Moved Stars45 to StarsEx

1 files changed, 210 insertions, 0 deletions

diff --git a/StarsEx/Camera.cpp b/StarsEx/Camera.cpp
new file mode 100644
index 0000000..c8671e1
--- /dev/null
+++ b/StarsEx/Camera.cpp
@@ -0,0 +1,210 @@
+/*  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
+    ========
+    Camera Class - Position and Point of View
+*/
+
+#include "Camera.h"
+
+// +--------------------------------------------------------------------+
+
+Camera::Camera(double x, double y, double z)
+    : pos(x,y,z)
+{ }
+
+Camera::~Camera()
+{ }
+
+// +--------------------------------------------------------------------+
+
+void
+Camera::MoveTo(double x, double y, double z)
+{
+    pos.x = x;
+    pos.y = y;
+    pos.z = z;
+}
+
+void
+Camera::MoveTo(const Point& p)
+{
+    pos.x = p.x;
+    pos.y = p.y;
+    pos.z = p.z;
+}
+
+// +--------------------------------------------------------------------+
+
+void
+Camera::MoveBy(double dx, double dy, double dz)
+{
+    pos.x += dx;
+    pos.y += dz;
+    pos.z += dy;
+}
+
+void
+Camera::MoveBy(const Point& p)
+{
+    pos.x += p.x;
+    pos.y += p.y;
+    pos.z += p.z;
+}
+
+// +--------------------------------------------------------------------+
+
+void
+Camera::Clone(const Camera& cam)
+{
+    pos         = cam.pos;
+    orientation = cam.orientation;
+}
+
+// +--------------------------------------------------------------------+
+
+void
+Camera::LookAt(const Point& target, const Point& eye, const Point& up)
+{
+    Point zaxis = target - eye;         zaxis.Normalize();
+    Point xaxis = up.cross(zaxis);      xaxis.Normalize();
+    Point yaxis = zaxis.cross(xaxis);   yaxis.Normalize();
+
+    orientation(0,0)  = xaxis.x;
+    orientation(0,1)  = xaxis.y;
+    orientation(0,2)  = xaxis.z;
+
+    orientation(1,0)  = yaxis.x;
+    orientation(1,1)  = yaxis.y;
+    orientation(1,2)  = yaxis.z;
+
+    orientation(2,0)  = zaxis.x;
+    orientation(2,1)  = zaxis.y;
+    orientation(2,2)  = zaxis.z;
+
+    pos               = eye;
+}
+
+// +--------------------------------------------------------------------+
+
+void
+Camera::LookAt(const Point& target)
+{
+    // No navel gazing:
+    if (target == Pos())
+    return;
+
+    Point tgt, tmp = target - Pos();
+
+    // Rotate into the view orientation:
+    tgt.x = (tmp * vrt());
+    tgt.y = (tmp * vup());
+    tgt.z = (tmp * vpn());
+
+    if (tgt.z == 0) {
+        Pitch(0.5);
+        Yaw(0.5);
+        LookAt(target);
+        return;
+    }
+
+    double az = atan(tgt.x/tgt.z);
+    double el = atan(tgt.y/tgt.z);
+
+    // if target is behind, offset by 180 degrees:
+    if (tgt.z < 0)
+    az -= PI;
+
+    Pitch(-el);
+    Yaw(az);
+
+    // roll to upright position:
+    double deflection = vrt().y;
+    while  (fabs(deflection) > 0.001) {
+        double theta = asin(deflection/vrt().length());
+        Roll(-theta);
+
+        deflection = vrt().y;
+    }
+}
+
+
+// +--------------------------------------------------------------------+
+
+bool
+Camera::Padlock(const Point& target, double alimit, double e_lo, double e_hi)
+{
+    // No navel gazing:
+    if (target == Pos())
+    return false;
+
+    Point tgt, tmp = target - Pos();
+
+    // Rotate into the view orientation:
+    tgt.x = (tmp * vrt());
+    tgt.y = (tmp * vup());
+    tgt.z = (tmp * vpn());
+
+    if (tgt.z == 0) {
+        Yaw(0.1);
+
+        tgt.x = (tmp * vrt());
+        tgt.y = (tmp * vup());
+        tgt.z = (tmp * vpn());
+
+        if (tgt.z == 0)
+        return false;
+    }
+
+    bool   locked  = true;
+    double az      = atan(tgt.x/tgt.z);
+    double orig    = az;
+
+    // if target is behind, offset by 180 degrees:
+    if (tgt.z < 0)
+    az -= PI;
+
+    while (az >  PI) az -= 2*PI;
+    while (az < -PI) az += 2*PI;
+
+    if (alimit > 0) {
+        if (az < -alimit) {
+            az = -alimit;
+            locked = false;
+        }
+        else if (az > alimit) {
+            az = alimit;
+            locked = false;
+        }
+    }
+
+    Yaw(az);
+
+    // Rotate into the new view orientation:
+    tgt.x = (tmp * vrt());
+    tgt.y = (tmp * vup());
+    tgt.z = (tmp * vpn());
+
+    double el      = atan(tgt.y/tgt.z);
+
+    if (e_lo > 0 && el < -e_lo) {
+        el = -e_lo;
+        locked = false;
+    }
+
+    else if (e_hi > 0 && el > e_hi) {
+        el = e_hi;
+        locked = false;
+    }
+
+    Pitch(-el);
+
+    return locked;
+}
+