]> git.mxchange.org Git - flightgear.git/blobdiff - src/Objects/obj.cxx
Moved some of the low level scene graph construction code over to simgear.
[flightgear.git] / src / Objects / obj.cxx
index a3ca51c92e955083b726c8124e4938b4b70ebc24..09fab77b734bb91132e79282a19d74aaf160eddf 100644 (file)
@@ -1,4 +1,5 @@
-// obj.cxx -- routines to handle "sorta" WaveFront .obj format files.
+// obj.cxx -- routines to handle loading scenery and building the plib
+//            scene graph.
 //
 // Written by Curtis Olson, started October 1997.
 //
 #include <string.h>
 
 #include <simgear/compiler.h>
+#include <simgear/sg_inlines.h>
 #include <simgear/io/sg_binobj.hxx>
 
 #include STL_STRING
-#include <map>                 // STL
-#include <vector>              // STL
-#include <ctype.h>             // isdigit()
+#include <map>                  // STL
+#include <vector>               // STL
+#include <ctype.h>              // isdigit()
 
 #include <simgear/constants.h>
 #include <simgear/debug/logstream.hxx>
 #include <simgear/math/polar3d.hxx>
 #include <simgear/math/sg_geodesy.hxx>
 #include <simgear/math/sg_random.h>
+#include <simgear/math/vector.hxx>
 #include <simgear/misc/sgstream.hxx>
 #include <simgear/misc/stopwatch.hxx>
 #include <simgear/misc/texcoord.hxx>
+#include <simgear/scene/material/mat.hxx>
+#include <simgear/scene/material/matlib.hxx>
+#include <simgear/scene/tgdb/leaf.hxx>
+#include <simgear/scene/tgdb/pt_lights.hxx>
 
 #include <Main/globals.hxx>
 #include <Main/fg_props.hxx>
 #include <Time/light.hxx>
-#include <Scenery/tileentry.hxx>
 
-#include "newmat.hxx"
-#include "matlib.hxx"
+
 #include "obj.hxx"
 
 SG_USING_STD(string);
@@ -68,85 +73,43 @@ typedef int_list::iterator int_list_iterator;
 typedef int_list::const_iterator int_point_list_iterator;
 
 
-static double normals[FG_MAX_NODES][3];
-static double tex_coords[FG_MAX_NODES*3][3];
-
+// not used because plib branches don't honor call backs.
 static int
-runway_lights_predraw (ssgEntity * e)
+runway_lights_pretrav (ssgEntity * e, int mask)
 {
-                               // Turn on lights only at night
+                                // Turn on lights only at night
     float sun_angle = cur_light_params.sun_angle * SGD_RADIANS_TO_DEGREES;
-    return int(sun_angle > 90.0);
-}
-
-
-#define FG_TEX_CONSTANT 69.0
-
-// Calculate texture coordinates for a given point.
-static Point3D local_calc_tex_coords(const Point3D& node, const Point3D& ref) {
-    Point3D cp;
-    Point3D pp;
-    // double tmplon, tmplat;
-
-    // cout << "-> " << node[0] << " " << node[1] << " " << node[2] << endl;
-    // cout << "-> " << ref.x() << " " << ref.y() << " " << ref.z() << endl;
-
-    cp = Point3D( node[0] + ref.x(),
-                 node[1] + ref.y(),
-                 node[2] + ref.z() );
-
-    pp = sgCartToPolar3d(cp);
-
-    // tmplon = pp.lon() * SGD_RADIANS_TO_DEGREES;
-    // tmplat = pp.lat() * SGD_RADIANS_TO_DEGREES;
-    // cout << tmplon << " " << tmplat << endl;
-
-    pp.setx( fmod(SGD_RADIANS_TO_DEGREES * FG_TEX_CONSTANT * pp.x(), 11.0) );
-    pp.sety( fmod(SGD_RADIANS_TO_DEGREES * FG_TEX_CONSTANT * pp.y(), 11.0) );
-
-    if ( pp.x() < 0.0 ) {
-       pp.setx( pp.x() + 11.0 );
-    }
-
-    if ( pp.y() < 0.0 ) {
-       pp.sety( pp.y() + 11.0 );
-    }
-
-    // cout << pp << endl;
-
-    return(pp);
+    return int((sun_angle > 85.0) ||
+               (fgGetDouble("/environment/visibility-m") < 5000.0));
 }
 
 
 // Generate an ocean tile
 bool fgGenTile( const string& path, SGBucket b,
-                     Point3D *center,
-                     double *bounding_radius,
-                     ssgBranch* geometry )
+                Point3D *center, double *bounding_radius,
+                SGMaterialLib *matlib, ssgBranch* geometry )
 {
-    FGNewMat *newmat;
-
     ssgSimpleState *state = NULL;
 
-    geometry -> setName ( (char *)path.c_str() ) ;
+    geometry->setName( (char *)path.c_str() );
 
     double tex_width = 1000.0;
     // double tex_height;
 
     // find Ocean material in the properties list
-    newmat = material_lib.find( "Ocean" );
-    if ( newmat != NULL ) {
-       // set the texture width and height values for this
-       // material
-       tex_width = newmat->get_xsize();
-       // tex_height = newmat->get_ysize();
-       
-       // set ssgState
-       state = newmat->get_state();
+    SGMaterial *mat = matlib->find( "Ocean" );
+    if ( mat != NULL ) {
+        // set the texture width and height values for this
+        // material
+        tex_width = mat->get_xsize();
+        // tex_height = newmat->get_ysize();
+        
+        // set ssgState
+        state = mat->get_state();
     } else {
-       SG_LOG( SG_TERRAIN, SG_ALERT, 
-               "Ack! unknown usemtl name = " << "Ocean" 
-               << " in " << path );
+        SG_LOG( SG_TERRAIN, SG_ALERT, 
+                "Ack! unknown usemtl name = " << "Ocean" 
+                << " in " << path );
     }
 
     // Calculate center point
@@ -156,8 +119,8 @@ bool fgGenTile( const string& path, SGBucket b,
     double width = b.get_width();
 
     *center = sgGeodToCart( Point3D(clon*SGD_DEGREES_TO_RADIANS,
-                                   clat*SGD_DEGREES_TO_RADIANS,
-                                   0.0) );
+                                    clat*SGD_DEGREES_TO_RADIANS,
+                                    0.0) );
     // cout << "center = " << center << endl;;
     
     // Caculate corner vertices
@@ -177,9 +140,9 @@ bool fgGenTile( const string& path, SGBucket b,
 
     Point3D cart[4], rel[4];
     for ( i = 0; i < 4; ++i ) {
-       cart[i] = sgGeodToCart(rad[i]);
-       rel[i] = cart[i] - *center;
-       // cout << "corner " << i << " = " << cart[i] << endl;
+        cart[i] = sgGeodToCart(rad[i]);
+        rel[i] = cart[i] - *center;
+        // cout << "corner " << i << " = " << cart[i] << endl;
     }
 
     // Calculate bounding radius
@@ -189,22 +152,24 @@ bool fgGenTile( const string& path, SGBucket b,
     // Calculate normals
     Point3D normals[4];
     for ( i = 0; i < 4; ++i ) {
-       double length = cart[i].distance3D( Point3D(0.0) );
-       normals[i] = cart[i] / length;
-       // cout << "normal = " << normals[i] << endl;
+        double length = cart[i].distance3D( Point3D(0.0) );
+        normals[i] = cart[i] / length;
+        // cout << "normal = " << normals[i] << endl;
     }
 
     // Calculate texture coordinates
     point_list geod_nodes;
     geod_nodes.clear();
+    geod_nodes.reserve(4);
     int_list rectangle;
     rectangle.clear();
+    rectangle.reserve(4);
     for ( i = 0; i < 4; ++i ) {
-       geod_nodes.push_back( geod[i] );
-       rectangle.push_back( i );
+        geod_nodes.push_back( geod[i] );
+        rectangle.push_back( i );
     }
     point_list texs = calc_tex_coords( b, geod_nodes, rectangle, 
-                                      1000.0 / tex_width );
+                                       1000.0 / tex_width );
 
     // Allocate ssg structure
     ssgVertexArray   *vl = new ssgVertexArray( 4 );
@@ -226,20 +191,20 @@ bool fgGenTile( const string& path, SGBucket b,
     sgVec2 tmp2;
     sgVec3 tmp3;
     for ( i = 0; i < 4; ++i ) {
-       sgSetVec3( tmp3, 
-                  rel[i].x(), rel[i].y(), rel[i].z() );
-       vl->add( tmp3 );
+        sgSetVec3( tmp3, 
+                   rel[i].x(), rel[i].y(), rel[i].z() );
+        vl->add( tmp3 );
 
-       sgSetVec3( tmp3, 
-                  normals[i].x(), normals[i].y(), normals[i].z() );
-       nl->add( tmp3 );
+        sgSetVec3( tmp3, 
+                   normals[i].x(), normals[i].y(), normals[i].z() );
+        nl->add( tmp3 );
 
-       sgSetVec2( tmp2, texs[i].x(), texs[i].y());
-       tl->add( tmp2 );
+        sgSetVec2( tmp2, texs[i].x(), texs[i].y());
+        tl->add( tmp2 );
     }
     
     ssgLeaf *leaf = 
-       new ssgVtxTable ( GL_TRIANGLE_FAN, vl, nl, tl, cl );
+        new ssgVtxTable ( GL_TRIANGLE_FAN, vl, nl, tl, cl );
 
     leaf->setState( state );
 
@@ -250,972 +215,623 @@ bool fgGenTile( const string& path, SGBucket b,
 
 
 static void random_pt_inside_tri( float *res,
-                                 float *n1, float *n2, float *n3 )
+                                  float *n1, float *n2, float *n3 )
 {
-    sgVec3 p1, p2, p3;
-
     double a = sg_random();
     double b = sg_random();
     if ( a + b > 1.0 ) {
-       a = 1.0 - a;
-       b = 1.0 - b;
+        a = 1.0 - a;
+        b = 1.0 - b;
     }
     double c = 1 - a - b;
 
-    sgScaleVec3( p1, n1, a );
-    sgScaleVec3( p2, n2, b );
-    sgScaleVec3( p3, n3, c );
-
-    sgAddVec3( res, p1, p2 );
-    sgAddVec3( res, p3 );
+    res[0] = n1[0]*a + n2[0]*b + n3[0]*c;
+    res[1] = n1[1]*a + n2[1]*b + n3[1]*c;
+    res[2] = n1[2]*a + n2[2]*b + n3[2]*c;
 }
 
 
-static void gen_random_surface_points( ssgLeaf *leaf, ssgVertexArray *lights,
-                                      double factor ) {
-    int num = leaf->getNumTriangles();
-    if ( num > 0 ) {
-       short int n1, n2, n3;
-       float *p1, *p2, *p3;
-       sgVec3 result;
-
-       // generate a repeatable random seed
-       p1 = leaf->getVertex( 0 );
-       unsigned int seed = (unsigned int)p1[0];
-       sg_srandom( seed );
-
-       for ( int i = 0; i < num; ++i ) {
-           leaf->getTriangle( i, &n1, &n2, &n3 );
-           p1 = leaf->getVertex(n1);
-           p2 = leaf->getVertex(n2);
-           p3 = leaf->getVertex(n3);
-           double area = sgTriArea( p1, p2, p3 );
-           double num = area / factor;
-
-           // generate a light point for each unit of area
-           while ( num > 1.0 ) {
-               random_pt_inside_tri( result, p1, p2, p3 );
-               lights->add( result );
-               num -= 1.0;
-           }
-           // for partial units of area, use a zombie door method to
-           // create the proper random chance of a light being created
-           // for this triangle
-           if ( num > 0.0 ) {
-               if ( sg_random() <= num ) {
-                   // a zombie made it through our door
-                   random_pt_inside_tri( result, p1, p2, p3 );
-                   lights->add( result );
-               }
-           }
-       }
-    }
-}
+/**
+ * User data for populating leaves when they come in range.
+ */
+class LeafUserData : public ssgBase
+{
+public:
+    bool is_filled_in;
+    ssgLeaf *leaf;
+    SGMaterial *mat;
+    ssgBranch *branch;
+    float sin_lat;
+    float cos_lat;
+    float sin_lon;
+    float cos_lon;
+
+    void setup_triangle( int i );
+};
 
 
 /**
- * Add an object to a random location inside a triangle.
- *
- * @param p1 The first vertex of the triangle.
- * @param p2 The second vertex of the triangle.
- * @param p3 The third vertex of the triangle.
- * @param center The center of the triangle.
- * @param ROT The world-up rotation matrix.
- * @param mat The material object.
- * @param object_index The index of the dynamically-placed object in
- *        the material.
- * @param branch The branch where the object should be added to the
- *        scene graph.
+ * User data for populating triangles when they come in range.
  */
-static void
-add_object_to_triangle (sgVec3 p1, sgVec3 p2, sgVec3 p3, sgVec3 center,
-                       sgMat4 ROT, FGNewMat * mat, int object_index,
-                       ssgBranch * branch)
+class TriUserData : public ssgBase
 {
-    sgVec3 result;
-
-    random_pt_inside_tri(result, p1, p2, p3);
-    sgSubVec3(result, center);
-    sgMat4 OBJ_pos, OBJ;
-    sgMakeTransMat4(OBJ_pos, result);
-    sgCopyMat4(OBJ, ROT);
-    sgPostMultMat4(OBJ, OBJ_pos);
-    ssgTransform * pos = new ssgTransform;
-    pos->setTransform(OBJ);
-    pos->addKid(mat->get_object(object_index));
-    branch->addKid(pos);
-}
+public:
+  bool is_filled_in;
+  float * p1;
+  float * p2;
+  float * p3;
+    sgVec3 center;
+    double area;
+  SGMaterial::ObjectGroup * object_group;
+  ssgBranch * branch;
+    LeafUserData * leafData;
+  unsigned int seed;
+
+    void fill_in_triangle();
+    void add_object_to_triangle(SGMaterial::Object * object);
+    void makeWorldMatrix (sgMat4 ROT, double hdg_deg );
+};
 
 
 /**
- * Create a rotation matrix to align an object for the current lat/lon.
- *
- * By default, objects are aligned for the north pole.  This code
- * calculates a matrix to rotate them for the surface of the earth in
- * the current location.
+ * Fill in a triangle with randomly-placed objects.
  *
- * TODO: there should be a single version of this method somewhere
- * for all of SimGear.
+ * This method is invoked by a callback when the triangle is in range
+ * but not yet populated.
  *
- * @param ROT The resulting rotation matrix.
- * @param hdg_deg The object heading in degrees.
- * @param lon_deg The longitude in degrees.
- * @param lat_deg The latitude in degrees.
  */
-static void
-makeWorldUpRotationMatrix (sgMat4 ROT, double hdg_deg,
-                          double lon_deg, double lat_deg)
-{
-    sgVec3 obj_right, obj_up;
-    sgSetVec3(obj_right, 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_deg, obj_up);
-    sgMakeRotMat4(ROT_lat, 90 - lat_deg, obj_right);
-    sgMakeRotMat4(ROT_hdg, hdg_deg, obj_up);
-    sgCopyMat4(ROT, ROT_hdg);
-    sgPostMultMat4(ROT, ROT_lat);
-    sgPostMultMat4(ROT, ROT_lon);
-}
-
 
-static void
-gen_random_surface_objects (ssgLeaf *leaf,
-                           ssgBranch *branch,
-                           float lon_deg,
-                           float lat_deg,
-                           const string &material_name)
+void TriUserData::fill_in_triangle ()
 {
-    float hdg_deg = 0.0;       // do something here later
-
-                               // First, look up the material
-                               // for this surface.
-    FGNewMat * mat = material_lib.find(material_name);
-    if (mat == 0) {
-      SG_LOG(SG_INPUT, SG_ALERT, "Unknown material " << material_name);
-      return;
-    }
+                                // generate a repeatable random seed
+    sg_srandom(seed);
 
-                               // If the material has no randomly-placed
-                               // objects, return now.
-    int num_objects = mat->get_object_count();
-    if (num_objects < 1)
-      return;
+    int nObjects = object_group->get_object_count();
 
-                               // If the surface has no triangles, return
-                               // now.
-    int num_tris = leaf->getNumTriangles();
-    if (num_tris < 1)
-      return;
-
-                               // Make a rotation matrix to align the
-                               // object for this point on the earth's
-                               // surface.
-    sgMat4 ROT;
-    makeWorldUpRotationMatrix(ROT, hdg_deg, lon_deg, lat_deg);
-
-    short int n1, n2, n3;
-    float *p1, *p2, *p3;
-    sgVec3 result;
-
-                               // generate a repeatable random seed
-    p1 = leaf->getVertex( 0 );
-    unsigned int seed = (unsigned int)p1[0];
-    sg_srandom( seed );
+    for (int i = 0; i < nObjects; i++) {
+      SGMaterial::Object * object = object_group->get_object(i);
+      double num = area / object->get_coverage_m2();
 
-                               // Iterate through all the triangles
-    for ( int i = 0; i < num_tris; ++i ) {
-      leaf->getTriangle( i, &n1, &n2, &n3 );
-      p1 = leaf->getVertex(n1);
-      p2 = leaf->getVertex(n2);
-      p3 = leaf->getVertex(n3);
-      double area = sgTriArea( p1, p2, p3 );
-
-                               // Set up a single center point for LOD
-      sgVec3 center;
-      sgSetVec3(center,
-               (p1[0] + p2[0] + p3[0]) / 3.0,
-               (p1[1] + p2[1] + p3[1]) / 3.0,
-               (p1[2] + p2[2] + p3[2]) / 3.0);
-      
-                               // Set up a transformation to the center
-                               // point, so that everything else can
-                               // be specified relative to it.
-      ssgTransform * location = new ssgTransform;
-      sgMat4 TRANS;
-      sgMakeTransMat4(TRANS, center);
-      location->setTransform(TRANS);
-      branch->addKid(location);
-
-                               // Iterate through all the objects.
-      for (int j = 0; j < num_objects; j++) {
-       double num = area / mat->get_object_coverage(j);
-       float ranges[] = {0, mat->get_object_lod(j)};
-       ssgRangeSelector * lod = new ssgRangeSelector;
-       lod->setRanges(ranges, 2);
-       location->addKid(lod);
-       ssgBranch * objects = new ssgBranch;
-       lod->addKid(objects);
-             
-       // place an object each unit of area
-       while ( num > 1.0 ) {
-         add_object_to_triangle(p1, p2, p3, center,
-                                ROT, mat, j, objects);
-         num -= 1.0;
-       }
-       // for partial units of area, use a zombie door method to
-       // create the proper random chance of an object being created
-       // for this triangle
-       if ( num > 0.0 ) {
-         if ( sg_random() <= num ) {
-           // a zombie made it through our door
-           add_object_to_triangle(p1, p2, p3, center,
-                                  ROT, mat, j, objects);
-         }
-       }
+      // place an object each unit of area
+      while ( num > 1.0 ) {
+          add_object_to_triangle(object);
+          num -= 1.0;
+      }
+      // for partial units of area, use a zombie door method to
+      // create the proper random chance of an object being created
+      // for this triangle
+      if ( num > 0.0 ) {
+        if ( sg_random() <= num ) {
+          // a zombie made it through our door
+                add_object_to_triangle(object);
+        }
       }
     }
 }
 
-
-\f
-////////////////////////////////////////////////////////////////////////
-// Scenery loaders.
-////////////////////////////////////////////////////////////////////////
-
-
-// Load an Ascii obj file
-ssgBranch *fgAsciiObjLoad( const string& path, FGTileEntry *t,
-                          ssgVertexArray *lights, const bool is_base)
+void TriUserData::add_object_to_triangle (SGMaterial::Object * object)
 {
-    FGNewMat *newmat = NULL;
-    string material;
-    float coverage = -1;
-    Point3D pp;
-    // sgVec3 approx_normal;
-    // double normal[3], scale = 0.0;
-    // double x, y, z, xmax, xmin, ymax, ymin, zmax, zmin;
-    // GLfloat sgenparams[] = { 1.0, 0.0, 0.0, 0.0 };
-    // GLint display_list = 0;
-    int shading;
-    bool in_faces = false;
-    int vncount, vtcount;
-    int n1 = 0, n2 = 0, n3 = 0;
-    int tex;
-    // int last1 = 0, last2 = 0;
-    bool odd = false;
-    point_list nodes;
-    Point3D node;
-    Point3D center;
-    double scenery_version = 0.0;
-    double tex_width = 1000.0, tex_height = 1000.0;
-    bool shared_done = false;
-    int_list fan_vertices;
-    int_list fan_tex_coords;
-    int i;
-    ssgSimpleState *state = NULL;
-    sgVec3 *vtlist, *vnlist;
-    sgVec2 *tclist;
-
-    ssgBranch *tile = new ssgBranch () ;
-
-    tile -> setName ( (char *)path.c_str() ) ;
+    // Set up the random heading if required.
+    double hdg_deg = 0;
+    if (object->get_heading_type() == SGMaterial::Object::HEADING_RANDOM)
+        hdg_deg = sg_random() * 360;
 
-    // Attempt to open "path.gz" or "path"
-    sg_gzifstream in( path );
-    if ( ! in.is_open() ) {
-       SG_LOG( SG_TERRAIN, SG_DEBUG, "Cannot open file: " << path );
-       SG_LOG( SG_TERRAIN, SG_DEBUG, "default to ocean tile: " << path );
+    sgMat4 mat;
+    makeWorldMatrix(mat, hdg_deg);
 
-        delete tile;
-
-       return NULL;
-    }
-
-    shading = fgGetBool("/sim/rendering/shading");
+    ssgTransform * pos = new ssgTransform;
+    pos->setTransform(mat);
+    pos->addKid( object->get_random_model( globals->get_model_loader(),
+                                           globals->get_fg_root(),
+                                           globals->get_props(),
+                                           globals->get_sim_time_sec() )
+                 );
+    branch->addKid(pos);
+}
 
-    if ( is_base ) {
-       t->ncount = 0;
-    }
-    vncount = 0;
-    vtcount = 0;
-    if ( is_base ) {
-       t->bounding_radius = 0.0;
+void TriUserData::makeWorldMatrix (sgMat4 mat, double hdg_deg )
+{
+    if (hdg_deg == 0) {
+        mat[0][0] =  leafData->sin_lat * leafData->cos_lon;
+        mat[0][1] =  leafData->sin_lat * leafData->sin_lon;
+        mat[0][2] = -leafData->cos_lat;
+        mat[0][3] =  SG_ZERO;
+
+        mat[1][0] =  -leafData->sin_lon;
+        mat[1][1] =  leafData->cos_lon;
+        mat[1][2] =  SG_ZERO;
+        mat[1][3] =  SG_ZERO;
+    } else {
+        float sin_hdg = sin( hdg_deg * SGD_DEGREES_TO_RADIANS ) ;
+        float cos_hdg = cos( hdg_deg * SGD_DEGREES_TO_RADIANS ) ;
+        mat[0][0] =  cos_hdg * leafData->sin_lat * leafData->cos_lon - sin_hdg * leafData->sin_lon;
+        mat[0][1] =  cos_hdg * leafData->sin_lat * leafData->sin_lon + sin_hdg * leafData->cos_lon;
+        mat[0][2] = -cos_hdg * leafData->cos_lat;
+        mat[0][3] =  SG_ZERO;
+
+        mat[1][0] = -sin_hdg * leafData->sin_lat * leafData->cos_lon - cos_hdg * leafData->sin_lon;
+        mat[1][1] = -sin_hdg * leafData->sin_lat * leafData->sin_lon + cos_hdg * leafData->cos_lon;
+        mat[1][2] =  sin_hdg * leafData->cos_lat;
+        mat[1][3] =  SG_ZERO;
     }
-    center = t->center;
 
-    // StopWatch stopwatch;
-    // stopwatch.start();
+    mat[2][0] = leafData->cos_lat * leafData->cos_lon;
+    mat[2][1] = leafData->cos_lat * leafData->sin_lon;
+    mat[2][2] = leafData->sin_lat;
+    mat[2][3] = SG_ZERO;
 
-    // ignore initial comments and blank lines. (priming the pump)
-    // in >> skipcomment;
-    // string line;
+    // translate to random point in triangle
+    sgVec3 result;
+    random_pt_inside_tri(result, p1, p2, p3);
+    sgSubVec3(mat[3], result, center);
 
-    string token;
-    char c;
+    mat[3][3] = SG_ONE ;
+}
 
-#ifdef __MWERKS__
-    while ( in.get(c) && c  != '\0' ) {
-       in.putback(c);
-#else
-    while ( ! in.eof() ) {
-#endif
+/**
+ * SSG callback for an in-range triangle of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is traversed
+ * only when a triangle is in range.  If the triangle is not currently
+ * populated with randomly-placed objects, this callback will populate
+ * it.
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 1, to allow traversal and culling to continue.
+ */
+static int
+tri_in_range_callback (ssgEntity * entity, int mask)
+{
+  TriUserData * data = (TriUserData *)entity->getUserData();
+  if (!data->is_filled_in) {
+        data->fill_in_triangle();
+    data->is_filled_in = true;
+  }
+  return 1;
+}
 
-       in >> ::skipws;
-
-       if ( in.get( c ) && c == '#' ) {
-           // process a comment line
-
-           // getline( in, line );
-           // cout << "comment = " << line << endl;
-
-           in >> token;
-
-           if ( token == "Version" ) {
-               // read scenery versions number
-               in >> scenery_version;
-               // cout << "scenery_version = " << scenery_version << endl;
-               if ( scenery_version > 0.4 ) {
-                   SG_LOG( SG_TERRAIN, SG_ALERT, 
-                           "\nYou are attempting to load a tile format that\n"
-                           << "is newer than this version of flightgear can\n"
-                           << "handle.  You should upgrade your copy of\n"
-                           << "FlightGear to the newest version.  For\n"
-                           << "details, please see:\n"
-                           << "\n    http://www.flightgear.org\n" );
-                   exit(-1);
-               }
-           } else if ( token == "gbs" ) {
-               // reference point (center offset)
-               if ( is_base ) {
-                   in >> t->center >> t->bounding_radius;
-               } else {
-                   Point3D junk1;
-                   double junk2;
-                   in >> junk1 >> junk2;
-               }
-               center = t->center;
-               // cout << "center = " << center 
-               //      << " radius = " << t->bounding_radius << endl;
-           } else if ( token == "bs" ) {
-               // reference point (center offset)
-               // (skip past this)
-               Point3D junk1;
-               double junk2;
-               in >> junk1 >> junk2;
-           } else if ( token == "usemtl" ) {
-               // material property specification
-
-               // if first usemtl with shared_done = false, then set
-               // shared_done true and build the ssg shared lists
-               if ( ! shared_done ) {
-                   // sanity check
-                   if ( (int)nodes.size() != vncount ) {
-                       SG_LOG( SG_TERRAIN, SG_ALERT, 
-                               "Tile has mismatched nodes = " << nodes.size()
-                               << " and normals = " << vncount << " : " 
-                               << path );
-                       // exit(-1);
-                   }
-                   shared_done = true;
-
-                   vtlist = new sgVec3 [ nodes.size() ];
-                   t->vec3_ptrs.push_back( vtlist );
-                   vnlist = new sgVec3 [ vncount ];
-                   t->vec3_ptrs.push_back( vnlist );
-                   tclist = new sgVec2 [ vtcount ];
-                   t->vec2_ptrs.push_back( tclist );
-
-                   for ( i = 0; i < (int)nodes.size(); ++i ) {
-                       sgSetVec3( vtlist[i], 
-                                  nodes[i][0], nodes[i][1], nodes[i][2] );
-                   }
-                   for ( i = 0; i < vncount; ++i ) {
-                       sgSetVec3( vnlist[i], 
-                                  normals[i][0], 
-                                  normals[i][1],
-                                  normals[i][2] );
-                   }
-                   for ( i = 0; i < vtcount; ++i ) {
-                       sgSetVec2( tclist[i],
-                                  tex_coords[i][0],
-                                  tex_coords[i][1] );
-                   }
-               }
-
-               // display_list = xglGenLists(1);
-               // xglNewList(display_list, GL_COMPILE);
-               // printf("xglGenLists(); xglNewList();\n");
-               in_faces = false;
-
-               // scan the material line
-               in >> material;
-               
-               // find this material in the properties list
-
-               newmat = material_lib.find( material );
-               if ( newmat == NULL ) {
-                   // see if this is an on the fly texture
-                   string file = path;
-                   int pos = file.rfind( "/" );
-                   file = file.substr( 0, pos );
-                   // cout << "current file = " << file << endl;
-                   file += "/";
-                   file += material;
-                   // cout << "current file = " << file << endl;
-                   if ( ! material_lib.add_item( file ) ) {
-                       SG_LOG( SG_TERRAIN, SG_ALERT, 
-                               "Ack! unknown usemtl name = " << material 
-                               << " in " << path );
-                   } else {
-                       // locate our newly created material
-                       newmat = material_lib.find( material );
-                       if ( newmat == NULL ) {
-                           SG_LOG( SG_TERRAIN, SG_ALERT, 
-                                   "Ack! bad on the fly materia create = "
-                                   << material << " in " << path );
-                       }
-                   }
-               }
-
-               if ( newmat != NULL ) {
-                   // set the texture width and height values for this
-                   // material
-                   tex_width = newmat->get_xsize();
-                   tex_height = newmat->get_ysize();
-                   state = newmat->get_state();
-                   coverage = newmat->get_light_coverage();
-                   // cout << "(w) = " << tex_width << " (h) = "
-                   //      << tex_width << endl;
-               } else {
-                   coverage = -1;
-               }
-           } else {
-               // unknown comment, just gobble the input until the
-               // end of line
-
-               in >> skipeol;
-           }
-       } else {
-           in.putback( c );
-       
-           in >> token;
-
-           // cout << "token = " << token << endl;
-
-           if ( token == "vn" ) {
-               // vertex normal
-               if ( vncount < FG_MAX_NODES ) {
-                   in >> normals[vncount][0]
-                      >> normals[vncount][1]
-                      >> normals[vncount][2];
-                   vncount++;
-               } else {
-                   SG_LOG( SG_TERRAIN, SG_ALERT, 
-                           "Read too many vertex normals in " << path 
-                           << " ... dying :-(" );
-                   exit(-1);
-               }
-           } else if ( token == "vt" ) {
-               // vertex texture coordinate
-               if ( vtcount < FG_MAX_NODES*3 ) {
-                   in >> tex_coords[vtcount][0]
-                      >> tex_coords[vtcount][1];
-                   vtcount++;
-               } else {
-                   SG_LOG( SG_TERRAIN, SG_ALERT, 
-                           "Read too many vertex texture coords in " << path
-                           << " ... dying :-("
-                           );
-                   exit(-1);
-               }
-           } else if ( token == "v" ) {
-               // node (vertex)
-               if ( t->ncount < FG_MAX_NODES ) {
-                   /* in >> nodes[t->ncount][0]
-                      >> nodes[t->ncount][1]
-                      >> nodes[t->ncount][2]; */
-                   in >> node;
-                   nodes.push_back(node);
-                   if ( is_base ) {
-                       t->ncount++;
-                   }
-               } else {
-                   SG_LOG( SG_TERRAIN, SG_ALERT, 
-                           "Read too many nodes in " << path 
-                           << " ... dying :-(");
-                   exit(-1);
-               }
-           } else if ( (token == "tf") || (token == "ts") || (token == "f") ) {
-               // triangle fan, strip, or individual face
-               // SG_LOG( SG_TERRAIN, SG_INFO, "new fan or strip");
-
-               fan_vertices.clear();
-               fan_tex_coords.clear();
-               odd = true;
-
-               // xglBegin(GL_TRIANGLE_FAN);
-
-               in >> n1;
-               fan_vertices.push_back( n1 );
-               // xglNormal3dv(normals[n1]);
-               if ( in.get( c ) && c == '/' ) {
-                   in >> tex;
-                   fan_tex_coords.push_back( tex );
-                   if ( scenery_version >= 0.4 ) {
-                       if ( tex_width > 0 ) {
-                           tclist[tex][0] *= (1000.0 / tex_width);
-                       }
-                       if ( tex_height > 0 ) {
-                           tclist[tex][1] *= (1000.0 / tex_height);
-                       }
-                   }
-                   pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
-                   pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
-               } else {
-                   in.putback( c );
-                   pp = local_calc_tex_coords(nodes[n1], center);
-               }
-               // xglTexCoord2f(pp.x(), pp.y());
-               // xglVertex3dv(nodes[n1].get_n());
-
-               in >> n2;
-               fan_vertices.push_back( n2 );
-               // xglNormal3dv(normals[n2]);
-               if ( in.get( c ) && c == '/' ) {
-                   in >> tex;
-                   fan_tex_coords.push_back( tex );
-                   if ( scenery_version >= 0.4 ) {
-                       if ( tex_width > 0 ) {
-                           tclist[tex][0] *= (1000.0 / tex_width);
-                       }
-                       if ( tex_height > 0 ) {
-                           tclist[tex][1] *= (1000.0 / tex_height);
-                       }
-                   }
-                   pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
-                   pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
-               } else {
-                   in.putback( c );
-                   pp = local_calc_tex_coords(nodes[n2], center);
-               }
-               // xglTexCoord2f(pp.x(), pp.y());
-               // xglVertex3dv(nodes[n2].get_n());
-               
-               // read all subsequent numbers until next thing isn't a number
-               while ( true ) {
-                   in >> ::skipws;
-
-                   char c;
-                   in.get(c);
-                   in.putback(c);
-                   if ( ! isdigit(c) || in.eof() ) {
-                       break;
-                   }
-
-                   in >> n3;
-                   fan_vertices.push_back( n3 );
-                   // cout << "  triangle = "
-                   //      << n1 << "," << n2 << "," << n3
-                   //      << endl;
-                   // xglNormal3dv(normals[n3]);
-                   if ( in.get( c ) && c == '/' ) {
-                       in >> tex;
-                       fan_tex_coords.push_back( tex );
-                       if ( scenery_version >= 0.4 ) {
-                           if ( tex_width > 0 ) {
-                               tclist[tex][0] *= (1000.0 / tex_width);
-                           }
-                           if ( tex_height > 0 ) {
-                               tclist[tex][1] *= (1000.0 / tex_height);
-                           }
-                       }
-                       pp.setx( tex_coords[tex][0] * (1000.0 / tex_width) );
-                       pp.sety( tex_coords[tex][1] * (1000.0 / tex_height) );
-                   } else {
-                       in.putback( c );
-                       pp = local_calc_tex_coords(nodes[n3], center);
-                   }
-                   // xglTexCoord2f(pp.x(), pp.y());
-                   // xglVertex3dv(nodes[n3].get_n());
-
-                   if ( (token == "tf") || (token == "f") ) {
-                       // triangle fan
-                       n2 = n3;
-                   } else {
-                       // triangle strip
-                       odd = !odd;
-                       n1 = n2;
-                       n2 = n3;
-                   }
-               }
-
-               // xglEnd();
-
-               // build the ssg entity
-               int size = (int)fan_vertices.size();
-               ssgVertexArray   *vl = new ssgVertexArray( size );
-               ssgNormalArray   *nl = new ssgNormalArray( size );
-               ssgTexCoordArray *tl = new ssgTexCoordArray( size );
-               ssgColourArray   *cl = new ssgColourArray( 1 );
-
-               sgVec4 color;
-               sgSetVec4( color, 1.0, 1.0, 1.0, 1.0 );
-               cl->add( color );
-
-               sgVec2 tmp2;
-               sgVec3 tmp3;
-               for ( i = 0; i < size; ++i ) {
-                   sgCopyVec3( tmp3, vtlist[ fan_vertices[i] ] );
-                   vl -> add( tmp3 );
-
-                   sgCopyVec3( tmp3, vnlist[ fan_vertices[i] ] );
-                   nl -> add( tmp3 );
-
-                   sgCopyVec2( tmp2, tclist[ fan_tex_coords[i] ] );
-                   tl -> add( tmp2 );
-               }
-
-               ssgLeaf *leaf = NULL;
-               if ( token == "tf" ) {
-                   // triangle fan
-                   leaf = 
-                       new ssgVtxTable ( GL_TRIANGLE_FAN, vl, nl, tl, cl );
-               } else if ( token == "ts" ) {
-                   // triangle strip
-                   leaf = 
-                       new ssgVtxTable ( GL_TRIANGLE_STRIP, vl, nl, tl, cl );
-               } else if ( token == "f" ) {
-                   // triangle
-                   leaf = 
-                       new ssgVtxTable ( GL_TRIANGLES, vl, nl, tl, cl );
-               }
-               // leaf->makeDList();
-               leaf->setState( state );
-
-               tile->addKid( leaf );
-
-               if ( is_base ) {
-                   if ( coverage > 0.0 ) {
-                       if ( coverage < 10000.0 ) {
-                           SG_LOG(SG_INPUT, SG_ALERT, "Light coverage is "
-                                  << coverage << ", pushing up to 10000");
-                           coverage = 10000;
-                       }
-                       gen_random_surface_points(leaf, lights, coverage);
-                   }
-               }
-           } else {
-               SG_LOG( SG_TERRAIN, SG_WARN, "Unknown token in " 
-                       << path << " = " << token );
-           }
-
-           // eat white space before start of while loop so if we are
-           // done with useful input it is noticed before hand.
-           in >> ::skipws;
-       }
-    }
 
-    if ( is_base ) {
-       t->nodes = nodes;
-    }
+/**
+ * SSG callback for an out-of-range triangle of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is traversed
+ * only when a triangle is out of range.  If the triangle is currently
+ * populated with randomly-placed objects, the objects will be removed.
+ *
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 0, to prevent any further traversal or culling.
+ */
+static int
+tri_out_of_range_callback (ssgEntity * entity, int mask)
+{
+  TriUserData * data = (TriUserData *)entity->getUserData();
+  if (data->is_filled_in) {
+    data->branch->removeAllKids();
+    data->is_filled_in = false;
+  }
+  return 0;
+}
 
-    // stopwatch.stop();
-    // SG_LOG( SG_TERRAIN, SG_DEBUG, 
-    //     "Loaded " << path << " in " 
-    //     << stopwatch.elapsedSeconds() << " seconds" );
 
-    return tile;
-}
+/**
+ * ssgEntity with a dummy bounding sphere, to fool culling.
+ *
+ * This forces the in-range and out-of-range branches to be visited
+ * when appropriate, even if they have no children.  It's ugly, but
+ * it works and seems fairly efficient (since branches can still
+ * be culled when they're out of the view frustum).
+ */
+class DummyBSphereEntity : public ssgBranch
+{
+public:
+  DummyBSphereEntity (float radius)
+  {
+    bsphere.setCenter(0, 0, 0);
+    bsphere.setRadius(radius);
+  }
+  virtual ~DummyBSphereEntity () {}
+  virtual void recalcBSphere () { bsphere_is_invalid = false; }
+};
 
 
-ssgLeaf *gen_leaf( const string& path,
-                  const GLenum ty, const string& material,
-                  const point_list& nodes, const point_list& normals,
-                  const point_list& texcoords,
-                  const int_list node_index,
-                  const int_list normal_index,
-                  const int_list& tex_index,
-                  const bool calc_lights, ssgVertexArray *lights )
+/**
+ * Calculate the bounding radius of a triangle from its center.
+ *
+ * @param center The triangle center.
+ * @param p1 The first point in the triangle.
+ * @param p2 The second point in the triangle.
+ * @param p3 The third point in the triangle.
+ * @return The greatest distance any point lies from the center.
+ */
+static inline float
+get_bounding_radius( sgVec3 center, float *p1, float *p2, float *p3)
 {
-    double tex_width = 1000.0, tex_height = 1000.0;
-    ssgSimpleState *state = NULL;
-    float coverage = -1;
-
-    FGNewMat *newmat = material_lib.find( material );
-    if ( newmat == NULL ) {
-       // see if this is an on the fly texture
-       string file = path;
-       int pos = file.rfind( "/" );
-       file = file.substr( 0, pos );
-       // cout << "current file = " << file << endl;
-       file += "/";
-       file += material;
-       // cout << "current file = " << file << endl;
-       if ( ! material_lib.add_item( file ) ) {
-           SG_LOG( SG_TERRAIN, SG_ALERT, 
-                   "Ack! unknown usemtl name = " << material 
-                   << " in " << path );
-       } else {
-           // locate our newly created material
-           newmat = material_lib.find( material );
-           if ( newmat == NULL ) {
-               SG_LOG( SG_TERRAIN, SG_ALERT, 
-                       "Ack! bad on the fly material create = "
-                       << material << " in " << path );
-           }
-       }
-    }
+   return sqrt( SG_MAX3( sgDistanceSquaredVec3(center, p1),
+                         sgDistanceSquaredVec3(center, p2),
+                         sgDistanceSquaredVec3(center, p3) ) );
+}
 
-    if ( newmat != NULL ) {
-       // set the texture width and height values for this
-       // material
-       tex_width = newmat->get_xsize();
-       tex_height = newmat->get_ysize();
-       state = newmat->get_state();
-       coverage = newmat->get_light_coverage();
-       // cout << "(w) = " << tex_width << " (h) = "
-       //      << tex_width << endl;
-    } else {
-       coverage = -1;
-    }
 
-    sgVec2 tmp2;
-    sgVec3 tmp3;
-    sgVec4 tmp4;
-    int i;
+/**
+ * Set up a triangle for randomly-placed objects.
+ *
+ * No objects will be added unless the triangle comes into range.
+ *
+ */
 
-    // vertices
-    int size = node_index.size();
-    if ( size < 1 ) {
-       SG_LOG( SG_TERRAIN, SG_ALERT, "Woh! node list size < 1" );
-       exit(-1);
-    }
-    ssgVertexArray *vl = new ssgVertexArray( size );
-    Point3D node;
-    for ( i = 0; i < size; ++i ) {
-       node = nodes[ node_index[i] ];
-       sgSetVec3( tmp3, node[0], node[1], node[2] );
-       vl -> add( tmp3 );
+void LeafUserData::setup_triangle (int i )
+{
+    short n1, n2, n3;
+    leaf->getTriangle(i, &n1, &n2, &n3);
+
+    float * p1 = leaf->getVertex(n1);
+    float * p2 = leaf->getVertex(n2);
+    float * p3 = leaf->getVertex(n3);
+
+                                // Set up a single center point for LOD
+    sgVec3 center;
+    sgSetVec3(center,
+              (p1[0] + p2[0] + p3[0]) / 3.0,
+              (p1[1] + p2[1] + p3[1]) / 3.0,
+              (p1[2] + p2[2] + p3[2]) / 3.0);
+    double area = sgTriArea(p1, p2, p3);
+      
+                                // maximum radius of an object from center.
+    double bounding_radius = get_bounding_radius(center, p1, p2, p3);
+
+                                // Set up a transformation to the center
+                                // point, so that everything else can
+                                // be specified relative to it.
+    ssgTransform * location = new ssgTransform;
+    sgMat4 TRANS;
+    sgMakeTransMat4(TRANS, center);
+    location->setTransform(TRANS);
+    branch->addKid(location);
+
+                                // Iterate through all the object types.
+    int num_groups = mat->get_object_group_count();
+    for (int j = 0; j < num_groups; j++) {
+                                // Look up the random object.
+        SGMaterial::ObjectGroup * group = mat->get_object_group(j);
+
+                                // Set up the range selector for the entire
+                                // triangle; note that we use the object
+                                // range plus the bounding radius here, to
+                                // allow for objects far from the center.
+        float ranges[] = { 0,
+                          group->get_range_m() + bounding_radius,
+                SG_MAX };
+        ssgRangeSelector * lod = new ssgRangeSelector;
+        lod->setRanges(ranges, 3);
+        location->addKid(lod);
+
+                                // Create the in-range and out-of-range
+                                // branches.
+        ssgBranch * in_range = new ssgBranch;
+        ssgBranch * out_of_range = new ssgBranch;
+
+                                // Set up the user data for if/when
+                                // the random objects in this triangle
+                                // are filled in.
+        TriUserData * data = new TriUserData;
+        data->is_filled_in = false;
+        data->p1 = p1;
+        data->p2 = p2;
+        data->p3 = p3;
+        sgCopyVec3 (data->center, center);
+        data->area = area;
+        data->object_group = group;
+        data->branch = in_range;
+        data->leafData = this;
+        data->seed = (unsigned int)(p1[0] * j);
+
+                                // Set up the in-range node.
+        in_range->setUserData(data);
+        in_range->setTravCallback(SSG_CALLBACK_PRETRAV,
+                                 tri_in_range_callback);
+        lod->addKid(in_range);
+
+                                // Set up the out-of-range node.
+        out_of_range->setUserData(data);
+        out_of_range->setTravCallback(SSG_CALLBACK_PRETRAV,
+                                      tri_out_of_range_callback);
+        out_of_range->addKid(new DummyBSphereEntity(bounding_radius));
+        lod->addKid(out_of_range);
     }
+}
 
-    // normals
-    Point3D normal;
-    ssgNormalArray *nl = new ssgNormalArray( size );
-    if ( normal_index.size() ) {
-       // object file specifies normal indices (i.e. normal indices
-       // aren't 'implied'
-        for ( i = 0; i < size; ++i ) {
-            normal = normals[ normal_index[i] ];
-            sgSetVec3( tmp3, normal[0], normal[1], normal[2] );
-            nl -> add( tmp3 );
-        }
-    } else {
-       // use implied normal indices.  normal index = vertex index.
-       for ( i = 0; i < size; ++i ) {
-           normal = normals[ node_index[i] ];
-           sgSetVec3( tmp3, normal[0], normal[1], normal[2] );
-           nl -> add( tmp3 );
-       }
-    }
+/**
+ * SSG callback for an in-range leaf of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is
+ * traversed only when a leaf is in range.  If the leaf is not
+ * currently prepared to be populated with randomly-placed objects,
+ * this callback will prepare it (actual population is handled by
+ * the tri_in_range_callback for individual triangles).
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 1, to allow traversal and culling to continue.
+ */
+static int
+leaf_in_range_callback (ssgEntity * entity, int mask)
+{
+  LeafUserData * data = (LeafUserData *)entity->getUserData();
 
-    // colors
-    ssgColourArray *cl = new ssgColourArray( 1 );
-    sgSetVec4( tmp4, 1.0, 1.0, 1.0, 1.0 );
-    cl->add( tmp4 );
-
-    // texture coordinates
-    size = tex_index.size();
-    Point3D texcoord;
-    ssgTexCoordArray *tl = new ssgTexCoordArray( size );
-    if ( size == 1 ) {
-        texcoord = texcoords[ tex_index[0] ];
-       sgSetVec2( tmp2, texcoord[0], texcoord[1] );
-       sgSetVec2( tmp2, texcoord[0], texcoord[1] );
-       if ( tex_width > 0 ) {
-           tmp2[0] *= (1000.0 / tex_width);
-       }
-       if ( tex_height > 0 ) {
-           tmp2[1] *= (1000.0 / tex_height);
-       }
-       tl -> add( tmp2 );
-    } else if ( size > 1 ) {
-        for ( i = 0; i < size; ++i ) {
-            texcoord = texcoords[ tex_index[i] ];
-            sgSetVec2( tmp2, texcoord[0], texcoord[1] );
-            if ( tex_width > 0 ) {
-                tmp2[0] *= (1000.0 / tex_width);
-            }
-            if ( tex_height > 0 ) {
-                tmp2[1] *= (1000.0 / tex_height);
-            }
-            tl -> add( tmp2 );
-        }
+  if (!data->is_filled_in) {
+                                // Iterate through all the triangles
+                                // and populate them.
+    int num_tris = data->leaf->getNumTriangles();
+    for ( int i = 0; i < num_tris; ++i ) {
+            data->setup_triangle(i);
     }
+    data->is_filled_in = true;
+  }
+  return 1;
+}
 
-    ssgLeaf *leaf = new ssgVtxTable ( ty, vl, nl, tl, cl );
-
-    // lookup the state record
 
-    leaf->setState( state );
+/**
+ * SSG callback for an out-of-range leaf of randomly-placed objects.
+ *
+ * This pretraversal callback is attached to a branch that is
+ * traversed only when a leaf is out of range.  If the leaf is
+ * currently prepared to be populated with randomly-placed objects (or
+ * is actually populated), the objects will be removed.
+ *
+ * @param entity The entity to which the callback is attached (not used).
+ * @param mask The entity's traversal mask (not used).
+ * @return Always 0, to prevent any further traversal or culling.
+ */
+static int
+leaf_out_of_range_callback (ssgEntity * entity, int mask)
+{
+  LeafUserData * data = (LeafUserData *)entity->getUserData();
+  if (data->is_filled_in) {
+    data->branch->removeAllKids();
+    data->is_filled_in = false;
+  }
+  return 0;
+}
 
-    if ( calc_lights ) {
-       if ( coverage > 0.0 ) {
-           if ( coverage < 10000.0 ) {
-               SG_LOG(SG_INPUT, SG_ALERT, "Light coverage is "
-                      << coverage << ", pushing up to 10000");
-               coverage = 10000;
-           }
-           gen_random_surface_points(leaf, lights, coverage);
-       }
-    }
 
-    return leaf;
+/**
+ * Randomly place objects on a surface.
+ *
+ * The leaf node provides the geometry of the surface, while the
+ * material provides the objects and placement density.  Latitude
+ * and longitude are required so that the objects can be rotated
+ * to the world-up vector.  This function does not actually add
+ * any objects; instead, it attaches an ssgRangeSelector to the
+ * branch with callbacks to generate the objects when needed.
+ *
+ * @param leaf The surface where the objects should be placed.
+ * @param branch The branch that will hold the randomly-placed objects.
+ * @param center The center of the leaf in FlightGear coordinates.
+ * @param material_name The name of the surface's material.
+ */
+static void
+gen_random_surface_objects (ssgLeaf *leaf,
+                            ssgBranch *branch,
+                            Point3D *center,
+                            SGMaterial *mat )
+{
+                                // If the surface has no triangles, return
+                                // now.
+    int num_tris = leaf->getNumTriangles();
+    if (num_tris < 1)
+        return;
+
+                                // If the material has no randomly-placed
+                                // objects, return now.
+    if (mat->get_object_group_count() < 1)
+        return;
+
+                                // Calculate the geodetic centre of
+                                // the tile, for aligning automatic
+                                // objects.
+    double lon_deg, lat_rad, lat_deg, alt_m, sl_radius_m;
+    Point3D geoc = sgCartToPolar3d(*center);
+    lon_deg = geoc.lon() * SGD_RADIANS_TO_DEGREES;
+    sgGeocToGeod(geoc.lat(), geoc.radius(),
+                 &lat_rad, &alt_m, &sl_radius_m);
+    lat_deg = lat_rad * SGD_RADIANS_TO_DEGREES;
+
+                                // LOD for the leaf
+                                // max random object range: 20000m
+    float ranges[] = { 0, 20000, 1000000 };
+    ssgRangeSelector * lod = new ssgRangeSelector;
+    lod->setRanges(ranges, 3);
+    branch->addKid(lod);
+
+                                // Create the in-range and out-of-range
+                                // branches.
+    ssgBranch * in_range = new ssgBranch;
+    ssgBranch * out_of_range = new ssgBranch;
+    lod->addKid(in_range);
+    lod->addKid(out_of_range);
+
+    LeafUserData * data = new LeafUserData;
+    data->is_filled_in = false;
+    data->leaf = leaf;
+    data->mat = mat;
+    data->branch = in_range;
+    data->sin_lat = sin(lat_deg * SGD_DEGREES_TO_RADIANS);
+    data->cos_lat = cos(lat_deg * SGD_DEGREES_TO_RADIANS);
+    data->sin_lon = sin(lon_deg * SGD_DEGREES_TO_RADIANS);
+    data->cos_lon = cos(lon_deg * SGD_DEGREES_TO_RADIANS);
+
+    in_range->setUserData(data);
+    in_range->setTravCallback(SSG_CALLBACK_PRETRAV, leaf_in_range_callback);
+    out_of_range->setUserData(data);
+    out_of_range->setTravCallback(SSG_CALLBACK_PRETRAV,
+                                   leaf_out_of_range_callback);
+    out_of_range
+      ->addKid(new DummyBSphereEntity(leaf->getBSphere()->getRadius()));
 }
 
 
+\f
+////////////////////////////////////////////////////////////////////////
+// Scenery loaders.
+////////////////////////////////////////////////////////////////////////
+
 // Load an Binary obj file
 bool fgBinObjLoad( const string& path, const bool is_base,
-                  Point3D *center,
-                  double *bounding_radius,
-                  ssgBranch* geometry,
-                  ssgBranch* rwy_lights,
-                  ssgVertexArray *ground_lights )
+                   Point3D *center,
+                   double *bounding_radius,
+                   SGMaterialLib *matlib,
+                   ssgBranch* geometry,
+                   ssgBranch* rwy_lights,
+                   ssgBranch* taxi_lights,
+                   ssgVertexArray *ground_lights )
 {
     SGBinObject obj;
-    bool use_dynamic_objects =
-      fgGetBool("/sim/rendering/dynamic-objects", false);
+    bool use_random_objects =
+      fgGetBool("/sim/rendering/random-objects", true);
 
     if ( ! obj.read_bin( path ) ) {
-       return false;
+        return false;
     }
 
     geometry->setName( (char *)path.c_str() );
-   
-    double geod_lon = 0.0, geod_lat = 0.0, geod_alt = 0.0,
-      geod_sl_radius = 0.0;
-    if ( is_base ) {
-       // reference point (center offset/bounding sphere)
-       *center = obj.get_gbs_center();
-       *bounding_radius = obj.get_gbs_radius();
-
-                               // Calculate the geodetic centre of
-                               // the tile, for aligning automatic
-                               // objects.
-       Point3D geoc = sgCartToPolar3d(*center);
-       geod_lon = geoc.lon();
-       sgGeocToGeod(geoc.lat(), geoc.radius(),
-                    &geod_lat, &geod_alt, &geod_sl_radius);
-       geod_lon *= SGD_RADIANS_TO_DEGREES;
-       geod_lat *= SGD_RADIANS_TO_DEGREES;
-    }
 
-    point_list nodes = obj.get_wgs84_nodes();
-    point_list colors = obj.get_colors();
-    point_list normals = obj.get_normals();
-    point_list texcoords = obj.get_texcoords();
+    // reference point (center offset/bounding sphere)
+    *center = obj.get_gbs_center();
+    *bounding_radius = obj.get_gbs_radius();
+
+    point_list const& nodes = obj.get_wgs84_nodes();
+    // point_list const& colors = obj.get_colors();
+    point_list const& normals = obj.get_normals();
+    point_list const& texcoords = obj.get_texcoords();
 
-    string material, tmp_mat;
-    int_list vertex_index;
-    int_list normal_index;
+    string material;
     int_list tex_index;
 
-    int i;
-    bool is_lighting = false;
+    group_list::size_type i;
 
     // generate points
-    string_list pt_materials = obj.get_pt_materials();
-    group_list pts_v = obj.get_pts_v();
-    group_list pts_n = obj.get_pts_n();
-    for ( i = 0; i < (int)pts_v.size(); ++i ) {
-       // cout << "pts_v.size() = " << pts_v.size() << endl;
-       tmp_mat = pt_materials[i];
-       if ( tmp_mat.substr(0, 3) == "RWY" ) {
-           material = "LIGHTS";
-           is_lighting = true;
-       } else {
-           material = tmp_mat;
-       }
-       vertex_index = pts_v[i];
-       normal_index = pts_n[i];
-       tex_index.clear();
-       ssgLeaf *leaf = gen_leaf( path, GL_POINTS, material,
-                                 nodes, normals, texcoords,
-                                 vertex_index, normal_index, tex_index,
-                                 false, ground_lights );
-
-       if ( is_lighting ) {
-           float ranges[] = { 0, 12000 };
-           leaf->setCallback(SSG_CALLBACK_PREDRAW, runway_lights_predraw);
-           ssgRangeSelector * lod = new ssgRangeSelector;
-           lod->setRanges(ranges, 2);
-           lod->addKid(leaf);
-           rwy_lights->addKid(lod);
-       } else {
-           geometry->addKid( leaf );
-       }
+    string_list const& pt_materials = obj.get_pt_materials();
+    group_list const& pts_v = obj.get_pts_v();
+    group_list const& pts_n = obj.get_pts_n();
+    for ( i = 0; i < pts_v.size(); ++i ) {
+        // cout << "pts_v.size() = " << pts_v.size() << endl;
+       if ( pt_materials[i].substr(0, 3) == "RWY" ) {
+            sgVec3 up;
+            sgSetVec3( up, center->x(), center->y(), center->z() );
+            // returns a transform -> lod -> leaf structure
+            ssgBranch *branch = gen_directional_lights( nodes, normals,
+                                                        pts_v[i], pts_n[i],
+                                                        matlib, pt_materials[i],
+                                                        up );
+            // branches don't honor callbacks as far as I know so I'm
+            // commenting this out to avoid a plib runtime warning.
+            branch->setTravCallback( SSG_CALLBACK_PRETRAV,
+                                     runway_lights_pretrav );
+            if ( pt_materials[i].substr(0, 16) == "RWY_BLUE_TAXIWAY" ) {
+                taxi_lights->addKid( branch );
+            } else {
+                rwy_lights->addKid( branch );
+            }
+        } else {
+            material = pt_materials[i];
+            tex_index.clear();
+            ssgLeaf *leaf = sgMakeLeaf( path, GL_POINTS, matlib, material,
+                                        nodes, normals, texcoords,
+                                        pts_v[i], pts_n[i], tex_index,
+                                        false, ground_lights );
+            geometry->addKid( leaf );
+        }
+    }
+
+    // Put all randomly-placed objects under a separate branch
+    // (actually an ssgRangeSelector) named "random-models".
+    ssgBranch * random_object_branch = 0;
+    if (use_random_objects) {
+        float ranges[] = { 0, 20000 }; // Maximum 20km range for random objects
+        ssgRangeSelector * object_lod = new ssgRangeSelector;
+        object_lod->setRanges(ranges, 2);
+        object_lod->setName("random-models");
+        geometry->addKid(object_lod);
+        random_object_branch = new ssgBranch;
+        object_lod->addKid(random_object_branch);
     }
 
     // generate triangles
-    string_list tri_materials = obj.get_tri_materials();
-    group_list tris_v = obj.get_tris_v();
-    group_list tris_n = obj.get_tris_n();
-    group_list tris_tc = obj.get_tris_tc();
-    for ( i = 0; i < (int)tris_v.size(); ++i ) {
-       material = tri_materials[i];
-       vertex_index = tris_v[i];
-       normal_index = tris_n[i];
-       tex_index = tris_tc[i];
-       ssgLeaf *leaf = gen_leaf( path, GL_TRIANGLES, material,
-                                 nodes, normals, texcoords,
-                                 vertex_index, normal_index, tex_index,
-                                 is_base, ground_lights );
-
-       if (use_dynamic_objects)
-         gen_random_surface_objects(leaf, geometry, geod_lon, geod_lat,
-                                    material);
-       geometry->addKid( leaf );
+    string_list const& tri_materials = obj.get_tri_materials();
+    group_list const& tris_v = obj.get_tris_v();
+    group_list const& tris_n = obj.get_tris_n();
+    group_list const& tris_tc = obj.get_tris_tc();
+    for ( i = 0; i < tris_v.size(); ++i ) {
+        ssgLeaf *leaf = sgMakeLeaf( path, GL_TRIANGLES, matlib,
+                                    tri_materials[i],
+                                    nodes, normals, texcoords,
+                                    tris_v[i], tris_n[i], tris_tc[i],
+                                    is_base, ground_lights );
+
+        if ( use_random_objects ) {
+            SGMaterial *mat = matlib->find( tri_materials[i] );
+            if ( mat == NULL ) {
+                SG_LOG( SG_INPUT, SG_ALERT,
+                        "Unknown material for random surface objects = "
+                        << tri_materials[i] );
+            }
+            gen_random_surface_objects( leaf, random_object_branch,
+                                        center, mat );
+        }
+        geometry->addKid( leaf );
     }
 
     // generate strips
-    string_list strip_materials = obj.get_strip_materials();
-    group_list strips_v = obj.get_strips_v();
-    group_list strips_n = obj.get_strips_n();
-    group_list strips_tc = obj.get_strips_tc();
-    for ( i = 0; i < (int)strips_v.size(); ++i ) {
-       material = strip_materials[i];
-       vertex_index = strips_v[i];
-       normal_index = strips_n[i];
-       tex_index = strips_tc[i];
-       ssgLeaf *leaf = gen_leaf( path, GL_TRIANGLE_STRIP, material,
-                                 nodes, normals, texcoords,
-                                 vertex_index, normal_index, tex_index,
-                                 is_base, ground_lights );
-
-       if (use_dynamic_objects)
-         gen_random_surface_objects(leaf, geometry, geod_lon, geod_lat,
-                                    material);
-       geometry->addKid( leaf );
+    string_list const& strip_materials = obj.get_strip_materials();
+    group_list const& strips_v = obj.get_strips_v();
+    group_list const& strips_n = obj.get_strips_n();
+    group_list const& strips_tc = obj.get_strips_tc();
+    for ( i = 0; i < strips_v.size(); ++i ) {
+        ssgLeaf *leaf = sgMakeLeaf( path, GL_TRIANGLE_STRIP,
+                                    matlib, strip_materials[i],
+                                    nodes, normals, texcoords,
+                                    strips_v[i], strips_n[i], strips_tc[i],
+                                    is_base, ground_lights );
+
+        if ( use_random_objects ) {
+            SGMaterial *mat = matlib->find( strip_materials[i] );
+            if ( mat == NULL ) {
+                SG_LOG( SG_INPUT, SG_ALERT,
+                        "Unknown material for random surface objects = "
+                        << strip_materials[i] );
+            }
+            gen_random_surface_objects( leaf, random_object_branch,
+                                        center, mat );
+        }
+        geometry->addKid( leaf );
     }
 
     // generate fans
-    string_list fan_materials = obj.get_fan_materials();
-    group_list fans_v = obj.get_fans_v();
-    group_list fans_n = obj.get_fans_n();
-    group_list fans_tc = obj.get_fans_tc();
-    for ( i = 0; i < (int)fans_v.size(); ++i ) {
-       material = fan_materials[i];
-       vertex_index = fans_v[i];
-       normal_index = fans_n[i];
-       tex_index = fans_tc[i];
-       ssgLeaf *leaf = gen_leaf( path, GL_TRIANGLE_FAN, material,
-                                 nodes, normals, texcoords,
-                                 vertex_index, normal_index, tex_index,
-                                 is_base, ground_lights );
-       if (use_dynamic_objects)
-         gen_random_surface_objects(leaf, geometry, geod_lon, geod_lat,
-                                    material);
-       geometry->addKid( leaf );
+    string_list const& fan_materials = obj.get_fan_materials();
+    group_list const& fans_v = obj.get_fans_v();
+    group_list const& fans_n = obj.get_fans_n();
+    group_list const& fans_tc = obj.get_fans_tc();
+    for ( i = 0; i < fans_v.size(); ++i ) {
+        ssgLeaf *leaf = sgMakeLeaf( path, GL_TRIANGLE_FAN,
+                                    matlib, fan_materials[i],
+                                    nodes, normals, texcoords,
+                                    fans_v[i], fans_n[i], fans_tc[i],
+                                    is_base, ground_lights );
+        if ( use_random_objects ) {
+            SGMaterial *mat = matlib->find( fan_materials[i] );
+            if ( mat == NULL ) {
+                SG_LOG( SG_INPUT, SG_ALERT,
+                        "Unknown material for random surface objects = "
+                        << fan_materials[i] );
+            }
+            gen_random_surface_objects( leaf, random_object_branch,
+                                        center, mat );
+        }
+        geometry->addKid( leaf );
     }
 
     return true;