1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
|
#include "zobrist.h"
// ===================================================================
// Globals
// ===================================================================
static uint64_t *zobrist[15];
// ===================================================================
// Helpers
// ===================================================================
// ===================================================================
// Exported method implementations
// ===================================================================
int
zobrist_init(void) {
for (int k=0; k<15; k++) {
if (zobrist[k] != NULL) return EXIT_FAILURE;
}
for (int j=0; j<15; j++) {
zobrist[j] = malloc(sizeof(uint64_t)*board_size*board_size*(2*3+1));
for (int k=0; k<board_size*board_size*(2*3+1); k++) {
XORSHIFT64;
zobrist[j][k] = RANDOM64;
}
}
return EXIT_SUCCESS;
}
void
zobrist_free(void) {
for (int k=0; k<15; k++) {
if (zobrist[k] != NULL) {
free(zobrist[k]);
zobrist[k] = NULL;
}
}
}
uint64_t
zobrist_compute(void) {
uint64_t hash = 0;
for (uint8_t l=0; l<board_size*board_size; l++) {
colour_stack_t c = colours[l];
const uint8_t count = COUNT_AT(l);
enum STONE_VARIANT s = STONE_AT(l);
for (uint8_t h=0; h<count; h++, c >>= 1)
hash ^= zobrist[h][l*(2*3+1)+(c&1)*3+s];
}
return hash;
}
uint64_t
zobrist_apply(const action_t action, uint64_t hash) {
const enum A_TYPE type = GET_TYPE(action);
const int8_t loc = GET_LOC(action);
if (type == A_PLACE) {
enum COLOUR c = (current_colour == C_BLACK) ? C_WHITE : C_BLACK;
hash ^= zobrist[0][loc*(2*3+1)
+c*3
+GET_DATA0(action)];
} else {
const uint8_t gaps = GET_DATA0(action) & 0x7F,
crush = GET_DATA0(action) & 0x80,
num = GET_DATA1(action) & 0x0F,
dir = GET_DATA1(action) >> 4;
const int8_t delta = move_deltas[dir];
int8_t steps = 1;
uint8_t gap_bit = 1, num_dropped = 1, total = COUNT_AT(loc);
for (int8_t d = 1; d < num; d++, num_dropped++, gap_bit <<= 1) {
if (gaps & gap_bit) {
const int8_t target = loc+steps*delta, th = COUNT_AT(target);
// Stash these stones to offset for the height at source
total += num_dropped;
// Apply XOR for stones at source and current target
uint8_t point = 1;
for (int k = 0, ht = th-1, hs = total-1; k < num_dropped;
k++, ht--, hs--, point<<=1) {
hash ^= zobrist[ht][target*(2*3+1)
+(point & colours[target])*3
+STONE_FLAT];
hash ^= zobrist[hs][loc*(2*3+1)
+(point & colours[target])*3
+STONE_FLAT];
}
// Continue processing gap sequence
num_dropped = 0;
steps++;
}
}
total += num_dropped;
const int8_t target = loc+steps*delta, th = COUNT_AT(target);
const enum STONE_VARIANT top_stone = STONE_AT(target);
// Stash these stones to offset for the height at source
// Apply XOR for stones at source and end target. After this
// source will be correct, but we must account for crush @ target.
uint8_t point = 1;
for (int k = 0, ht = th-1, hs = total-1; k < num_dropped;
k++, ht--, hs--, point<<=1) {
if (k == 0) {
hash ^= zobrist[ht][target*(2*3+1)
+(point & colours[target])*3
+top_stone];
hash ^= zobrist[hs][loc*(2*3+1)
+(point & colours[target])*3
+top_stone];
} else {
hash ^= zobrist[ht][target*(2*3+1)
+(point & colours[target])*3
+STONE_FLAT];
hash ^= zobrist[hs][loc*(2*3+1)
+(point & colours[target])*3
+STONE_FLAT];
}
}
// Correct for crush
if (crush) {
hash ^= zobrist[th-1][target*(2*3+1)
+(colours[target] & 1)*3
+STONE_FLAT];
hash ^= zobrist[th-1][target*(2*3+1)
+(colours[target] & 1)*3
+STONE_STANDING];
}
}
return hash;
}
|
