]> git.mxchange.org Git - flightgear.git/blobdiff - src/Scenery/tileentry.cxx
Tweaks from Julian Foad:
[flightgear.git] / src / Scenery / tileentry.cxx
index 020c324369abd299a826600c6fe2e1fae7aec168..e2431a131b1b1c4580f4fcac8ebfbc2487be18be 100644 (file)
@@ -1,8 +1,8 @@
-// tile.cxx -- routines to handle a scenery tile
+// tileentry.cxx -- routines to handle a scenery tile
 //
 // Written by Curtis Olson, started May 1998.
 //
-// Copyright (C) 1998, 1999  Curtis L. Olson  - curt@flightgear.org
+// Copyright (C) 1998 - 2001  Curtis L. Olson  - curt@flightgear.org
 //
 // This program is free software; you can redistribute it and/or
 // modify it under the terms of the GNU General Public License as
 
 #include <simgear/compiler.h>
 
-#ifdef SG_MATH_EXCEPTION_CLASH
-#  include <math.h>
-#endif
-
-#include STL_FUNCTIONAL
-#include STL_ALGORITHM
-#include STL_STRING
-
 #include <simgear/bucket/newbucket.hxx>
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <Aircraft/aircraft.hxx>
 #include <Include/general.hxx>
 #include <Main/globals.hxx>
+#include <Main/viewer.hxx>
 #include <Scenery/scenery.hxx>
 #include <Time/light.hxx>
+#include <Objects/apt_signs.hxx>
 #include <Objects/matlib.hxx>
 #include <Objects/newmat.hxx>
 #include <Objects/obj.hxx>
 
 #include "tileentry.hxx"
-
-SG_USING_STD(for_each);
-SG_USING_STD(mem_fun_ref);
-SG_USING_STD(string);
+#include "tilemgr.hxx"
 
 
 // Constructor
@@ -64,7 +55,8 @@ FGTileEntry::FGTileEntry ( const SGBucket& b )
       tile_bucket( b ),
       terra_transform( new ssgTransform ),
       terra_range( new ssgRangeSelector ),
-      loaded(false)
+      loaded(false),
+      pending_models(0)
 {
     nodes.clear();
 
@@ -85,6 +77,91 @@ FGTileEntry::~FGTileEntry () {
 }
 
 
+#if 0
+// This is the current method cut and pasted from 
+//  FGTileEntry::load( const SGPath& base, bool is_base )
+void
+FGTileEntry::WorldCoordinate( sgCoord *obj_pos, Point3D center,
+                              double lat, double lon, double elev, double hdg)
+{
+    // setup transforms
+    Point3D geod( lon * SGD_DEGREES_TO_RADIANS,
+                  lat * SGD_DEGREES_TO_RADIANS,
+                  elev );
+       
+    Point3D world_pos = sgGeodToCart( geod );
+    Point3D offset = world_pos - center;
+       
+    sgMat4 POS;
+    sgMakeTransMat4( POS, offset.x(), offset.y(), offset.z() );
+
+    sgVec3 obj_rt, obj_up;
+    sgSetVec3( obj_rt, 0.0, 1.0, 0.0); // Y axis
+    sgSetVec3( obj_up, 0.0, 0.0, 1.0); // Z axis
+
+    sgMat4 ROT_lon, ROT_lat, ROT_hdg;
+    sgMakeRotMat4( ROT_lon, lon, obj_up );
+    sgMakeRotMat4( ROT_lat, 90 - lat, obj_rt );
+    sgMakeRotMat4( ROT_hdg, hdg, obj_up );
+
+    sgMat4 TUX;
+    sgCopyMat4( TUX, ROT_hdg );
+    sgPostMultMat4( TUX, ROT_lat );
+    sgPostMultMat4( TUX, ROT_lon );
+    sgPostMultMat4( TUX, POS );
+
+    sgSetCoord( obj_pos, TUX );
+}
+#endif
+
+
+// Norman's 'fast hack' for above
+static void WorldCoordinate( sgCoord *obj_pos, Point3D center, double lat,
+                             double lon, double elev, double hdg )
+{
+    double lon_rad = lon * SGD_DEGREES_TO_RADIANS;
+    double lat_rad = lat * SGD_DEGREES_TO_RADIANS;
+    double hdg_rad = hdg * SGD_DEGREES_TO_RADIANS;
+
+    // setup transforms
+    Point3D geod( lon_rad, lat_rad, elev );
+       
+    Point3D world_pos = sgGeodToCart( geod );
+    Point3D offset = world_pos - center;
+
+    sgMat4 mat;
+
+    SGfloat sin_lat = (SGfloat)sin( lat_rad );
+    SGfloat cos_lat = (SGfloat)cos( lat_rad );
+    SGfloat cos_lon = (SGfloat)cos( lon_rad );
+    SGfloat sin_lon = (SGfloat)sin( lon_rad );
+    SGfloat sin_hdg = (SGfloat)sin( hdg_rad ) ;
+    SGfloat cos_hdg = (SGfloat)cos( hdg_rad ) ;
+
+    mat[0][0] =  cos_hdg * (SGfloat)sin_lat * (SGfloat)cos_lon - sin_hdg * (SGfloat)sin_lon;
+    mat[0][1] =  cos_hdg * (SGfloat)sin_lat * (SGfloat)sin_lon + sin_hdg * (SGfloat)cos_lon;
+    mat[0][2] =        -cos_hdg * (SGfloat)cos_lat;
+    mat[0][3] =         SG_ZERO;
+
+    mat[1][0] = -sin_hdg * (SGfloat)sin_lat * (SGfloat)cos_lon - cos_hdg * (SGfloat)sin_lon;
+    mat[1][1] = -sin_hdg * (SGfloat)sin_lat * (SGfloat)sin_lon + cos_hdg * (SGfloat)cos_lon;
+    mat[1][2] =         sin_hdg * (SGfloat)cos_lat;
+    mat[1][3] =         SG_ZERO;
+
+    mat[2][0] = (SGfloat)cos_lat * (SGfloat)cos_lon;
+    mat[2][1] = (SGfloat)cos_lat * (SGfloat)sin_lon;
+    mat[2][2] =        (SGfloat)sin_lat;
+    mat[2][3] =  SG_ZERO;
+
+    mat[3][0] = offset.x();
+    mat[3][1] = offset.y();
+    mat[3][2] = offset.z();
+    mat[3][3] = SG_ONE ;
+
+    sgSetCoord( obj_pos, mat );
+}
+
+
 // recurse an ssg tree and call removeKid() on every node from the
 // bottom up.  Leaves the original branch in existance, but empty so
 // it can be removed by the calling routine.
@@ -102,6 +179,515 @@ static void my_remove_branch( ssgBranch * branch ) {
     }
 }
 
+// ADA
+#define TEXRES_X 256
+#define TEXRES_Y 256
+unsigned char env_map[TEXRES_X][TEXRES_Y][4];
+// SetColor & SetColor2 functions were provided by Christian Mayer (26 April 2001) - used without change
+void setColor(float x, float y, float z, float angular_size, float r,
+float g, float b, float a)
+{
+    //normalize
+    float inv_length = 1.0 / sqrt(x*x + y*y + z*z);
+    x *= inv_length; y *= inv_length; z *= inv_length;
+  
+    float cos_angular_size = cos(angular_size*(22.0/7.0)/180.0);
+
+    for( int s = 0; s < TEXRES_X; s++) {
+        for( int t = 0; t < TEXRES_Y; t++) {
+
+            float s_2 = (float)s/TEXRES_X - 0.5; // centre of texture 0,0
+            float t_2 = (float)t/TEXRES_Y - 0.5; // elev
+
+            float rx, ry, rz;
+
+            if ((1.0 - 4.0*s_2*s_2 - 4.0*t_2*t_2) >= 0.0) {
+                // sphere
+                float m = 4.0 * sqrt(1.0 - 4.0*s_2*s_2 - 4.0*t_2*t_2);
+                rx = m * s_2;
+                ry = m * t_2;
+                rz = m*m / 8.0 - 1.0;
+            } else {
+                // singularity
+                rx = 0.0;
+                ry = 0.0;
+                rz = -1.0;
+            }
+
+            float tx = rx;  //mirroring on the z=0 plane
+            float ty = ry;  //assumes that the normal is allways
+            float tz = -rz; //n(0.0, 0.0, 1.0)
+         
+            if ( cos_angular_size < (x*tx + y*ty + z*tz) ) {
+                env_map[s][t][0] = (unsigned char) r * 255;  
+                env_map[s][t][1] = (unsigned char) g * 255;
+                env_map[s][t][2] = (unsigned char) b * 255;
+                env_map[s][t][3] = (unsigned char) a * 255;
+            }
+        }
+    }
+}
+
+// elevation_size, float azimuth_size are the *total* angular size of the light
+void setColor2(float elevation_size,float azimuth_size, float r, float g, float b, float a)
+{
+    for( int s = 0; s < TEXRES_X; s++) {
+        for( int t = 0; t < TEXRES_Y; t++) {
+            float s_2 = (float)s/TEXRES_X - 0.5;
+            float t_2 = (float)t/TEXRES_Y - 0.5;
+
+            float rx, ry, rz;
+
+            if ((1.0 - 4.0*s_2*s_2 - 4.0*t_2*t_2) >= 0.0) {
+
+                float m = 4.0 * sqrt(1.0 - 4.0*s_2*s_2 - 4.0*t_2*t_2);
+                rx = m * s_2;
+                ry = m * t_2;
+                rz = m*m / 8.0 - 1.0;
+            } else {
+                rx = 0.0;
+                ry = 0.0;
+                rz = -1.0;
+            }
+
+            float tx = rx;  //mirroring on the z=0 plane to reverse
+            float ty = ry;  //OpenGLs automatic mirroring
+            float tz = -rz; 
+
+            //get elevation => project t onto the x-z-plane
+            float tz_proj1 = tz / sqrt(tx*tx + tz*tz);
+            float televation = acos( -tz_proj1 ) * 180.0 / 3.1415;
+
+            //get azi => project t onto the y-z-plane
+            float tz_proj2 = tz / sqrt(ty*ty + tz*tz);
+            float tazimuth = acos( -tz_proj2 ) * 180.0 / 3.1415;
+
+            //note televation and tazimuth are the angles *between* the
+            //temporary vector and the normal (0,0,-1). They are *NOT*
+            //the elevation and azimuth angles
+
+            //square:
+            //if (((elevation_size > televation) || (elevation_size < -televation)) &&
+            //    ((azimuth_size   > tazimuth  ) || (azimuth_size   < -tazimuth  ))) 
+            //elliptical
+            if (((televation*televation) / (elevation_size*elevation_size / 4.0) +
+                 (tazimuth  *tazimuth  ) / (azimuth_size  *azimuth_size   / 4.0)) <= 1.0)
+            {
+                env_map[s][t][0] = (unsigned char) r * 255;  
+                env_map[s][t][1] = (unsigned char) g * 255;
+                env_map[s][t][2] = (unsigned char) b * 255;
+                env_map[s][t][3] = (unsigned char) a * 255;
+            }
+        }
+    }
+}
+
+// 23 March 2001
+// This function performs billboarding of polygons drawn using the UP and RIGHT vectors obtained
+// from the transpose of the MODEL_VIEW_MATRIX of the ssg_current_context. Each polygon is drawn
+// at the coordinate array and material state as passed thro arguments.
+void *fgBillboard( ssgBranch *lightmaps, ssgVertexArray *light_maps, ssgSimpleState *lightmap_state, float size) {
+    sgMat4 tmat;
+    sgVec3 rt, up, nrt, nup, pt, quads[4], lmaps[4];
+
+    ssgGetModelviewMatrix ( tmat );
+    sgSetVec3 (rt, tmat[0][0], tmat[1][0], tmat[2][0]);
+    sgSetVec3 (up, tmat[0][1], tmat[1][1], tmat[2][1]);
+    sgSetVec3 (nrt, tmat[0][0], tmat[1][0], tmat[2][0]);
+    sgSetVec3 (nup, tmat[0][1], tmat[1][1], tmat[2][1]);
+    sgNegateVec3 (nrt);
+    sgNegateVec3 (nup);
+
+    sgAddVec3 (quads[0], nrt, nup);
+    sgAddVec3 (quads[1],  rt, nup);
+    sgAddVec3 (quads[2],  rt,  up);
+    sgAddVec3 (quads[3], nrt,  up);
+
+    sgScaleVec3 (quads[0], size);
+    sgScaleVec3 (quads[1], size);
+    sgScaleVec3 (quads[2], size);
+    sgScaleVec3 (quads[3], size);
+
+    sgVec4 color;
+    sgSetVec4( color, 1.0, 1.0, 0.0, 1.0 );
+
+    sgVec2 texcoords[4];
+    sgSetVec2( texcoords[0], 1.0, 1.0 );
+    sgSetVec2( texcoords[1], 0.0, 1.0 );
+    sgSetVec2( texcoords[2], 0.0, 0.0 );
+    sgSetVec2( texcoords[3], 1.0, 0.0 );
+    
+    for (int j = 0; j < 4; j++ ) {
+        sgCopyVec3(lmaps[j]    ,quads[j]);
+    }
+
+    for ( int i = 0; i < light_maps->getNum(); ++i ) {
+        // Allocate ssg structure
+        ssgVertexArray   *vl = new ssgVertexArray( 1 );
+        ssgTexCoordArray *tl = new ssgTexCoordArray( 1 );
+        ssgColourArray   *cl = new ssgColourArray( 1 );
+
+        float *temp = light_maps->get(i);
+        sgSetVec3(pt,temp[0],temp[1],temp[2]);
+
+        for (int k=0; k<4; k++) {
+            sgAddVec3( quads[k],lmaps[k], pt );                        
+            vl->add(quads[k]);
+            tl->add(texcoords[k]);
+            cl->add(color);
+        }
+
+        ssgLeaf *leaf = NULL;
+        leaf = new ssgVtxTable ( GL_TRIANGLE_FAN, vl, NULL, tl, cl );
+        leaf->setState( lightmap_state );
+        lightmaps->addKid( leaf );
+    }
+
+    return NULL;
+}
+
+ssgBranch* FGTileEntry::gen_runway_lights( ssgVertexArray *points,ssgVertexArray *normal,
+                                           ssgVertexArray *dir, int type[]) 
+{
+
+    //************** HARD CODED RUNWAY LIGHT TEXTURES BEGIN ************************    
+    GLuint texEdge, texTaxi, texCenter, texTouchdown;
+    GLuint texThreshold, texCrossbar, texUndershoot, texApproach;
+    GLuint texRabbit, texVasi, texWhite, texRed, texGreen, texYellow;
+
+    //VASI lights
+    setColor(0.0,0.0,1.0,360.0, 0, 0, 0, 0);
+    setColor2(10.0, 40.0, 1, 1, 1, 1);
+    setColor2(6.0, 40.0, 1, 0.5, 0.5, 1);
+    setColor2(5.0, 40.0, 1, 0, 0, 1);
+    glGenTextures(1, &texVasi);
+    glBindTexture(GL_TEXTURE_2D, texVasi);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *vasi_state;
+    vasi_state = new ssgSimpleState();
+    vasi_state->ref();
+    vasi_state->setTexture( texVasi );
+    vasi_state->disable( GL_LIGHTING );
+    vasi_state->enable( GL_TEXTURE_2D );
+    vasi_state->setShadeModel( GL_SMOOTH );
+
+    //EDGE
+    setColor(0.0,0.0,-1.0,180.0, 1, 1, 0.5, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texEdge);
+    glBindTexture(GL_TEXTURE_2D, texEdge);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *edge_state;
+    edge_state = new ssgSimpleState();
+    edge_state->ref();
+    edge_state->setTexture( texEdge );
+    edge_state->disable( GL_LIGHTING );
+    edge_state->enable( GL_TEXTURE_2D );
+    edge_state->setShadeModel( GL_SMOOTH );
+
+    //TOUCHDOWN
+    setColor(0.0,0.0,-1.0,180.0, 0, 1, 0, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texTouchdown);
+    glBindTexture(GL_TEXTURE_2D, texTouchdown);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *touchdown_state;
+    touchdown_state = new ssgSimpleState();
+    touchdown_state->ref();
+    touchdown_state->setTexture( texTouchdown );
+    touchdown_state->disable( GL_LIGHTING );
+    touchdown_state->enable( GL_TEXTURE_2D );
+    touchdown_state->setShadeModel( GL_SMOOTH );
+       
+    //THRESHOLD
+    setColor(0.0,0.0,-1.0,180.0, 1, 0, 0, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texThreshold);
+    glBindTexture(GL_TEXTURE_2D, texThreshold);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *threshold_state;
+    threshold_state = new ssgSimpleState();
+    threshold_state->ref();
+    threshold_state->setTexture( texThreshold );
+    threshold_state->disable( GL_LIGHTING );
+    threshold_state->enable( GL_TEXTURE_2D );
+    threshold_state->setShadeModel( GL_SMOOTH );
+
+    //TAXI
+    setColor(0.0,0.0,-1.0,180.0, 0, 0, 1, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texTaxi);
+    glBindTexture(GL_TEXTURE_2D, texTaxi);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *taxi_state;
+    taxi_state = new ssgSimpleState();
+    taxi_state->ref();
+    taxi_state->setTexture( texTaxi );
+    taxi_state->disable( GL_LIGHTING );
+    taxi_state->enable( GL_TEXTURE_2D );
+    taxi_state->setShadeModel( GL_SMOOTH );
+
+    //WHITE
+    setColor(0.0,0.0,-1.0,180.0, 1, 1, 1, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texWhite);
+    glBindTexture(GL_TEXTURE_2D, texWhite);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *white_state;
+    white_state = new ssgSimpleState();
+    white_state->ref();
+    white_state->setTexture( texWhite );
+    white_state->disable( GL_LIGHTING );
+    white_state->enable( GL_TEXTURE_2D );
+    white_state->setShadeModel( GL_SMOOTH );
+
+    //RED
+    setColor(0.0,0.0,-1.0,180.0, 1, 0, 0, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texRed);
+    glBindTexture(GL_TEXTURE_2D, texRed);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *red_state;
+    red_state = new ssgSimpleState();
+    red_state->ref();
+    red_state->setTexture( texRed );
+    red_state->disable( GL_LIGHTING );
+    red_state->enable( GL_TEXTURE_2D );
+    red_state->setShadeModel( GL_SMOOTH );
+
+    //GREEN
+    setColor(0.0,0.0,-1.0,180.0, 0, 1, 0, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texGreen);
+    glBindTexture(GL_TEXTURE_2D, texGreen);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *green_state;
+    green_state = new ssgSimpleState();
+    green_state->ref();
+    green_state->setTexture( texGreen );
+    green_state->disable( GL_LIGHTING );
+    green_state->enable( GL_TEXTURE_2D );
+    green_state->setShadeModel( GL_SMOOTH );
+
+    //YELLOW
+    setColor(0.0,0.0,-1.0,180.0, 1, 1, 0, 1);
+    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
+    glGenTextures(1, &texYellow);
+    glBindTexture(GL_TEXTURE_2D, texYellow);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, TEXRES_X, TEXRES_Y, 0, GL_RGBA, GL_UNSIGNED_BYTE, env_map);
+    ssgSimpleState *yellow_state;
+    yellow_state = new ssgSimpleState();
+    yellow_state->ref();
+    yellow_state->setTexture( texYellow );
+    yellow_state->disable( GL_LIGHTING );
+    yellow_state->enable( GL_TEXTURE_2D );
+    yellow_state->setShadeModel( GL_SMOOTH );
+//************** HARD CODED RUNWAY LIGHT TEXTURES END ************************    
+
+    ssgBranch *runway_lights = new ssgBranch;
+    sgVec3 v2,v3,inf,side;
+
+    ssgLeaf *leaf1 = NULL;
+    ssgLeaf *leaf2 = NULL;
+    ssgLeaf *leaf7 = NULL;
+    ssgLeaf *leaf8 = NULL;
+    ssgLeaf *leaf9 = NULL;
+
+    ssgVertexArray   *vlw = new ssgVertexArray( 1 );
+    ssgNormalArray   *nlw = new ssgNormalArray( 1 );
+    ssgVertexArray   *vlt = new ssgVertexArray( 1 );
+    ssgNormalArray   *nlt = new ssgNormalArray( 1 );
+    ssgVertexArray   *vlr = new ssgVertexArray( 1 );
+    ssgNormalArray   *nlr = new ssgNormalArray( 1 );
+    ssgVertexArray   *vlg = new ssgVertexArray( 1 );
+    ssgNormalArray   *nlg = new ssgNormalArray( 1 );
+    ssgVertexArray   *vly = new ssgVertexArray( 1 );
+    ssgNormalArray   *nly = new ssgNormalArray( 1 );
+
+    for ( int i = 0; i < points->getNum()-1; i=i++ ) {
+
+        // Allocate ssg structure
+        ssgVertexArray   *vl = new ssgVertexArray( 1 );
+        ssgNormalArray   *nl = new ssgNormalArray( 1 );
+        ssgVertexArray   *vl1 = new ssgVertexArray( 1 );
+        ssgNormalArray   *nl1 = new ssgNormalArray( 1 );
+
+        float *n1 = normal->get(i);
+        float *d1 = dir->get(i);
+
+        /* TEMPORARY CODE BEGIN 
+           // calculate normal using 1st, 2nd & last vertices of the group
+           sgVec3 n1;
+           sgMakeNormal (n1, points->get(0), points->get(1), points->get(points->getNum()-1) );
+           sgVec3 d1;
+           sgSubVec3(d1,points->get(1),points->get(0));
+           printf("%f %f %f\n",n1[0],n1[1],n1[2]);
+           printf("%f %f %f\n",d1[0],d1[1],d1[2]);
+           type[i] = 2;
+           ----TEMPORARY CODE END */
+
+
+        sgNormaliseVec3 ( n1 );
+        sgNormaliseVec3 ( d1 );
+        sgVec3 d2;
+        d2[0] = -d1[0];
+        d2[1] = -d1[1];
+        d2[2] = -d1[2];
+
+        sgVectorProductVec3(side,n1,d1);
+        sgScaleVec3 (inf,n1,-50);
+        sgScaleVec3 (side,5);
+
+        float *v1 = points->get(i);
+        sgAddVec3(v2,v1,inf);
+        sgAddVec3(v3,v2,side);
+
+        if ( type[i] == 1) {        //POINT,WHITE
+
+            vlw->add(v1);
+            nlw->add(d1);
+
+        } else if (type[i] == 2) {  //POINT,TAXI
+
+            vlt->add(v1);
+            nlt->add(d1);
+
+        } else if (type[i] == 3) {  //SINGLE POLYGON,VASI
+
+            vl->add(v1);
+            nl->add(d1);
+            vl->add(v3);
+            nl->add(d1);
+            vl->add(v2);
+            nl->add(d1);
+
+            ssgLeaf *leaf3 = NULL;
+            leaf3 = new ssgVtxTable ( GL_POLYGON, vl, nl, NULL, NULL );
+            leaf3->setState( vasi_state );
+            runway_lights->addKid( leaf3 );
+
+        } else if (type[i] == 4) {  //BACK-TO-BACK POLYGONS,TOUCHDOWN/THRESHOLD
+               
+            vl->add(v1);
+            nl->add(d1);
+            vl->add(v3);
+            nl->add(d1);
+            vl->add(v2);
+            nl->add(d1);
+
+            vl1->add(v3);
+            nl1->add(d2);
+            vl1->add(v1);
+            nl1->add(d2);
+            vl1->add(v2);
+            nl1->add(d2);
+
+            ssgLeaf *leaf41 = NULL;
+            leaf41 = new ssgVtxTable ( GL_POLYGON, vl, nl, NULL, NULL );
+            leaf41->setState( touchdown_state );
+            runway_lights->addKid( leaf41 );
+
+            ssgLeaf *leaf42 = NULL;
+            leaf42 = new ssgVtxTable ( GL_POLYGON, vl1, nl1, NULL, NULL );
+            leaf42->setState( threshold_state );
+            runway_lights->addKid( leaf42 );
+
+        } else if ( type[i] == 5) {        //POINT,WHITE, SEQUENCE LIGHTS (RABBIT)
+
+            vl->add(v1);
+            nl->add(d1);
+            ssgLeaf *leaf5 = NULL;
+            leaf5 = new ssgVtxTable ( GL_POINTS, vl, nl, NULL, NULL );
+            leaf5->setState( white_state );
+            lightmaps_sequence->addKid (leaf5);
+
+        } else if ( type[i] == 6) {        //POINT,WHITE, SEQUENCE LIGHTS (RABBIT)
+
+            vl->add(v1);
+            nl->add(d1);
+            ssgLeaf *leaf6 = NULL;
+            leaf6 = new ssgVtxTable ( GL_POINTS, vl, nl, NULL, NULL );
+            leaf6->setState( yellow_state );
+            ols_transform->addKid (leaf6);
+            // DO NOT DELETE THIS CODE - This is to compare a discrete FLOLS (without LOD) with analog FLOLS
+            //                 lightmaps_sequence->addKid (leaf6);
+            // DO NOT DELETE THIS CODE - This is to compare a discrete FLOLS (without LOD) with analog FLOLS
+
+        } else if (type[i] == 7) {  //POINT,RED
+
+            vlr->add(v1);
+            nlr->add(d1);
+
+        } else if (type[i] == 8) {  //POINT,GREEN
+
+            vlg->add(v1);
+            nlg->add(d1);
+
+        } else if (type[i] == 9) {  //POINT,YELLOW
+
+            vly->add(v1);
+            nly->add(d1);
+
+        }
+
+    }
+
+    leaf1 = new ssgVtxTable ( GL_POINTS, vlw, nlw, NULL, NULL );
+    leaf1->setState( white_state );
+    runway_lights->addKid( leaf1 );
+
+    leaf2 = new ssgVtxTable ( GL_POINTS, vlt, nlt, NULL, NULL );
+    leaf2->setState( taxi_state );
+    runway_lights->addKid( leaf2 );
+       
+    leaf7 = new ssgVtxTable ( GL_POINTS, vlr, nlr, NULL, NULL );
+    leaf7->setState( red_state );
+    runway_lights->addKid( leaf7 );
+
+    leaf8 = new ssgVtxTable ( GL_POINTS, vlg, nlg, NULL, NULL );
+    leaf8->setState( green_state );
+    // DO NOT DELETE THIS CODE - This is to compare a discrete FLOLS (without LOD) with analog FLOLS
+    ols_transform->ref();
+    lightmaps_sequence->addKid (ols_transform);
+    // DO NOT DELETE THIS CODE - This is to compare a discrete FLOLS (without LOD) with analog FLOLS
+    lightmaps_sequence->addKid (leaf8);
+
+    leaf9 = new ssgVtxTable ( GL_POINTS, vly, nly, NULL, NULL );
+    leaf9->setState( yellow_state );
+    runway_lights->addKid( leaf9 );
+
+    lightmaps_sequence->select(0xFFFFFF);      
+    return runway_lights;
+}
+// ADA
+       
+#ifdef WISH_PLIB_WAS_THREADED // but it isn't
+
+// Schedule tile to be freed/removed
+void FGTileEntry::sched_removal() {
+    global_tile_mgr.ready_to_delete( this );
+}
+
+#endif
+
 
 // Clean up the memory used by this tile and delete the arrays used by
 // ssg as well as the whole ssg branch
@@ -134,46 +720,23 @@ void FGTileEntry::free_tile() {
     }
     index_ptrs.clear();
 
-    // delete the terrain branch
-    int pcount = terra_transform->getNumParents();
-    if ( pcount > 0 ) {
-       // find the first parent (should only be one)
-       ssgBranch *parent = terra_transform->getParent( 0 ) ;
-       if( parent ) {
-           // my_remove_branch( select_ptr );
-           parent->removeKid( terra_transform );
-           terra_transform = NULL;
-       } else {
-           SG_LOG( SG_TERRAIN, SG_ALERT,
-                   "parent pointer is NULL!  Dying" );
-           exit(-1);
-       }
-    } else {
-       SG_LOG( SG_TERRAIN, SG_ALERT,
-               "Parent count is zero for an ssg tile!  Dying" );
-       exit(-1);
-    }
+    // delete the terrain branch (this should already have been
+    // disconnected from the scene graph)
+    ssgDeRefDelete( terra_transform );
 
     if ( lights_transform ) {
-       // delete the terrain lighting branch
-       pcount = lights_transform->getNumParents();
-       if ( pcount > 0 ) {
-           // find the first parent (should only be one)
-           ssgBranch *parent = lights_transform->getParent( 0 ) ;
-           if( parent ) {
-               parent->removeKid( lights_transform );
-               lights_transform = NULL;
-           } else {
-               SG_LOG( SG_TERRAIN, SG_ALERT,
-                       "parent pointer is NULL!  Dying" );
-               exit(-1);
-           }
-       } else {
-           SG_LOG( SG_TERRAIN, SG_ALERT,
-                   "Parent count is zero for an ssg light tile!  Dying" );
-           exit(-1);
-       }
+       // delete the terrain lighting branch (this should already have been
+    // disconnected from the scene graph)
+       ssgDeRefDelete( lights_transform );
+    }
+
+    // ADA
+    if ( lightmaps_transform ) {
+       // delete the terrain lighting branch (this should already have been
+        // disconnected from the scene graph)
+       ssgDeRefDelete( lightmaps_transform );
     }
+    // ADA
 }
 
 
@@ -215,7 +778,7 @@ void FGTileEntry::prep_ssg_node( const Point3D& p, float vis) {
        double agl;
        if ( current_aircraft.fdm_state ) {
            agl = current_aircraft.fdm_state->get_Altitude() * SG_FEET_TO_METER
-               - scenery.cur_elev;
+               - scenery.get_cur_elev();
        } else {
            agl = 0.0;
        }
@@ -247,6 +810,91 @@ void FGTileEntry::prep_ssg_node( const Point3D& p, float vis) {
            lights_brightness->select(0x00);
        }
     }
+
+    // ADA
+    // Transform & Render runway lights - 23 Mar 2001
+    sgSetVec3( sgTrans, offset.x(), offset.y(), offset.z() );
+    if ( lightmaps_transform ) {
+        static unsigned int selectnode = 0;
+       // Run-time extension check.
+       if (!glutExtensionSupported("GL_EXT_point_parameters")) {
+            //use lightmaps on billboarded polygons
+        } else {
+            // using GL_EXT_point_parameters
+               
+            // This part is same as ground-lights code above by Curt
+            sgVec3 up1;
+            sgCopyVec3( up1, globals->get_current_view()->get_world_up() );
+            
+            double agl1;
+            if ( current_aircraft.fdm_state ) {
+                agl1 = current_aircraft.fdm_state->get_Altitude() * SG_FEET_TO_METER
+                    - scenery.get_cur_elev();
+            } else {
+                agl1 = 0.0;
+            }
+
+            // sgTrans just happens to be the
+            // vector from scenery center to the center of this tile which
+            // is what we want to calculate the distance of
+            sgVec3 to1;
+            sgCopyVec3( to1, sgTrans );
+            double dist1 = sgLengthVec3( to1 );
+
+            if ( general.get_glDepthBits() > 16 ) {
+                sgScaleVec3( up1, 0.0 + agl1 / 2000.0 + dist1 / 10000 );
+            } else {
+                sgScaleVec3( up1, 0.0 + agl1 / 20.0 + dist1 / 5000 );
+            }
+            sgAddVec3( sgTrans, up1 );
+            lightmaps_transform->setTransform( sgTrans );
+
+            float sun_angle1 = cur_light_params.sun_angle * SGD_RADIANS_TO_DEGREES;
+            if ( (sun_angle1 > 89) ) {
+                lightmaps_brightness->select(0x01);
+                selectnode *=2;
+                selectnode = selectnode | 0x000001;
+                if (selectnode > 0xFFFFFF) selectnode = 1;
+                lightmaps_sequence->select(selectnode);
+            } else {
+                lightmaps_brightness->select(0x00);
+                lightmaps_sequence->select(0x000000);
+            } 
+       } // end of GL_EXT_point_parameters section
+
+    } // end of runway lights section
+    // ADA
+
+}
+
+
+// Set up lights rendering call backs
+static int fgLightsPredraw( ssgEntity *e ) {
+#if 0
+#ifdef GL_EXT_point_parameters
+    if (glutExtensionSupported("GL_EXT_point_parameters")) {
+       static float quadratic[3] = {1.0, 0.01, 0.0001};
+       glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT, quadratic);
+       glPointParameterfEXT(GL_POINT_SIZE_MIN_EXT, 1.0); 
+       glPointSize(4.0);
+    }
+#endif
+#endif
+    return true;
+}
+
+static int fgLightsPostdraw( ssgEntity *e ) {
+#if 0
+#ifdef GL_EXT_point_parameters
+    if (glutExtensionSupported("GL_EXT_point_parameters")) {
+       static float default_attenuation[3] = {1.0, 0.0, 0.0};
+       glPointParameterfvEXT(GL_DISTANCE_ATTENUATION_EXT,
+                             default_attenuation);
+       glPointSize(1.0);
+    }
+#endif
+#endif
+    return true;
 }
 
 
@@ -302,6 +950,8 @@ ssgLeaf* FGTileEntry::gen_lights( ssgVertexArray *lights, int inc, float bright
     // assign state
     FGNewMat *newmat = material_lib.find( "LIGHTS" );
     leaf->setState( newmat->get_state() );
+    leaf->setCallback( SSG_CALLBACK_PREDRAW, fgLightsPredraw );
+    leaf->setCallback( SSG_CALLBACK_POSTDRAW, fgLightsPostdraw );
 
     return leaf;
 }
@@ -331,35 +981,39 @@ FGTileEntry::obj_load( const std::string& path,
 void
 FGTileEntry::load( const SGPath& base, bool is_base )
 {
+    cout << "load() base = " << base.str() << endl;
+
+    // Generate names for later use
     string index_str = tile_bucket.gen_index_str();
 
     SGPath tile_path = base;
-    // Generate name of file to load.
     tile_path.append( tile_bucket.gen_base_path() );
+
     SGPath basename = tile_path;
     basename.append( index_str );
-    string path = basename.str();
+    // string path = basename.str();
 
-    SG_LOG( SG_TERRAIN, SG_INFO, "Loading tile " << path );
+    SG_LOG( SG_TERRAIN, SG_INFO, "Loading tile " << basename.str() );
 
-    // fgObjLoad will generate ground lighting for us ...
-    ssgVertexArray *light_pts = new ssgVertexArray( 100 );
+#define FG_MAX_LIGHTS 1000
 
-    ssgBranch* new_tile = obj_load( path, light_pts, is_base );
-    if ( new_tile != NULL ) {
-       terra_range->addKid( new_tile );
-    }
+    // obj_load() will generate ground lighting for us ...
+    ssgVertexArray *light_pts = new ssgVertexArray( 100 );
 
-    // load custom objects
-    SG_LOG( SG_TERRAIN, SG_DEBUG, "Checking for custom objects ..." );
+    // ADA
+    ssgVertexArray *lights_rway = new ssgVertexArray( 100 );
+    ssgVertexArray *lights_dir = new ssgVertexArray( 100 );
+    ssgVertexArray *lights_normal = new ssgVertexArray( 100 );
+    int lights_type[FG_MAX_LIGHTS];
+    // ADA
 
-    SGPath index_path = tile_path;
-    index_path.append( index_str );
-    index_path.concat( ".ind" );
+    ssgBranch* new_tile = new ssgBranch;
 
-    SG_LOG( SG_TERRAIN, SG_DEBUG, "Looking in " << index_path.str() );
+    // Check for master .stg (scene terra gear) file
+    SGPath stg_name = basename;
+    stg_name.concat( ".stg" );
 
-    sg_gzifstream in( index_path.str() );
+    sg_gzifstream in( stg_name.str() );
 
     if ( in.is_open() ) {
        string token, name;
@@ -367,7 +1021,21 @@ FGTileEntry::load( const SGPath& base, bool is_base )
        while ( ! in.eof() ) {
            in >> token;
 
-           if ( token == "OBJECT" ) {
+           if ( token == "OBJECT_BASE" ) {
+               in >> name >> ::skipws;
+               SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                       << " name = " << name );
+
+               SGPath custom_path = tile_path;
+               custom_path.append( name );
+
+               ssgBranch *custom_obj
+                   = obj_load( custom_path.str(), light_pts, true );
+
+               if ( custom_obj != NULL ) {
+                   new_tile -> addKid( custom_obj );
+               }
+           } else if ( token == "OBJECT" ) {
                in >> name >> ::skipws;
                SG_LOG( SG_TERRAIN, SG_DEBUG, "token = " << token
                        << " name = " << name );
@@ -376,7 +1044,7 @@ FGTileEntry::load( const SGPath& base, bool is_base )
                custom_path.append( name );
                ssgBranch *custom_obj
                    = obj_load( custom_path.str(), NULL, false );
-               if ( (new_tile != NULL) && (custom_obj != NULL) ) {
+               if ( custom_obj != NULL ) {
                    new_tile -> addKid( custom_obj );
                }
            } else if ( token == "OBJECT_STATIC" ) {
@@ -389,57 +1057,243 @@ FGTileEntry::load( const SGPath& base, bool is_base )
                        << " elevation = " << elev
                        << " heading = " << hdg );
 
+               // object loading is deferred to main render thread,
+               // but lets figure out the paths right now.
+               SGPath custom_path = tile_path;
+               custom_path.append( name );
+
+               sgCoord obj_pos;
+               WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+               
+               ssgTransform *obj_trans = new ssgTransform;
+               obj_trans->setTransform( &obj_pos );
+
+               // wire as much of the scene graph together as we can
+               new_tile->addKid( obj_trans );
+
+               // bump up the pending models count
+               pending_models++;
+
+               // push an entry onto the model load queue
+               FGDeferredModel *dm
+                   = new FGDeferredModel( custom_path.str(), tile_path.str(),
+                                          this, obj_trans );
+               FGTileMgr::model_ready( dm );
+           } else if ( token == "OBJECT_TAXI_SIGN" ) {
+               // load object info
+               double lon, lat, elev, hdg;
+               in >> name >> lon >> lat >> elev >> hdg >> ::skipws;
+               SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                       << " name = " << name 
+                       << " pos = " << lon << ", " << lat
+                       << " elevation = " << elev
+                       << " heading = " << hdg );
+
                // load the object itself
                SGPath custom_path = tile_path;
-                ssgTexturePath( (char *)custom_path.c_str() );
                custom_path.append( name );
-               ssgEntity *obj_model = ssgLoad( (char *)custom_path.c_str() );
-
-               // setup transforms
-               Point3D geod( lon * SGD_DEGREES_TO_RADIANS,
-                             lat *  SGD_DEGREES_TO_RADIANS,
-                             elev );
-               Point3D world_pos = sgGeodToCart( geod );
-               Point3D offset = world_pos - center;
-               sgMat4 POS;
-               sgMakeTransMat4( POS, offset.x(), offset.y(), offset.z() );
-
-               sgVec3 obj_rt, obj_up;
-               sgSetVec3( obj_rt, 0.0, 1.0, 0.0); // Y axis
-               sgSetVec3( obj_up, 0.0, 0.0, 1.0); // Z axis
-
-               sgMat4 ROT_lon, ROT_lat, ROT_hdg;
-               sgMakeRotMat4( ROT_lon, lon, obj_up );
-               sgMakeRotMat4( ROT_lat, 90 - lat, obj_rt );
-               sgMakeRotMat4( ROT_hdg, hdg, obj_up );
-       
-               sgMat4 TUX;
-               sgCopyMat4( TUX, ROT_hdg );
-               sgPostMultMat4( TUX, ROT_lat );
-               sgPostMultMat4( TUX, ROT_lon );
-               sgPostMultMat4( TUX, POS );
 
                sgCoord obj_pos;
-               sgSetCoord( &obj_pos, TUX );
+               WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+
+               ssgTransform *obj_trans = new ssgTransform;
+               obj_trans->setTransform( &obj_pos );
+
+               ssgBranch *custom_obj
+                   = gen_taxi_sign( custom_path.str(), name );
+
+               // wire the pieces together
+               if ( custom_obj != NULL ) {
+                   obj_trans -> addKid( custom_obj );
+               }
+               new_tile->addKid( obj_trans );
+           } else if ( token == "OBJECT_RUNWAY_SIGN" ) {
+               // load object info
+               double lon, lat, elev, hdg;
+               in >> name >> lon >> lat >> elev >> hdg >> ::skipws;
+               SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                       << " name = " << name 
+                       << " pos = " << lon << ", " << lat
+                       << " elevation = " << elev
+                       << " heading = " << hdg );
+
+               // load the object itself
+               SGPath custom_path = tile_path;
+               custom_path.append( name );
+
+               sgCoord obj_pos;
+               WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+
                ssgTransform *obj_trans = new ssgTransform;
                obj_trans->setTransform( &obj_pos );
 
-               // wire the scene graph together
-               obj_trans->addKid( obj_model );
+               ssgBranch *custom_obj
+                   = gen_runway_sign( custom_path.str(), name );
+
+               // wire the pieces together
+               if ( custom_obj != NULL ) {
+                   obj_trans -> addKid( custom_obj );
+               }
                new_tile->addKid( obj_trans );
+           } else if ( token == "RWY_LIGHTS" ) {
+               double lon, lat, hdg, len, width;
+               string common, end1, end2;
+               in >> lon >> lat >> hdg >> len >> width
+                  >> common >> end1 >> end2;
+               SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                       << " pos = " << lon << ", " << lat
+                       << " hdg = " << hdg
+                       << " size = " << len << ", " << width
+                       << " codes = " << common << " "
+                       << end1 << " " << end2 );
            } else {
                SG_LOG( SG_TERRAIN, SG_ALERT,
                        "Unknown token " << token << " in "
-                       << index_path.str() );
+                       << stg_name.str() );
                in >> ::skipws;
            }
        }
+    } else {
+        // no .stg file so this must be old scenery
+
+        new_tile = obj_load( basename.str(), light_pts, true );
+
+        // load custom objects
+        SG_LOG( SG_TERRAIN, SG_DEBUG, "Checking for custom objects ..." );
+
+        SGPath index_path = tile_path;
+        index_path.append( index_str );
+        index_path.concat( ".ind" );
+
+        SG_LOG( SG_TERRAIN, SG_DEBUG, "Looking in " << index_path.str() );
+
+        sg_gzifstream in( index_path.str() );
+
+        if ( in.is_open() ) {
+            string token, name;
+
+            while ( ! in.eof() ) {
+                in >> token;
+
+                if ( token == "OBJECT" ) {
+                    in >> name >> ::skipws;
+                    SG_LOG( SG_TERRAIN, SG_DEBUG, "token = " << token
+                            << " name = " << name );
+
+                    SGPath custom_path = tile_path;
+                    custom_path.append( name );
+                    ssgBranch *custom_obj
+                        = obj_load( custom_path.str(), NULL, false );
+                    if ( (new_tile != NULL) && (custom_obj != NULL) ) {
+                        new_tile -> addKid( custom_obj );
+                    }
+                } else if ( token == "OBJECT_STATIC" ) {
+                    // load object info
+                    double lon, lat, elev, hdg;
+                    in >> name >> lon >> lat >> elev >> hdg >> ::skipws;
+                    SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                            << " name = " << name 
+                            << " pos = " << lon << ", " << lat
+                            << " elevation = " << elev
+                            << " heading = " << hdg );
+
+                    // object loading is deferred to main render thread,
+                    // but lets figure out the paths right now.
+                    SGPath custom_path = tile_path;
+                    custom_path.append( name );
+
+                    sgCoord obj_pos;
+                    WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+               
+                    ssgTransform *obj_trans = new ssgTransform;
+                    obj_trans->setTransform( &obj_pos );
+
+                    // wire as much of the scene graph together as we can
+                    new_tile->addKid( obj_trans );
+
+                    // bump up the pending models count
+                    pending_models++;
+
+                    // push an entry onto the model load queue
+                    FGDeferredModel *dm
+                        = new FGDeferredModel( custom_path.str(),
+                                               tile_path.str(),
+                                               this, obj_trans );
+                    FGTileMgr::model_ready( dm );
+                } else if ( token == "OBJECT_TAXI_SIGN" ) {
+                    // load object info
+                    double lon, lat, elev, hdg;
+                    in >> name >> lon >> lat >> elev >> hdg >> ::skipws;
+                    SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                            << " name = " << name 
+                            << " pos = " << lon << ", " << lat
+                            << " elevation = " << elev
+                            << " heading = " << hdg );
+
+                    // load the object itself
+                    SGPath custom_path = tile_path;
+                    custom_path.append( name );
+
+                    sgCoord obj_pos;
+                    WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+
+                    ssgTransform *obj_trans = new ssgTransform;
+                    obj_trans->setTransform( &obj_pos );
+
+                    ssgBranch *custom_obj
+                        = gen_taxi_sign( custom_path.str(), name );
+
+                    // wire the pieces together
+                    if ( (new_tile != NULL) && (custom_obj != NULL) ) {
+                        obj_trans -> addKid( custom_obj );
+                    }
+                    new_tile->addKid( obj_trans );
+                } else if ( token == "OBJECT_RUNWAY_SIGN" ) {
+                    // load object info
+                    double lon, lat, elev, hdg;
+                    in >> name >> lon >> lat >> elev >> hdg >> ::skipws;
+                    SG_LOG( SG_TERRAIN, SG_INFO, "token = " << token
+                            << " name = " << name 
+                            << " pos = " << lon << ", " << lat
+                            << " elevation = " << elev
+                            << " heading = " << hdg );
+
+                    // load the object itself
+                    SGPath custom_path = tile_path;
+                    custom_path.append( name );
+
+                    sgCoord obj_pos;
+                    WorldCoordinate( &obj_pos, center, lat, lon, elev, hdg );
+
+                    ssgTransform *obj_trans = new ssgTransform;
+                    obj_trans->setTransform( &obj_pos );
+
+                    ssgBranch *custom_obj
+                        = gen_runway_sign( custom_path.str(), name );
+
+                    // wire the pieces together
+                    if ( (new_tile != NULL) && (custom_obj != NULL) ) {
+                        obj_trans -> addKid( custom_obj );
+                    }
+                    new_tile->addKid( obj_trans );
+                } else {
+                    SG_LOG( SG_TERRAIN, SG_ALERT,
+                            "Unknown token " << token << " in "
+                            << index_path.str() );
+                    in >> ::skipws;
+                }
+           }
+       }
+    }
+
+    if ( new_tile != NULL ) {
+        terra_range->addKid( new_tile );
     }
 
     terra_transform->addKid( terra_range );
 
     // calculate initial tile offset
-    SetOffset( scenery.center );
+    SetOffset( scenery.get_center() );
     sgCoord sgcoord;
     sgSetCoord( &sgcoord,
                offset.x(), offset.y(), offset.z(),
@@ -472,15 +1326,149 @@ FGTileEntry::load( const SGPath& base, bool is_base )
         // ground->addKid( lights_transform );
     }
     /* end of ground light section */
+
+    // ADA
+    // Create runway lights - 23 Mar 2001
+    lightmaps_transform = NULL;
+    lightmaps_sequence = NULL;
+    ols_transform = NULL;
+    //    lightmaps_range = NULL;
+
+    if ( lights_rway->getNum() ) {
+       SG_LOG( SG_TERRAIN, SG_DEBUG, "generating airport lights" );
+       lightmaps_transform = new ssgTransform;
+        //     lightmaps_range = new ssgRangeSelector;
+       lightmaps_brightness = new ssgSelector;
+       lightmaps_sequence = new ssgSelector;
+       ols_transform = new ssgTransform;
+        ssgBranch *lightmaps_branch;
+
+        // call function to generate the runway lights
+        lightmaps_branch = gen_runway_lights( lights_rway, 
+                                              lights_normal, lights_dir, lights_type);
+       lightmaps_brightness->addKid( lightmaps_branch );
+       
+       // build the runway lights' scene
+        //    lightmaps_range->addKid( lightmaps_brightness ); //dont know why this doesnt work !!
+        //     lightmaps_transform->addKid( lightmaps_range );    //dont know why this doesnt work !!
+       lightmaps_transform->addKid( lightmaps_brightness );
+        lightmaps_sequence->setTraversalMaskBits( SSGTRAV_HOT );
+       lightmaps_transform->addKid( lightmaps_sequence );
+       lightmaps_transform->setTransform( &sgcoord );
+    }
+    // ADA
 }
 
 
 void
 FGTileEntry::add_ssg_nodes( ssgBranch* terrain, ssgBranch* ground )
 {
+    // bump up the ref count so we can remove this later without
+    // having ssg try to free the memory.
+    terra_transform->ref();
     terrain->addKid( terra_transform );
-    if (lights_transform != 0)
+
+    SG_LOG( SG_TERRAIN, SG_DEBUG,
+            "connected a tile into scene graph.  terra_transform = "
+            << terra_transform );
+    SG_LOG( SG_TERRAIN, SG_DEBUG, "num parents now = "
+            << terra_transform->getNumParents() );
+
+    if ( lights_transform != 0 ) {
+       // bump up the ref count so we can remove this later without
+       // having ssg try to free the memory.
+       lights_transform->ref();
        ground->addKid( lights_transform );
+    }
+
+    // ADA
+    if ( lightmaps_transform != 0 ) {
+       // bump up the ref count so we can remove this later without
+       // having ssg try to free the memory.
+       lightmaps_transform->ref();
+       ground->addKid( lightmaps_transform );
+    }
+    // ADA
 
     loaded = true;
 }
+
+
+void
+FGTileEntry::disconnect_ssg_nodes()
+{
+    SG_LOG( SG_TERRAIN, SG_INFO, "disconnecting ssg nodes" );
+
+    if ( ! loaded ) {
+        SG_LOG( SG_TERRAIN, SG_INFO, "removing a not-fully loaded tile!" );
+    } else {
+        SG_LOG( SG_TERRAIN, SG_INFO, "removing a fully loaded tile!  terra_transform = " << terra_transform );
+    }
+        
+    // find the terrain branch parent
+    int pcount = terra_transform->getNumParents();
+    if ( pcount > 0 ) {
+       // find the first parent (should only be one)
+       ssgBranch *parent = terra_transform->getParent( 0 ) ;
+       if( parent ) {
+           // disconnect the tile (we previously ref()'d it so it
+           // won't get freed now)
+           parent->removeKid( terra_transform );
+       } else {
+           SG_LOG( SG_TERRAIN, SG_ALERT,
+                   "parent pointer is NULL!  Dying" );
+           exit(-1);
+       }
+    } else {
+       SG_LOG( SG_TERRAIN, SG_ALERT,
+               "Parent count is zero for an ssg tile!  Dying" );
+       exit(-1);
+    }
+
+    // find the terrain lighting branch
+    if ( lights_transform ) {
+       pcount = lights_transform->getNumParents();
+       if ( pcount > 0 ) {
+           // find the first parent (should only be one)
+           ssgBranch *parent = lights_transform->getParent( 0 ) ;
+           if( parent ) {
+               // disconnect the light branch (we previously ref()'d
+               // it so it won't get freed now)
+               parent->removeKid( lights_transform );
+           } else {
+               SG_LOG( SG_TERRAIN, SG_ALERT,
+                       "parent pointer is NULL!  Dying" );
+               exit(-1);
+           }
+       } else {
+           SG_LOG( SG_TERRAIN, SG_ALERT,
+                   "Parent count is zero for an ssg light tile!  Dying" );
+           exit(-1);
+       }
+    }
+
+    // ADA
+    //runway lights - 23 Mar 2001
+    // Delete runway lights and free memory
+    if ( lightmaps_transform ) {
+       // delete the runway lighting branch
+       pcount = lightmaps_transform->getNumParents();
+       if ( pcount > 0 ) {
+           // find the first parent (should only be one)
+           ssgBranch *parent = lightmaps_transform->getParent( 0 ) ;
+           if( parent ) {
+               parent->removeKid( lightmaps_transform );
+               lightmaps_transform = NULL;
+           } else {
+               SG_LOG( SG_TERRAIN, SG_ALERT,
+                       "lightmaps parent pointer is NULL!  Dying" );
+               exit(-1);
+           }
+       } else {
+           SG_LOG( SG_TERRAIN, SG_ALERT,
+                   "Parent count is zero for an ssg lightmap tile!  Dying" );
+           exit(-1);
+       }
+    }
+    // ADA
+}