-
Notifications
You must be signed in to change notification settings - Fork 1
/
Copy pathcheckers.wat
308 lines (265 loc) · 10.5 KB
/
checkers.wat
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
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
;; Learning sources:
;; https://pragprog.com/titles/khrust/programming-webassembly-with-rust/
;; https://rustwasm.github.io/book
;; https://github.com/sunfishcode/wasm-reference-manual
;; https://developer.mozilla.org/en-US/docs/WebAssembly/Understanding_the_text_format
;; https://openhome.cc/eGossip/WebAssembly/index.html
;; https://blog.scottlogic.com/2018/04/26/webassembly-by-hand.html
;; https://evilmartians.com/chronicles/hands-on-webassembly-try-the-basics
(module
(import "events" "piecemoved"
(func $notify_piecemoved (param $from_x i32) (param $from_y i32) (param $to_x i32) (param $to_y i32)))
(import "events" "piececrowned"
(func $notify_piececrowned (param $x i32) (param $y i32)))
;; 8x8 i32 linear board
;; 4 bytes per square
;; 8 * 4 = 32 bytes per row
;; 32 * 8 = 256 bytes per board
(memory $mem 1)
;; 0cwb
;; c - is crowned
;; w - is white
;; b - is black
;; 0000 - unoccupied
;; 0001 - occupied by black
;; 0010 - occupied by white
;; 0101 - occupied by crowned black
(global $EMPTY i32 (i32.const 0))
(global $BLACK i32 (i32.const 1))
(global $WHITE i32 (i32.const 2))
(global $BLACK_OR_WHITE i32 (i32.const 3))
(global $CROWN i32 (i32.const 4))
(global $current_player (mut i32) (i32.const 1))
;; calculates offset in memory for a given position (x, y)
(func $offset_for_position (param $x i32) (param $y i32) (result i32)
(i32.mul
(i32.const 4)
(i32.add
(i32.mul
(i32.const 8)
(get_local $y))
(get_local $x)))
)
;; checks if a piece is crowned
(func $is_crowned (param $piece i32) (result i32)
(i32.eq
(i32.and (get_local $piece) (get_global $CROWN))
(get_global $CROWN))
)
;; checks if a piece is black
(func $is_black (param $piece i32) (result i32)
(i32.eq
(i32.and (get_local $piece) (get_global $BLACK))
(get_global $BLACK))
)
;; checks if a piece is white
(func $is_white (param $piece i32) (result i32)
(i32.eq
(i32.and (get_local $piece) (get_global $WHITE))
(get_global $WHITE))
)
;; adds a crown to a piece
(func $with_crown (param $piece i32) (result i32)
(i32.or
(get_local $piece)
(get_global $CROWN))
)
;; removes a crown from a piece
(func $without_crown (param $piece i32) (result i32)
(i32.and
(get_local $piece)
(get_global $BLACK_OR_WHITE))
)
;; checks if a coordinate is within the board's range
(func $is_in_range (param $coord i32) (result i32)
(i32.and
(i32.ge_s (get_local $coord) (i32.const 0))
(i32.le_s (get_local $coord) (i32.const 7)))
)
;; gets a piece at (x, y) coordinate
(func $get_piece (param $x i32) (param $y i32) (result i32)
(if (result i32)
(i32.and
(call $is_in_range (get_local $x))
(call $is_in_range (get_local $y)))
(then
(i32.load
(call $offset_for_position (get_local $x) (get_local $y))))
(else
(unreachable)))
)
;; sets a piece at (x, y) coordinate
(func $set_piece (param $x i32) (param $y i32) (param $piece i32)
(if
(i32.and
(call $is_in_range (get_local $x))
(call $is_in_range (get_local $y)))
(then
(i32.store
(call $offset_for_position (get_local $x) (get_local $y))
(get_local $piece)))
(else
(unreachable)))
)
;; checks if a piece belongs to the current player
(func $is_current_player_piece (param $piece i32) (result i32)
(i32.eq
(i32.and
(call $get_current_player)
(get_local $piece))
(call $get_current_player))
)
;; gets the current player
(func $get_current_player (result i32)
(get_global $current_player)
)
;; sets the current player
(func $set_current_player (param $player i32)
(set_global $current_player (get_local $player))
)
;; toggles the current player
(func $toggle_current_player
(if
(i32.eq (call $get_current_player) (get_global $BLACK))
(then
(call $set_current_player (get_global $WHITE)))
(else
(call $set_current_player (get_global $BLACK))))
)
;; check if a piece should be crowned
(func $should_crown_piece (param $x i32) (param $y i32) (result i32)
(local $piece i32)
(set_local $piece (call $get_piece (get_local $x) (get_local $y)))
(i32.or
(i32.and
(call $is_white (get_local $piece))
(i32.eq (get_local $y) (i32.const 7)))
(i32.and
(call $is_black (get_local $piece))
(i32.eq (get_local $y) (i32.const 0))))
)
;; add a crown to a piece at (x, y) coordinate
(func $crown_piece (param $x i32) (param $y i32)
(local $piece i32)
(set_local $piece (call $get_piece (get_local $x) (get_local $y)))
(set_local $piece (call $with_crown (get_local $piece)))
(call $set_piece (get_local $x) (get_local $y) (get_local $piece))
(call $notify_piececrowned (get_local $x) (get_local $y))
)
;; a piece can move by 1 square in any direction if the target position
;; is not occupied and the piece belongs to the current player
(func $is_valid_move (param $from_x i32) (param $from_y i32) (param $to_x i32) (param $to_y i32) (result i32)
(local $piece i32)
(local $target i32)
(set_local $piece (call $get_piece (get_local $from_x) (get_local $from_y)))
(set_local $target (call $get_piece (get_local $to_x) (get_local $to_y)))
(i32.and
(call $is_valid_move_distance
(get_local $from_x) (get_local $from_y)
(get_local $to_x) (get_local $to_y))
(i32.and
(call $is_current_player_piece (get_local $piece))
(i32.eq (get_local $target) (get_global $EMPTY))))
)
(func $is_valid_move_distance (param $from_x i32) (param $from_y i32) (param $to_x i32) (param $to_y i32) (result i32)
(local $diff_x i32)
(local $diff_y i32)
(set_local $diff_x (i32.sub (get_local $from_x) (get_local $to_x)))
(set_local $diff_y (i32.sub (get_local $from_y) (get_local $to_y)))
(i32.and
(i32.and
(i32.ge_s (get_local $diff_x) (i32.const -1))
(i32.le_s (get_local $diff_x) (i32.const 1)))
(i32.and
(i32.ge_s (get_local $diff_y) (i32.const -1))
(i32.le_s (get_local $diff_y) (i32.const 1))))
)
;; moves a piece at a given coordinated if possible
(func $move_piece (param $from_x i32) (param $from_y i32) (param $to_x i32) (param $to_y i32) (result i32)
(if (result i32)
(call $is_valid_move
(get_local $from_x) (get_local $from_y)
(get_local $to_x) (get_local $to_y))
(then
(call $perform_piece_move
(get_local $from_x) (get_local $from_y)
(get_local $to_x) (get_local $to_y)))
(else
(i32.const 0)))
)
(func $perform_piece_move (param $from_x i32) (param $from_y i32) (param $to_x i32) (param $to_y i32) (result i32)
(local $piece i32)
(set_local $piece (call $get_piece (get_local $from_x) (get_local $from_y)))
(call $set_piece (get_local $to_x) (get_local $to_y) (get_local $piece))
(call $set_piece (get_local $from_x) (get_local $from_y) (get_global $EMPTY))
(if
(call $should_crown_piece (get_local $to_x) (get_local $to_y))
(then
(call $crown_piece (get_local $to_x) (get_local $to_y))))
(call $notify_piecemoved (get_local $from_x) (get_local $from_y) (get_local $to_x) (get_local $to_y))
(call $toggle_current_player)
(i32.const 1)
)
(func $init_board
(local $x i32)
(local $y i32)
;; reset all squares
(set_local $x (i32.const 0))
(loop $x_loop
(set_local $y (i32.const 0))
(loop $y_loop
(call $set_piece (get_local $x) (get_local $y) (get_global $EMPTY))
(set_local $y (i32.add (get_local $y) (i32.const 1)))
(br_if $y_loop (i32.le_s (get_local $y) (i32.const 7))))
(set_local $x (i32.add (get_local $x) (i32.const 1)))
(br_if $x_loop (i32.le_s (get_local $x) (i32.const 7))))
;; set 12 white pieces
(call $set_piece (i32.const 1) (i32.const 0) (get_global $WHITE))
(call $set_piece (i32.const 3) (i32.const 0) (get_global $WHITE))
(call $set_piece (i32.const 5) (i32.const 0) (get_global $WHITE))
(call $set_piece (i32.const 7) (i32.const 0) (get_global $WHITE))
(call $set_piece (i32.const 0) (i32.const 1) (get_global $WHITE))
(call $set_piece (i32.const 2) (i32.const 1) (get_global $WHITE))
(call $set_piece (i32.const 4) (i32.const 1) (get_global $WHITE))
(call $set_piece (i32.const 6) (i32.const 1) (get_global $WHITE))
(call $set_piece (i32.const 1) (i32.const 2) (get_global $WHITE))
(call $set_piece (i32.const 3) (i32.const 2) (get_global $WHITE))
(call $set_piece (i32.const 5) (i32.const 2) (get_global $WHITE))
(call $set_piece (i32.const 7) (i32.const 2) (get_global $WHITE))
;; set 12 black pieces
(call $set_piece (i32.const 0) (i32.const 7) (get_global $BLACK))
(call $set_piece (i32.const 2) (i32.const 7) (get_global $BLACK))
(call $set_piece (i32.const 4) (i32.const 7) (get_global $BLACK))
(call $set_piece (i32.const 6) (i32.const 7) (get_global $BLACK))
(call $set_piece (i32.const 1) (i32.const 6) (get_global $BLACK))
(call $set_piece (i32.const 3) (i32.const 6) (get_global $BLACK))
(call $set_piece (i32.const 5) (i32.const 6) (get_global $BLACK))
(call $set_piece (i32.const 7) (i32.const 6) (get_global $BLACK))
(call $set_piece (i32.const 0) (i32.const 5) (get_global $BLACK))
(call $set_piece (i32.const 2) (i32.const 5) (get_global $BLACK))
(call $set_piece (i32.const 4) (i32.const 5) (get_global $BLACK))
(call $set_piece (i32.const 6) (i32.const 5) (get_global $BLACK))
;; set current player to black
(call $set_current_player (get_global $BLACK))
)
(export "offsetForPosition" (func $offset_for_position))
(export "isCrowned" (func $is_crowned))
(export "isBlack" (func $is_black))
(export "isWhite" (func $is_white))
(export "withCrown" (func $with_crown))
(export "withoutCrown" (func $without_crown))
(export "getPiece" (func $get_piece))
(export "setPiece" (func $set_piece))
(export "isCurrentPlayerPiece" (func $is_current_player_piece))
(export "getCurrentPlayer" (func $get_current_player))
(export "setCurrentPlayer" (func $set_current_player))
(export "toggleCurrentPlayer" (func $toggle_current_player))
(export "shouldCrownPiece" (func $should_crown_piece))
(export "crownPiece" (func $crown_piece))
(export "isValidMove" (func $is_valid_move))
(export "isValidMoveDistance" (func $is_valid_move_distance))
(export "movePiece" (func $move_piece))
(export "performPieceMove" (func $perform_piece_move))
(export "initBoard" (func $init_board))
(export "memory" (memory $mem))
)