Update various life regen and related hook docs.

patches/tModLoader/Terraria/ModLoader/GlobalNPC.cs

@@ -188,7 +188,10 @@ public virtual void HitEffect(NPC npc, NPC.HitInfo hit)
 	}
 
 	/// <summary>
-	/// Allows you to make the NPC either regenerate health or take damage over time by setting npc.lifeRegen. Regeneration or damage will occur at a rate of half of npc.lifeRegen per second. The damage parameter is the number that appears above the NPC's head if it takes damage over time.
+	/// Allows you to make the NPC either regenerate health or take damage over time by setting <see cref="NPC.lifeRegen"/>. This is useful for implementing damage over time debuffs such as <see cref="BuffID.Poisoned"/> or <see cref="BuffID.OnFire"/>. Regeneration or damage will occur at a rate of half of <see cref="NPC.lifeRegen"/> per second.
+	/// <para/>Essentially, modders implementing damage over time debuffs should subtract from <see cref="NPC.lifeRegen"/> a number that is twice as large as the intended damage per second. See <see href="https://github.com/tModLoader/tModLoader/blob/stable/ExampleMod/Common/GlobalNPCs/DamageOverTimeGlobalNPC.cs#L16">DamageOverTimeGlobalNPC.cs</see> for an example of this.
+	/// <para/>The damage parameter is the number that appears above the NPC's head if it takes damage over time.
+	/// <para/>Multiple debuffs work together by following some conventions: <see cref="NPC.lifeRegen"/> should not be assigned a number, rather it should be subtracted from. <paramref name="damage"/> should only be assigned if the intended popup text is larger then its current value.  
 	/// </summary>
 	/// <param name="npc"></param>
 	/// <param name="damage"></param>

patches/tModLoader/Terraria/ModLoader/ModNPC.cs

@@ -278,7 +278,10 @@ public virtual void HitEffect(NPC.HitInfo hit)
 	}
 
 	/// <summary>
-	/// Allows you to make the NPC either regenerate health or take damage over time by setting NPC.lifeRegen. Regeneration or damage will occur at a rate of half of NPC.lifeRegen per second. The damage parameter is the number that appears above the NPC's head if it takes damage over time.
+	/// Allows you to make the NPC either regenerate health or take damage over time by setting <see cref="NPC.lifeRegen"/>. This is useful for implementing damage over time debuffs such as <see cref="BuffID.Poisoned"/> or <see cref="BuffID.OnFire"/>. Regeneration or damage will occur at a rate of half of <see cref="NPC.lifeRegen"/> per second.
+	/// <para/>Essentially, modders implementing damage over time debuffs should subtract from <see cref="NPC.lifeRegen"/> a number that is twice as large as the intended damage per second. See <see href="https://github.com/tModLoader/tModLoader/blob/stable/ExampleMod/Common/GlobalNPCs/DamageOverTimeGlobalNPC.cs#L16">DamageOverTimeGlobalNPC.cs</see> for an example of this.
+	/// <para/>The damage parameter is the number that appears above the NPC's head if it takes damage over time.
+	/// <para/>Multiple debuffs work together by following some conventions: <see cref="NPC.lifeRegen"/> should not be assigned a number, rather it should be subtracted from. <paramref name="damage"/> should only be assigned if the intended popup text is larger then its current value.  
 	/// </summary>
 	/// <param name="damage"></param>
 	public virtual void UpdateLifeRegen(ref int damage)

patches/tModLoader/Terraria/NPC.cs.patch

@@ -120,6 +120,26 @@
  	public bool canDisplayBuffs = true;
  	public bool midas;
  	public bool ichor;
+@@ -136,7 +_,19 @@
+ 	public bool shadowFlame;
+ 	public bool soulDrain;
+ 	public bool shimmering;
++	/// <summary>
++	/// The rate of this player's life regeneration or loss in health per tick, divided by <c>120</c>. To put it another way, it is health regeneration every 2 seconds. Used to implement the damage over time of debuffs.
++	/// <br/> For example, subtracting <c>12</c> from this value loses <c>12 / 120</c> = <c>1/10</c> health per tick, or 6 health per second.
++	/// <br/> Life regeneration is accumulated every tick in <see cref="lifeRegenCount"/>.
++	/// <br/> This value should be subtracted from in <see cref="ModNPC.UpdateLifeRegen(ref int)"/> or <see cref="GlobalNPC.UpdateLifeRegen(NPC, ref int)"/>. See <see href="https://github.com/tModLoader/tModLoader/blob/stable/ExampleMod/Common/GlobalNPCs/DamageOverTimeGlobalNPC.cs#L16">DamageOverTimeGlobalNPC.cs</see> for an example. The game does not actually use positive life regen for NPC, so positive values might not work as expected. 
++	/// </summary>
+ 	public int lifeRegen;
++	/// <summary>
++	/// This NPC's accumulated life regeneration.
++	/// <br/> If this value reaches or exceeds <c>120</c>, the NPC gains <c><see cref="lifeRegenCount"/> / 120</c> health and this value decreases until it no longer exceeds <c>120</c>.
++	/// <br/> If this value reaches or exceeds <c>-120</c>, the NPC loses health in the same way.
++	/// <br/> In either case, text will appear above the NPC indicating the life regeneration or life loss.
++	/// </summary>
+ 	public int lifeRegenCount;
+ 	public int lifeRegenExpectedLossPerSecond = -1;
+ 	public bool confused;
 @@ -182,35 +_,149 @@
  	public static bool unlockedArmsDealerSpawn = false;
  	public static bool unlockedNurseSpawn = false;

patches/tModLoader/Terraria/Player.cs.patch

@@ -397,7 +397,7 @@
  	public float manaCost = 1f;
  	public bool fireWalk;
  	public bool channel;
-@@ -961,23 +_,96 @@
+@@ -961,23 +_,97 @@
  	public int golferScoreAccumulated;
  	public int bartenderQuestLog;
  	public bool downedDD2EventAnyDifficulty;
@@ -464,7 +464,7 @@
  	public int statManaMax2;
 +
 +	/// <summary>
-+	/// The rate of this player's life regeneration in health/ticks, divided by <c>120</c>.
++	/// The rate of this player's life regeneration in health per tick, divided by <c>120</c>. To put it another way, it is health regeneration every 2 seconds. Used to implement the damage over time of debuffs and life regeneration accessories such as <see cref="ItemID.BandofRegeneration"/>.
 +	/// <br/> For example, adding <c>10</c> to this value regenerates <c>10 / 120</c> = <c>1/6</c> health per tick, or 5 health per second.
 +	/// <br/> Life regeneration is accumulated every tick in <see cref="lifeRegenCount"/>.
 +	/// <br/> This value should be subtracted from in <see cref="ModPlayer.UpdateBadLifeRegen"/> and added to in <see cref="ModPlayer.UpdateLifeRegen"/>.
@@ -475,6 +475,7 @@
 +	/// This player's accumulated life regeneration.
 +	/// <br/> If this value reaches or exceeds <c>120</c>, the player gains <c><see cref="lifeRegenCount"/> / 120</c> health and this value decreases until it no longer exceeds <c>120</c>.
 +	/// <br/> If this value reaches or exceeds <c>-120</c>, the player loses health in the same way.
++	/// <br/> In either case, text will appear above the player indicating the life regeneration or life loss.
 +	/// </summary>
  	public int lifeRegenCount;
 +