From e33e19d0587146859d48a134ec9fd94e7b7ba5cd Mon Sep 17 00:00:00 2001
From: "FWoltermann@gmail.com"
 <FWoltermann@gmail.com@076cb2c4-205e-83fd-5cf3-1be9aa105544>
Date: Thu, 8 Dec 2011 14:53:40 +0000
Subject: Initial upload

---
 Stars45/SeekerAI.cpp | 257 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 257 insertions(+)
 create mode 100644 Stars45/SeekerAI.cpp

(limited to 'Stars45/SeekerAI.cpp')

diff --git a/Stars45/SeekerAI.cpp b/Stars45/SeekerAI.cpp
new file mode 100644
index 0000000..c57219c
--- /dev/null
+++ b/Stars45/SeekerAI.cpp
@@ -0,0 +1,257 @@
+/*  Project Starshatter 4.5
+    Destroyer Studios LLC
+    Copyright © 1997-2004. All Rights Reserved.
+
+    SUBSYSTEM:    Stars.exe
+    FILE:         SeekerAI.cpp
+    AUTHOR:       John DiCamillo
+
+
+    OVERVIEW
+    ========
+    Seeker Missile (low-level) Artificial Intelligence class
+*/
+
+#include "MemDebug.h"
+#include "SeekerAI.h"
+#include "Ship.h"
+#include "Shot.h"
+#include "System.h"
+#include "WeaponDesign.h"
+
+#include "Game.h"
+
+// +----------------------------------------------------------------------+
+
+SeekerAI::SeekerAI(SimObject* s)
+   : SteerAI(s), shot((Shot*) s), orig_target(0),
+     pursuit(1), delay(0), overshot(false)
+{
+   ai_type = SEEKER;
+
+   seek_gain = 25;
+   seek_damp = 0.55;
+}
+
+
+// +--------------------------------------------------------------------+
+
+SeekerAI::~SeekerAI()
+{
+   if (shot) {
+      if (shot->Owner())
+         ((Ship*) shot->Owner())->SetMissileEta(shot->Identity(), 0);
+   }
+}
+
+// +--------------------------------------------------------------------+
+
+void
+SeekerAI::ExecFrame(double seconds)
+{
+   // setup:
+   FindObjective();
+
+   // adaptive behavior:
+   Navigator();
+}
+
+// +--------------------------------------------------------------------+
+
+void
+SeekerAI::Navigator()
+{
+   if (delay > 0) {
+      delay -= Game::FrameTime();
+   }
+   else {
+      Steer s = SeekTarget();
+      self->ApplyYaw((float) s.yaw);
+      self->ApplyPitch((float) s.pitch);
+   }
+}
+
+void
+SeekerAI::SetTarget(SimObject* targ, System* sub)
+{
+   if (!orig_target && targ && targ->Type() == SimObject::SIM_SHIP) {
+      orig_target = (Ship*) targ;
+      Observe(orig_target);
+   }
+
+   SteerAI::SetTarget(targ, sub);
+
+   if (!target) {
+      shot->SetEta(0);
+
+      if (shot->Owner())
+         ((Ship*) shot->Owner())->SetMissileEta(shot->Identity(), 0);
+   }
+}
+
+void
+SeekerAI::FindObjective()
+{
+   if (!shot || !target) return;
+
+   if (target->Life() == 0) {
+      if (target != orig_target)
+         SetTarget(orig_target,0);
+      else
+         SetTarget(0,0);
+
+      return;
+   }
+
+   Point tloc = target->Location();
+   tloc = Transform(tloc);
+
+   // seeker head limit of 45 degrees:
+   if (tloc.z < 0 || tloc.z < fabs(tloc.x) || tloc.z < fabs(tloc.y)) {
+      overshot = true;
+      SetTarget(0,0);
+      return;
+   }
+   
+   // distance from self to target:
+   distance = Point(target->Location() - self->Location()).length();
+
+   // are we being spoofed?
+   CheckDecoys(distance);
+
+   Point cv = ClosingVelocity();
+
+   // time to reach target:
+   double time    = distance / cv.length();
+   double predict = time;
+   if (predict > 15)
+      predict = 15;
+
+   // pure pursuit:
+   if (pursuit == 1 || time < 0.1) {
+      obj_w = target->Location();
+   }
+
+   // lead pursuit:
+   else {
+      // where the target will be when we reach it:
+      Point run_vec = target->Velocity();
+            obj_w   = target->Location() + (run_vec * predict);
+   }
+
+   // subsystem offset:
+   if (subtarget) {
+      Point offset = target->Location() - subtarget->MountLocation();
+      obj_w -= offset;
+   }
+   else if (target->Type() == SimObject::SIM_SHIP) {
+      Ship* tgt_ship = (Ship*) target;
+
+      if (tgt_ship->IsGroundUnit())
+         obj_w += Point(0,150,0);
+   }
+
+
+   distance = Point(obj_w - self->Location()).length();
+   time     = distance / cv.length();
+
+   // where we will be when the target gets there:
+   if (predict > 0.1 && predict < 15) {
+      Point self_dest = self->Location() + cv * predict;
+      Point err = obj_w - self_dest;
+
+      obj_w += err;
+   }
+
+   // transform into camera coords:
+   objective = Transform(obj_w);
+   objective.Normalize();
+
+   shot->SetEta((int) time);
+
+   if (shot->Owner())
+      ((Ship*) shot->Owner())->SetMissileEta(shot->Identity(), (int) time);
+}
+
+// +--------------------------------------------------------------------+
+
+void
+SeekerAI::CheckDecoys(double target_distance)
+{
+   // if the assigned target has the burner lit,
+   // ignore the decoys:
+   if (orig_target && orig_target->Augmenter()) {
+      SetTarget(orig_target);
+      return;
+   }
+
+   if (target && 
+       target == orig_target && 
+       orig_target->GetActiveDecoys().size()) {
+
+      ListIter<Shot> decoy = orig_target->GetActiveDecoys();
+
+      while (++decoy) {
+         double decoy_distance = Point(decoy->Location() - self->Location()).length();
+
+         if (decoy_distance < target_distance) {
+            if (rand() < 1600) {
+               SetTarget(decoy.value(), 0);
+               return;
+            }
+         }
+      }
+   }
+}
+
+// +--------------------------------------------------------------------+
+
+bool
+SeekerAI::Overshot()
+{
+   return overshot;
+}
+
+// +--------------------------------------------------------------------+
+
+Steer
+SeekerAI::AvoidCollision()
+{
+   return Steer();
+}
+
+// +--------------------------------------------------------------------+
+
+Steer
+SeekerAI::SeekTarget()
+{
+   if (!self || !target || Overshot())
+      return Steer();
+
+   return Seek(objective);
+}
+
+// +--------------------------------------------------------------------+
+
+bool
+SeekerAI::Update(SimObject* obj)
+{
+   if (obj == target) {
+      if (obj->Type() == SimObject::SIM_SHOT && orig_target != 0)
+         target = orig_target;
+   }
+
+   if (obj == orig_target)
+      orig_target = 0;
+
+   return SteerAI::Update(obj);
+}
+
+const char*
+SeekerAI::GetObserverName() const
+{
+   static char name[64];
+   sprintf(name, "SeekerAI(%s)", self->Name());
+   return name;
+}
+
-- 
cgit v1.1