From d130a43aa069c1fea82c20b04b1ac1713007a613 Mon Sep 17 00:00:00 2001
From: Christoph Oelckers <coelckers@users.noreply.github.com>
Date: Wed, 8 Sep 2021 22:08:55 +0200
Subject: [PATCH] - preparations for cleaning up Exhumed's event dispatcher.

---
 source/games/exhumed/src/aistuff.h   | 43 ++++++++++++++++++++++
 source/games/exhumed/src/runlist.cpp | 55 ++++++++++++++++++++++++++++
 2 files changed, 98 insertions(+)

diff --git a/source/games/exhumed/src/aistuff.h b/source/games/exhumed/src/aistuff.h
index 6aeaf83fe..b9ff35b1e 100644
--- a/source/games/exhumed/src/aistuff.h
+++ b/source/games/exhumed/src/aistuff.h
@@ -389,6 +389,49 @@ struct RunChannel
     short d;
 };
 
+enum class EMessageType
+{
+    ProcessChannel = 1,
+    Tick,
+    Process,
+    Use,
+    TouchFloor,
+    LeaveSector,
+    EnterSector,
+    Damage,
+    Draw,
+    RadialDamage
+};
+
+struct RunListEvent
+{
+    EMessageType nMessage;
+    int nIndex;                 // mostly the player, sometimes the channel list
+    tspritetype* pTSprite;      // for the draw event
+    DExhumedActor* pActor;      // for the damage event, radialSpr for radial damage - owner will not be passed as it can be retrieved from this.
+    int nDamage, nRun;
+
+    int nRadialDamage;          // Radial damage needs a bit more info.
+    int nDamageRadius;
+};
+
+struct ExhumedAI
+{
+    virtual ~ExhumedAI() = default;
+    virtual void ProcessChannel(RunListEvent* ev) {}
+    virtual void Tick(RunListEvent* ev) {}
+    virtual void Process(RunListEvent* ev) {}
+    virtual void Use(RunListEvent* ev) {}
+    virtual void TouchFloor(RunListEvent* ev) {}
+    virtual void LeaveSector(RunListEvent* ev) {}
+    virtual void EnterSector(RunListEvent* ev) {}
+    virtual void Damage(RunListEvent* ev) {}
+    virtual void Draw(RunListEvent* ev) {}
+    virtual void RadialDamage(RunListEvent* ev) {}
+};
+
+void runlist_DispatchEvent(ExhumedAI* ai, int nObject, int nMessage, int nDamage, int nRun);
+
 typedef void(*AiFunc)(int, int, int, int nRun);
 
 extern FreeListArray<RunStruct, kMaxRuns> RunData;
diff --git a/source/games/exhumed/src/runlist.cpp b/source/games/exhumed/src/runlist.cpp
index ac5ae5f07..12b69e725 100644
--- a/source/games/exhumed/src/runlist.cpp
+++ b/source/games/exhumed/src/runlist.cpp
@@ -1699,5 +1699,60 @@ void runlist_DamageEnemy(int nSprite, int nSprite2, short nDamage)
     }
 }
 
+// This is only temporary so that the event system can be refactored in smaller steps.
+void runlist_DispatchEvent(ExhumedAI* ai, int nObject, int nMessage, int nDamage, int nRun)
+{
+    RunListEvent ev;
+    ev.nMessage = (EMessageType)(nMessage >> 16);
+    ev.nIndex = nObject;
+    switch (ev.nMessage)
+    {
+    case EMessageType::ProcessChannel:
+        ai->ProcessChannel(&ev);
+        break;
+
+    case EMessageType::Tick:
+        ai->Tick(&ev);
+        break;
+
+    case EMessageType::Process:
+        ai->Process(&ev);
+        break;
+
+    case EMessageType::Use:
+        ai->Use(&ev);
+        break;
+
+    case EMessageType::TouchFloor:
+        ai->TouchFloor(&ev);
+        break;
+
+    case EMessageType::LeaveSector:
+        ai->LeaveSector(&ev);
+        break;
+
+    case EMessageType::EnterSector:
+        ai->EnterSector(&ev);
+        break;
+
+    case EMessageType::Damage:
+        ev.pActor = &exhumedActors[nObject];
+        ai->Damage(&ev);
+        break;
+
+    case EMessageType::Draw:
+        ev.pTSprite = &mytsprite[nObject];
+        ai->Draw(&ev);
+        break;
+
+    case EMessageType::RadialDamage:
+        ev.nRadialDamage = nRadialDamage;
+        ev.nDamageRadius = nDamageRadius;
+        ev.pActor = &exhumedActors[nRadialSpr];
+        ai->RadialDamage(&ev);
+        break;
+    }
+}
+
 
 END_PS_NS