X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=energy.c;h=19f32e2fa3a0459ab94339a202b6844120b0a8b1;hp=9c351a52b9349b327547b7122172944071a9e0d3;hb=32c7d2a5c5cb58ed3a8fb9fc383a31a80b01c052;hpb=289edb461ff46150a66983e290438a725505d261

diff --git a/energy.c b/energy.c
index 9c351a5..19f32e2 100644
--- a/energy.c
+++ b/energy.c
@@ -1,180 +1,304 @@
- /*
-  * We try to find an optimal triangle grid
-  */
-
- #include "common.h"
- #include "minimise.h"
- #include "mgraph.h"
-
- double vertex_areas[N], vertex_mean_edge_lengths[N], edge_lengths[N][V6];
-
- static double best_energy= DBL_MAX;
-
- static void addcost(double *energy, double tweight, double tcost, int pr);
- #define COST(weight, compute) addcost(&energy, (weight), (compute), printing)
-
- void energy_init(void) {
- }
-
- /*---------- main energy computation and subroutines ----------*/
-
- double compute_energy(const struct Vertices *vs) {
-   static int bests_unprinted;
-
-   double energy;
-   int printing;
-
-   compute_edge_lengths(vs->a);
-   compute_vertex_areas(vs->a);
-   energy= 0;
-
-   printing= printing_check(pr_cost,0);
-
-   if (printing) printf("%15lld c>e |", evaluations);
-
-   if (XBITS==3) {
-     COST(  3e3,   line_bending_cost(vs->a));
-     COST(  3e3,   edge_length_variation_cost(vs->a));
-     COST( 0.4e3,  rim_proximity_cost(vs->a));
-     COST(  1e6,   edge_angle_cost(vs->a, 0.5/1.7));
- //    COST(  1e1,   small_triangles_cost(vs->a));
-     COST(  1e12,   noncircular_rim_cost(vs->a));
-     stop_epsilon= 1e-6;
-   } else if (XBITS==4) {
-     COST(  3e5,   line_bending_cost(vs->a));
-     COST( 10e2,   edge_length_variation_cost(vs->a));
-     COST( 9.0e1,  rim_proximity_cost(vs->a)); // 5e1 is too much
-						  // 2.5e1 is too little
-     // 0.2e1 grows compared to previous ?
-     // 0.6e0 shrinks compared to previous ?
-     COST(  1e12,   edge_angle_cost(vs->a, 0.5/1.3));
-     COST(  1e18,   noncircular_rim_cost(vs->a));
-     stop_epsilon= 1e-6;
-   } else {
-     abort();
-   }
-
-   if (printing) printf("| total %# e |", energy);
-
-   if (energy < best_energy) {
-     FILE *best_f;
-     int r;
-
-     if (printing) {
-       printf(" BEST");
-       if (bests_unprinted) printf(" [%4d]",bests_unprinted);
-       bests_unprinted= 0;
-     } else {
-       bests_unprinted++;
-     }
-
-     best_f= fopen(best_file_tmp,"wb");  if (!best_f) diee("fopen new out");
-     r= fwrite(vs->a,sizeof(vs->a),1,best_f); if (r!=1) diee("fwrite");
-     if (fclose(best_f)) diee("fclose new best");
-     if (rename(best_file_tmp,best_file)) diee("rename install new best");
-
-     best_energy= energy;
-   }
-   if (printing) {
-     putchar('\n');
-     flushoutput();
-   }
-
-   evaluations++;
-   return energy;
- }
-
- static void addcost(double *energy, double tweight, double tcost, int pr) {
-   double tenergy= tweight * tcost;
-   if (pr) printf(" %# e x %g > %# e* |", tcost, tweight, tenergy);
-   *energy += tenergy;
- }
-
- /*---------- Precomputations ----------*/
-
- void compute_edge_lengths(const Vertices vertices) {
-   int v1,e,v2;
-
-   FOR_EDGE(v1,e,v2)
-     edge_lengths[v1][e]= hypotD(vertices[v1],vertices[v2]);
- }
-
- void compute_vertex_areas(const Vertices vertices) {
-   int v0,v1,v2, e1,e2;
- //  int k;
-
-   FOR_VERTEX(v0) {
-     double total= 0.0, edges_total=0;
-     int count= 0;
-
-     FOR_VEDGE(v0,e1,v1) {
-       e2= (e1+1) % V6;
-       v2= EDGE_END2(v0,e2);
-       if (v2<0) continue;
-
-       edges_total += edge_lengths[v0][e1];
-
- //      double e1v[D3], e2v[D3], av[D3];
- //      K {
- //	e1v[k]= vertices[v1][k] - vertices[v0][k];
- //	e2v[k]= vertices[v2][k] - vertices[v0][k];
- //      }
- //      xprod(av, e1v, e2v);
- //      total += magnD(av);
-
-       count++;
-     }
-     vertex_areas[v0]= total / count;
-     vertex_mean_edge_lengths[v0]= edges_total / count;
-   }
- }
-
- /*---------- Edgewise vertex displacement ----------*/
-
-   /*
-    * Definition:
-    *
-    *    At each vertex Q, in each direction e:
-    *
-    *                   	              e
-    *                           Q ----->----- R
-    *		          _,-'\__/
-    *   	       	      _,-'     	 delta
-    * 		   P '
-    *
-    *                      r
-    *       cost    = delta          (we use r=3)
-    *           Q,e
-    *
-    *
-    * Calculation:
-    *
-    *      Let vector A = PQ
-    *                 B = QR
-    *
-    *   		       -1   A . B
-    *      delta =  tan     -------
-    *     		  | A x B |
-    *
-    *      which is always in the range 0..pi because the denominator
-    *      is nonnegative.  We add epsilon to |AxB| to avoid division
-    *      by zero.
-    *
-    *                     r
-    *      cost    = delta
-    *          Q,e
-    */
-
- double line_bending_cost(const Vertices vertices) {
-   static const double axb_epsilon= 1e-6;
-   static const double exponent_r= 4;
-
-   int pi,e,qi,ri, k;
-   double  a[D3], b[D3], axb[D3];
-   double total_cost= 0;
-
-   FOR_EDGE(qi,e,ri) {
-     pi= EDGE_END2(qi,(e+3)%V6); if (pi<0) continue;
+/*
+ * We try to find an optimal triangle grid
+ */
+
+#include "common.h"
+#include "minimise.h"
+#include "mgraph.h"
+#include "parallel.h"
+
+double vertex_areas[N], vertex_mean_edge_lengths[N], edge_lengths[N][V6];
+
+static double best_energy= DBL_MAX;
+
+static void addcost(double *energy, double tweight, double tcost, int pr);
+
+/*---------- main energy computation, weights, etc. ----------*/
+
+typedef double CostComputation(const Vertices vertices, int section);
+typedef void PreComputation(const Vertices vertices, int section);
+
+typedef struct {
+  double weight;
+  CostComputation *fn;
+} CostContribution;
+
+#define NPRECOMPS ((sizeof(precomps)/sizeof(precomps[0])))
+#define NCOSTS ((sizeof(costs)/sizeof(costs[0])))
+#define COST(weight, compute) { (weight),(compute) },
+
+static PreComputation *const precomps[]= {
+  compute_edge_lengths,
+  compute_vertex_areas
+};
+
+static const CostContribution costs[]= {
+
+#if XBITS==3
+#define STOP_EPSILON 1e-6
+    COST(  3e3,   vertex_displacement_cost)
+    COST( 0.4e3,  rim_proximity_cost)
+    COST(  1e7,   edge_angle_cost)
+                  #define EDGE_ANGLE_COST_CIRCCIRCRAT (0.2/1.7)
+    COST(  1e2,   small_triangles_cost)
+    COST(  1e12,   noncircular_rim_cost)
+#endif
+
+#if XBITS==4
+#define STOP_EPSILON 1.2e-4
+    COST(  3e3,   vertex_displacement_cost)
+    COST( 0.2e3,  rim_proximity_cost)
+//    COST(  1e6,   edge_angle_cost)
+                  #define EDGE_ANGLE_COST_CIRCCIRCRAT (0.5/1.7)
+//    COST(  1e1,   small_triangles_cost)
+    COST(  1e12,   noncircular_rim_cost)
+#endif
+
+#if XBITS==5
+#define STOP_EPSILON 1.2e-4
+    COST(  3e7,   line_bending_cost)
+    COST( 10e2,   prop_edge_length_variation_cost)
+    COST( 9.0e3,  rim_proximity_cost) // 5e1 is too much
+				      // 2.5e1 is too little
+    // 0.2e1 grows compared to previous ?
+    // 0.6e0 shrinks compared to previous ?
+
+//    COST(  1e12,   edge_angle_cost)
+                  #define EDGE_ANGLE_COST_CIRCCIRCRAT (0.5/1.3)
+    COST(  1e18,   noncircular_rim_cost)
+#endif
+
+#if XBITS>=6 /* nonsense follows but never mind */
+#define STOP_EPSILON 1e-6
+    COST(  3e5,   line_bending_cost)
+    COST( 10e2,   edge_length_variation_cost)
+    COST( 9.0e1,  rim_proximity_cost) // 5e1 is too much
+				      // 2.5e1 is too little
+    // 0.2e1 grows compared to previous ?
+    // 0.6e0 shrinks compared to previous ?
+
+    COST(  1e12,   edge_angle_cost)
+                  #define EDGE_ANGLE_COST_CIRCCIRCRAT (0.5/1.3)
+    COST(  1e18,   noncircular_rim_cost)
+#endif
+
+};
+
+const double edge_angle_cost_circcircrat= EDGE_ANGLE_COST_CIRCCIRCRAT;
+
+void energy_init(void) {
+  stop_epsilon= STOP_EPSILON;
+}
+
+/*---------- energy computation machinery ----------*/
+
+void compute_energy_separately(const struct Vertices *vs,
+			 int section, void *energies_v, void *totals_v) {
+  double *energies= energies_v;
+  int ci;
+  
+  for (ci=0; ci<NPRECOMPS; ci++) {
+    precomps[ci](vs->a, section);
+    inparallel_barrier();
+  }
+  for (ci=0; ci<NCOSTS; ci++)
+    energies[ci]= costs[ci].fn(vs->a, section);
+}
+
+void compute_energy_combine(const struct Vertices *vertices,
+			 int section, void *energies_v, void *totals_v) {
+  int ci;
+  double *energies= energies_v;
+  double *totals= totals_v;
+
+  for (ci=0; ci<NCOSTS; ci++)
+    totals[ci] += energies[ci];
+}
+
+double compute_energy(const struct Vertices *vs) {
+  static int bests_unprinted;
+
+  double totals[NCOSTS], energy;
+  int ci, printing;
+
+  printing= printing_check(pr_cost,0);
+
+  if (printing) printf("%15lld c>e |", evaluations);
+
+  for (ci=0; ci<NCOSTS; ci++)
+    totals[ci]= 0;
+
+  inparallel(vs,
+	     compute_energy_separately,
+	     compute_energy_combine,
+	     sizeof(totals) /* really, size of energies */,
+	     totals);
+
+  energy= 0;
+  for (ci=0; ci<NCOSTS; ci++)
+    addcost(&energy, costs[ci].weight, totals[ci], printing);
+
+  if (printing) printf("| total %# e |", energy);
+
+  if (energy < best_energy) {
+    FILE *best_f;
+    int r;
+
+    if (printing) {
+      printf(" BEST");
+      if (bests_unprinted) printf(" [%4d]",bests_unprinted);
+      bests_unprinted= 0;
+    } else {
+      bests_unprinted++;
+    }
+
+    best_f= fopen(best_file_tmp,"wb");  if (!best_f) diee("fopen new out");
+    r= fwrite(vs->a,sizeof(vs->a),1,best_f); if (r!=1) diee("fwrite");
+    if (fclose(best_f)) diee("fclose new best");
+    if (rename(best_file_tmp,best_file)) diee("rename install new best");
+
+    best_energy= energy;
+  }
+  if (printing) {
+    putchar('\n');
+    flushoutput();
+  }
+
+  evaluations++;
+  return energy;
+}
+
+static void addcost(double *energy, double tweight, double tcost, int pr) {
+  double tenergy= tweight * tcost;
+  if (pr) printf(" %# e x %g > %# e* |", tcost, tweight, tenergy);
+  *energy += tenergy;
+}
+
+/*---------- Precomputations ----------*/
+
+void compute_edge_lengths(const Vertices vertices, int section) {
+  int v1,e,v2;
+
+  FOR_EDGE(v1,e,v2, OUTER)
+    edge_lengths[v1][e]= hypotD(vertices[v1],vertices[v2]);
+}
+
+void compute_vertex_areas(const Vertices vertices, int section) {
+  int v0,v1,v2, e1,e2;
+//  int k;
+
+  FOR_VERTEX(v0, OUTER) {
+    double total= 0.0, edges_total=0;
+    int count= 0;
+
+    FOR_VEDGE(v0,e1,v1) {
+      e2= (e1+1) % V6;
+      v2= EDGE_END2(v0,e2);
+      if (v2<0) continue;
+
+      edges_total += edge_lengths[v0][e1];
+
+//      double e1v[D3], e2v[D3], av[D3];
+//      K {
+//	e1v[k]= vertices[v1][k] - vertices[v0][k];
+//	e2v[k]= vertices[v2][k] - vertices[v0][k];
+//      }
+//      xprod(av, e1v, e2v);
+//      total += magnD(av);
+
+      count++;
+    }
+    vertex_areas[v0]= total / count;
+    vertex_mean_edge_lengths[v0]= edges_total / count;
+  }
+}
+
+/*---------- combined vertex displacement ----------*/
+
+  /*
+   *   At vertex Q considering edge direction e to R
+   *   and corresponding opposite edge to P.
+   *
+   *   Let  R' = Q + PQ
+   *        D  = R' - R
+   *                                                             delta
+   *              [       -1                                    ]
+   *   cost    =  [ lambda  . ( D . PQ/|PQ| ) + | D x PQ/|PQ| | ]
+   *       Q,e    [ ------------------------------------------- ]
+   *              [                      |PQ|                   ]
+   */
+
+double vertex_displacement_cost(const Vertices vertices, int section) {
+  const double inv_lambda= 1.0/1; //2;
+  const double delta= 4;
+  const double pqlen2_epsilon= 1e-12;
+
+  int pi,e,qi,ri, k;
+  double pq[D3], d[D3], ddot, dcross[D3];
+  double total_cost= 0;
+
+  FOR_EDGE(qi,e,ri, OUTER) {
+    pi= EDGE_END2(qi,(e+3)%V6); if (pi<0) continue;
+
+    K pq[k]= -vertices[pi][k] + vertices[qi][k];
+    K d[k]= vertices[qi][k] + pq[k] - vertices[ri][k];
+    ddot= dotprod(d,pq);
+    xprod(dcross, d,pq);
+    double pqlen2= magnD2(pq);
+    double cost_basis= inv_lambda * ddot + magnD(dcross);
+    double cost= pow(cost_basis / (pqlen2 + pqlen2_epsilon), delta);
+
+    total_cost += cost;
+  }
+  return total_cost;
+}
+
+/*---------- at-vertex edge angles ----------*/
+
+  /*
+   * Definition:
+   *
+   *    At each vertex Q, in each direction e:
+   *
+   *                   	              e
+   *                           Q ----->----- R
+   *		          _,-'\__/
+   *   	       	      _,-'     	 delta
+   * 		   P '
+   *
+   *                      r
+   *       cost    = delta          (we use r=3)
+   *           Q,e
+   *
+   *
+   * Calculation:
+   *
+   *      Let vector A = PQ
+   *                 B = QR
+   *
+   *   		       -1   A . B
+   *      delta =  tan     -------
+   *     		  | A x B |
+   *
+   *      which is always in the range 0..pi because the denominator
+   *      is nonnegative.  We add epsilon to |AxB| to avoid division
+   *      by zero.
+   *
+   *                     r
+   *      cost    = delta
+   *          Q,e
+   */
+
+double line_bending_cost(const Vertices vertices, int section) {
+  static const double axb_epsilon= 1e-6;
+  static const double exponent_r= 4;
+
+  int pi,e,qi,ri, k;
+  double  a[D3], b[D3], axb[D3];
+  double total_cost= 0;
+
+  FOR_EDGE(qi,e,ri, OUTER) {
+    pi= EDGE_END2(qi,(e+3)%V6); if (pi<0) continue;
 
 //if (!(qi&XMASK)) fprintf(stderr,"%02x-%02x-%02x (%d)\n",pi,qi,ri,e);
 
@@ -202,11 +326,11 @@
    *           Q,e
    */
 
-double edge_length_variation_cost(const Vertices vertices) {
+double edge_length_variation_cost(const Vertices vertices, int section) {
   double diff, cost= 0, exponent_r= 2;
   int q, e,r, eback;
 
-  FOR_EDGE(q,e,r) {
+  FOR_EDGE(q,e,r, OUTER) {
     eback= edge_reverse(q,e);
     diff= edge_lengths[q][e] - edge_lengths[q][eback];
     cost += pow(diff,exponent_r);
@@ -214,6 +338,34 @@ double edge_length_variation_cost(const Vertices vertices) {
   return cost;
 }
 
+/*---------- proportional edge length variation ----------*/
+
+  /*
+   * Definition:
+   *
+   *    See the diagram above.
+   *                                r
+   *       cost    = ( |PQ| - |QR| )
+   *           Q,e
+   */
+
+double prop_edge_length_variation_cost(const Vertices vertices, int section) {
+  const double num_epsilon= 1e-6;
+
+  double cost= 0, exponent_r= 2;
+  int q, e,r, eback;
+
+  FOR_EDGE(q,e,r, OUTER) {
+    eback= edge_reverse(q,e);
+    double le= edge_lengths[q][e];
+    double leback= edge_lengths[q][eback];
+    double diff= le - leback;
+    double num= MIN(le, leback);
+    cost += pow(diff / (num + num_epsilon), exponent_r);
+  }
+  return cost;
+}
+
 /*---------- rim proximity cost ----------*/
 
 static void find_nearest_oncircle(double oncircle[D3], const double p[D3]) {
@@ -227,11 +379,11 @@ static void find_nearest_oncircle(double oncircle[D3], const double p[D3]) {
   oncircle[1] *= mult;
 }
 
-double rim_proximity_cost(const Vertices vertices) {
+double rim_proximity_cost(const Vertices vertices, int section) {
   double oncircle[3], cost=0;
   int v;
 
-  FOR_VERTEX(v) {
+  FOR_VERTEX(v, OUTER) {
     int y= v >> YSHIFT;
     int nominal_edge_distance= y <= Y/2 ? y : Y-1-y;
     if (nominal_edge_distance==0) continue;
@@ -248,12 +400,12 @@ double rim_proximity_cost(const Vertices vertices) {
 
 /*---------- noncircular rim cost ----------*/
 
-double noncircular_rim_cost(const Vertices vertices) {
+double noncircular_rim_cost(const Vertices vertices, int section) {
   int vy,vx,v;
   double cost= 0.0;
   double oncircle[3];
 
-  FOR_RIM_VERTEX(vy,vx,v) {
+  FOR_RIM_VERTEX(vy,vx,v, OUTER) {
     find_nearest_oncircle(oncircle, vertices[v]);
 
     double d2= hypotD2(vertices[v], oncircle);
@@ -289,7 +441,7 @@ double noncircular_rim_cost(const Vertices vertices) {
    *     vd, edge PQ      vd
    */
 
-double edge_angle_cost(const Vertices vertices, double circcircrat) {
+double edge_angle_cost(const Vertices vertices, int section) {
   double pq1[D3], rp[D3], ps[D3], rp_2d[D3], ps_2d[D3], rs_2d[D3];
   double a,b,c,s,r;
   const double minradius_base= 0.2;
@@ -298,7 +450,7 @@ double edge_angle_cost(const Vertices vertices, double circcircrat) {
 //  double our_epsilon=1e-6;
   double total_cost= 0;
 
-  FOR_EDGE(pi,e,qi) {
+  FOR_EDGE(pi,e,qi, OUTER) {
 //    if (!(RIM_VERTEX_P(pi) || RIM_VERTEX_P(qi))) continue;
 
     si= EDGE_END2(pi,(e+V6-1)%V6);  if (si<0) continue;
@@ -322,7 +474,7 @@ double edge_angle_cost(const Vertices vertices, double circcircrat) {
     s= 0.5*(a+b+c);
     r= a*b*c / sqrt((a+b+c)*(a-b+c)*(b-c+a)*(c-a+b) + 1e-6);
 
-    double minradius= minradius_base + circcircrat*(a+b);
+    double minradius= minradius_base + edge_angle_cost_circcircrat*(a+b);
     double deficit= minradius - r;
     if (deficit < 0) continue;
     double cost= deficit*deficit;
@@ -358,14 +510,14 @@ double edge_angle_cost(const Vertices vertices, double circcircrat) {
    *     vd, edge PQ      vd
    */
 
-double small_triangles_cost(const Vertices vertices) {
+double small_triangles_cost(const Vertices vertices, int section) {
   double pq[D3], ps[D3];
   double x[D3];
   int pi,e,qi,si, k;
 //  double our_epsilon=1e-6;
   double total_cost= 0;
 
-  FOR_EDGE(pi,e,qi) {
+  FOR_EDGE(pi,e,qi, OUTER) {
 //    if (!(RIM_VERTEX_P(pi) || RIM_VERTEX_P(qi))) continue;
 
     si= EDGE_END2(pi,(e+V6-1)%V6);  if (si<0) continue;