Moved Stars45 to StarsEx

1 files changed, 255 insertions, 0 deletions

diff --git a/StarsEx/SeekerAI.cpp b/StarsEx/SeekerAI.cpp
new file mode 100644
index 0000000..7976dfd
--- /dev/null
+++ b/StarsEx/SeekerAI.cpp
@@ -0,0 +1,255 @@
+/*  Starshatter: The Open Source Project
+    Copyright (c) 2021-2022, Starshatter: The Open Source Project Contributors
+    Copyright (c) 2011-2012, Starshatter OpenSource Distribution Contributors
+    Copyright (c) 1997-2006, Destroyer Studios LLC.
+
+    AUTHOR:       John DiCamillo
+
+
+    OVERVIEW
+    ========
+    Seeker Missile (low-level) Artificial Intelligence class
+*/
+
+#include "SeekerAI.h"
+#include "Ship.h"
+#include "Shot.h"
+#include "System.h"
+#include "WeaponDesign.h"
+
+#include "Clock.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 -= Clock::GetInstance()->Delta();
+    }
+    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_s(name, "SeekerAI(%s)", self->Name());
+    return name;
+}
+