From f16c355d117ebfc10abf43b38f913c0ca4f0473b Mon Sep 17 00:00:00 2001
From: Hleb Valoshka <375gnu@gmail.com>
Date: Mon, 8 Mar 2021 12:36:31 +0200
Subject: [PATCH] Add a new body parameter "reflectivity" complementing albedos

---
 src/celengine/body.cpp            | 15 ++++++++++++++-
 src/celengine/body.h              |  7 +++++--
 src/celengine/render.cpp          |  2 +-
 src/celengine/solarsys.cpp        | 30 +++++++++++++++++++++++++++---
 src/celscript/lua/celx_object.cpp |  3 +++
 5 files changed, 50 insertions(+), 7 deletions(-)

diff --git a/src/celengine/body.cpp b/src/celengine/body.cpp
index b4fd75ea0..74e06b3fc 100644
--- a/src/celengine/body.cpp
+++ b/src/celengine/body.cpp
@@ -79,6 +79,7 @@ void Body::setDefaultProperties()
     density = 0.0f;
     bondAlbedo = 0.5f;
     geomAlbedo = 0.5f;
+    reflectivity = 0.5f;
     temperature = 0.0f;
     tempDiscrepancy = 0.0f;
     geometryOrientation = Quaternionf::Identity();
@@ -347,6 +348,18 @@ void Body::setBondAlbedo(float _bondAlbedo)
 }
 
 
+float Body::getReflectivity() const
+{
+    return reflectivity;
+}
+
+
+void Body::setReflectivity(float _reflectivity)
+{
+    reflectivity = _reflectivity;
+}
+
+
 float Body::getTemperature(double time) const
 {
     if (temperature > 0)
@@ -789,7 +802,7 @@ float Body::getLuminosity(float sunLuminosity,
     // Compute the total energy hitting the planet
     double incidentEnergy = satIrradiance * circleArea(radius * 1000);
 
-    double reflectedEnergy = incidentEnergy * geomAlbedo;
+    double reflectedEnergy = incidentEnergy * getReflectivity();
 
     // Compute the luminosity (i.e. power relative to solar power)
     return (float) (reflectedEnergy / astro::SOLAR_POWER);
diff --git a/src/celengine/body.h b/src/celengine/body.h
index 545b5e036..b96ba9862 100644
--- a/src/celengine/body.h
+++ b/src/celengine/body.h
@@ -233,12 +233,14 @@ class Body : public AstroObject
     void setDensity(float);
 
     // Albedo functions and temperature
-    /* [[deprecated]] */ float getAlbedo() const;
-    /* [[deprecated]] */ void setAlbedo(float);
+    [[deprecated]] float getAlbedo() const;
+    [[deprecated]] void setAlbedo(float);
     float getGeomAlbedo() const;
     void setGeomAlbedo(float);
     float getBondAlbedo() const;
     void setBondAlbedo(float);
+    float getReflectivity() const;
+    void setReflectivity(float);
     float getTemperature(double t = 0) const;
     void setTemperature(float);
     float getTempDiscrepancy() const;
@@ -392,6 +394,7 @@ class Body : public AstroObject
     float density{ 0.0f };
     float geomAlbedo{ 0.5f };
     float bondAlbedo{ 0.5f };
+    float reflectivity{ 0.5f };
     float temperature{ 0.0f };
     float tempDiscrepancy{ 0.0f };
 
diff --git a/src/celengine/render.cpp b/src/celengine/render.cpp
index 17a67ae75..66595ce0d 100644
--- a/src/celengine/render.cpp
+++ b/src/celengine/render.cpp
@@ -1513,7 +1513,7 @@ setupSecondaryLightSources(vector<SecondaryIlluminator>& secondaryIlluminators,
             i.reflectedIrradiance += j.luminosity / ((float) (i.position_v - j.position).squaredNorm() * au2);
         }
 
-        i.reflectedIrradiance *= i.body->getAlbedo();
+        i.reflectedIrradiance *= i.body->getReflectivity();
     }
 }
 
diff --git a/src/celengine/solarsys.cpp b/src/celengine/solarsys.cpp
index 1b2e0bdba..3090d1759 100644
--- a/src/celengine/solarsys.cpp
+++ b/src/celengine/solarsys.cpp
@@ -13,6 +13,8 @@
 #include <config.h>
 #include <cassert>
 #include <limits>
+#include <fmt/format.h>
+#include <fmt/printf.h>
 #include <celmath/mathlib.h>
 #include <celutil/debug.h>
 #include <celutil/gettext.h>
@@ -796,7 +798,7 @@ static Body* CreateBody(const string& name,
         {
             // Relative URL, the base directory is the current one,
             // not the main installation directory
-            const string p = path.string();
+            const string &p = path.string();
             if (p[1] == ':')
                 // Absolute Windows path, file:/// is required
                 infoURL = "file:///" + p + "/" + infoURL;
@@ -814,14 +816,36 @@ static Body* CreateBody(const string& name,
     }
 
     if (planetData->getNumber("GeomAlbedo", t))
-        body->setGeomAlbedo((float) t);
+    {
+        if (t > 0.0)
+        {
+            body->setGeomAlbedo((float) t);
+            // Set the BondAlbedo and Reflectivity values if it is <1, otherwise as 1.
+            if (t > 1.0)
+                t = 1.0;
+            body->setBondAlbedo((float) t);
+            body->setReflectivity((float) t);
+        }
+        else
+        {
+            fmt::print(cerr, _("Incorrect GeomAlbedo value: {}\n"), t);
+        }
+    }
+
+    if (planetData->getNumber("Reflectivity", t))
+    {
+        if (t >= 0.0 && t <= 1.0)
+            body->setReflectivity((float) t);
+        else
+            fmt::print(cerr, _("Incorrect Reflectivity value: {}\n"), t);
+    }
 
     if (planetData->getNumber("BondAlbedo", t))
     {
         if (t >= 0.0 && t <= 1.0)
             body->setBondAlbedo((float) t);
         else
-            fmt::fprintf(cerr, "Incorrect BondAlbedo value: %lf\n", t);
+            fmt::print(cerr, _("Incorrect BondAlbedo value: {}\n"), t);
     }
 
     if (planetData->getNumber("Temperature", t))
diff --git a/src/celscript/lua/celx_object.cpp b/src/celscript/lua/celx_object.cpp
index c9f537f8a..8b61b4d47 100644
--- a/src/celscript/lua/celx_object.cpp
+++ b/src/celscript/lua/celx_object.cpp
@@ -626,6 +626,9 @@ static int object_getinfo(lua_State* l)
         celx.setTable("name", body->getName().c_str());
         celx.setTable("mass", (lua_Number)body->getMass());
         celx.setTable("albedo", (lua_Number)body->getAlbedo());
+        celx.setTable("geomAlbedo", (lua_Number)body->getGeomAlbedo());
+        celx.setTable("bondAlbedo", (lua_Number)body->getBondAlbedo());
+        celx.setTable("reflectivity", (lua_Number)body->getReflectivity());
         celx.setTable("infoURL", body->getInfoURL().c_str());
         celx.setTable("radius", (lua_Number)body->getRadius());