[Add] Make display lists of planets within range. Nice FPS improvment.

:D

src/planet.cpp

@@ -12,6 +12,7 @@ Planet::Planet(StarSystem::SBody* sbody) : Body() {
   this->sbody = *sbody;
   this->sbody.children.clear();
   this->sbody.parent = 0;
+  crudDList = 0;
 }
 
 Planet::~Planet(void) {
@@ -566,6 +567,10 @@ void Planet::Render(const Frame* a_camFrame) {
   glColor3f(1, 1, 1);
 
   if(apparent_size < 0.001) {
+    if(crudDList) {
+      glDeleteLists(crudDList, 1);
+      crudDList = 0;
+    }
     glDisable(GL_LIGHTING);
     glPointSize(1.0);
     glBegin(GL_POINTS);
@@ -573,13 +578,19 @@ void Planet::Render(const Frame* a_camFrame) {
     glEnd();
     glEnable(GL_LIGHTING);
   } else {
-    glScalef(rad, rad, rad);
+    if(!crudDList) {
+      crudDList = glGenLists(1);
+      glNewList(crudDList, GL_COMPILE);
       /* This is a rather brittle test.. */
       if(sbody.type < StarSystem::TYPE_PLANET_DWARF) {
         DrawGasGiant();
       } else {
         DrawRockyPlanet();
       }
+      glEndList();
+    }
+    glScalef(rad, rad, rad);
+    glCallList(crudDList);
     glClear(GL_DEPTH_BUFFER_BIT);
   }
   glPopMatrix();

src/planet.h

@@ -22,5 +22,6 @@ private:
   double radius;
   dGeomID geom;
   StarSystem::SBody sbody;
+  GLuint crudDList;
 };