Add an new config parameter: SolarSystemMaxDistance

It will define maximal distance where solar system objects are
rendered.

It's value is inside [1, 10] LY.

src/celestia/configfile.cpp

@@ -106,6 +106,10 @@ CelestiaConfig* ReadCelestiaConfig(const string& filename, CelestiaConfig *confi
     configParams->getString("LogoTexture", config->logoTextureFile);
     configParams->getString("Cursor", config->cursor);
 
+    float maxDist = 1.0;
+    configParams->getNumber("SolarSystemMaxDistance", maxDist);
+    config->SolarSystemMaxDistance = min(max(maxDist, 1.0f), 10.0f);
+
     double aaSamples = 1;
     configParams->getNumber("AntialiasingSamples", aaSamples);
     config->aaSamples = (unsigned int) aaSamples;

src/celestia/configfile.h

@@ -74,6 +74,8 @@ public:
 
     float getFloatValue(const std::string& name);
     const std::string getStringValue(const std::string& name);
+
+    float SolarSystemMaxDistance;
 };
 
 CelestiaConfig* ReadCelestiaConfig(const std::string& filename, CelestiaConfig* config = nullptr);