From d26c7dd536c4c98a1847edbb618d8d549f85ba06 Mon Sep 17 00:00:00 2001
From: Quantum <quantum2048@gmail.com>
Date: Sat, 26 Oct 2013 11:48:58 -0400
Subject: [PATCH] Added handling of inclination, longitude of ascending node,
 and argument of periapsis.

Signed-off-by: Xiaomao Chen <xiaomao5@live.com>
---
 punyverse/entity.py | 12 ++++----
 punyverse/game.py   |  4 +--
 punyverse/orbit.py  | 73 ++++++++++++++++++++++++++++++++++++++++-----
 punyverse/world.py  |  3 +-
 4 files changed, 77 insertions(+), 15 deletions(-)

diff --git a/punyverse/entity.py b/punyverse/entity.py
index b6d28e9..1274d51 100644
--- a/punyverse/entity.py
+++ b/punyverse/entity.py
@@ -52,15 +52,17 @@ class Satellite(Planet):
         self.orbit_speed = kwargs.pop('orbit_speed', 1)
 
         # Semi-major axis and eccentricity defines orbit
-        self.distance = kwargs.pop('distance', 100)
-        self.eccentricity = kwargs.pop('eccentricity', 0)
+        distance = kwargs.pop('distance', 100)
+        eccentricity = kwargs.pop('eccentricity', 0)
 
-        # Inclination and longitude of ascending node defines orbital plane
-        self.inclination = kwargs.pop('inclination', 0)
+        # Inclination, longitude of ascending node, and argument of periapsis defines orbital plane
+        inclination = kwargs.pop('inclination', 0)
+        longitude = kwargs.pop('longitude', 0)
+        argument = kwargs.pop('argument', 0)
 
         self.theta = 0
         # OpenGL's z-axis is reversed
-        self.orbit = KeplerOrbit(self.distance, self.eccentricity, -self.inclination)
+        self.orbit = KeplerOrbit(distance, eccentricity, inclination, longitude, argument)
         super(Satellite, self).__init__(*args, **kwargs)
 
     def update(self):
diff --git a/punyverse/game.py b/punyverse/game.py
index 202d09f..72ff54e 100644
--- a/punyverse/game.py
+++ b/punyverse/game.py
@@ -159,9 +159,9 @@ class Applet(pyglet.window.Window):
             elif symbol == key.NUM_DIVIDE:
                 self.speed -= 10
             elif symbol == key.PAGEUP:
-                self.speed += 1000
+                self.speed += 100
             elif symbol == key.PAGEDOWN:
-                self.speed -= 1000
+                self.speed -= 100
             elif symbol == key.I:
                 self.info = not self.info
             elif symbol == key.D:
diff --git a/punyverse/orbit.py b/punyverse/orbit.py
index fb21589..eac60c7 100644
--- a/punyverse/orbit.py
+++ b/punyverse/orbit.py
@@ -1,15 +1,69 @@
-from math import sin, cos, tan, atan, sqrt, radians
+from math import sin, cos, tan, atan, sqrt, radians, degrees
 
 
 class KeplerOrbit(object):
-    def __init__(self, sma, eccentricity, inclination=0):
+    def __init__(self, sma, eccentricity, inclination=0, longitude=0, argument=0):
         self.sma = sma
         self.eccentricity = eccentricity
-        self.inclination = radians(inclination)
+        self.inclination = inclination
+        self.longitude = longitude
+        self.argument = argument
         self.__true_anomaly_factor = sqrt((1 + eccentricity)/(1 - eccentricity))
         self.__distance_factor = sma * (1 - eccentricity ** 2)
-        self.__sin_inclination = sin(self.inclination)
-        self.__cos_inclination = cos(self.inclination)
+
+    @property
+    def inclination(self):
+        return degrees(self._inclination)
+
+    @inclination.setter
+    def inclination(self, value):
+        self.inclination_radian = radians(value)
+
+    @property
+    def inclination_radian(self):
+        return self._inclination
+
+    @inclination_radian.setter
+    def inclination_radian(self, value):
+        self._inclination = value
+        self.__sin_inclination = sin(self._inclination)
+        self.__cos_inclination = cos(self._inclination)
+
+    @property
+    def longitude(self):
+        return degrees(self._longitude)
+
+    @longitude.setter
+    def longitude(self, value):
+        self.longitude_radian = radians(value)
+
+    @property
+    def longitude_radian(self):
+        return self._longitude
+
+    @longitude_radian.setter
+    def longitude_radian(self, value):
+        self._longitude = value
+        self.__sin_longitude = sin(self._longitude)
+        self.__cos_longitude = cos(self._longitude)
+
+    @property
+    def argument(self):
+        return degrees(self._argument)
+
+    @argument.setter
+    def argument(self, value):
+        self.argument_radian = radians(value)
+
+    @property
+    def argument_radian(self):
+        return self._argument
+
+    @argument_radian.setter
+    def argument_radian(self, value):
+        self._argument = value
+        self.__sin_argument = sin(self._argument)
+        self.__cos_argument = cos(self._argument)
 
     def eccentric_anomaly(self, mean_anomaly):
         e1 = mean_anomaly
@@ -30,7 +84,12 @@ class KeplerOrbit(object):
         y = r * sin(phi)
         z = 0
 
-        x, z = (x * self.__cos_inclination - z * self.__sin_inclination,
-                x * self.__sin_inclination + z * self.__cos_inclination)
+        # phi = longitude, theta = inclination, psi = argument
+        x, y = (x * self.__cos_longitude + y * self.__sin_longitude,
+               -x * self.__sin_longitude + y * self.__cos_longitude)
+        x, z = (x * self.__cos_inclination + z * self.__sin_inclination,
+               -x * self.__sin_inclination + z * self.__cos_inclination)
+        x, y = (x * self.__cos_argument + y * self.__sin_argument,
+               -x * self.__sin_argument + y * self.__cos_argument)
 
         return x, y, z
diff --git a/punyverse/world.py b/punyverse/world.py
index e684059..2b8d921 100644
--- a/punyverse/world.py
+++ b/punyverse/world.py
@@ -109,7 +109,8 @@ def load_world(file):
                 x -= distance
                 type = partial(Satellite, parent=parent, orbit_speed=info.get('orbit_speed', 1),
                                distance=distance, eccentricity=info.get('eccentricity', 0),
-                               inclination=info.get('inclination', 0))
+                               inclination=info.get('inclination', 0), longitude=info.get('longitude', 0),
+                               argument=info.get('argument', 0))
 
             atmosphere_id = 0
             cloudmap_id = 0