Fix some minor inconsistencies and inefficiencies:

- no extra nodes are created at all if the material has no random
  objects defined

- the range selector is place correctly under the transformation

- there is only one range selector for each object type in each
  triangle (experimental -- doesn't seem to make a difference in speed
  or memory)

This patch removes Curt's patch that randomized ranges slightly, since
individual random objects no longer have their own range selectors.
It also leaves the object-group-range value unused, for now.

diff --git a/src/Objects/obj.cxx b/src/Objects/obj.cxx
index ba81c0efa7f88430953461ce46169b5e5d3ad0a3..a3ca51c92e955083b726c8124e4938b4b70ebc24 100644 (file)
--- a/src/Objects/obj.cxx
+++ b/src/Objects/obj.cxx
@@ -342,18 +342,7 @@ add_object_to_triangle (sgVec3 p1, sgVec3 p2, sgVec3 p3, sgVec3 center,
     sgPostMultMat4(OBJ, OBJ_pos);
     ssgTransform * pos = new ssgTransform;
     pos->setTransform(OBJ);
-    float obj_range = mat->get_object_lod(object_index);
-    float range_div = (sg_random() * obj_range);
-    if (range_div < 0.0000001) {
-      // avoid a divide by zero error
-      range_div = 1.0;
-    }
-    float random_range = 160.0 * obj_range / range_div + obj_range;
-    float ranges[] = {0, random_range};
-    ssgRangeSelector *range = new ssgRangeSelector;
-    range->setRanges(ranges, 2);
-    range->addKid(mat->get_object(object_index));
-    pos->addKid(range);
+    pos->addKid(mat->get_object(object_index));
     branch->addKid(pos);
 }
 
@@ -397,73 +386,94 @@ gen_random_surface_objects (ssgLeaf *leaf,
                            float lat_deg,
                            const string &material_name)
 {
+    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;
     }
 
-    int num = leaf->getNumTriangles();
-    float hdg_deg = 0.0;       // do something here later
+                               // If the material has no randomly-placed
+                               // objects, return now.
+    int num_objects = mat->get_object_count();
+    if (num_objects < 1)
+      return;
 
+                               // 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);
 
-    if ( num > 0 ) {
-       short int n1, n2, n3;
-       float *p1, *p2, *p3;
-       sgVec3 result;
+    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 );
+                               // generate a repeatable random seed
+    p1 = leaf->getVertex( 0 );
+    unsigned int seed = (unsigned int)p1[0];
+    sg_srandom( seed );
+
+                               // 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 );
 
-       int num_objects = mat->get_object_count();
-       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 );
                                // 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);
-           ssgTransform * location = new ssgTransform;
-           sgMat4 TRANS;
-           sgMakeTransMat4(TRANS, center);
-           location->setTransform(TRANS);
-
-           for (int j = 0; j < num_objects; j++) {
-             double num = area / mat->get_object_coverage(j);
-             float ranges[] = {0, mat->get_object_group_lod(j)};
-             ssgRangeSelector * lod = new ssgRangeSelector;
-             lod->setRanges(ranges, 2);
-             lod->addKid(location);
-             branch->addKid(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, location);
-               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, location);
-               }
-             }
-           }
+       // 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);
+         }
        }
+      }
     }
 }