/*
* We try to find an optimal triangle grid
- *
- * Vertices in strip are numbered as follows:
- *
- * ___ X-2 ___ X-1 ___ 0 ___ 1 ___ 2 ___ 3 ___ 4 __
- * Y-1 Y-1 0 0 0 0 0
- * / \ / \ / \ / \ / \ / \ / \
- * / \ / \ / \ / \ / \ / \ / \
- * X-3 ___ X-2 ___ X-1 ___ 0 ___ 1 ___ 2 ___ 3 ___ 4
- * Y-2 Y-2 Y-2 1 1 1 1 1
- * \ / \ / \ / \ / \ / \ / \ /
- * \ / \ / \ / \ / \ / \ / \ /
- * ___ X-3 ___ X-2 ___ X-1 ___ 0 ___ 1 ___ 2 ___ 3 __
- * Y-3 Y-3 Y-3 2 2 2 2
- *
- * . . . . . . . . . . . . . . .
- *
- * X-4 ___ X-3 ___ X-2 ___ X-1 ___ 0 ___ 1 ___ 2 ___ 3
- * 1 1 1 1 Y-2 Y-2 Y-2 Y-2
- * \ / \ / \ / \ / \ / \ / \ /
- * \ / \ / \ / \ / \ / \ / \ /
- * ___ X-4 ___ X-3 ___ X-2 ___ X-1 ___ 0 ___ 1 ___ 2 __
- * 0 0 0 0 Y-1 Y-1 Y-1
- *
- * Node x,y for
- * 0 <= x < X x = distance along
- * 0 <= y < Y y = distance across
- *
- * Vertices are in reading order from diagram above ie x varies fastest.
- *
- * Y must be even. The actual location opposite (0,0) is (X-(Y-1)/2,0),
- * and likewise opposite (0,Y-1) is ((Y-1)/2,0).
- *
- * To label edges, we counte anticlockwise[*] from to-the-right:
- *
- * \2 /1
- * \ /
- * ___ 0 __
- * 3 1 0
- * / \
- * 4/ 5\
- *
- * [*] That is, in the direction represented as anticlockwise for
- * the vertices (0,*)..(4,*) in the diagram above; and of course
- * that is clockwise for the vertices (X-5,*)..(X-1,*). The
- * numbering has an actual discontinuity between (X-1,*) and (0,*).
- *
- * When we iterate over edges, we iterate first over vertices and then
- * over edges 0 to 2, disregarding edges 3 to 5.
*/
-#define XBITS 4
-#define X (1<<XBITS)
-#define YBITS 4
-#define Y (1<<YBITS)
-
-/* vertex number: 0000 | y | x
- * YBITS XBITS
- */
-
-#define N (X*Y)
-#define XMASK (X-1)
-#define YSHIFT XBITS
-#define Y1 (1 << YSHIFT)
-#define YMASK (Y-1 << YSHIFT)
-
/* Energy has the following parts right now:
*/
/*
* and the huge energy ought then to be sufficient for the model to
* avoid being close to R=S. */
-#define V6 6
-
-static int edge_end2(unsigned v1, int e) {
- /* The topology is equivalent to that of a square lattice with only
- * half of the diagonals. Ie, the result of shearing the triangular
- * lattice to make the lines of constant x vertical. This gives
- * these six directions:
- *
- * 2 1
- * | /
- * |/
- * 3--*--0
- * /|
- * / |
- * 4 5
- *
- * This also handily makes vertical the numbering discontinuity,
- * where the join happens.
- */
- static const unsigned dx[V6]= { +1, +1, 0, -1, -1, 0 },
- dy[V6]= { 0, +Y1, +Y1, 0, -Y1, -Y1 };
- unsigned x, y;
-
- y= (v1 & YMASK) + dy[e];
- if (y & ~YMASK) return -1;
-
- x= (v1 & XMASK) + dx[e];
- if (x & ~XMASK) {
- y= (Y-1)*Y1 - y;
- x &= XMASK;;
- }
- return x | y;
-}
-
-#define D3 3
-
-#define FOR_VERTEX(v) \
- for ((v)=0; (v)<N; (v)++)
-
-#define FOR_VPEDGE(v,e) \
- for ((e)=0; (e)<V6; (e)++)
-
-#define EDGE_END2 edge_end2
-
-#define FOR_VEDGE(v1,e,v2) \
- FOR_VPEDGE((v1),(e))
- if (((v2)= EDGE_END2((v1),(e))) < 0) ; else
-
-#define FOR_EDGE(v1,e,v2) \
- FOR_VERTEX((v1)) \
- FOR_VEDGE((v1),(e),(v2))
-
-#define FOR_COORD(k) \
- for ((k)=0; (k)<D3; (k)++)
-
-#define K FOR_COORD(k)
-
static double hypotD(const double p[], const double q[]) {
int k;
double pq[D3];