X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=moebius2.git;a=blobdiff_plain;f=energy.c;h=19f32e2fa3a0459ab94339a202b6844120b0a8b1;hp=cca777f8cff22ded6570402e06cfbb3fe2fe5b59;hb=32c7d2a5c5cb58ed3a8fb9fc383a31a80b01c052;hpb=ca6581b23c843e3117d3450a4ecf13bd6b71b8a5

diff --git a/energy.c b/energy.c
index cca777f..19f32e2 100644
--- a/energy.c
+++ b/energy.c
@@ -5,54 +5,138 @@
 #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);
-#define COST(weight, compute) addcost(&energy, (weight), (compute), printing)
+
+/*---------- 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);
 }
 
-/*---------- main energy computation and subroutines ----------*/
+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 energy;
-  int printing;
 
-  compute_edge_lengths(vs->a);
-  compute_vertex_areas(vs->a);
-  energy= 0;
+  double totals[NCOSTS], energy;
+  int ci, printing;
 
   printing= printing_check(pr_cost,0);
 
   if (printing) printf("%15lld c>e |", evaluations);
 
-  if (XBITS==3) {
-    COST(  3e2,   line_bending_cost(vs->a));
-    COST(  1e3,   edge_length_variation_cost(vs->a));
-    COST( 0.4e3,  rim_proximity_cost(vs->a));
-    COST(  1e6,   edge_angle_cost(vs->a));
-//    COST(  1e1,   small_triangles_cost(vs->a));
-    COST(  1e12,   noncircular_rim_cost(vs->a));
-    stop_epsilon= 1e-6;
-  } else if (XBITS==4) {
-    COST(  3e2,   line_bending_cost(vs->a));
-    COST(  3e3,   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));
-    COST(  1e12,   noncircular_rim_cost(vs->a));
-    stop_epsilon= 1e-5;
-  } else {
-    abort();
-  }
+  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);
 
@@ -92,18 +176,18 @@ static void addcost(double *energy, double tweight, double tcost, int pr) {
 
 /*---------- Precomputations ----------*/
 
-void compute_edge_lengths(const Vertices vertices) {
+void compute_edge_lengths(const Vertices vertices, int section) {
   int v1,e,v2;
 
-  FOR_EDGE(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) {
+void compute_vertex_areas(const Vertices vertices, int section) {
   int v0,v1,v2, e1,e2;
 //  int k;
 
-  FOR_VERTEX(v0) {
+  FOR_VERTEX(v0, OUTER) {
     double total= 0.0, edges_total=0;
     int count= 0;
 
@@ -129,7 +213,47 @@ void compute_vertex_areas(const Vertices vertices) {
   }
 }
 
-/*---------- Edgewise vertex displacement ----------*/
+/*---------- 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:
@@ -165,17 +289,19 @@ void compute_vertex_areas(const Vertices vertices) {
    *          Q,e
    */
 
-double line_bending_cost(const Vertices vertices) {
+double line_bending_cost(const Vertices vertices, int section) {
   static const double axb_epsilon= 1e-6;
-  static const double exponent_r= 3;
+  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) {
+  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);
+
     K a[k]= -vertices[pi][k] + vertices[qi][k];
     K b[k]= -vertices[qi][k] + vertices[ri][k];
 
@@ -184,9 +310,6 @@ double line_bending_cost(const Vertices vertices) {
     double delta= atan2(magnD(axb) + axb_epsilon, dotprod(a,b));
     double cost= pow(delta,exponent_r);
 
-    if (!e && !(qi & ~XMASK))
-      cost *= 10;
-
     total_cost += cost;
   }
   return total_cost;
@@ -203,11 +326,11 @@ double line_bending_cost(const Vertices vertices) {
    *           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);
@@ -215,6 +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]) {
@@ -228,11 +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;
@@ -249,12 +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);
@@ -263,22 +414,24 @@ double noncircular_rim_cost(const Vertices vertices) {
   return cost;
 }
 
-/*---------- triangle bad normals cost ----------*/
+/*---------- overly sharp edge cost ----------*/
 
   /*
    *
    *   	            Q `-_
-   *              / |    `-_
-   *             /  |       `-.
-   *            /   |           S
-   *           /    |      _,-'
-   *          /     |  _,-'
-   *         /    , P '
-   *        /  ,-'
-   *       /,-'
+   *              / |    `-_		               P'Q' ------ S'
+   *             /  |       `-.		             _,' `.       .
+   *            /   |           S	          _,'     :      .
+   *           /    |      _,-'                _,'        :r    .r
+   *          /     |  _,-'		   R' '           `.   .
+   *         /    , P '			       ` .   r     :  .
+   *        /  ,-'			            `  .   : 
+   *       /,-'				                 ` C'
    *      /'
    *   	 R
    *
+   *
+   *
    *  Let delta =  angle between two triangles' normals
    *
    *  Giving energy contribution:
@@ -288,44 +441,47 @@ double noncircular_rim_cost(const Vertices vertices) {
    *     vd, edge PQ      vd
    */
 
-double edge_angle_cost(const Vertices vertices) {
-  double sq[D3], pq[D3], qr[D3], sqp[D3], pqr[D3], rs[D3];
-  double x[D3], y[D3];
+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;
+
   int pi,e,qi,ri,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;
     ri= EDGE_END2(pi,(e   +1)%V6);  if (ri<0) continue;
 
     K {
-      sq[k]= vertices[si][k] - vertices[qi][k];
-      pq[k]= vertices[pi][k] - vertices[qi][k];
-      qr[k]= vertices[qi][k] - vertices[ri][k];
+      pq1[k]= -vertices[pi][k] + vertices[qi][k];
+      rp[k]=  -vertices[ri][k] + vertices[pi][k];
+      ps[k]=  -vertices[pi][k] + vertices[si][k];
     }
-    xprod(sqp, pq,sq);
-    xprod(pqr, pq,qr);
-
-    double dot= dotprod(sqp,pqr);
-    xprod(x,sqp,pqr);
 
-    K rs[k]= -vertices[ri][k] + vertices[si][k];
-    xprod(y, pq,rs);
+    normalise(pq1,1,1e-6);
+    xprod(rp_2d, rp,pq1); /* projects RP into plane normal to PQ */
+    xprod(ps_2d, ps,pq1); /* likewise PS */
+    K rs_2d[k]= rp_2d[k] + ps_2d[k];
+    /* radius of circumcircle of R'P'S' from Wikipedia
+     * `Circumscribed circle' */
+    a= magnD(rp_2d);
+    b= magnD(ps_2d);
+    c= magnD(rs_2d);
+    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 + edge_angle_cost_circcircrat*(a+b);
+    double deficit= minradius - r;
+    if (deficit < 0) continue;
+    double cost= deficit*deficit;
 
-    double delta=
-      pow(atan2(magnD(x), dot), 2.0) * pow(magnD2(pq), 2.0) /
-      (pow(magnD(y), 0.3) + 1e-6);
-    double cost= pow(delta, 2.0);
-
-//double cost= pow(magnD(spqxpqr), 3);
-//assert(dot>=-1 && dot <=1);
-//double cost= 1-dot;
     total_cost += cost;
   }
-  
+
   return total_cost;
 }
 
@@ -354,14 +510,14 @@ double edge_angle_cost(const Vertices vertices) {
    *     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;
@@ -379,6 +535,6 @@ double small_triangles_cost(const Vertices vertices) {
 //double cost= 1-dot;
     total_cost += cost;
   }
-  
+
   return total_cost;
 }