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1 | import { ChessRules } from "@/base_rules"; |
2 | import { ArrayFun } from "@/utils/array"; | |
3 | import { randInt, shuffle } from "@/utils/alea"; | |
4 | ||
5 | export const VariantRules = class RoyalraceRules extends ChessRules { | |
6 | static get HasFlags() { | |
7 | return false; | |
8 | } | |
9 | ||
10 | static get HasEnpassant() { | |
11 | return false; | |
12 | } | |
13 | ||
14 | static get CanFlip() { | |
15 | return false; | |
16 | } | |
17 | ||
18 | static get size() { | |
19 | return { x: 11, y: 11 }; | |
20 | } | |
21 | ||
22 | static GenRandInitFen() { | |
23 | let pieces = { w: new Array(10), b: new Array(10) }; | |
24 | // Shuffle pieces on first and second rank | |
25 | for (let c of ["w", "b"]) { | |
26 | // Reserve 4 and 5 which are pawns positions | |
27 | let positions = ArrayFun.range(10).filter(i => i != 4 && i != 5); | |
28 | ||
29 | // Get random squares for bishops | |
30 | let randIndex = 2 * randInt(4); | |
31 | const bishop1Pos = positions[randIndex]; | |
32 | // The second bishop must be on a square of different color | |
33 | let randIndex_tmp = 2 * randInt(4) + 1; | |
34 | const bishop2Pos = positions[randIndex_tmp]; | |
35 | // Remove chosen squares | |
36 | positions.splice(Math.max(randIndex, randIndex_tmp), 1); | |
37 | positions.splice(Math.min(randIndex, randIndex_tmp), 1); | |
38 | ||
39 | // Place the king at random on (remaining squares of) first row | |
40 | let maxIndex = 4; | |
41 | if (positions[maxIndex-1] >= 4) | |
42 | maxIndex--; | |
43 | if (positions[maxIndex-1] >= 4) | |
44 | maxIndex--; | |
45 | randIndex = randInt(maxIndex); | |
46 | const kingPos = positions[randIndex]; | |
47 | positions.splice(randIndex, 1); | |
48 | ||
49 | // Get random squares for knights | |
50 | randIndex = randInt(5); | |
51 | const knight1Pos = positions[randIndex]; | |
52 | positions.splice(randIndex, 1); | |
53 | randIndex = randInt(4); | |
54 | const knight2Pos = positions[randIndex]; | |
55 | positions.splice(randIndex, 1); | |
56 | ||
57 | // Get random squares for rooks | |
58 | randIndex = randInt(3); | |
59 | const rook1Pos = positions[randIndex]; | |
60 | positions.splice(randIndex, 1); | |
61 | randIndex = randInt(2); | |
62 | const rook2Pos = positions[randIndex]; | |
63 | positions.splice(randIndex, 1); | |
64 | ||
65 | // Queen position is now determined, | |
66 | // because pawns are not placed at random | |
67 | const queenPos = positions[0]; | |
68 | ||
69 | // Finally put the shuffled pieces in the board array | |
70 | pieces[c][rook1Pos] = "r"; | |
71 | pieces[c][knight1Pos] = "n"; | |
72 | pieces[c][bishop1Pos] = "b"; | |
73 | pieces[c][queenPos] = "q"; | |
74 | pieces[c][kingPos] = "k"; | |
75 | pieces[c][bishop2Pos] = "b"; | |
76 | pieces[c][knight2Pos] = "n"; | |
77 | pieces[c][rook2Pos] = "r"; | |
78 | pieces[c][4] = "p"; | |
79 | pieces[c][5] = "p"; | |
80 | } | |
81 | const whiteFen = pieces["w"].join("").toUpperCase(); | |
82 | const blackFen = pieces["b"].join(""); | |
83 | return ( | |
84 | "11/11/11/11/11/11/11/11/11/" + | |
85 | whiteFen.substr(5).split("").reverse().join("") + | |
86 | "1" + | |
f446ee64 | 87 | blackFen.substr(5).split("").join("") + |
0ba6420d | 88 | "/" + |
f446ee64 BA |
89 | whiteFen.substr(0,5) + |
90 | "1" + | |
91 | blackFen.substr(0,5).split("").reverse().join("") + | |
0ba6420d BA |
92 | " w 0" |
93 | ); | |
94 | } | |
95 | ||
96 | getPotentialPawnMoves([x, y]) { | |
97 | // Normal moves (as a rook) | |
98 | let moves = | |
99 | this.getSlideNJumpMoves([x, y], V.steps[V.ROOK]).filter(m => { | |
100 | // Remove captures. Alt: redefine canTake | |
101 | return m.vanish.length == 1; | |
102 | }); | |
103 | ||
f446ee64 BA |
104 | // Captures (in both directions) |
105 | for (let shiftX of [-1, 1]) { | |
106 | for (let shiftY of [-1, 1]) { | |
107 | if ( | |
108 | V.OnBoard(x + shiftX, y + shiftY) && | |
109 | this.board[x + shiftX][y + shiftY] != V.EMPTY && | |
110 | this.canTake([x, y], [x + shiftX, y + shiftY]) | |
111 | ) { | |
112 | moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY])); | |
113 | } | |
0ba6420d BA |
114 | } |
115 | } | |
116 | ||
117 | return moves; | |
118 | } | |
119 | ||
120 | getPotentialKnightMoves(sq) { | |
121 | // Knight becomes knightrider: | |
122 | return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT]); | |
123 | } | |
124 | ||
125 | // What are the king moves from square x,y ? | |
126 | getPotentialKingMoves(sq) { | |
127 | return this.getSlideNJumpMoves( | |
128 | sq, | |
129 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), | |
130 | "oneStep" | |
131 | ); | |
132 | } | |
133 | ||
134 | filterValid(moves) { | |
135 | if (moves.length == 0) return []; | |
136 | const color = this.turn; | |
137 | const oppCol = V.GetOppCol(color); | |
138 | return moves.filter(m => { | |
139 | this.play(m); | |
140 | // Giving check is forbidden as well: | |
141 | const res = !this.underCheck(color) && !this.underCheck(oppCol); | |
142 | this.undo(m); | |
143 | return res; | |
144 | }); | |
145 | } | |
146 | ||
147 | isAttackedByPawn([x, y], colors) { | |
148 | const pawnShift = 1; | |
149 | if (x + pawnShift < V.size.x) { | |
150 | for (let c of colors) { | |
151 | for (let i of [-1, 1]) { | |
152 | if ( | |
153 | y + i >= 0 && | |
154 | y + i < V.size.y && | |
155 | this.getPiece(x + pawnShift, y + i) == V.PAWN && | |
156 | this.getColor(x + pawnShift, y + i) == c | |
157 | ) { | |
158 | return true; | |
159 | } | |
160 | } | |
161 | } | |
162 | } | |
163 | return false; | |
164 | } | |
165 | ||
166 | isAttackedByKnight(sq, colors) { | |
167 | return this.isAttackedBySlideNJump( | |
168 | sq, | |
169 | colors, | |
170 | V.KNIGHT, | |
171 | V.steps[V.KNIGHT] | |
172 | ); | |
173 | } | |
174 | ||
175 | getCurrentScore() { | |
176 | // Turn has changed: | |
177 | const color = V.GetOppCol(this.turn); | |
178 | if (this.kingPos[color][0] == 0) | |
179 | // The opposing edge is reached! | |
180 | return color == "w" ? "1-0" : "0-1"; | |
c3a86f01 BA |
181 | if (this.atLeastOneMove()) |
182 | return "*"; | |
183 | // Stalemate (will probably never happen) | |
184 | return "1/2"; | |
0ba6420d BA |
185 | } |
186 | ||
187 | static get SEARCH_DEPTH() { | |
188 | return 2; | |
189 | } | |
190 | ||
191 | static get VALUES() { | |
192 | return { | |
193 | p: 2, | |
194 | r: 5, | |
195 | n: 3, | |
196 | b: 3, | |
197 | q: 9, | |
198 | k: 1000 | |
199 | }; | |
200 | } | |
201 | ||
202 | evalPosition() { | |
203 | // Count material: | |
204 | let evaluation = super.evalPosition(); | |
205 | // Ponder with king position: | |
206 | return evaluation/5 + this.kingPos["b"][0] - this.kingPos["w"][0]; | |
207 | } | |
208 | ||
209 | getNotation(move) { | |
210 | // Since pawns are much more mobile, treat them as other pieces: | |
211 | return ( | |
212 | move.vanish[0].p.toUpperCase() + | |
213 | (move.vanish.length > move.appear.length ? "x" : "") + | |
214 | V.CoordsToSquare(move.end) | |
215 | ); | |
216 | } | |
217 | }; |