]> git.mxchange.org Git - flightgear.git/blobdiff - src/Main/main.cxx
revert the move of the sound positioning code, at least till i found out why it doesn...
[flightgear.git] / src / Main / main.cxx
index 0915f2d23aaa55c27196ebf9702950f84d7f517e..54d2bdbc74735aa043db4fd53c2af6c619e1b014 100644 (file)
@@ -2,7 +2,7 @@
 //
 // Written by Curtis Olson, started May 1997.
 //
-// Copyright (C) 1997 - 2002  Curtis L. Olson  - curt@flightgear.org
+// Copyright (C) 1997 - 2002  Curtis L. Olson  - http://www.flightgear.org/~curt
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License as
@@ -16,7 +16,7 @@
 //
 // You should have received a copy of the GNU General Public License
 // along with this program; if not, write to the Free Software
-// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 //
 // $Id$
 
 #  include <signal.h>
 #endif
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
-#ifdef HAVE_WINDOWS_H
-#  include <windows.h>
-#  include <float.h>
-#endif
+#include <iostream>
 
-#include <plib/ssg.h>
 #include <plib/netSocket.h>
 
-#include <simgear/screen/extensions.hxx>
+#include <osg/Camera>
+#include <osg/GraphicsContext>
+#include <osgDB/Registry>
+
+// Class references
+#include <simgear/ephemeris/ephemeris.hxx>
+#include <simgear/scene/model/modellib.hxx>
 #include <simgear/scene/material/matlib.hxx>
-#include <simgear/props/props.hxx>
+#include <simgear/scene/model/animation.hxx>
 #include <simgear/scene/sky/sky.hxx>
+#include <simgear/structure/event_mgr.hxx>
+#include <simgear/props/props.hxx>
 #include <simgear/timing/sg_time.hxx>
-#include <simgear/scene/model/animation.hxx>
-#include <simgear/ephemeris/ephemeris.hxx>
-#include <simgear/scene/model/placement.hxx>
 #include <simgear/math/sg_random.h>
-#include <simgear/scene/model/modellib.hxx>
 
-#ifdef FG_USE_CLOUDS_3D
-#  include <simgear/scene/sky/clouds3d/SkySceneLoader.hpp>
-#  include <simgear/scene/sky/clouds3d/SkyUtil.hpp>
-#endif
-
-#include <Include/general.hxx>
-#include <Scenery/tileentry.hxx>
 #include <Time/light.hxx>
-#include <Time/light.hxx>
-#include <Aircraft/aircraft.hxx>
-#include <Cockpit/panel.hxx>
+#include <Include/general.hxx>
+#include <Aircraft/replay.hxx>
 #include <Cockpit/cockpit.hxx>
-#include <Cockpit/radiostack.hxx>
 #include <Cockpit/hud.hxx>
 #include <Model/panelnode.hxx>
 #include <Model/modelmgr.hxx>
 #include <Model/acmodel.hxx>
 #include <Scenery/scenery.hxx>
 #include <Scenery/tilemgr.hxx>
+#include <Sound/beacon.hxx>
+#include <Sound/morse.hxx>
 #include <FDM/flight.hxx>
-#include <FDM/UIUCModel/uiuc_aircraftdir.h>
-#include <FDM/ADA.hxx>
-#include <ATC/ATCdisplay.hxx>
-#include <ATC/ATCmgr.hxx>
-#include <ATC/AIMgr.hxx>
-#include <Replay/replay.hxx>
+#include <ATCDCL/ATCmgr.hxx>
+#include <ATCDCL/AIMgr.hxx>
 #include <Time/tmp.hxx>
 #include <Time/fg_timer.hxx>
 #include <Environment/environment_mgr.hxx>
 #include <GUI/new_gui.hxx>
+#include <MultiPlayer/multiplaymgr.hxx>
 
-#ifdef FG_MPLAYER_AS
-#include <MultiPlayer/multiplaytxmgr.hxx>
-#include <MultiPlayer/multiplayrxmgr.hxx>
-#endif
-
-#include "splash.hxx"
+#include "CameraGroup.hxx"
 #include "fg_commands.hxx"
 #include "fg_io.hxx"
+#include "renderer.hxx"
+#include "splash.hxx"
 #include "main.hxx"
+#include "util.hxx"
+#include "fg_init.hxx"
+#include "WindowSystemAdapter.hxx"
 
-float default_attenuation[3] = {1.0, 0.0, 0.0};
-ssgSelector *ship_sel=NULL;
-// upto 32 instances of a same object can be loaded.
-ssgTransform *ship_pos[32];
-double obj_lat[32],obj_lon[32],obj_alt[32],obj_pitch[32],obj_roll[32];
-int objc=0;
-ssgSelector *lightpoints_brightness = new ssgSelector;
-ssgTransform *lightpoints_transform = new ssgTransform;
-FGTileEntry *dummy_tile;
-sgVec3 rway_ols;
-// ADA
-// Clip plane settings...
-float scene_nearplane = 0.5f;
-float scene_farplane = 120000.0f;
 
 static double real_delta_time_sec = 0.0;
-static double delta_time_sec = 0.0;
-
-glPointParameterfProc glPointParameterfPtr = 0;
-glPointParameterfvProc glPointParameterfvPtr = 0;
-bool glPointParameterIsSupported = false;
+double delta_time_sec = 0.0;
+extern float init_volume;
 
+using namespace flightgear;
 
-#ifdef macintosh
-#  include <console.h>         // -dw- for command line dialog
-#endif
+using std::cerr;
 
 // This is a record containing a bit of global housekeeping information
 FGGeneral general;
@@ -129,805 +97,17 @@ FGGeneral general;
 // Specify our current idle function state.  This is used to run all
 // our initializations out of the idle callback so that we can get a
 // splash screen up and running right away.
-static int idle_state = 0;
-static long global_multi_loop;
-
-// fog constants.  I'm a little nervous about putting actual code out
-// here but it seems to work (?)
-static const double m_log01 = -log( 0.01 );
-static const double sqrt_m_log01 = sqrt( m_log01 );
-static GLfloat fog_exp_density;
-static GLfloat fog_exp2_density;
-static GLfloat rwy_exp2_punch_through;
-static GLfloat taxi_exp2_punch_through;
-static GLfloat ground_exp2_punch_through;
-
-// Sky structures
-SGSky *thesky;
-
-#ifdef FG_USE_CLOUDS_3D
-  SkySceneLoader *sgClouds3d;
-  bool _bcloud_orig = true;
-#endif
-
-// hack
-sgMat4 copy_of_ssgOpenGLAxisSwapMatrix =
-{
-  {  1.0f,  0.0f,  0.0f,  0.0f },
-  {  0.0f,  0.0f, -1.0f,  0.0f },
-  {  0.0f,  1.0f,  0.0f,  0.0f },
-  {  0.0f,  0.0f,  0.0f,  1.0f }
-};
-
-ssgSimpleState *cloud3d_imposter_state;
-ssgSimpleState *default_state;
-ssgSimpleState *hud_and_panel;
-ssgSimpleState *menus;
+int idle_state = 0;
+long global_multi_loop;
 
 SGTimeStamp last_time_stamp;
 SGTimeStamp current_time_stamp;
 
-// The atexit() functio handler should know when the graphical subsystem
+// The atexit() function handler should know when the graphical subsystem
 // is initialized.
 extern int _bootstrap_OSInit;
 
 
-void fgBuildRenderStates( void ) {
-    default_state = new ssgSimpleState;
-    default_state->ref();
-    default_state->disable( GL_TEXTURE_2D );
-    default_state->enable( GL_CULL_FACE );
-    default_state->enable( GL_COLOR_MATERIAL );
-    default_state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
-    default_state->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
-    default_state->setMaterial( GL_SPECULAR, 0, 0, 0, 1 );
-    default_state->disable( GL_BLEND );
-    default_state->disable( GL_ALPHA_TEST );
-    default_state->disable( GL_LIGHTING );
-
-    cloud3d_imposter_state = new ssgSimpleState;
-    cloud3d_imposter_state->ref();
-    cloud3d_imposter_state->enable( GL_TEXTURE_2D );
-    cloud3d_imposter_state->enable( GL_CULL_FACE );
-    cloud3d_imposter_state->enable( GL_COLOR_MATERIAL );
-    cloud3d_imposter_state->setColourMaterial( GL_AMBIENT_AND_DIFFUSE );
-    cloud3d_imposter_state->setMaterial( GL_DIFFUSE, 1, 1, 1, 1 );
-    cloud3d_imposter_state->setMaterial( GL_AMBIENT, 1, 1, 1, 1 );
-    cloud3d_imposter_state->setMaterial( GL_EMISSION, 0, 0, 0, 1 );
-    cloud3d_imposter_state->setMaterial( GL_SPECULAR, 0, 0, 0, 1 );
-    cloud3d_imposter_state->enable( GL_BLEND );
-    cloud3d_imposter_state->enable( GL_ALPHA_TEST );
-    cloud3d_imposter_state->disable( GL_LIGHTING );
-
-    hud_and_panel = new ssgSimpleState;
-    hud_and_panel->ref();
-    hud_and_panel->disable( GL_CULL_FACE );
-    hud_and_panel->disable( GL_TEXTURE_2D );
-    hud_and_panel->disable( GL_LIGHTING );
-    hud_and_panel->enable( GL_BLEND );
-
-    menus = new ssgSimpleState;
-    menus->ref();
-    menus->disable( GL_CULL_FACE );
-    menus->disable( GL_TEXTURE_2D );
-    menus->enable( GL_BLEND );
-}
-
-
-// fgInitVisuals() -- Initialize various GL/view parameters
-void fgInitVisuals( void ) {
-
-    FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
-
-    // Go full screen if requested ...
-    if ( fgGetBool("/sim/startup/fullscreen") ) {
-        fgOSFullScreen();
-    }
-
-    // If enabled, normal vectors specified with glNormal are scaled
-    // to unit length after transformation.  Enabling this has
-    // performance implications.  See the docs for glNormal.
-    // glEnable( GL_NORMALIZE );
-
-    glEnable( GL_LIGHTING );
-    glEnable( GL_LIGHT0 );
-    // glLightfv( GL_LIGHT0, GL_POSITION, l->sun_vec );  // done later with ssg
-
-    sgVec3 sunpos;
-    sgSetVec3( sunpos, l->sun_vec()[0], l->sun_vec()[1], l->sun_vec()[2] );
-    ssgGetLight( 0 ) -> setPosition( sunpos );
-
-    glFogi (GL_FOG_MODE, GL_EXP2);
-    if ( (!strcmp(fgGetString("/sim/rendering/fog"), "disabled")) || 
-         (!fgGetBool("/sim/rendering/shading"))) {
-        // if fastest fog requested, or if flat shading force fastest
-        glHint ( GL_FOG_HINT, GL_FASTEST );
-    } else if ( !strcmp(fgGetString("/sim/rendering/fog"), "nicest") ) {
-        glHint ( GL_FOG_HINT, GL_NICEST );
-    }
-    if ( fgGetBool("/sim/rendering/wireframe") ) {
-        // draw wire frame
-        glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
-    }
-
-    // This is the default anyways, but it can't hurt
-    glFrontFace ( GL_CCW );
-
-    // Just testing ...
-    // glEnable(GL_POINT_SMOOTH);
-    // glEnable(GL_LINE_SMOOTH);
-    // glEnable(GL_POLYGON_SMOOTH);      
-}
-
-
-// For HiRes screen Dumps using Brian Pauls TR Library
-void trRenderFrame( void ) {
-#ifdef FG_ENABLE_MULTIPASS_CLOUDS
-    bool multi_pass_clouds = fgGetBool("/sim/rendering/multi-pass-clouds") &&
-                            !SGCloudLayer::enable_bump_mapping; // ugly artefact now
-#else
-    bool multi_pass_clouds = false;
-#endif
-    bool draw_clouds = fgGetBool("/environment/clouds/status");
-
-    if ( fgPanelVisible() ) {
-        GLfloat height = fgGetInt("/sim/startup/ysize");
-        GLfloat view_h =
-            (globals->get_current_panel()->getViewHeight() - globals->get_current_panel()->getYOffset())
-            * (height / 768.0) + 1;
-        glTranslatef( 0.0, view_h, 0.0 );
-    }
-
-    static GLfloat black[4] = { 0.0, 0.0, 0.0, 1.0 };
-    static GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
-
-    FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
-
-    glClearColor(l->adj_fog_color()[0], l->adj_fog_color()[1], 
-                 l->adj_fog_color()[2], l->adj_fog_color()[3]);
-
-    glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
-
-    // set the opengl state to known default values
-    default_state->force();
-
-    glEnable( GL_FOG );
-    glFogf  ( GL_FOG_DENSITY, fog_exp2_density);
-    glFogi  ( GL_FOG_MODE,    GL_EXP2 );
-    glFogfv ( GL_FOG_COLOR,   l->adj_fog_color() );
-
-    // GL_LIGHT_MODEL_AMBIENT has a default non-zero value so if
-    // we only update GL_AMBIENT for our lights we will never get
-    // a completely dark scene.  So, we set GL_LIGHT_MODEL_AMBIENT
-    // explicitely to black.
-    glLightModelfv( GL_LIGHT_MODEL_AMBIENT, black );
-    glLightModeli( GL_LIGHT_MODEL_LOCAL_VIEWER, GL_FALSE );
-
-    ssgGetLight( 0 ) -> setColour( GL_AMBIENT, l->scene_ambient() );
-
-    // texture parameters
-    glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ) ;
-    glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST ) ;
-
-    // we need a white diffuse light for the phase of the moon
-    ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, white );
-    thesky->preDraw( cur_fdm_state->get_Altitude() * SG_FEET_TO_METER,
-                     fog_exp2_density );
-
-    // draw the ssg scene
-    // return to the desired diffuse color
-    ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
-    glEnable( GL_DEPTH_TEST );
-    ssgSetNearFar( scene_nearplane, scene_farplane );
-    if ( draw_clouds ) {
-        // Draw the terrain
-        FGTileMgr::set_tile_filter( true );
-        sgSetModelFilter( false );
-        globals->get_aircraft_model()->select( false );
-        ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-        // Disable depth buffer update, draw the clouds
-        glDepthMask( GL_FALSE );
-        thesky->drawUpperClouds();
-        if ( multi_pass_clouds ) {
-            thesky->drawLowerClouds();
-        }
-        glDepthMask( GL_TRUE );
-        if ( multi_pass_clouds ) {
-            // Draw the objects except the aircraft
-            //  and update the stencil buffer with 1
-            glEnable( GL_STENCIL_TEST );
-            glStencilFunc( GL_ALWAYS, 1, 1 );
-            glStencilOp( GL_KEEP, GL_KEEP, GL_REPLACE );
-        }
-        FGTileMgr::set_tile_filter( false );
-        sgSetModelFilter( true );
-        ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-    } else {
-        FGTileMgr::set_tile_filter( true );
-        sgSetModelFilter( true );
-        globals->get_aircraft_model()->select( false );
-        ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-    }
-
-    // draw the lights
-    glFogf (GL_FOG_DENSITY, rwy_exp2_punch_through);
-    ssgSetNearFar( scene_nearplane, scene_farplane );
-    ssgCullAndDraw( globals->get_scenery()->get_vasi_lights_root() );
-    ssgCullAndDraw( globals->get_scenery()->get_rwy_lights_root() );
-
-    ssgCullAndDraw( globals->get_scenery()->get_gnd_lights_root() );
-
-    if ( draw_clouds ) {
-        if ( multi_pass_clouds ) {
-            // Disable depth buffer update, draw the clouds where the
-            //  objects overwrite the already drawn clouds, by testing
-            //  the stencil buffer against 1
-            glDepthMask( GL_FALSE );
-            glStencilFunc( GL_EQUAL, 1, 1 );
-            glStencilOp( GL_KEEP, GL_KEEP, GL_KEEP );
-            thesky->drawUpperClouds();
-            thesky->drawLowerClouds();
-            glDepthMask( GL_TRUE );
-            glDisable( GL_STENCIL_TEST );
-        } else {
-            glDepthMask( GL_FALSE );
-            thesky->drawLowerClouds();
-            glDepthMask( GL_TRUE );
-        }
-    }
-
-    globals->get_aircraft_model()->select( true );
-    globals->get_model_mgr()->draw();
-    globals->get_aircraft_model()->draw();
-}
-
-
-// Update all Visuals (redraws anything graphics related)
-void fgRenderFrame() {
-    bool scenery_loaded = fgGetBool("sim/sceneryloaded") || fgGetBool("sim/sceneryloaded-override");
-    bool draw_otw = fgGetBool("/sim/rendering/draw-otw");
-    bool skyblend = fgGetBool("/sim/rendering/skyblend");
-    bool enhanced_lighting = fgGetBool("/sim/rendering/enhanced-lighting");
-    bool distance_attenuation = fgGetBool("/sim/rendering/distance-attenuation");
-#ifdef FG_ENABLE_MULTIPASS_CLOUDS
-    bool multi_pass_clouds = fgGetBool("/sim/rendering/multi-pass-clouds") && 
-                                !SGCloudLayer::enable_bump_mapping;  // ugly artefact now
-#else
-    bool multi_pass_clouds = false;
-#endif
-    bool draw_clouds = fgGetBool("/environment/clouds/status");
-
-    GLfloat black[4] = { 0.0, 0.0, 0.0, 1.0 };
-    GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
-
-    // static const SGPropertyNode *longitude
-    //     = fgGetNode("/position/longitude-deg");
-    // static const SGPropertyNode *latitude
-    //     = fgGetNode("/position/latitude-deg");
-    // static const SGPropertyNode *altitude
-    //     = fgGetNode("/position/altitude-ft");
-    static const SGPropertyNode *groundlevel_nearplane
-        = fgGetNode("/sim/current-view/ground-level-nearplane-m");
-
-    FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
-    static double last_visibility = -9999;
-
-    // update fog params
-    double actual_visibility;
-    if (fgGetBool("/environment/clouds/status"))
-        actual_visibility = thesky->get_visibility();
-    else
-        actual_visibility = fgGetDouble("/environment/visibility-m");
-    if ( actual_visibility != last_visibility ) {
-        last_visibility = actual_visibility;
-
-        fog_exp_density = m_log01 / actual_visibility;
-        fog_exp2_density = sqrt_m_log01 / actual_visibility;
-        ground_exp2_punch_through = sqrt_m_log01 / (actual_visibility * 1.5);
-        if ( actual_visibility < 8000 ) {
-            rwy_exp2_punch_through = sqrt_m_log01 / (actual_visibility * 2.5);
-            taxi_exp2_punch_through = sqrt_m_log01 / (actual_visibility * 1.5);
-        } else {
-            rwy_exp2_punch_through = sqrt_m_log01 / ( 8000 * 2.5 );
-            taxi_exp2_punch_through = sqrt_m_log01 / ( 8000 * 1.5 );
-        }
-    }
-
-    // double angle;
-    // GLfloat black[4] = { 0.0, 0.0, 0.0, 1.0 };
-    // GLfloat white[4] = { 1.0, 1.0, 1.0, 1.0 };
-    // GLfloat terrain_color[4] = { 0.54, 0.44, 0.29, 1.0 };
-    // GLfloat mat_shininess[] = { 10.0 };
-    GLbitfield clear_mask;
-
-    if ( idle_state != 1000 || !scenery_loaded ) {
-        // still initializing, draw the splash screen
-        if ( fgGetBool("/sim/startup/splash-screen") ) {
-            fgSplashUpdate(0.0, 1.0);
-        }
-        // Keep resetting sim time while the sim is initializing
-        globals->set_sim_time_sec( 0.0 );
-        SGAnimation::set_sim_time_sec( 0.0 );
-    } else {
-        // idle_state is now 1000 meaning we've finished all our
-        // initializations and are running the main loop, so this will
-        // now work without seg faulting the system.
-
-        FGViewer *current__view = globals->get_current_view();
-
-        // calculate our current position in cartesian space
-        globals->get_scenery()->set_center( globals->get_scenery()->get_next_center() );
-
-        // update view port
-        fgReshape( fgGetInt("/sim/startup/xsize"),
-                   fgGetInt("/sim/startup/ysize") );
-
-        if ( fgGetBool("/sim/rendering/clouds3d") ) {
-            glClear( GL_DEPTH_BUFFER_BIT | GL_COLOR_BUFFER_BIT );
-            cloud3d_imposter_state->force();
-            glDisable( GL_FOG );
-            glColor4f( 1.0, 1.0, 1.0, 1.0 );
-            glEnable(GL_DEPTH_TEST);
-            glEnable(GL_BLEND);
-            glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA ) ;
-
-#ifdef FG_USE_CLOUDS_3D
-            if ( _bcloud_orig ) {
-                Point3D c = globals->get_scenery()->get_center();
-                sgClouds3d->Set_Cloud_Orig( &c );
-                _bcloud_orig = false;
-            }
-            sgClouds3d->Update( current__view->get_absolute_view_pos() );
-#endif
-            glBlendFunc( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
-            glDisable(GL_DEPTH_TEST);
-        }
-
-        clear_mask = GL_DEPTH_BUFFER_BIT;
-        if ( fgGetBool("/sim/rendering/wireframe") ) {
-            clear_mask |= GL_COLOR_BUFFER_BIT;
-        }
-
-        if ( skyblend ) {
-            if ( fgGetBool("/sim/rendering/textures") ) {
-            // glClearColor(black[0], black[1], black[2], black[3]);
-            glClearColor(l->adj_fog_color()[0], l->adj_fog_color()[1],
-                         l->adj_fog_color()[2], l->adj_fog_color()[3]);
-            clear_mask |= GL_COLOR_BUFFER_BIT;
-            }
-        } else {
-            glClearColor(l->sky_color()[0], l->sky_color()[1],
-                         l->sky_color()[2], l->sky_color()[3]);
-            clear_mask |= GL_COLOR_BUFFER_BIT;
-        }
-        if ( multi_pass_clouds && draw_clouds ) {
-            glClearStencil( 0 );
-            clear_mask |= GL_STENCIL_BUFFER_BIT;
-        }
-        glClear( clear_mask );
-
-        // Tell GL we are switching to model view parameters
-
-        // I really should create a derived ssg node or use a call
-        // back or something so that I can draw the sky within the
-        // ssgCullAndDraw() function, but for now I just mimic what
-        // ssg does to set up the model view matrix
-        glMatrixMode(GL_MODELVIEW);
-        glLoadIdentity();
-        ssgSetCamera( (sgVec4 *)current__view->get_VIEW() );
-
-        // set the opengl state to known default values
-        default_state->force();
-
-        // update fog params if visibility has changed
-        double visibility_meters = fgGetDouble("/environment/visibility-m");
-        thesky->set_visibility(visibility_meters);
-
-        thesky->modify_vis( cur_fdm_state->get_Altitude() * SG_FEET_TO_METER,
-                            ( global_multi_loop * fgGetInt("/sim/speed-up") )
-                            / (double)fgGetInt("/sim/model-hz") );
-
-        // Set correct opengl fog density
-        glFogf (GL_FOG_DENSITY, fog_exp2_density);
-
-        // update the sky dome
-        if ( skyblend ) {
-            /*
-             SG_LOG( SG_GENERAL, SG_BULK, "thesky->repaint() sky_color = "
-             << l->sky_color()[0] << " "
-             << l->sky_color()[1] << " "
-             << l->sky_color()[2] << " "
-             << l->sky_color()[3] );
-            SG_LOG( SG_GENERAL, SG_BULK, "    fog = "
-             << l->fog_color()[0] << " "
-             << l->fog_color()[1] << " "
-             << l->fog_color()[2] << " "
-             << l->fog_color()[3] ); 
-            SG_LOG( SG_GENERAL, SG_BULK,
-                    "    sun_angle = " << l->sun_angle
-             << "    moon_angle = " << l->moon_angle );
-            */
-
-            static SGSkyColor scolor;
-            FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
-
-            scolor.sky_color   = l->sky_color();
-            scolor.fog_color   = l->adj_fog_color();
-            scolor.cloud_color = l->cloud_color();
-            scolor.sun_angle   = l->get_sun_angle();
-            scolor.moon_angle  = l->get_moon_angle();
-            scolor.nplanets    = globals->get_ephem()->getNumPlanets();
-            scolor.nstars      = globals->get_ephem()->getNumStars();
-            scolor.planet_data = globals->get_ephem()->getPlanets();
-            scolor.star_data   = globals->get_ephem()->getStars();
-
-            thesky->repaint( scolor );
-
-            /*
-            SG_LOG( SG_GENERAL, SG_BULK,
-                    "thesky->reposition( view_pos = " << view_pos[0] << " "
-             << view_pos[1] << " " << view_pos[2] );
-            SG_LOG( SG_GENERAL, SG_BULK,
-                    "    zero_elev = " << zero_elev[0] << " "
-             << zero_elev[1] << " " << zero_elev[2]
-             << " lon = " << cur_fdm_state->get_Longitude()
-             << " lat = " << cur_fdm_state->get_Latitude() );
-            SG_LOG( SG_GENERAL, SG_BULK,
-                    "    sun_rot = " << l->get_sun_rotation
-             << " gst = " << SGTime::cur_time_params->getGst() );
-            SG_LOG( SG_GENERAL, SG_BULK,
-                 "    sun ra = " << globals->get_ephem()->getSunRightAscension()
-              << " sun dec = " << globals->get_ephem()->getSunDeclination()
-              << " moon ra = " << globals->get_ephem()->getMoonRightAscension()
-              << " moon dec = " << globals->get_ephem()->getMoonDeclination() );
-            */
-
-            // The sun and moon distances are scaled down versions
-            // of the actual distance to get both the moon and the sun
-            // within the range of the far clip plane.
-            // Moon distance:    384,467 kilometers
-            // Sun distance: 150,000,000 kilometers
-            double sun_horiz_eff, moon_horiz_eff;
-            if (fgGetBool("/sim/rendering/horizon-effect")) {
-            sun_horiz_eff = 0.67+pow(0.5+cos(l->get_sun_angle())*2/2, 0.33)/3;
-            moon_horiz_eff = 0.67+pow(0.5+cos(l->get_moon_angle())*2/2, 0.33)/3;
-            } else {
-               sun_horiz_eff = moon_horiz_eff = 1.0;
-            }
-
-            static SGSkyState sstate;
-
-            sstate.view_pos  = current__view->get_view_pos();
-            sstate.zero_elev = current__view->get_zero_elev();
-            sstate.view_up   = current__view->get_world_up();
-            sstate.lon       = current__view->getLongitude_deg()
-                                * SGD_DEGREES_TO_RADIANS;
-            sstate.lat       = current__view->getLatitude_deg()
-                                * SGD_DEGREES_TO_RADIANS;
-            sstate.alt       = current__view->getAltitudeASL_ft()
-                                * SG_FEET_TO_METER;
-            sstate.spin      = l->get_sun_rotation();
-            sstate.gst       = globals->get_time_params()->getGst();
-            sstate.sun_ra    = globals->get_ephem()->getSunRightAscension();
-            sstate.sun_dec   = globals->get_ephem()->getSunDeclination();
-            sstate.sun_dist  = 50000.0 * sun_horiz_eff;
-            sstate.moon_ra   = globals->get_ephem()->getMoonRightAscension();
-            sstate.moon_dec  = globals->get_ephem()->getMoonDeclination();
-            sstate.moon_dist = 40000.0 * moon_horiz_eff;
-
-            thesky->reposition( sstate, delta_time_sec );
-        }
-
-        glEnable( GL_DEPTH_TEST );
-        if ( strcmp(fgGetString("/sim/rendering/fog"), "disabled") ) {
-            glEnable( GL_FOG );
-            glFogi( GL_FOG_MODE, GL_EXP2 );
-            glFogfv( GL_FOG_COLOR, l->adj_fog_color() );
-        }
-
-        // set sun/lighting parameters
-        ssgGetLight( 0 ) -> setPosition( l->sun_vec() );
-
-        // GL_LIGHT_MODEL_AMBIENT has a default non-zero value so if
-        // we only update GL_AMBIENT for our lights we will never get
-        // a completely dark scene.  So, we set GL_LIGHT_MODEL_AMBIENT
-        // explicitely to black.
-        glLightModelfv( GL_LIGHT_MODEL_AMBIENT, black );
-
-        ssgGetLight( 0 ) -> setColour( GL_AMBIENT, l->scene_ambient() );
-        ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
-        ssgGetLight( 0 ) -> setColour( GL_SPECULAR, l->scene_specular() );
-
-        // texture parameters
-        // glEnable( GL_TEXTURE_2D );
-        glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_MODULATE ) ;
-        glHint( GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST ) ;
-
-        // glMatrixMode( GL_PROJECTION );
-        // glLoadIdentity();
-        ssgSetFOV( current__view->get_h_fov(),
-                   current__view->get_v_fov() );
-
-        double agl =
-            current_aircraft.fdm_state->get_Altitude() * SG_FEET_TO_METER
-            - globals->get_scenery()->get_cur_elev();
-
-        if ( agl > 10.0 ) {
-            scene_nearplane = 10.0f;
-            scene_farplane = 120000.0f;
-        } else {
-            scene_nearplane = groundlevel_nearplane->getDoubleValue();
-            scene_farplane = 120000.0f;
-        }
-
-        ssgSetNearFar( scene_nearplane, scene_farplane );
-
-#ifdef FG_MPLAYER_AS
-        // Update any multiplayer models
-        globals->get_multiplayer_rx_mgr()->Update();
-#endif
-
-        if ( draw_otw && skyblend ) {
-            // draw the sky backdrop
-
-            // we need a white diffuse light for the phase of the moon
-            ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, white );
-            thesky->preDraw( cur_fdm_state->get_Altitude() * SG_FEET_TO_METER,
-                             fog_exp2_density );
-            // return to the desired diffuse color
-            ssgGetLight( 0 ) -> setColour( GL_DIFFUSE, l->scene_diffuse() );
-        }
-
-        // draw the ssg scene
-        glEnable( GL_DEPTH_TEST );
-
-        ssgSetNearFar( scene_nearplane, scene_farplane );
-
-        if ( fgGetBool("/sim/rendering/wireframe") ) {
-            // draw wire frame
-            glPolygonMode( GL_FRONT_AND_BACK, GL_LINE );
-        }
-        if ( draw_otw ) {
-            if ( draw_clouds ) {
-
-                // Draw the terrain
-                FGTileMgr::set_tile_filter( true );
-                sgSetModelFilter( false );
-                globals->get_aircraft_model()->select( false );
-                ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-
-                // Disable depth buffer update, draw the clouds
-                glDepthMask( GL_FALSE );
-                thesky->drawUpperClouds();
-                if ( multi_pass_clouds ) {
-                    thesky->drawLowerClouds();
-                }
-                glDepthMask( GL_TRUE );
-
-                if ( multi_pass_clouds ) {
-                    // Draw the objects except the aircraft
-                    //  and update the stencil buffer with 1
-                    glEnable( GL_STENCIL_TEST );
-                    glStencilFunc( GL_ALWAYS, 1, 1 );
-                    glStencilOp( GL_KEEP, GL_KEEP, GL_REPLACE );
-                }
-                FGTileMgr::set_tile_filter( false );
-                sgSetModelFilter( true );
-                ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-            } else {
-                FGTileMgr::set_tile_filter( true );
-                sgSetModelFilter( true );
-                globals->get_aircraft_model()->select( false );
-                ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-            }
-        }
-
-        // This is a bit kludgy.  Every 200 frames, do an extra
-        // traversal of the scene graph without drawing anything, but
-        // with the field-of-view set to 360x360 degrees.  This
-        // ensures that out-of-range random objects that are not in
-        // the current view frustum will still be freed properly.
-        static int counter = 0;
-        counter++;
-        if (counter == 200) {
-            sgFrustum f;
-            f.setFOV(360, 360);
-                    // No need to put the near plane too close;
-                    // this way, at least the aircraft can be
-                    // culled.
-            f.setNearFar(1000, 1000000);
-            sgMat4 m;
-            ssgGetModelviewMatrix(m);
-            FGTileMgr::set_tile_filter( true );
-            sgSetModelFilter( true );
-            globals->get_scenery()->get_scene_graph()->cull(&f, m, true);
-            counter = 0;
-        }
-
-        // change state for lighting here
-
-        // draw runway lighting
-        glFogf (GL_FOG_DENSITY, rwy_exp2_punch_through);
-        ssgSetNearFar( scene_nearplane, scene_farplane );
-
-        if ( enhanced_lighting ) {
-
-            // Enable states for drawing points with GL_extension
-            glEnable(GL_POINT_SMOOTH);
-
-            if ( distance_attenuation && glPointParameterIsSupported )
-            {
-                // Enable states for drawing points with GL_extension
-                glEnable(GL_POINT_SMOOTH);
-
-                float quadratic[3] = {1.0, 0.001, 0.0000001};
-                // makes the points fade as they move away
-                glPointParameterfvPtr(GL_DISTANCE_ATTENUATION_EXT, quadratic);
-                glPointParameterfPtr(GL_POINT_SIZE_MIN_EXT, 1.0); 
-            }
-
-            glPointSize(4.0);
-
-            // blending function for runway lights
-            glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) ;
-        }
-
-        glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
-        glTexGeni(GL_T, GL_TEXTURE_GEN_MODE, GL_SPHERE_MAP);
-        glEnable(GL_TEXTURE_GEN_S);
-        glEnable(GL_TEXTURE_GEN_T);
-        glPolygonMode(GL_FRONT, GL_POINT);
-
-        // draw runway lighting
-        if ( draw_otw ) {
-            ssgCullAndDraw( globals->get_scenery()->get_vasi_lights_root() );
-            ssgCullAndDraw( globals->get_scenery()->get_rwy_lights_root() );
-        }
-
-        // change punch through and then draw taxi lighting
-        glFogf ( GL_FOG_DENSITY, fog_exp2_density );
-        // sgVec3 taxi_fog;
-        // sgSetVec3( taxi_fog, 0.0, 0.0, 0.0 );
-        // glFogfv ( GL_FOG_COLOR, taxi_fog );
-        if ( draw_otw ) {
-            ssgCullAndDraw( globals->get_scenery()->get_taxi_lights_root() );
-        }
-
-        // clean up lighting
-        glPolygonMode(GL_FRONT, GL_FILL);
-        glDisable(GL_TEXTURE_GEN_S);
-        glDisable(GL_TEXTURE_GEN_T);
-
-        //static int _frame_count = 0;
-        //if (_frame_count % 30 == 0) {
-        //  printf("SSG: %s\n", ssgShowStats());
-        //}
-        //else {
-        //  ssgShowStats();
-        //}
-        //_frame_count++;
-
-
-        if ( enhanced_lighting ) {
-            if ( distance_attenuation && glPointParameterIsSupported ) {
-                glPointParameterfvPtr(GL_DISTANCE_ATTENUATION_EXT,
-                                      default_attenuation);
-            }
-
-            glPointSize(1.0);
-            glDisable(GL_POINT_SMOOTH);
-        }
-
-        // draw ground lighting
-        glFogf (GL_FOG_DENSITY, ground_exp2_punch_through);
-        if ( draw_otw ) {
-            ssgCullAndDraw( globals->get_scenery()->get_gnd_lights_root() );
-        }
-
-        if ( draw_otw && fgGetBool("/sim/rendering/clouds3d") ) {
-            glDisable( GL_FOG );
-            glDisable( GL_LIGHTING );
-            // cout << "drawing new clouds" << endl;
-
-            glEnable(GL_DEPTH_TEST);
-            glEnable(GL_BLEND);
-            glBlendFunc( GL_ONE, GL_ONE_MINUS_SRC_ALPHA ) ;
-
-            /*
-            glEnable( GL_TEXTURE_2D );
-            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
-            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
-            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
-            glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
-            */
-
-#ifdef FG_USE_CLOUDS_3D
-            sgClouds3d->Draw((sgVec4 *)current__view->get_VIEW());
-#endif
-            glEnable( GL_FOG );
-            glEnable( GL_LIGHTING );
-            glEnable( GL_DEPTH_TEST );
-            glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
-        }
-
-        if ( draw_otw && draw_clouds ) {
-            if ( multi_pass_clouds ) {
-                // Disable depth buffer update, draw the clouds where the
-                //  objects overwrite the already drawn clouds, by testing
-                //  the stencil buffer against 1
-                glDepthMask( GL_FALSE );
-                glStencilFunc( GL_EQUAL, 1, 1 );
-                glStencilOp( GL_KEEP, GL_KEEP, GL_KEEP );
-                thesky->drawUpperClouds();
-                thesky->drawLowerClouds();
-                glDepthMask( GL_TRUE );
-                glDisable( GL_STENCIL_TEST );
-            } else {
-                glDepthMask( GL_FALSE );
-                thesky->drawLowerClouds();
-                glDepthMask( GL_TRUE );
-            }
-        }
-
-        if ( draw_otw ) {
-            FGTileMgr::set_tile_filter( false );
-            sgSetModelFilter( false );
-            globals->get_aircraft_model()->select( true );
-            globals->get_model_mgr()->draw();
-            globals->get_aircraft_model()->draw();
-            // If the view is internal, the previous line draw the 
-            //  cockpit with modified near/far clip planes and deselect
-            //  the aircraft in the global scenegraph
-            // Otherwise, it just enables the aircraft: The scenegraph
-            //  must be drawn again to see the plane.
-            ssgCullAndDraw( globals->get_scenery()->get_scene_graph() );
-            FGTileMgr::set_tile_filter( true );
-            sgSetModelFilter( true );
-            globals->get_aircraft_model()->select( true );
-        }
-
-        // display HUD && Panel
-        glDisable( GL_FOG );
-        glDisable( GL_DEPTH_TEST );
-        // glDisable( GL_CULL_FACE );
-        // glDisable( GL_TEXTURE_2D );
-
-        // update the controls subsystem
-        globals->get_controls()->update(delta_time_sec);
-
-        hud_and_panel->apply();
-        fgCockpitUpdate();
-
-        // Use the hud_and_panel ssgSimpleState for rendering the ATC output
-        // This only works properly if called before the panel call
-        if((fgGetBool("/sim/ATC/enabled")) || (fgGetBool("/sim/ai-traffic/enabled")))
-            globals->get_ATC_display()->update(delta_time_sec);
-
-        // update the panel subsystem
-        if ( globals->get_current_panel() != NULL ) {
-            globals->get_current_panel()->update(delta_time_sec);
-        }
-        fgUpdate3DPanels();
-
-        // We can do translucent menus, so why not. :-)
-        menus->apply();
-        glBlendFunc ( GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA ) ;
-        puDisplay();
-        // glDisable ( GL_BLEND ) ;
-
-        glEnable( GL_DEPTH_TEST );
-        glEnable( GL_FOG );
-
-        // Fade out the splash screen over the first three seconds.
-        double t = globals->get_sim_time_sec();
-        if ( t <= 1.0 ) {
-            fgSplashUpdate(0.0, 1.0);
-        } else if ( t <= 3.0) {
-            fgSplashUpdate(0.0, (3.0 - t) / 2.0);
-        }
-    }
-}
-
 
 // Update internal time dependent calculations (i.e. flight model)
 // FIXME: this distinction is obsolete; all subsystems now get delta
@@ -935,8 +115,8 @@ void fgRenderFrame() {
 void fgUpdateTimeDepCalcs() {
     static bool inited = false;
 
-    static const SGPropertyNode *replay_master
-        = fgGetNode( "/sim/freeze/replay", true );
+    static const SGPropertyNode *replay_state
+        = fgGetNode( "/sim/freeze/replay-state", true );
     static SGPropertyNode *replay_time
         = fgGetNode( "/sim/replay/time", true );
     // static const SGPropertyNode *replay_end_time
@@ -950,15 +130,21 @@ void fgUpdateTimeDepCalcs() {
     // cout << "cur_fdm_state->get_inited() = " << cur_fdm_state->get_inited() 
     //      << " cur_elev = " << scenery.get_cur_elev() << endl;
 
-    if ( !cur_fdm_state->get_inited() &&
-         globals->get_scenery()->get_cur_elev() > -9990 )
-    {
-        SG_LOG(SG_FLIGHT,SG_INFO, "Finally initializing fdm");  
-        cur_fdm_state->init();
-        if ( cur_fdm_state->get_bound() ) {
-            cur_fdm_state->unbind();
+    if (!cur_fdm_state->get_inited()) {
+        // Check for scenery around the aircraft.
+        double lon = fgGetDouble("/sim/presets/longitude-deg");
+        double lat = fgGetDouble("/sim/presets/latitude-deg");
+        // We require just to have 50 meter scenery availabe around
+        // the aircraft.
+        double range = 1000.0;
+        if (globals->get_scenery()->scenery_available(lat, lon, range)) {
+            //SG_LOG(SG_FLIGHT, SG_INFO, "Finally initializing fdm");
+            cur_fdm_state->init();
+            if ( cur_fdm_state->get_bound() ) {
+                cur_fdm_state->unbind();
+            }
+            cur_fdm_state->bind();
         }
-        cur_fdm_state->bind();
     }
 
     // conceptually, the following block could be done for each fdm
@@ -966,19 +152,27 @@ void fgUpdateTimeDepCalcs() {
     if ( cur_fdm_state->get_inited() ) {
         // we have been inited, and  we are good to go ...
 
-        if ( !inited ) {
-            inited = true;
-        }
-
-        if ( ! replay_master->getBoolValue() ) {
+        if ( replay_state->getIntValue() == 0 ) {
+            // replay off, run fdm
             cur_fdm_state->update( delta_time_sec );
         } else {
             FGReplay *r = (FGReplay *)(globals->get_subsystem( "replay" ));
             r->replay( replay_time->getDoubleValue() );
-            replay_time->setDoubleValue( replay_time->getDoubleValue()
-                                         + ( delta_time_sec
-                                             * fgGetInt("/sim/speed-up") ) );
+            if ( replay_state->getIntValue() == 1 ) {
+                // normal playback
+                replay_time->setDoubleValue( replay_time->getDoubleValue()
+                                             + ( delta_time_sec
+                                               * fgGetInt("/sim/speed-up") ) );
+            } else if ( replay_state->getIntValue() == 2 ) {
+                // paused playback (don't advance replay time)
+            }
         }
+
+        if ( !inited ) {
+            inited = true;
+            fgSetBool("/sim/signals/fdm-initialized", true);
+        }
+
     } else {
         // do nothing, fdm isn't inited yet
     }
@@ -986,16 +180,11 @@ void fgUpdateTimeDepCalcs() {
     globals->get_model_mgr()->update(delta_time_sec);
     globals->get_aircraft_model()->update(delta_time_sec);
 
-    // update the view angle
-    globals->get_viewmgr()->update(delta_time_sec);
-
     // Update solar system
     globals->get_ephem()->update( globals->get_time_params()->getMjd(),
                                   globals->get_time_params()->getLst(),
                                   cur_fdm_state->get_Latitude() );
 
-    // Update radio stack model
-    current_radiostack->update(delta_time_sec);
 }
 
 
@@ -1013,20 +202,26 @@ static const double alt_adjust_m = alt_adjust_ft * SG_FEET_TO_METER;
 static void fgMainLoop( void ) {
     int model_hz = fgGetInt("/sim/model-hz");
 
-    static const SGPropertyNode *longitude
+    static SGConstPropertyNode_ptr longitude
         = fgGetNode("/position/longitude-deg");
-    static const SGPropertyNode *latitude
+    static SGConstPropertyNode_ptr latitude
         = fgGetNode("/position/latitude-deg");
-    static const SGPropertyNode *altitude
+    static SGConstPropertyNode_ptr altitude
         = fgGetNode("/position/altitude-ft");
-    static const SGPropertyNode *clock_freeze
+    static SGConstPropertyNode_ptr clock_freeze
         = fgGetNode("/sim/freeze/clock", true);
-    static const SGPropertyNode *cur_time_override
+    static SGConstPropertyNode_ptr cur_time_override
         = fgGetNode("/sim/time/cur-time-override", true);
-    // static const SGPropertyNode *replay_master
-    //     = fgGetNode("/sim/freeze/replay", true);
+    static SGConstPropertyNode_ptr max_simtime_per_frame
+        = fgGetNode("/sim/max-simtime-per-frame", true);
+    static SGPropertyNode_ptr frame_signal
+        = fgGetNode("/sim/signals/frame", true);
+
+    frame_signal->fireValueChanged();
+    SGCloudLayer::enable_bump_mapping = fgGetBool("/sim/rendering/bump-mapping");
 
-    SGCloudLayer::enable_bump_mapping = fgGetBool("/sim/rendering/bump-mapping",true);
+    bool scenery_loaded = fgGetBool("sim/sceneryloaded");
+    bool wait_for_scenery = !(scenery_loaded || fgGetBool("sim/sceneryloaded-override"));
 
     // Update the elapsed time.
     static bool first_time = true;
@@ -1036,11 +231,56 @@ static void fgMainLoop( void ) {
     }
 
     double throttle_hz = fgGetDouble("/sim/frame-rate-throttle-hz", 0.0);
-    if ( throttle_hz > 0.0 ) {
-        // simple frame rate throttle
-        double dt = 1000000.0 / throttle_hz;
+    if ( throttle_hz > 0.0 && !wait_for_scenery ) {
+        // optionally throttle the frame rate (to get consistent frame
+        // rates or reduce cpu usage.
+
+        double frame_us = 1000000.0 / throttle_hz;
+
+#define FG_SLEEP_BASED_TIMING 1
+#if defined(FG_SLEEP_BASED_TIMING)
+        // sleep based timing loop.
+        //
+        // Calling sleep, even usleep() on linux is less accurate than
+        // we like, but it does free up the cpu for other tasks during
+        // the sleep so it is desirable.  Because of the way sleep()
+        // is implemented in consumer operating systems like windows
+        // and linux, you almost always sleep a little longer than the
+        // requested amount.
+        //
+        // To combat the problem of sleeping too long, we calculate the
+        // desired wait time and shorten it by 2000us (2ms) to avoid
+        // [hopefully] over-sleep'ing.  The 2ms value was arrived at
+        // via experimentation.  We follow this up at the end with a
+        // simple busy-wait loop to get the final pause timing exactly
+        // right.
+        //
+        // Assuming we don't oversleep by more than 2000us, this
+        // should be a reasonable compromise between sleep based
+        // waiting, and busy waiting.
+
+        // sleep() will always overshoot by a bit so undersleep by
+        // 2000us in the hopes of never oversleeping.
+        frame_us -= 2000.0;
+        if ( frame_us < 0.0 ) {
+            frame_us = 0.0;
+        }
+        current_time_stamp.stamp();
+        /* Convert to ms */
+        double elapsed_us = current_time_stamp - last_time_stamp;
+        if ( elapsed_us < frame_us ) {
+            double requested_us = frame_us - elapsed_us;
+            ulMilliSecondSleep ( (int)(requested_us / 1000.0) ) ;
+        }
+#endif
+
+        // busy wait timing loop.
+        //
+        // This yields the most accurate timing.  If the previous
+        // ulMilliSecondSleep() call is omitted this will peg the cpu
+        // (which is just fine if FG is the only app you care about.)
         current_time_stamp.stamp();
-        while ( current_time_stamp - last_time_stamp < dt ) {
+        while ( current_time_stamp - last_time_stamp < frame_us ) {
             current_time_stamp.stamp();
         }
     } else {
@@ -1050,14 +290,39 @@ static void fgMainLoop( void ) {
 
     real_delta_time_sec
         = double(current_time_stamp - last_time_stamp) / 1000000.0;
-    if ( clock_freeze->getBoolValue() ) {
+
+    // Limit the time we need to spend in simulation loops
+    // That means, if the /sim/max-simtime-per-frame value is strictly positive
+    // you can limit the maximum amount of time you will do simulations for
+    // one frame to display. The cpu time spent in simulations code is roughly
+    // at least O(real_delta_time_sec). If this is (due to running debug
+    // builds or valgrind or something different blowing up execution times)
+    // larger than the real time you will no longer get any response
+    // from flightgear. This limits that effect. Just set to property from
+    // your .fgfsrc or commandline ...
+    double dtMax = max_simtime_per_frame->getDoubleValue();
+    if (0 < dtMax && dtMax < real_delta_time_sec)
+        real_delta_time_sec = dtMax;
+
+    // round the real time down to a multiple of 1/model-hz.
+    // this way all systems are updated the _same_ amount of dt.
+    {
+        static double rem = 0.0;
+        real_delta_time_sec += rem;
+        double hz = model_hz;
+        double nit = floor(real_delta_time_sec*hz);
+        rem = real_delta_time_sec - nit/hz;
+        real_delta_time_sec = nit/hz;
+    }
+
+
+    if (clock_freeze->getBoolValue() || wait_for_scenery) {
         delta_time_sec = 0;
     } else {
         delta_time_sec = real_delta_time_sec;
     }
     last_time_stamp = current_time_stamp;
     globals->inc_sim_time_sec( delta_time_sec );
-    SGAnimation::set_sim_time_sec( globals->get_sim_time_sec() );
 
     // These are useful, especially for Nasal scripts.
     fgSetDouble("/sim/time/delta-realtime-sec", real_delta_time_sec);
@@ -1075,19 +340,9 @@ static void fgMainLoop( void ) {
 
     SGTime *t = globals->get_time_params();
 
-    globals->get_event_mgr()->update(delta_time_sec);
-
     SG_LOG( SG_ALL, SG_DEBUG, "Running Main Loop");
     SG_LOG( SG_ALL, SG_DEBUG, "======= ==== ====");
 
-#if defined( ENABLE_PLIB_JOYSTICK )
-    // Read joystick and update control settings
-    // if ( fgGetString("/sim/control-mode") == "joystick" )
-    // {
-    //    fgJoystickRead();
-    // }
-#endif
-
     // Fix elevation.  I'm just sticking this here for now, it should
     // probably move eventually
 
@@ -1135,22 +390,22 @@ static void fgMainLoop( void ) {
                globals->get_warp() );
 
     if (globals->get_warp_delta() != 0) {
-       FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
-       l->update( 0.5 );
+        FGLight *l = (FGLight *)(globals->get_subsystem("lighting"));
+        l->update( 0.5 );
     }
 
     // update magvar model
     globals->get_mag()->update( longitude->getDoubleValue()
-                              * SGD_DEGREES_TO_RADIANS,
-                            latitude->getDoubleValue()
-                              * SGD_DEGREES_TO_RADIANS,
-                            altitude->getDoubleValue() * SG_FEET_TO_METER,
-                            globals->get_time_params()->getJD() );
+                                * SGD_DEGREES_TO_RADIANS,
+                                latitude->getDoubleValue()
+                                * SGD_DEGREES_TO_RADIANS,
+                                altitude->getDoubleValue() * SG_FEET_TO_METER,
+                                globals->get_time_params()->getJD() );
 
     // Get elapsed time (in usec) for this past frame
     elapsed = fgGetTimeInterval();
-    SG_LOG( SG_ALL, SG_DEBUG, 
-            "Elapsed time interval is = " << elapsed 
+    SG_LOG( SG_ALL, SG_DEBUG,
+            "Elapsed time interval is = " << elapsed
             << ", previous remainder is = " << remainder );
 
     // Calculate frame rate average
@@ -1176,7 +431,7 @@ static void fgMainLoop( void ) {
     if ( (t->get_cur_time() != last_time) && (last_time > 0) ) {
         general.set_frame_rate( frames );
         fgSetInt("/sim/frame-rate", frames);
-        SG_LOG( SG_ALL, SG_DEBUG, 
+        SG_LOG( SG_ALL, SG_DEBUG,
             "--> Frame rate is = " << general.get_frame_rate() );
         frames = 0;
     }
@@ -1184,11 +439,17 @@ static void fgMainLoop( void ) {
     ++frames;
 #endif
 
+    // Update any multiplayer's network queues, the AIMultiplayer
+    // implementation is an AI model and depends on that
+    globals->get_multiplayer_mgr()->Update();
+
     // Run ATC subsystem
-    if (fgGetBool("/sim/ATC/enabled"))
+    if (fgGetBool("/sim/atc/enabled"))
         globals->get_ATC_mgr()->update(delta_time_sec);
 
     // Run the AI subsystem
+    // FIXME: run that also if we have multiplaying enabled since the
+    // multiplayer information is interpreted by an AI model
     if (fgGetBool("/sim/ai-traffic/enabled"))
         globals->get_AI_mgr()->update(delta_time_sec);
 
@@ -1199,159 +460,83 @@ static void fgMainLoop( void ) {
 
     global_multi_loop = (long)(((double)elapsed * 0.000001) * model_hz );
     remainder = elapsed - ( (global_multi_loop*1000000) / model_hz );
-    SG_LOG( SG_ALL, SG_DEBUG, 
+    SG_LOG( SG_ALL, SG_DEBUG,
             "Model iterations needed = " << global_multi_loop
             << ", new remainder = " << remainder );
-        
-    // chop max interations to something reasonable if the sim was
-    // delayed for an excesive amount of time
+
+    // chop max iterations to something reasonable if the sim was
+    // delayed for an excessive amount of time
     if ( global_multi_loop > 2.0 * model_hz ) {
         global_multi_loop = (int)(2.0 * model_hz );
         remainder = 0;
     }
 
-    bool scenery_loaded = fgGetBool("sim/sceneryloaded") || fgGetBool("sim/sceneryloaded-override");
-
     // flight model
     if ( global_multi_loop > 0) {
-        // first run the flight model each frame until it is intialized
+        // first run the flight model each frame until it is initialized
         // then continue running each frame only after initial scenery load is complete.
-        if (!cur_fdm_state->get_inited() || scenery_loaded) {
-            fgUpdateTimeDepCalcs();
-        }
+        fgUpdateTimeDepCalcs();
     } else {
-        SG_LOG( SG_ALL, SG_DEBUG, 
+        SG_LOG( SG_ALL, SG_DEBUG,
             "Elapsed time is zero ... we're zinging" );
     }
 
-    // Do any I/O channel work that might need to be done
-    globals->get_io()->update( real_delta_time_sec );
-
-    // see if we need to load any deferred-load textures
-    globals->get_matlib()->load_next_deferred();
-
-    // Run audio scheduler
-#ifdef ENABLE_AUDIO_SUPPORT
-    if ( globals->get_soundmgr()->is_working() ) {
-        globals->get_soundmgr()->update( delta_time_sec );
-    }
-#endif
-
     globals->get_subsystem_mgr()->update(delta_time_sec);
 
     //
     // Tile Manager updates - see if we need to load any new scenery tiles.
     //   this code ties together the fdm, viewer and scenery classes...
-    //   we may want to move this to it's own class at some point
+    //   we may want to move this to its own class at some point
     //
     double visibility_meters = fgGetDouble("/environment/visibility-m");
-    FGViewer *current_view = globals->get_current_view();
-
-    // get the location data for the primary FDM (now hardcoded to ac model)...
-    SGLocation *acmodel_loc = NULL;
-    acmodel_loc = (SGLocation *)globals->
-        get_aircraft_model()->get3DModel()->getSGLocation();
-
-    // update tile manager for FDM...
-    // ...only if location is different than the current-view location
-    // (to avoid duplicating effort)
-    if( !fgGetBool("/sim/current-view/config/from-model") ) {
-        if( acmodel_loc != NULL ) {
-            globals->get_tile_mgr()->prep_ssg_nodes( acmodel_loc,
-                                                     visibility_meters );
-            globals->get_tile_mgr()->
-                update( acmodel_loc, visibility_meters,
-                        acmodel_loc->
-                        get_absolute_view_pos(globals->
-                                              get_scenery()->get_center()) );
-            // save results of update in SGLocation for fdm...
-            if ( globals->get_scenery()->get_cur_elev() > -9990 ) {
-                acmodel_loc->
-                    set_cur_elev_m( globals->get_scenery()->get_cur_elev() );
-                fgSetDouble("/position/ground-elev-m",
-                            globals->get_scenery()->get_cur_elev());
-            }
-            acmodel_loc->
-                set_tile_center( globals->get_scenery()->get_next_center() );
-        }
-    }
 
-    globals->get_tile_mgr()->prep_ssg_nodes( current_view->getSGLocation(),
-                                             visibility_meters );
+    globals->get_tile_mgr()->prep_ssg_nodes( visibility_meters );
     // update tile manager for view...
-    // IMPORTANT!!! the tilemgr update for view location _must_ be
-    // done last after the FDM's until all of Flight Gear code
-    // references the viewer's location for elevation instead of the
-    // "scenery's" current elevation.
     SGLocation *view_location = globals->get_current_view()->getSGLocation();
-    globals->get_tile_mgr()->update( view_location, visibility_meters,
-                                     current_view->get_absolute_view_pos() );
-    // save results of update in SGLocation for fdm...
-    if ( globals->get_scenery()->get_cur_elev() > -9990 ) {
-        current_view->getSGLocation()->
-            set_cur_elev_m( globals->get_scenery()->get_cur_elev() );
+    globals->get_tile_mgr()->update( view_location, visibility_meters );
+    {
+        double lon = view_location->getLongitude_deg();
+        double lat = view_location->getLatitude_deg();
+        double alt = view_location->getAltitudeASL_ft() * SG_FEET_TO_METER;
+
+        // check if we can reuse the groundcache for that purpose.
+        double ref_time, r;
+        SGVec3d pt;
+        bool valid = cur_fdm_state->is_valid_m(&ref_time, pt.sg(), &r);
+        SGVec3d viewpos(globals->get_current_view()->get_view_pos());
+        if (valid && distSqr(viewpos, pt) < r*r) {
+            // Reuse the cache ...
+            double lev
+                = cur_fdm_state->get_groundlevel_m(lat*SGD_DEGREES_TO_RADIANS,
+                                                   lon*SGD_DEGREES_TO_RADIANS,
+                                                   alt + 2.0);
+            view_location->set_cur_elev_m( lev );
+        } else {
+            // Do full intersection test.
+            double lev;
+            if (globals->get_scenery()->get_elevation_m(lat, lon, alt+2, lev, 0))
+                view_location->set_cur_elev_m( lev );
+            else
+                view_location->set_cur_elev_m( -9999.0 );
+        }
     }
-    current_view->getSGLocation()->
-        set_tile_center( globals->get_scenery()->get_next_center() );
 
-#ifdef ENABLE_AUDIO_SUPPORT
-    // Right now we make a simplifying assumption that the primary
-    // aircraft is the source of all sounds and that all sounds are
-    // positioned relative to the current view position.
-
-    static sgVec3 last_pos_offset;
-
-    // set positional offset for sources
-    sgVec3 source_pos_offset;
-    sgSubVec3( source_pos_offset,
-               view_location->get_view_pos(), acmodel_loc->get_view_pos() );
-    // cout << "pos all = " << source_pos_offset[0] << " " << source_pos_offset[1] << " " << source_pos_offset[2] << endl;
-    globals->get_soundmgr()->set_source_pos_all( source_pos_offset );
-
-    // set the velocity
-    sgVec3 source_vel;
-    sgSubVec3( source_vel, source_pos_offset, last_pos_offset );
-    sgScaleVec3( source_vel, delta_time_sec );
-    sgCopyVec3( last_pos_offset, source_pos_offset );
-    // cout << "vel = " << source_vel[0] << " " << source_vel[1] << " " << source_vel[2] << endl;
-    globals->get_soundmgr()->set_source_vel_all( source_vel );
-
-    // Right now we make a simplifying assumption that the listener is
-    // always positioned at the origin.
-    sgVec3 listener_pos;
-    sgSetVec3( listener_pos, 0.0, 0.0, 0.0 );
-    // cout << "listener = " << listener_pos[0] << " " << listener_pos[1] << " " << listener_pos[2] << endl;
-    globals->get_soundmgr()->set_listener_pos( listener_pos );
-#endif
+    // run Nasal's settimer() loops right before the view manager
+    globals->get_event_mgr()->update(delta_time_sec);
 
-    // If fdm location is same as viewer's then we didn't do the
-    // update for fdm location above so we need to save the viewer
-    // results in the fdm SGLocation as well...
-    if( fgGetBool("/sim/current-view/config/from-model") ) {
-        if( acmodel_loc != 0 ) {
-            if ( globals->get_scenery()->get_cur_elev() > -9990 ) {
-                acmodel_loc->set_cur_elev_m( globals->get_scenery()->
-                                             get_cur_elev() );
-                fgSetDouble("/position/ground-elev-m",
-                            globals->get_scenery()->get_cur_elev());
-            }
-            acmodel_loc->set_tile_center( globals->get_scenery()->
-                                          get_next_center() );
-        }
-    }
+    // update the view angle as late as possible, but before sound calculations
+    globals->get_viewmgr()->update(delta_time_sec);
+
+    // Do any I/O channel work that might need to be done (must come after viewmgr)
+    globals->get_io()->update(real_delta_time_sec);
 
     // END Tile Manager udpates
 
-    if (!scenery_loaded && globals->get_tile_mgr()->all_queues_empty() && cur_fdm_state->get_inited()) {
+    if (!scenery_loaded && globals->get_tile_mgr()->isSceneryLoaded()
+        && cur_fdm_state->get_inited()) {
         fgSetBool("sim/sceneryloaded",true);
-    }
-
-    if (fgGetBool("/sim/rendering/specular-highlight")) {
-        glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL, GL_SEPARATE_SPECULAR_COLOR);
-       // glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_TRUE);
-    } else {
-        glLightModeli(GL_LIGHT_MODEL_COLOR_CONTROL, GL_SINGLE_COLOR);
-        // glLightModeli(GL_LIGHT_MODEL_TWO_SIDE, GL_FALSE);
+        fgSetFloat("/sim/sound/volume", init_volume);
+        globals->get_soundmgr()->set_volume(init_volume);
     }
 
     fgRequestRedraw();
@@ -1359,6 +544,34 @@ static void fgMainLoop( void ) {
     SG_LOG( SG_ALL, SG_DEBUG, "" );
 }
 
+// Operation for querying OpenGL parameters. This must be done in a
+// valid OpenGL context, potentially in another thread.
+namespace
+{
+struct GeneralInitOperation : public GraphicsContextOperation
+{
+    GeneralInitOperation()
+        : GraphicsContextOperation(std::string("General init"))
+    {
+    }
+    void run(osg::GraphicsContext* gc)
+    {
+        general.set_glVendor( (char *)glGetString ( GL_VENDOR ) );
+        general.set_glRenderer( (char *)glGetString ( GL_RENDERER ) );
+        general.set_glVersion( (char *)glGetString ( GL_VERSION ) );
+        SG_LOG( SG_GENERAL, SG_INFO, general.get_glRenderer() );
+
+        GLint tmp;
+        glGetIntegerv( GL_MAX_TEXTURE_SIZE, &tmp );
+        general.set_glMaxTexSize( tmp );
+        SG_LOG ( SG_GENERAL, SG_INFO, "Max texture size = " << tmp );
+
+        glGetIntegerv( GL_DEPTH_BITS, &tmp );
+        general.set_glDepthBits( tmp );
+        SG_LOG ( SG_GENERAL, SG_INFO, "Depth buffer bits = " << tmp );
+    }
+};
+}
 
 // This is the top level master main function that is registered as
 // our idle funciton
@@ -1368,18 +581,187 @@ static void fgMainLoop( void ) {
 // then on.
 
 static void fgIdleFunction ( void ) {
-    // printf("idle state == %d\n", idle_state);
-
+    static osg::ref_ptr<GeneralInitOperation> genOp;
     if ( idle_state == 0 ) {
-        fgSetBool("sim/initialised", false);
+        idle_state++;
+        // Pick some window on which to do queries.
+        // XXX Perhaps all this graphics initialization code should be
+        // moved to renderer.cxx?
+        genOp = new GeneralInitOperation;
+        osg::Camera* guiCamera = getGUICamera(CameraGroup::getDefault());
+        WindowSystemAdapter* wsa = WindowSystemAdapter::getWSA();
+        osg::GraphicsContext* gc = 0;
+        if (guiCamera)
+            gc = guiCamera->getGraphicsContext();
+        if (gc) {
+            gc->add(genOp.get());
+        } else {
+            wsa->windows[0]->gc->add(genOp.get());
+        }
+        guiStartInit(gc);
+    } else if ( idle_state == 1 ) {
+        if (genOp.valid()) {
+            if (!genOp->isFinished())
+                return;
+            genOp = 0;
+        }
+        if (!guiFinishInit())
+            return;
+        idle_state++;
+        fgSplashProgress("reading aircraft list");
+
+
+    } else if ( idle_state == 2 ) {
+        idle_state++;
+        // Read the list of available aircraft
+        fgReadAircraft();
+        fgSplashProgress("reading airport & navigation data");
+
 
-        // Initialize the splash screen right away
-        if ( fgGetBool("/sim/startup/splash-screen") ) {
-            fgSplashInit(fgGetString("/sim/startup/splash-texture"));
+    } else if ( idle_state == 3 ) {
+        idle_state++;
+        fgInitNav();
+        fgSplashProgress("setting up scenery");
+
+
+    } else if ( idle_state == 4 ) {
+        idle_state++;
+        // based on the requested presets, calculate the true starting
+        // lon, lat
+        fgInitPosition();
+        fgInitTowerLocationListener();
+
+        SGTime *t = fgInitTime();
+        globals->set_time_params( t );
+
+        // Do some quick general initializations
+        if( !fgInitGeneral()) {
+            SG_LOG( SG_GENERAL, SG_ALERT,
+                "General initialization failed ..." );
+            exit(-1);
         }
-        
+
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the property-based built-in commands
+        ////////////////////////////////////////////////////////////////////
+        fgInitCommands();
+
+
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the material manager
+        ////////////////////////////////////////////////////////////////////
+        globals->set_matlib( new SGMaterialLib );
+        simgear::SGModelLib::init(globals->get_fg_root());
+
+
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the TG scenery subsystem.
+        ////////////////////////////////////////////////////////////////////
+        globals->set_scenery( new FGScenery );
+        globals->get_scenery()->init();
+        globals->get_scenery()->bind();
+        globals->set_tile_mgr( new FGTileMgr );
+
+
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the general model subsystem.
+        ////////////////////////////////////////////////////////////////////
+        globals->set_model_mgr(new FGModelMgr);
+        globals->get_model_mgr()->init();
+        globals->get_model_mgr()->bind();
+        fgSplashProgress("loading aircraft");
+
+
+    } else if ( idle_state == 5 ) {
+        idle_state++;
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the 3D aircraft model subsystem (has a dependency on
+        // the scenery subsystem.)
+        ////////////////////////////////////////////////////////////////////
+        globals->set_aircraft_model(new FGAircraftModel);
+        globals->get_aircraft_model()->init();
+        globals->get_aircraft_model()->bind();
+
+        ////////////////////////////////////////////////////////////////////
+        // Initialize the view manager subsystem.
+        ////////////////////////////////////////////////////////////////////
+        FGViewMgr *viewmgr = new FGViewMgr;
+        globals->set_viewmgr( viewmgr );
+        viewmgr->init();
+        viewmgr->bind();
+        fgSplashProgress("generating sky elements");
+
+
+    } else if ( idle_state == 6 ) {
+        idle_state++;
+        // Initialize the sky
+        SGPath ephem_data_path( globals->get_fg_root() );
+        ephem_data_path.append( "Astro" );
+        SGEphemeris *ephem = new SGEphemeris( ephem_data_path.c_str() );
+        ephem->update( globals->get_time_params()->getMjd(),
+                       globals->get_time_params()->getLst(),
+                       0.0 );
+        globals->set_ephem( ephem );
+
+        // TODO: move to environment mgr
+        thesky = new SGSky;
+        SGPath texture_path(globals->get_fg_root());
+        texture_path.append("Textures");
+        texture_path.append("Sky");
+        for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
+            SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
+            thesky->add_cloud_layer(layer);
+        }
+
+        SGPath sky_tex_path( globals->get_fg_root() );
+        sky_tex_path.append( "Textures" );
+        sky_tex_path.append( "Sky" );
+        thesky->texture_path( sky_tex_path.str() );
+
+        // The sun and moon diameters are scaled down numbers of the
+        // actual diameters. This was needed to fit both the sun and the
+        // moon within the distance to the far clip plane.
+        // Moon diameter:    3,476 kilometers
+        // Sun diameter: 1,390,000 kilometers
+        thesky->build( 80000.0, 80000.0,
+                       463.3, 361.8,
+                       globals->get_ephem()->getNumPlanets(),
+                       globals->get_ephem()->getPlanets(),
+                       globals->get_ephem()->getNumStars(),
+                       globals->get_ephem()->getStars(),
+                       fgGetNode("/environment", true));
+
+        // Initialize MagVar model
+        SGMagVar *magvar = new SGMagVar();
+        globals->set_mag( magvar );
+
+
+                                    // kludge to initialize mag compass
+                                    // (should only be done for in-flight
+                                    // startup)
+        // update magvar model
+        globals->get_mag()->update( fgGetDouble("/position/longitude-deg")
+                                    * SGD_DEGREES_TO_RADIANS,
+                                    fgGetDouble("/position/latitude-deg")
+                                    * SGD_DEGREES_TO_RADIANS,
+                                    fgGetDouble("/position/altitude-ft")
+                                    * SG_FEET_TO_METER,
+                                    globals->get_time_params()->getJD() );
+        double var = globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES;
+        fgSetDouble("/instrumentation/heading-indicator/offset-deg", -var);
+        fgSetDouble("/instrumentation/heading-indicator-fg/offset-deg", -var);
+
+
+        // airport = new ssgBranch;
+        // airport->setName( "Airport Lighting" );
+        // lighting->addKid( airport );
+
+        // build our custom render states
+        fgSplashProgress("initializing subsystems");
+
+
+    } else if ( idle_state == 7 ) {
         idle_state++;
-    } else if ( idle_state == 1 ) {
         // Initialize audio support
 #ifdef ENABLE_AUDIO_SUPPORT
 
@@ -1388,7 +770,7 @@ static void fgIdleFunction ( void ) {
             SGPath mp3file( globals->get_fg_root() );
             mp3file.append( "Sounds/intro.mp3" );
 
-            SG_LOG( SG_GENERAL, SG_INFO, 
+            SG_LOG( SG_GENERAL, SG_INFO,
                 "Starting intro music: " << mp3file.str() );
 
 #if defined( __CYGWIN__ )
@@ -1402,121 +784,64 @@ static void fgIdleFunction ( void ) {
             system ( command.c_str() );
         }
 #endif
-
-        idle_state++;
-    } else if ( idle_state == 2 ) {
-        // These are a few miscellaneous things that aren't really
-        // "subsystems" but still need to be initialized.
-
-#ifdef USE_GLIDE
-        if ( strstr ( general.get_glRenderer(), "Glide" ) ) {
-            grTexLodBiasValue ( GR_TMU0, 1.0 ) ;
-        }
-#endif
-
-        idle_state++;
-    } else if ( idle_state == 3 ) {
         // This is the top level init routine which calls all the
         // other subsystem initialization routines.  If you are adding
-        // a subsystem to flightgear, its initialization call should
+        // a subsystem to flightgear, its initialization call should be
         // located in this routine.
         if( !fgInitSubsystems()) {
             SG_LOG( SG_GENERAL, SG_ALERT,
-                "Subsystem initializations failed ..." );
+                "Subsystem initialization failed ..." );
             exit(-1);
         }
+        fgSplashProgress("setting up time & renderer");
 
-        idle_state++;
-    } else if ( idle_state == 4 ) {
+
+    } else if ( idle_state == 8 ) {
+        idle_state = 1000;
         // Initialize the time offset (warp) after fgInitSubsystem
         // (which initializes the lighting interpolation tables.)
         fgInitTimeOffset();
 
         // setup OpenGL view parameters
-        fgInitVisuals();
-
-        // Read the list of available aircrafts
-        fgReadAircraft();
-
-        idle_state++;
-    } else if ( idle_state == 5 ) {
-
-        idle_state++;
-    } else if ( idle_state == 6 ) {
-        // sleep(1);
-
-        idle_state = 1000;
+        globals->get_renderer()->init();
 
         SG_LOG( SG_GENERAL, SG_INFO, "Panel visible = " << fgPanelVisible() );
-        fgReshape( fgGetInt("/sim/startup/xsize"),
-               fgGetInt("/sim/startup/ysize") );
+        globals->get_renderer()->resize( fgGetInt("/sim/startup/xsize"),
+                                         fgGetInt("/sim/startup/ysize") );
 
-    } 
+        fgSplashProgress("loading scenery objects");
+
+    }
 
     if ( idle_state == 1000 ) {
         // We've finished all our initialization steps, from now on we
         // run the main loop.
-        fgSetBool("sim/initialised",true);
-        fgSetBool("sim/sceneryloaded",false);
-
-        fgRegisterIdleHandler(fgMainLoop);
-    } else {
-        if ( fgGetBool("/sim/startup/splash-screen") ) {
-            fgSplashUpdate(0.0, 1.0);
-        }
+        fgSetBool("sim/sceneryloaded", false);
+        fgRegisterIdleHandler( fgMainLoop );
     }
 }
 
-// options.cxx needs to see this for toggle_panel()
-// Handle new window size or exposure
-void fgReshape( int width, int height ) {
-    int view_h;
 
-    if ( (!fgGetBool("/sim/virtual-cockpit"))
-         && fgPanelVisible() && idle_state == 1000 ) {
-        view_h = (int)(height * (globals->get_current_panel()->getViewHeight() -
-                             globals->get_current_panel()->getYOffset()) / 768.0);
+static void upper_case_property(const char *name)
+{
+    SGPropertyNode *p = fgGetNode(name, false);
+    if (!p) {
+        p = fgGetNode(name, true);
+        p->setStringValue("");
     } else {
-        view_h = height;
-    }
-
-    glViewport( 0, (GLint)(height - view_h), (GLint)(width), (GLint)(view_h) );
-
-    fgSetInt("/sim/startup/xsize", width);
-    fgSetInt("/sim/startup/ysize", height);
-    guiInitMouse(width, height);
-
-    // for all views
-    FGViewMgr *viewmgr = globals->get_viewmgr();
-    if (viewmgr) {
-      for ( int i = 0; i < viewmgr->size(); ++i ) {
-        viewmgr->get_view(i)->
-          set_aspect_ratio((float)view_h / (float)width);
-      }
-
-      ssgSetFOV( viewmgr->get_current_view()->get_h_fov(),
-               viewmgr->get_current_view()->get_v_fov() );
-
-#ifdef FG_USE_CLOUDS_3D
-      sgClouds3d->Resize( viewmgr->get_current_view()->get_h_fov(),
-               viewmgr->get_current_view()->get_v_fov() );
-#endif
+        SGPropertyNode::Type t = p->getType();
+        if (t == SGPropertyNode::NONE || t == SGPropertyNode::UNSPECIFIED)
+            p->setStringValue("");
+        else
+            assert(t == SGPropertyNode::STRING);
     }
-
-    fgHUDReshape();
-
+    p->addChangeListener(new FGMakeUpperCase);
 }
 
 
 // Main top level initialization
 bool fgMainInit( int argc, char **argv ) {
 
-#if defined( macintosh )
-    freopen ("stdout.txt", "w", stdout );
-    freopen ("stderr.txt", "w", stderr );
-    argc = ccommand( &argv );
-#endif
-
     // set default log levels
     sglog().setLogLevels( SG_ALL, SG_ALERT );
 
@@ -1535,7 +860,7 @@ bool fgMainInit( int argc, char **argv ) {
 
     globals = new FGGlobals;
 
-    // seed the random number generater
+    // seed the random number generator
     sg_srandom_time();
 
     FGControls *controls = new FGControls;
@@ -1544,12 +869,18 @@ bool fgMainInit( int argc, char **argv ) {
     string_list *col = new string_list;
     globals->set_channel_options_list( col );
 
+    fgValidatePath("", false);  // initialize static variables
+    upper_case_property("/sim/presets/airport-id");
+    upper_case_property("/sim/presets/runway");
+    upper_case_property("/sim/tower/airport-id");
+    upper_case_property("/autopilot/route-manager/input");
+
     // Scan the config file(s) and command line options to see if
     // fg_root was specified (ignore all other options for now)
     fgInitFGRoot(argc, argv);
 
     // Check for the correct base package version
-    static char required_version[] = "0.9.6";
+    static char required_version[] = "1.0.0";
     string base_version = fgBasePackageVersion();
     if ( !(base_version == required_version) ) {
         // tell the operator how to use this application
@@ -1566,11 +897,8 @@ bool fgMainInit( int argc, char **argv ) {
         exit(-1);
     }
 
-    // Initialize the Aircraft directory to "" (UIUC)
-    aircraft_dir = "";
-
     // Load the configuration parameters.  (Command line options
-    // overrides config file options.  Config file options override
+    // override config file options.  Config file options override
     // defaults.)
     if ( !fgInitConfig(argc, argv) ) {
         SG_LOG( SG_GENERAL, SG_ALERT, "Config option parsing failed ..." );
@@ -1578,17 +906,12 @@ bool fgMainInit( int argc, char **argv ) {
     }
 
     // Initialize the Window/Graphics environment.
-#if !defined(__APPLE__) || defined(OSX_BUNDLE)
-    // Mac OS X command line ("non-bundle") applications call this
-    // from main(), in bootstrap.cxx.  Andy doesn't know why, someone
-    // feel free to add comments...
     fgOSInit(&argc, argv);
     _bootstrap_OSInit++;
-#endif
 
-    fgRegisterWindowResizeHandler( fgReshape );
-    fgRegisterIdleHandler( fgIdleFunction );
-    fgRegisterDrawHandler( fgRenderFrame );
+    fgRegisterWindowResizeHandler( &FGRenderer::resize );
+    fgRegisterIdleHandler( &fgIdleFunction );
+    fgRegisterDrawHandler( &FGRenderer::update );
 
 #ifdef FG_ENABLE_MULTIPASS_CLOUDS
     bool get_stencil_buffer = true;
@@ -1596,199 +919,19 @@ bool fgMainInit( int argc, char **argv ) {
     bool get_stencil_buffer = false;
 #endif
 
-    // Clouds3D requires an alpha channel
-    // clouds may require stencil buffer
-    fgOSOpenWindow( fgGetInt("/sim/startup/xsize"),
-                    fgGetInt("/sim/startup/ysize"),
-                    fgGetInt("/sim/rendering/bits-per-pixel"),
-                    fgGetBool("/sim/rendering/clouds3d"),
-                    get_stencil_buffer,
-                    fgGetBool("/sim/startup/fullscreen") );
-
-    // This seems to be the absolute earliest in the init sequence
-    // that these calls will return valid info.  Too bad it's after
-    // we've already created and sized out window. :-(
-    general.set_glVendor( (char *)glGetString ( GL_VENDOR ) );
-    general.set_glRenderer( (char *)glGetString ( GL_RENDERER ) );
-    general.set_glVersion( (char *)glGetString ( GL_VERSION ) );
-    SG_LOG( SG_GENERAL, SG_INFO, general.get_glRenderer() );
-
-    GLint tmp;
-    glGetIntegerv( GL_MAX_TEXTURE_SIZE, &tmp );
-    general.set_glMaxTexSize( tmp );
-    SG_LOG ( SG_GENERAL, SG_INFO, "Max texture size = " << tmp );
-
-    glGetIntegerv( GL_DEPTH_BITS, &tmp );
-    general.set_glDepthBits( tmp );
-    SG_LOG ( SG_GENERAL, SG_INFO, "Depth buffer bits = " << tmp );
-
     // Initialize plib net interface
     netInit( &argc, argv );
 
-    // Initialize ssg (from plib).  Needs to come before we do any
-    // other ssg stuff, but after opengl has been initialized.
-    ssgInit();
-
-    // Initialize the user interface (we need to do this before
-    // passing off control to the OS main loop and before
-    // fgInitGeneral to get our fonts !!!
-    guiInit();
-
-    // Read the list of available aircrafts
-    fgReadAircraft();
-
-#ifdef GL_EXT_texture_lod_bias
-    glTexEnvf( GL_TEXTURE_FILTER_CONTROL_EXT, GL_TEXTURE_LOD_BIAS_EXT, -0.5 ) ;
-#endif
-
-            // get the address of our OpenGL extensions
-    if ( fgGetBool("/sim/rendering/distance-attenuation") )
-    {
-        if (SGIsOpenGLExtensionSupported("GL_EXT_point_parameters") ) {
-            glPointParameterIsSupported = true;
-            glPointParameterfPtr = (glPointParameterfProc)
-                                   SGLookupFunction("glPointParameterfEXT");
-            glPointParameterfvPtr = (glPointParameterfvProc)
-                                    SGLookupFunction("glPointParameterfvEXT");
-
-        } else if ( SGIsOpenGLExtensionSupported("GL_ARB_point_parameters") ) {
-            glPointParameterIsSupported = true;
-            glPointParameterfPtr = (glPointParameterfProc)
-                                   SGLookupFunction("glPointParameterfARB");
-            glPointParameterfvPtr = (glPointParameterfvProc)
-                                    SGLookupFunction("glPointParameterfvARB");
-        } else
-            glPointParameterIsSupported = false;
-   }
-
-    // based on the requested presets, calculate the true starting
-    // lon, lat
-    fgInitNav();
-    fgInitPosition();
-
-    SGTime *t = fgInitTime();
-    globals->set_time_params( t );
-
-    // Do some quick general initializations
-    if( !fgInitGeneral()) {
-        SG_LOG( SG_GENERAL, SG_ALERT, 
-            "General initializations failed ..." );
-        exit(-1);
-    }
+    // Clouds3D requires an alpha channel
+    // clouds may require stencil buffer
+    fgOSOpenWindow(get_stencil_buffer);
 
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the property-based built-in commands
-    ////////////////////////////////////////////////////////////////////
-    fgInitCommands();
-
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the material manager
-    ////////////////////////////////////////////////////////////////////
-    globals->set_matlib( new SGMaterialLib );
-
-    globals->set_model_lib(new SGModelLib);
-
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the TG scenery subsystem.
-    ////////////////////////////////////////////////////////////////////
-    globals->set_scenery( new FGScenery );
-    globals->get_scenery()->init();
-    globals->get_scenery()->bind();
-    globals->set_tile_mgr( new FGTileMgr );
-
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the general model subsystem.
-    ////////////////////////////////////////////////////////////////////
-    globals->set_model_mgr(new FGModelMgr);
-    globals->get_model_mgr()->init();
-    globals->get_model_mgr()->bind();
-
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the 3D aircraft model subsystem (has a dependency on
-    // the scenery subsystem.)
-    ////////////////////////////////////////////////////////////////////
-    globals->set_aircraft_model(new FGAircraftModel);
-    globals->get_aircraft_model()->init();
-    globals->get_aircraft_model()->bind();
-
-    ////////////////////////////////////////////////////////////////////
-    // Initialize the view manager subsystem.
-    ////////////////////////////////////////////////////////////////////
-    FGViewMgr *viewmgr = new FGViewMgr;
-    globals->set_viewmgr( viewmgr );
-    viewmgr->init();
-    viewmgr->bind();
-
-
-    // Initialize the sky
-    SGPath ephem_data_path( globals->get_fg_root() );
-    ephem_data_path.append( "Astro" );
-    SGEphemeris *ephem = new SGEphemeris( ephem_data_path.c_str() );
-    ephem->update( globals->get_time_params()->getMjd(),
-                   globals->get_time_params()->getLst(),
-                   0.0 );
-    globals->set_ephem( ephem );
-
-    // TODO: move to environment mgr
-    thesky = new SGSky;
-    SGPath texture_path(globals->get_fg_root());
-    texture_path.append("Textures");
-    texture_path.append("Sky");
-    for (int i = 0; i < FGEnvironmentMgr::MAX_CLOUD_LAYERS; i++) {
-        SGCloudLayer * layer = new SGCloudLayer(texture_path.str());
-        thesky->add_cloud_layer(layer);
-    }
+    // Initialize the splash screen right away
+    fntInit();
+    fgSplashInit();
 
-    SGPath sky_tex_path( globals->get_fg_root() );
-    sky_tex_path.append( "Textures" );
-    sky_tex_path.append( "Sky" );
-    thesky->texture_path( sky_tex_path.str() );
-
-    // The sun and moon diameters are scaled down numbers of the
-    // actual diameters. This was needed to fit bot the sun and the
-    // moon within the distance to the far clip plane.
-    // Moon diameter:    3,476 kilometers
-    // Sun diameter: 1,390,000 kilometers
-    thesky->build( 80000.0, 80000.0,
-                   463.3, 361.8,
-                   globals->get_ephem()->getNumPlanets(), 
-                   globals->get_ephem()->getPlanets(),
-                   globals->get_ephem()->getNumStars(),
-                   globals->get_ephem()->getStars() );
-
-    // Initialize MagVar model
-    SGMagVar *magvar = new SGMagVar();
-    globals->set_mag( magvar );
-
-
-                                // kludge to initialize mag compass
-                                // (should only be done for in-flight
-                                // startup)
-    // update magvar model
-    globals->get_mag()->update( fgGetDouble("/position/longitude-deg")
-                                * SGD_DEGREES_TO_RADIANS,
-                                fgGetDouble("/position/latitude-deg")
-                                * SGD_DEGREES_TO_RADIANS,
-                                fgGetDouble("/position/altitude-ft")
-                                * SG_FEET_TO_METER,
-                                globals->get_time_params()->getJD() );
-    double var = globals->get_mag()->get_magvar() * SGD_RADIANS_TO_DEGREES;
-    fgSetDouble("/instrumentation/heading-indicator/offset-deg", -var);
-
-    // airport = new ssgBranch;
-    // airport->setName( "Airport Lighting" );
-    // lighting->addKid( airport );
-
-    // build our custom render states
-    fgBuildRenderStates();
-
-    try {
-        // pass control off to the master event handler
-        fgOSMainLoop();
-    } catch (...) {
-        SG_LOG( SG_ALL, SG_ALERT,
-            "Unknown exception in the main loop. Aborting..." );
-    }
+    // pass control off to the master event handler
+    fgOSMainLoop();
 
     // we never actually get here ... but to avoid compiler warnings,
     // etc.
@@ -1796,4 +939,3 @@ bool fgMainInit( int argc, char **argv ) {
 }
 
 
-// end of main.cxx