Start of support for precalculating texture coordinates.

Try to avoid a situation where you cycle between too many nodes and two few
  nodes with just a single increment of error level.

Tools/Construct/GenOutput/genobj.cxx

@@ -60,6 +60,70 @@ void FGGenOutput::calc_gbs( FGConstruct& c ) {
 }
 
 
+#define FG_TEX_CONSTANT 69.0
+
+// traverse the specified fan and attempt to calculate "none
+// stretching" texture coordinates
+int_list FGGenOutput::calc_tex_coords( point_list geod_nodes, int_list fan ) {
+    // cout << "calculating texture coordinates for a specific fan of size = "
+    //      << fan.size() << endl;
+
+    // find min/max of fan
+    Point3D min, max, p, t;
+    bool first = true;
+
+    for ( int i = 0; i < (int)fan.size(); ++i ) {
+	p = geod_nodes[ fan[i] ];
+	t.setx( p.x() * FG_TEX_CONSTANT );
+	t.sety( p.y() * FG_TEX_CONSTANT );
+
+	if ( first ) {
+	    min = max = t;
+	    first = false;
+	} else {
+	    if ( t.x() < min.x() ) {
+		min.setx( t.x() );
+	    }
+	    if ( t.y() < min.y() ) {
+		min.sety( t.y() );
+	    }
+	    if ( t.x() > max.x() ) {
+		max.setx( t.x() );
+	    }
+	    if ( t.y() > max.y() ) {
+		max.sety( t.y() );
+	    }
+	}
+    }
+    min.setx( (double)( (int)min.x() - 1 ) );
+    min.sety( (double)( (int)min.y() - 1 ) );
+    // cout << "found min = " << min << endl;
+
+    // generate tex_list
+    Point3D shifted_t;
+    int index;
+    int_list tex;
+    tex.clear();
+    for ( int i = 0; i < (int)fan.size(); ++i ) {
+	p = geod_nodes[ fan[i] ];
+	t.setx( p.x() * FG_TEX_CONSTANT );
+	t.sety( p.y() * FG_TEX_CONSTANT );
+	shifted_t = t - min;
+	if ( shifted_t.x() < FG_EPSILON ) {
+	    shifted_t.setx( 0.0 );
+	}
+	if ( shifted_t.y() < FG_EPSILON ) {
+	    shifted_t.sety( 0.0 );
+	}
+	shifted_t.setz( 0.0 );
+	index = tex_coords.unique_add( shifted_t );
+	tex.push_back( index );
+    }
+
+    return tex;
+}
+
+
 // build the necessary output structures based on the triangulation
 // data
 int FGGenOutput::build( FGConstruct& c ) {
@@ -92,6 +156,20 @@ int FGGenOutput::build( FGConstruct& c ) {
 	}
     }
 
+    // build the texture coordinate list and make a parallel structure
+    // to the fan list for pointers into the texture list
+    cout << "calculating texture coordinates" << endl;
+    tex_coords.clear();
+
+    for ( int i = 0; i < FG_MAX_AREA_TYPES; ++i ) {
+	for ( int j = 0; j < (int)fans[i].size(); ++j ) {
+	    int_list t_list = calc_tex_coords( geod_nodes, fans[i][j] );
+	    // cout << fans[i][j].size() << " === " 
+	    //      << t_list.size() << endl; 
+	    textures[i].push_back( t_list );
+	}
+    }
+
     // calculate the global bounding sphere
     calc_gbs( c );
     cout << "center = " << gbs_center << " radius = " << gbs_radius << endl;
@@ -247,6 +325,14 @@ int FGGenOutput::write( FGConstruct &c ) {
     }
     fprintf(fp, "\n");
 
+    // write texture coordinates
+    point_list tex_coord_list = tex_coords.get_node_list();
+    for ( int i = 0; i < (int)tex_coord_list.size(); ++i ) {
+	p = tex_coord_list[i];
+	fprintf(fp, "vt %.5f %.5f\n", p.x(), p.y());
+    }
+    fprintf(fp, "\n");
+
     // write triangles (grouped by type for now)
     Point3D center;
     double radius;
@@ -265,33 +351,13 @@ int FGGenOutput::write( FGConstruct &c ) {
 	    fprintf(fp, "# bs %.4f %.4f %.4f %.2f\n", 
 		    center.x(), center.y(), center.z(), radius);
 
-	    fan_list_iterator f_current = fans[i].begin();
-	    fan_list_iterator f_last = fans[i].end();
-	    for ( ; f_current != f_last; ++f_current ) {
+	    for ( int j = 0; j < (int)fans[i].size(); ++j ) {
 		fprintf( fp, "tf" );
-		total_tris += f_current->size() - 2;
-		int_list_iterator i_current = f_current->begin();
-		int_list_iterator i_last = f_current->end();
-		for ( ; i_current != i_last; ++i_current ) {
-		    fprintf( fp, " %d", *i_current );
+		total_tris += fans[i][j].size() - 2;
+		for ( int k = 0; k < (int)fans[i][j].size(); ++k ) {
+		    fprintf( fp, " %d/%d", fans[i][j][k], textures[i][j][k] );
 		}
 		fprintf( fp, "\n" );
-
-#if 0
-		{
-		    int_list_iterator i_current = f_current->begin();
-		    int_list_iterator i_last = f_current->end();
-		    int center = *i_current;
-		    ++i_current;
-		    int n2 = *i_current;
-		    ++i_current;
-		    for ( ; i_current != i_last; ++i_current ) {
-			int n3 = *i_current;
-			fprintf( fp, "f %d %d %d\n", center, n2, n3 );
-			n2 = n3;
-		    }
-		}
-#endif
 	    }
 
 	    fprintf( fp, "\n" );

Tools/Construct/GenOutput/genobj.hxx

@@ -48,6 +48,10 @@ FG_USING_STD(string);
 FG_USING_STD(vector);
 
 
+typedef vector < int_list > tex_list;
+typedef tex_list::iterator tex_list_iterator;
+typedef tex_list::const_iterator const_tex_list_iterator;
+
 class FGGenOutput {
 
 private:
@@ -58,9 +62,15 @@ private:
     // triangles (by index into point list)
     triele_list tri_elements;
 
+    // texture coordinates
+    FGTriNodes tex_coords;
+
     // fan list
     fan_list fans[FG_MAX_AREA_TYPES];
 
+    // textures pointer list
+    tex_list textures[FG_MAX_AREA_TYPES];
+
     // global bounding sphere
     Point3D gbs_center;
     double gbs_radius;
@@ -77,6 +87,10 @@ private:
     void calc_bounding_sphere( FGConstruct& c, const FGTriEle& t, 
 			       Point3D *center, double *radius );
 
+    // traverse the specified fan and attempt to calculate "none
+    // stretching" texture coordinates
+    int_list calc_tex_coords( point_list geod_nodes, int_list fan );
+
 public:
 
     // Constructor && Destructor

Tools/Construct/Main/main.cxx

@@ -341,6 +341,9 @@ void construct_tile( FGConstruct& c ) {
     // arbitrarily complex tiles.
 
     bool acceptable = false;
+    bool growing = false;
+    bool shrinking = false;
+
     double error = 200.0;
     int count = 0;
 
@@ -371,8 +374,14 @@ void construct_tile( FGConstruct& c ) {
 	    cout << "produced too few nodes ..." << endl;
 
 	    acceptable = false;
+	    growing = true;
 
-	    error /= 1.5;
+	    if ( shrinking ) {
+		error /= 1.25;
+		shrinking = false;
+	    } else {
+		error /= 1.5;
+	    }
 	    cout << "Setting error to " << error << " and retrying fit." 
 		 << endl;
 	}
@@ -383,8 +392,15 @@ void construct_tile( FGConstruct& c ) {
 	    cout << "produced too many nodes ..." << endl;
 	    
 	    acceptable = false;
+	    shrinking = true;
+
+	    if ( growing ) {
+		error *= 1.25;
+		growing = false;
+	    } else {
+		error *= 1.5;
+	    }
 
-	    error *= 1.5;
 	    cout << "Setting error to " << error << " and retrying fit." 
 		 << endl;
 	}

Tools/Construct/Main/master.cxx

@@ -117,10 +117,10 @@ main(int argc, char **argv) {
     FGBucket tmp1( 0.0, 0.0 );
 
     double dy = tmp1.get_height();
-    lat = 44.25 + dy * 0.5;
+    lat = 68.75 + dy * 0.5;
 
     bool start_lon = true;
-    lon = -85.75 + (1.0/16.0);
+    lon = -152.9 /* + (1.0/16.0) */;
 
     while ( lat <= 90.0 ) {
 	FGBucket tmp2( 0.0, lat );

Tools/Construct/Triangulate/triangle.cxx

@@ -413,9 +413,10 @@ int FGTriangle::run_triangulate( int pass ) {
     if ( pass == 1 ) {
 	// use a quality value of 10 (q10) meaning no interior
 	// triangle angles less than 10 degrees
+	// tri_options = "pczAen";
 	tri_options = "pczq10Aen";
-	// string tri_options = "pzAen";
-	// string tri_options = "pczq15S400Aen";
+	// // string tri_options = "pzAen";
+	// // string tri_options = "pczq15S400Aen";
     } else if ( pass == 2 ) {
 	// no new points on boundary (Y), no internal segment
 	// splitting (YY), no quality refinement ()