.h b/src/script/lua_api/l_util.h
index cc91e8d39..314e92f5c 100644
--- a/src/script/lua_api/l_util.h
+++ b/src/script/lua_api/l_util.h
@@ -50,10 +50,10 @@ private:
 	// write_json(data[, styled])
 	static int l_write_json(lua_State *L);
 
-	// get_dig_params(groups, tool_capabilities[, time_from_last_punch])
+	// get_dig_params(groups, tool_capabilities[, wear])
 	static int l_get_dig_params(lua_State *L);
 
-	// get_hit_params(groups, tool_capabilities[, time_from_last_punch])
+	// get_hit_params(groups, tool_capabilities[, time_from_last_punch[, wear]])
 	static int l_get_hit_params(lua_State *L);
 
 	// check_password_entry(name, entry, password)
diff --git a/src/server/luaentity_sao.cpp b/src/server/luaentity_sao.cpp
index 1d65ac306..82f6da231 100644
--- a/src/server/luaentity_sao.cpp
+++ b/src/server/luaentity_sao.cpp
@@ -305,10 +305,11 @@ void LuaEntitySAO::getStaticData(std::string *result) const
 	*result = os.str();
 }
 
-u16 LuaEntitySAO::punch(v3f dir,
+u32 LuaEntitySAO::punch(v3f dir,
 		const ToolCapabilities *toolcap,
 		ServerActiveObject *puncher,
-		float time_from_last_punch)
+		float time_from_last_punch,
+		u16 initial_wear)
 {
 	if (!m_registered) {
 		// Delete unknown LuaEntities when punched
@@ -326,7 +327,8 @@ u16 LuaEntitySAO::punch(v3f dir,
 			m_armor_groups,
 			toolcap,
 			&tool_item,
-			time_from_last_punch);
+			time_from_last_punch,
+			initial_wear);
 
 	bool damage_handled = m_env->getScriptIface()->luaentity_Punch(m_id, puncher,
 			time_from_last_punch, toolcap, dir, result.did_punch ? result.damage : 0);
diff --git a/src/server/luaentity_sao.h b/src/server/luaentity_sao.h
index 6883ae1b9..87b664a8b 100644
--- a/src/server/luaentity_sao.h
+++ b/src/server/luaentity_sao.h
@@ -44,9 +44,10 @@ public:
 	bool isStaticAllowed() const { return m_prop.static_save; }
 	bool shouldUnload() const { return true; }
 	void getStaticData(std::string *result) const;
-	u16 punch(v3f dir, const ToolCapabilities *toolcap = nullptr,
+	u32 punch(v3f dir, const ToolCapabilities *toolcap = nullptr,
 			ServerActiveObject *puncher = nullptr,
-			float time_from_last_punch = 1000000.0f);
+			float time_from_last_punch = 1000000.0f,
+			u16 initial_wear = 0);
 	void rightClick(ServerActiveObject *clicker);
 	void setPos(const v3f &pos);
 	void moveTo(v3f pos, bool continuous);
diff --git a/src/server/player_sao.cpp b/src/server/player_sao.cpp
index 690823bb7..83e17f830 100644
--- a/src/server/player_sao.cpp
+++ b/src/server/player_sao.cpp
@@ -409,10 +409,11 @@ void PlayerSAO::setLookPitchAndSend(const float pitch)
 	m_env->getGameDef()->SendMovePlayer(m_peer_id);
 }
 
-u16 PlayerSAO::punch(v3f dir,
+u32 PlayerSAO::punch(v3f dir,
 	const ToolCapabilities *toolcap,
 	ServerActiveObject *puncher,
-	float time_from_last_punch)
+	float time_from_last_punch,
+	u16 initial_wear)
 {
 	if (!toolcap)
 		return 0;
@@ -430,7 +431,7 @@ u16 PlayerSAO::punch(v3f dir,
 
 	s32 old_hp = getHP();
 	HitParams hitparams = getHitParams(m_armor_groups, toolcap,
-			time_from_last_punch);
+			time_from_last_punch, initial_wear);
 
 	PlayerSAO *playersao = m_player->getPlayerSAO();
 
diff --git a/src/server/player_sao.h b/src/server/player_sao.h
index 1429d7129..47fe85413 100644
--- a/src/server/player_sao.h
+++ b/src/server/player_sao.h
@@ -109,8 +109,8 @@ public:
 		Interaction interface
 	*/
 
-	u16 punch(v3f dir, const ToolCapabilities *toolcap, ServerActiveObject *puncher,
-			float time_from_last_punch);
+	u32 punch(v3f dir, const ToolCapabilities *toolcap, ServerActiveObject *puncher,
+			float time_from_last_punch, u16 initial_wear = 0);
 	void rightClick(ServerActiveObject *clicker);
 	void setHP(s32 hp, const PlayerHPChangeReason &reason) override
 	{
diff --git a/src/server/serveractiveobject.h b/src/server/serveractiveobject.h
index 51f445914..5b0ee2d9b 100644
--- a/src/server/serveractiveobject.h
+++ b/src/server/serveractiveobject.h
@@ -145,11 +145,12 @@ public:
 	virtual bool shouldUnload() const
 	{ return true; }
 
-	// Returns tool wear
-	virtual u16 punch(v3f dir,
+	// Returns added tool wear
+	virtual u32 punch(v3f dir,
 			const ToolCapabilities *toolcap = nullptr,
 			ServerActiveObject *puncher = nullptr,
-			float time_from_last_punch = 1000000.0f)
+			float time_from_last_punch = 1000000.0f,
+			u16 initial_wear = 0)
 	{ return 0; }
 	virtual void rightClick(ServerActiveObject *clicker)
 	{}
diff --git a/src/tool.cpp b/src/tool.cpp
index 3f639a69e..b0749286d 100644
--- a/src/tool.cpp
+++ b/src/tool.cpp
@@ -183,9 +183,74 @@ void ToolCapabilities::deserializeJson(std::istream &is)
 	}
 }
 
+static u32 calculateResultWear(const u32 uses, const u16 initial_wear)
+{
+	if (uses == 0) {
+		// Trivial case: Infinite uses
+		return 0;
+	}
+	/* Finite uses. This is not trivial,
+	as the maximum wear is not neatly evenly divisible by
+	most possible uses numbers. For example, for 128
+	uses, the calculation of wear is trivial, as
+	65536 / 128 uses = 512 wear,
+	so the tool will get 512 wear 128 times in its lifetime.
+	But for a number like 130, this does not work:
+	65536 / 130 uses = 504.123... wear.
+	Since wear must be an integer, we will get
+	504*130 = 65520, which would lead to the wrong number
+	of uses.
+
+	Instead, we partition the "wear range" into blocks:
+	A block represents a single use and can be
+	of two possible sizes: normal and oversized.
+	A normal block is equal to floor(65536 / uses).
+	An oversized block is a normal block plus 1.
+	Then we determine how many oversized and normal
+	blocks we need and finally, whether we add
+	the normal wear or the oversized wear.
+
+	Example for 130 uses:
+	* Normal wear = 504
+	* Number of normal blocks = 114
+	* Oversized wear = 505
+	* Number of oversized blocks = 16
+
+	If we add everything together, we get:
+	  114*504 + 16*505 = 65536
+	*/
+	u32 result_wear;
+	u32 wear_normal = ((U16_MAX+1) / uses);
+	// Will be non-zero if its not evenly divisible
+	u16 blocks_oversize = (U16_MAX+1) % uses;
+	// Whether to add one extra wear point in case
+	// of oversized wear.
+	u16 wear_extra = 0;
+	if (blocks_oversize > 0) {
+		u16 blocks_normal = uses - blocks_oversize;
+		/* When the wear has reached this value, we
+		   know that wear_normal has been applied
+		   for blocks_normal times, therefore,
+		   only oversized blocks remain.
+		   This also implies the raw tool wear number
+		   increases a bit faster after this point,
+		   but this should be barely noticable by the
+		   player.
+		*/
+		u16 wear_extra_at = blocks_normal * wear_normal;
+		if (initial_wear >= wear_extra_at) {
+			wear_extra = 1;
+		}
+	}
+	result_wear = wear_normal + wear_extra;
+	return result_wear;
+}
+
 DigParams getDigParams(const ItemGroupList &groups,
-		const ToolCapabilities *tp)
+		const ToolCapabilities *tp,
+		const u16 initial_wear)
 {
+
 	// Group dig_immediate defaults to fixed time and no wear
 	if (tp->groupcaps.find("dig_immediate") == tp->groupcaps.cend()) {
 		switch (itemgroup_get(groups, "dig_immediate")) {
@@ -201,7 +266,7 @@ DigParams getDigParams(const ItemGroupList &groups,
 	// Values to be returned (with a bit of conversion)
 	bool result_diggable = false;
 	float result_time = 0.0;
-	float result_wear = 0.0;
+	u32 result_wear = 0;
 	std::string result_main_group;
 
 	int level = itemgroup_get(groups, "level");
@@ -224,20 +289,22 @@ DigParams getDigParams(const ItemGroupList &groups,
 		if (!result_diggable || time < result_time) {
 			result_time = time;
 			result_diggable = true;
-			if (cap.uses != 0)
-				result_wear = 1.0 / cap.uses / pow(3.0, leveldiff);
-			else
-				result_wear = 0;
+			// The actual number of uses increases
+			// exponentially with leveldiff.
+			// If the levels are equal, real_uses equals cap.uses.
+			u32 real_uses = cap.uses * pow(3.0, leveldiff);
+			real_uses = MYMIN(real_uses, U16_MAX);
+			result_wear = calculateResultWear(real_uses, initial_wear);
 			result_main_group = groupname;
 		}
 	}
 
-	u16 wear_i = U16_MAX * result_wear;
-	return DigParams(result_diggable, result_time, wear_i, result_main_group);
+	return DigParams(result_diggable, result_time, result_wear, result_main_group);
 }
 
 HitParams getHitParams(const ItemGroupList &armor_groups,
-		const ToolCapabilities *tp, float time_from_last_punch)
+		const ToolCapabilities *tp, float time_from_last_punch,
+		u16 initial_wear)
 {
 	s16 damage = 0;
 	float result_wear = 0.0f;
@@ -249,10 +316,12 @@ HitParams getHitParams(const ItemGroupList &armor_groups,
 		damage += damageGroup.second * punch_interval_multiplier * armor / 100.0;
 	}
 
-	if (tp->punch_attack_uses > 0)
-		result_wear = 1.0f / tp->punch_attack_uses * punch_interval_multiplier;
+	if (tp->punch_attack_uses > 0) {
+		result_wear = calculateResultWear(tp->punch_attack_uses, initial_wear);
+		result_wear *= punch_interval_multiplier;
+	}
 
-	u16 wear_i = U16_MAX * result_wear;
+	u32 wear_i = (u32) result_wear;
 	return {damage, wear_i};
 }
 
@@ -266,7 +335,8 @@ PunchDamageResult getPunchDamage(
 		const ItemGroupList &armor_groups,
 		const ToolCapabilities *toolcap,
 		const ItemStack *punchitem,
-		float time_from_last_punch
+		float time_from_last_punch,
+		u16 initial_wear
 ){
 	bool do_hit = true;
 	{
@@ -286,7 +356,8 @@ PunchDamageResult getPunchDamage(
 	if(do_hit)
 	{
 		HitParams hitparams = getHitParams(armor_groups, toolcap,
-				time_from_last_punch);
+				time_from_last_punch,
+				punchitem->wear);
 		result.did_punch = true;
 		result.wear = hitparams.wear;
 		result.damage = hitparams.hp;
diff --git a/src/tool.h b/src/tool.h
index 59dd501f5..0e3388485 100644
--- a/src/tool.h
+++ b/src/tool.h
@@ -88,10 +88,10 @@ struct DigParams
 	// Digging time in seconds
 	float time;
 	// Caused wear
-	u16 wear;
+	u32 wear; // u32 because wear could be 65536 (single-use tool)
 	std::string main_group;
 
-	DigParams(bool a_diggable = false, float a_time = 0.0f, u16 a_wear = 0,
+	DigParams(bool a_diggable = false, float a_time = 0.0f, u32 a_wear = 0,
 			const std::string &a_main_group = ""):
 		diggable(a_diggable),
 		time(a_time),
@@ -101,21 +101,24 @@ struct DigParams
 };
 
 DigParams getDigParams(const ItemGroupList &groups,
-		const ToolCapabilities *tp);
+		const ToolCapabilities *tp,
+		const u16 initial_wear = 0);
 
 struct HitParams
 {
 	s16 hp;
-	u16 wear;
+	// Caused wear
+	u32 wear; // u32 because wear could be 65536 (single-use weapon)
 
-	HitParams(s16 hp_ = 0, u16 wear_ = 0):
+	HitParams(s16 hp_ = 0, u32 wear_ = 0):
 		hp(hp_),
 		wear(wear_)
 	{}
 };
 
 HitParams getHitParams(const ItemGroupList &armor_groups,
-		const ToolCapabilities *tp, float time_from_last_punch);
+		const ToolCapabilities *tp, float time_from_last_punch,
+		u16 initial_wear = 0);
 
 HitParams getHitParams(const ItemGroupList &armor_groups,
 		const ToolCapabilities *tp);
@@ -135,7 +138,8 @@ PunchDamageResult getPunchDamage(
 		const ItemGroupList &armor_groups,
 		const ToolCapabilities *toolcap,
 		const ItemStack *punchitem,
-		float time_from_last_punch
+		float time_from_last_punch,
+		u16 initial_wear = 0
 );
 
 f32 getToolRange(const ItemDefinition &def_selected, const ItemDefinition &def_hand);