pattern.h

   1 #ifndef ZZGO_PATTERN_H
   2 #define ZZGO_PATTERN_H
   3
   4 /* Matching of multi-featured patterns. */
   5
   6 #include "board.h"
   7 #include "move.h"
   8
   9 /* When someone says "pattern", you imagine a configuration of stones in given
  10  * area (e.g. as matched very efficiently by pattern3 in case of 3x3 area).
  11  * However, we use a richer definition of pattern, where this is merely one
  12  * pattern _feature_. Another features may be is-a-selfatari, is-a-capture,
  13  * number of liberties, distance from last move, etc. */
  14
  15 /* ! NOTE NOTE NOTE ! We provide infrastructure for matching patterns, but we
  16  * also replicate the most bare-bone part of it for tiny subset of features
  17  * in board.c:board_gamma_update() for fast incremental probability
  18  * distribution maintenance. Aside of using the constants defined here, that
  19  * implementation is completely independent and does not call back here. */
  20
  21 /* Each feature is represented by its id and an optional 32-bit payload;
  22  * when matching, discrete (id,payload) pairs are considered. */
  23
  24 /* This is heavily influenced by (Coulom, 2007), of course. */
  25 /* TODO: Try completely separate ko / no-ko features. */
  26
  27 /* See the HACKING file for another description of the pattern matcher and
  28  * instructions on how to harvest and inspect patterns. */
  29
  30 /* If you add a payload bit for a feature, don't forget to update the value
  31  * in feature_info. */
  32 enum feature_id {
  33         /* Implemented: */
  34
  35         /* This is a pass. */
  36         /* Payload: [bit0] Last move was also pass? */
  37 #define PF_PASS_LASTPASS        0
  38         FEAT_PASS,
  39
  40         /* Simple capture move. */
  41         /* Payload: [bit0] Capturing laddered group? */
  42 #define PF_CAPTURE_LADDER       0
  43         /*          [bit1] Re-capturing last move? */
  44 #define PF_CAPTURE_RECAPTURE    1 /* TODO */
  45         /*          [bit2] Enables our atari group get more libs? */
  46 #define PF_CAPTURE_ATARIDEF     2
  47         /*          [bit3] Capturing ko? */
  48 #define PF_CAPTURE_KO           3
  49         FEAT_CAPTURE,
  50
  51         /* Atari escape (extension). */
  52         /* Payload: [bit0] Escaping with laddered group? */
  53 #define PF_AESCAPE_LADDER       0
  54         FEAT_AESCAPE,
  55
  56         /* Self-atari move. */
  57         /* Payload: [bit0] Matched by trivial definition? */
  58         /*          [bit1] Matched by complex definition? (tries to be aware of nakade, throwins, ...) */
  59 #define PF_SELFATARI_STUPID     0
  60 #define PF_SELFATARI_SMART      1
  61         FEAT_SELFATARI,
  62
  63         /* Atari move. */
  64         /* Payload: [bit0] The atari'd group gets laddered? */
  65 #define PF_ATARI_LADDER         0
  66         /*          [bit1] Playing ko? */
  67 #define PF_ATARI_KO             1
  68         FEAT_ATARI,
  69
  70         /* Border distance. */
  71         /* Payload: The distance - "line number". Only up to 4. */
  72         FEAT_BORDER,
  73
  74         /* Last move distance. */
  75         /* Payload: The distance - gridcular metric. */
  76         FEAT_LDIST,
  77
  78         /* Next-to-last move distance. */
  79         /* Payload: The distance - gridcular metric. */
  80         FEAT_LLDIST,
  81
  82         /* Continuity. */
  83         /* Payload: [bit0] The move is in 8-neighborhood of last move (ldist<=3) */
  84         /* This is a fast substitution to ldist/lldist. */
  85         FEAT_CONTIGUITY,
  86
  87         /* Spatial configuration of stones in certain board area,
  88          * with black to play. */
  89         /* Payload: Index in the spatial_dict. */
  90         FEAT_SPATIAL,
  91
  92         /* Spatial configuration of stones in fixed 3x3 square,
  93          * with black to play. */
  94         /* This is a fast substitution to spatial. */
  95         /* Payload: Pattern3 hash (see pattern3.h). */
  96         /* Note that the hash describes only one particular rotation;
  97          * no normalization across rotations and transpositions is done
  98          * during the matching, only color normalization. The patternscan
  99          * and gamma machineries is taking care of the rotations. */
 100         FEAT_PATTERN3,
 101
 102
 103         /* Unimplemented - TODO: */
 104
 105         /* Monte-carlo owner. */
 106         /* Payload: #of playouts owning this point at the final
 107          * position, scaled to 0..15 (lowest 4 bits). */
 108         FEAT_MCOWNER,
 109
 110         FEAT_MAX
 111 };
 112
 113 struct feature {
 114         enum feature_id id;
 115         uint16_t payload;
 116 };
 117
 118 struct pattern {
 119         /* Pattern (matched) is set of features. */
 120         int n;
 121 #define FEATURES 32
 122         struct feature f[FEATURES];
 123 };
 124
 125 struct spatial_dict;
 126 struct pattern_config {
 127         /* FEAT_SPATIAL: Generate patterns only for these sizes (gridcular). */
 128         int spat_min, spat_max;
 129         /* FEAT_BORDER: Generate features only up to this board distance. */
 130         int bdist_max;
 131         /* FEAT_LDIST, FEAT_LLDIST: Generate features only for these move
 132          * distances. */
 133         int ldist_min, ldist_max;
 134         /* FEAT_MCOWNER: Generate feature after this number of simulations. */
 135         int mcsims;
 136
 137         /* The spatial patterns dictionary, used by FEAT_SPATIAL. */
 138         struct spatial_dict *spat_dict;
 139 };
 140 extern struct pattern_config DEFAULT_PATTERN_CONFIG;
 141 extern struct pattern_config FAST_PATTERN_CONFIG;
 142
 143 /* The pattern_spec[] specifies which features to tests for;
 144  * highest bit controls whether to test for the feature at all,
 145  * then for bitmap features (except FEAT_SPATIAL) the rest
 146  * of the bits controls various PF tests; for non-bitmap
 147  * features, you will need to tweak the patternconfig to
 148  * fine-tune them. */
 149 typedef uint16_t pattern_spec[FEAT_MAX];
 150 /* Match all supported features. */
 151 extern pattern_spec PATTERN_SPEC_MATCHALL;
 152 /* Match only "quick" features, suitable for MC simulations. */
 153 extern pattern_spec PATTERN_SPEC_MATCHFAST;
 154
 155
 156 /* Append feature to string. */
 157 char *feature2str(char *str, struct feature *f);
 158 /* Convert string to feature, return pointer after the featurespec. */
 159 char *str2feature(char *str, struct feature *f);
 160 /* Get name of given feature. */
 161 char *feature_name(enum feature_id f);
 162 /* Get number of possible payload values associated with the feature. */
 163 int feature_payloads(struct pattern_config *pc, enum feature_id f);
 164
 165 /* Append pattern as feature spec string. */
 166 char *pattern2str(char *str, struct pattern *p);
 167
 168 /* Initialize p and fill it with features matched by the
 169  * given board move. */
 170 void pattern_match(struct pattern_config *pc, pattern_spec ps, struct pattern *p, struct board *b, struct move *m);
 171
 172
 173 /* Comparative strengths of all feature-payload pairs (initialized to 1 for
 174  * unspecified pairs). */
 175 struct features_gamma {
 176         /* Indexed by feature and payload; each feature array is allocated for
 177          * all possible payloads to fit in. */
 178         double *gamma[FEAT_MAX];
 179         struct pattern_config *pc;
 180 };
 181 /* Default gamma filename to use. */
 182 extern const char *features_gamma_filename;
 183
 184 /* Initializes gamma values, pre-loading existing records from given file
 185  * (NULL for default), falling back to gamma==1 for unspecified values. */
 186 struct features_gamma *features_gamma_init(struct pattern_config *pc, const char *file);
 187
 188 /* Look up gamma of given feature, or set one if gamma is not NULL. */
 189 static double feature_gamma(struct features_gamma *fg, struct feature *f, double *gamma);
 190
 191 /* Destroy the structure. */
 192 void features_gamma_done(struct features_gamma *fg);
 193
 194
 195 static inline double
 196 feature_gamma(struct features_gamma *fg, struct feature *f, double *gamma)
 197 {
 198         if (gamma) fg->gamma[f->id][f->payload] = *gamma;
 199         return fg->gamma[f->id][f->payload];
 200 }
 201
 202 #endif