}
/*
- * edge descriptor f = 00 | e | y | x
- * 3 YBITS XBITS
+ * edge descriptor f = 0000 | e | y | x
+ * 3 YBITS XBITS
*
- * e is 0..5. The edge is edge e out of vertex (x,y).
+ * e is 0..6. The edge is edge e out of vertex (x,y), or if
+ * e==6 it's the `at end' value for the out edge iterator.
*
* BGL expects an undirected graph's edges to have two descriptors
- * each, one in each direction.
+ * each, one in each direction (otherwise e would be just 0..2).
*/
/*
*/
#define VMASK (YMASK|XMASK)
-#define ESHIFT (YBITS|XBITS)
-
-class Graph { }; // this is a dummy as our graph has no actual representation
+#define ESHIFT (YBITS+XBITS)
using namespace boost;
-struct OutEdgeIterator :
+/*
+ * We iterate over edges in the following order:
+ *
+ * \#0 /1#
+ * \ /
+ * ___ 0 __
+ * #2 1 #3
+ * / \
+ * #4/ #5\ and finally #6 is V6
+ *
+ *
+ * This ordering permits the order-4 nodes at the strip's edge
+ * to have a contiguous edge iterator values. The iterator
+ * starts at #0 which is edge 2 (see mgraph.h), or #2 (edge 3).
+ */
+static const int oei_edge_delta[V6]=
+ /* 0 1 2 3 4 5 initial e
+ * #3 #1 #0 #2 #4 #5 initial ix
+ * #4 #2 #1 #3 #5 #6 next ix
+ * 4 3 1 0 5 V6 next e
+ */ {
+ 4<<ESHIFT, 2<<ESHIFT, -1<<ESHIFT,
+ -3<<ESHIFT, 1<<ESHIFT, (V6-5)<<ESHIFT
+};
+
+class OutEdgeIterator :
public iterator_facade<
OutEdgeIterator,
int const,
forward_traversal_tag
> {
int f;
- void increment() { f += 1<<ESHIFT; }
+ public:
+ void increment() {
+ //printf("incrementing f=%03x..",f);
+ f += oei_edge_delta[f>>ESHIFT];
+ //printf("%03x\n",f);
+ }
bool equal(OutEdgeIterator const& other) const { return f == other.f; }
int const& dereference() const { return f; }
OutEdgeIterator() { }
OutEdgeIterator(int _f) : f(_f) { }
- OutEdgeIterator(int v, int e) : f(e << ESHIFT | v) { }
+ OutEdgeIterator(int v, int e) : f(e<<ESHIFT | v) {
+ //printf("constructed v=%02x e=%x f=%03x\n",v,e,f);
+ }
+
+ static int voe_min(int _v) { return (_v & YMASK) ? 2 : 3; }
+ static int voe_max(int _v) { return (_v & YMASK)==(Y-1) ? V6 : 4; }
+ static int voe_degree(int _v) { return RIM_VERTEX_P(_v) ? 4 : V6; }
};
typedef counting_iterator<int> VertexIterator;
namespace boost {
+ class Graph { }; // this is a dummy as our graph has no actual representation
+
// We make Graph a model of various BGL Graph concepts.
// This mainly means that graph_traits<Graph> has lots of stuff.
public virtual vertex_list_graph_tag,
public virtual edge_list_graph_tag { };
+ template<>
struct graph_traits<Graph> {
// Concept Graph:
typedef int vertex_descriptor; /* vertex number, -1 => none */
// Concept IncidenceGraph:
inline int source(int f, const Graph&) { return f&VMASK; }
- inline int target(int f, const Graph&) { return EDGE_END2(f&VMASK, f>>ESHIFT); }
+ inline int target(int f, const Graph&) {
+ int v2= EDGE_END2(f&VMASK, f>>ESHIFT);
+ //printf("traversed %03x..%02x\n",f,v2);
+ return v2;
+ }
inline std::pair<OutEdgeIterator,OutEdgeIterator>
out_edges(int v, const Graph&) {
- return std::make_pair(OutEdgeIterator(v, VE_MIN(v)),
- OutEdgeIterator(v, VE_MAX(v)));
+ return std::make_pair(OutEdgeIterator(v, OutEdgeIterator::voe_min(v)),
+ OutEdgeIterator(v, OutEdgeIterator::voe_max(v)));
}
inline unsigned out_degree(int v, const Graph&) {
- return VE_MAX(v) - VE_MIN(v);
+ return OutEdgeIterator::voe_degree(v);
}
// Concept VertexListGraph:
- inline std::pair<VertexIterator,VertexIterator> vertices(const Graph&) {
+ inline
+ std::pair<VertexIterator,VertexIterator> vertices(const Graph&) {
return std::make_pair(VertexIterator(0), VertexIterator(N));
}
inline unsigned num_vertices(const Graph&) { return N; }
*/
static const double d2_epsilon= 1e-6;
- double edge_weights[N*V6], vertex_distances[N], total_cost=0;
+ double edge_weights[V6<<ESHIFT], vertex_distances[N], total_cost=0;
int v1,v2,e,f;
FOR_VERTEX(v1)
double a1= vertex_areas[v1];
single_source_shortest_paths(v1, edge_weights, vertex_distances);
FOR_VERTEX(v2) {
+ if (v1 == v2) continue;
double a2= vertex_areas[v2];
double d2= hypotD2plus(v[v1],v[v2], d2_epsilon);
- double sd= vertex_distances[v2] / d2;
- double sd2= sd*sd;
- total_cost += a1*a2 * (sd2 - 1) / (d2*d2);
+ double s= vertex_distances[v2];
+ double s2= s*s + d2_epsilon;
+ double sd2= s2 / d2;
+ double cost_contrib= a1*a2 * (sd2 - 1) / (d2*d2);
+ if (cost_contrib < -1e-4) {
+ printf("layout %03x..%03x (a=%g,%g) s=%g s2=%g d2=%g sd2=%g"
+ " cost+=%g\n", v1,v2, a1,a2, s,s2,d2,sd2, cost_contrib);
+ abort();
+ }
+ total_cost += cost_contrib;
}
}
return total_cost;