Free the splash texture memory when it's no longer needed. Nowadays splash

textures are mostly 512x512 pixels, so we wasted 786 kB (RGB) or 1MB (RGBA)
during the whole fgfs runtime for mere startup prettification.

src/Main/renderer.cxx

@@ -153,6 +153,8 @@ public:
 
       glPopClientAttrib();
       glPopAttrib();
+    } else {
+      fgSplashExit();
     }
 
     state.popStateSet();

src/Main/splash.cxx

@@ -55,7 +55,7 @@
 #include "renderer.hxx"
 
 static const char *progress_text = 0;
-static SGTexture splash;
+static SGTexture *splash = new SGTexture;
 SGPropertyNode_ptr style = 0;
 
 
@@ -70,7 +70,7 @@ void fgSplashInit ( const char *splash_texture ) {
     if (!fgGetBool("/sim/startup/splash-screen"))
         return;
 
-    splash.bind();
+    splash->bind();
 
     SGPath tpath( globals->get_fg_root() );
     if (splash_texture == NULL || !strcmp(splash_texture, "")) {
@@ -85,15 +85,15 @@ void fgSplashInit ( const char *splash_texture ) {
     } else
         tpath.append( splash_texture );
 
-    splash.read_rgba_texture(tpath.c_str());
-    if (!splash.usable())
+    splash->read_rgba_texture(tpath.c_str());
+    if (!splash->usable())
     {
         // Try compressed
         SGPath fg_tpath = tpath;
         fg_tpath.concat( ".gz" );
 
-        splash.read_rgba_texture(fg_tpath.c_str());
-        if ( !splash.usable() )
+        splash->read_rgba_texture(fg_tpath.c_str());
+        if ( !splash->usable() )
         {
             SG_LOG( SG_GENERAL, SG_ALERT,
                     "Error in loading splash screen texture " << tpath.str() );
@@ -101,7 +101,14 @@ void fgSplashInit ( const char *splash_texture ) {
         }
     }
 
-    splash.select();
+    splash->select();
+}
+
+
+void fgSplashExit ()
+{
+    delete splash;
+    splash = 0;
 }
 
 
@@ -167,7 +174,7 @@ void fgSplashUpdate ( float alpha ) {
     // now draw the logo
     if (fgGetBool("/sim/startup/splash-screen", true)) {
         glEnable(GL_TEXTURE_2D);
-        splash.bind();
+        splash->bind();
         glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE);
 
         glColor4f( 1.0, 1.0, 1.0, alpha );

src/Main/splash.hxx

@@ -40,6 +40,9 @@ void fgSplashUpdate ( float alpha );
 // Set progress information
 void fgSplashProgress ( const char *text );
 
+// Free texture memory
+void fgSplashExit ();
+
 
 #endif // _SPLASH_HXX