pattern.h

   1 #ifndef PACHI_PATTERN_H
   2 #define PACHI_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 /* Each feature is represented by its id and an optional 32-bit payload;
  16  * when matching, discrete (id,payload) pairs are considered. */
  17
  18 /* This is heavily influenced by (Coulom, 2007), of course. In addition,
  19  * the work of van der Werf, de Groot, Stern et al. and possibly others
  20  * inspired this pattern matcher. */
  21 /* TODO: Try completely separate ko / no-ko features. And many other
  22  * features described in the literature. */
  23
  24 /* See the HACKING file for another description of the pattern matcher and
  25  * instructions on how to harvest and inspect patterns. */
  26
  27 /* If you add a payload bit for a feature, don't forget to update the value
  28  * in feature_info. */
  29 enum feature_id {
  30         /* Implemented: */
  31
  32         /* Simple capture move. */
  33         /* Payload: [bit0] Capturing laddered group? */
  34 #define PF_CAPTURE_LADDER       0
  35         /*          [bit2] Enables our atari group get more libs? */
  36 #define PF_CAPTURE_ATARIDEF     1
  37         /*          [bit3] Capturing ko? */
  38 #define PF_CAPTURE_KO           2
  39         /*          [bit4] Single-stone group? */
  40 #define PF_CAPTURE_1STONE       3
  41         /*          [bit5] Unsafe move for opponent? */
  42 #define PF_CAPTURE_TRAPPED      4
  43         /*          [bit6] Preventing connection to an outside group. */
  44 #define PF_CAPTURE_CONNECTION   5
  45         FEAT_CAPTURE,
  46
  47         /* Atari escape (extension). */
  48         /* Payload: [bit0] Escaping with laddered group? */
  49 #define PF_AESCAPE_LADDER       0
  50         /*          [bit1] Single-stone group? */
  51 #define PF_AESCAPE_1STONE       1
  52         /*          [bit2] Unsafe move for us? */
  53 #define PF_AESCAPE_TRAPPED      2
  54         /*          [bit3] Connecting out to an outside group. */
  55 #define PF_AESCAPE_CONNECTION   3
  56         FEAT_AESCAPE,
  57
  58         /* Self-atari move. */
  59         /* Payload: [bit0] Matched by trivial definition? */
  60         /*          [bit1] Matched by complex definition? (tries to be aware of nakade, throwins, ...) */
  61 #define PF_SELFATARI_STUPID     0
  62 #define PF_SELFATARI_SMART      1
  63         FEAT_SELFATARI,
  64
  65         /* Atari move. */
  66         /* Payload: [bit0] The atari'd group gets laddered? */
  67 #define PF_ATARI_LADDER         0
  68         /*          [bit1] Playing ko? */
  69 #define PF_ATARI_KO             1
  70         FEAT_ATARI,
  71
  72         /* Border distance. */
  73         /* Payload: The distance - "line number". Only up to 4. */
  74         FEAT_BORDER,
  75
  76         /* Continuity. */
  77         /* Payload: [bit0] The move is in 8-neighborhood of last move. */
  78         FEAT_CONTIGUITY,
  79
  80         /* Spatial configuration of stones in certain board area,
  81          * with black to play. */
  82         /* Payload: Index in the spatial_dict. */
  83         FEAT_SPATIAL,
  84
  85         /* TODO: MC owner, playing ko, #liberties, #libs of opponent, ... */
  86
  87         FEAT_MAX
  88 };
  89
  90 struct feature {
  91         enum feature_id id;
  92         uint32_t payload;
  93 };
  94
  95 struct pattern {
  96         /* Pattern (matched) is set of features. */
  97         int n;
  98 #define FEATURES 32
  99         struct feature f[FEATURES];
 100 };
 101
 102 struct spatial_dict;
 103 struct pattern_config {
 104         /* FEAT_BORDER: Generate features only up to this board distance. */
 105         int bdist_max;
 106
 107         /* FEAT_SPATIAL: Generate patterns only for these sizes (gridcular).
 108          * TODO: Special-case high values to match larger areas or the
 109          * whole board. */
 110         int spat_min, spat_max;
 111         /* Produce only a single spatial feature per pattern, corresponding
 112          * to the largest matched spatial pattern. */
 113         bool spat_largest;
 114         /* The spatial patterns dictionary used by FEAT_SPATIAL. */
 115         struct spatial_dict *spat_dict;
 116 };
 117 extern struct pattern_config DEFAULT_PATTERN_CONFIG;
 118
 119 /* The pattern_spec[] specifies which features to tests for;
 120  * highest bit controls whether to test for the feature at all,
 121  * then for bitmap features (except FEAT_SPATIAL) the rest
 122  * of the bits controls various PF tests; for non-bitmap
 123  * features, you will need to tweak the patternconfig to
 124  * fine-tune them. */
 125 typedef uint16_t pattern_spec[FEAT_MAX];
 126 /* Match (almost?) all supported features. */
 127 extern pattern_spec PATTERN_SPEC_MATCH_DEFAULT;
 128
 129
 130 /* Append feature to string. */
 131 char *feature2str(char *str, struct feature *f);
 132 /* Convert string to feature, return pointer after the featurespec. */
 133 char *str2feature(char *str, struct feature *f);
 134 /* Get name of given feature. */
 135 char *feature_name(enum feature_id f);
 136 /* Get number of possible payload values associated with the feature. */
 137 int feature_payloads(struct pattern_config *pc, enum feature_id f);
 138
 139 /* Append pattern as feature spec string. */
 140 char *pattern2str(char *str, struct pattern *p);
 141 /* Convert string to pattern, return pointer after the patternspec. */
 142 char *str2pattern(char *str, struct pattern *p);
 143 /* Compare two patterns for equality. Assumes fixed feature order. */
 144 static bool pattern_eq(struct pattern *p1, struct pattern *p2);
 145
 146 /* Initialize p and fill it with features matched by the
 147  * given board move. */
 148 void pattern_match(struct pattern_config *pc, pattern_spec ps, struct pattern *p, struct board *b, struct move *m);
 149
 150
 151 static inline bool
 152 pattern_eq(struct pattern *p1, struct pattern *p2)
 153 {
 154         if (p1->n != p2->n) return false;
 155         for (int i = 0; i < p1->n; i++)
 156                 if (p1->f[i].id != p2->f[i].id || p1->f[i].payload != p2->f[i].payload)
 157                         return false;
 158         return true;
 159 }
 160
 161 #endif