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0ba6420d BA |
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" + | |
87 | blackFen.substr(5).split("").reverse().join("") + | |
88 | "/" + | |
89 | whiteFen.substr(0,5) + "1" + blackFen.substr(0,5) + | |
90 | " w 0" | |
91 | ); | |
92 | } | |
93 | ||
94 | getPotentialPawnMoves([x, y]) { | |
95 | // Normal moves (as a rook) | |
96 | let moves = | |
97 | this.getSlideNJumpMoves([x, y], V.steps[V.ROOK]).filter(m => { | |
98 | // Remove captures. Alt: redefine canTake | |
99 | return m.vanish.length == 1; | |
100 | }); | |
101 | ||
102 | // Captures | |
103 | const shiftX = -1; | |
104 | for (let shiftY of [-1, 1]) { | |
105 | if ( | |
106 | V.OnBoard(x + shiftX, y + shiftY) && | |
107 | this.board[x + shiftX][y + shiftY] != V.EMPTY && | |
108 | this.canTake([x, y], [x + shiftX, y + shiftY]) | |
109 | ) { | |
110 | moves.push(this.getBasicMove([x, y], [x + shiftX, y + shiftY])); | |
111 | } | |
112 | } | |
113 | ||
114 | return moves; | |
115 | } | |
116 | ||
117 | getPotentialKnightMoves(sq) { | |
118 | // Knight becomes knightrider: | |
119 | return this.getSlideNJumpMoves(sq, V.steps[V.KNIGHT]); | |
120 | } | |
121 | ||
122 | // What are the king moves from square x,y ? | |
123 | getPotentialKingMoves(sq) { | |
124 | return this.getSlideNJumpMoves( | |
125 | sq, | |
126 | V.steps[V.ROOK].concat(V.steps[V.BISHOP]), | |
127 | "oneStep" | |
128 | ); | |
129 | } | |
130 | ||
131 | filterValid(moves) { | |
132 | if (moves.length == 0) return []; | |
133 | const color = this.turn; | |
134 | const oppCol = V.GetOppCol(color); | |
135 | return moves.filter(m => { | |
136 | this.play(m); | |
137 | // Giving check is forbidden as well: | |
138 | const res = !this.underCheck(color) && !this.underCheck(oppCol); | |
139 | this.undo(m); | |
140 | return res; | |
141 | }); | |
142 | } | |
143 | ||
144 | isAttackedByPawn([x, y], colors) { | |
145 | const pawnShift = 1; | |
146 | if (x + pawnShift < V.size.x) { | |
147 | for (let c of colors) { | |
148 | for (let i of [-1, 1]) { | |
149 | if ( | |
150 | y + i >= 0 && | |
151 | y + i < V.size.y && | |
152 | this.getPiece(x + pawnShift, y + i) == V.PAWN && | |
153 | this.getColor(x + pawnShift, y + i) == c | |
154 | ) { | |
155 | return true; | |
156 | } | |
157 | } | |
158 | } | |
159 | } | |
160 | return false; | |
161 | } | |
162 | ||
163 | isAttackedByKnight(sq, colors) { | |
164 | return this.isAttackedBySlideNJump( | |
165 | sq, | |
166 | colors, | |
167 | V.KNIGHT, | |
168 | V.steps[V.KNIGHT] | |
169 | ); | |
170 | } | |
171 | ||
172 | getCurrentScore() { | |
173 | // Turn has changed: | |
174 | const color = V.GetOppCol(this.turn); | |
175 | if (this.kingPos[color][0] == 0) | |
176 | // The opposing edge is reached! | |
177 | return color == "w" ? "1-0" : "0-1"; | |
178 | return "*"; | |
179 | } | |
180 | ||
181 | static get SEARCH_DEPTH() { | |
182 | return 2; | |
183 | } | |
184 | ||
185 | static get VALUES() { | |
186 | return { | |
187 | p: 2, | |
188 | r: 5, | |
189 | n: 3, | |
190 | b: 3, | |
191 | q: 9, | |
192 | k: 1000 | |
193 | }; | |
194 | } | |
195 | ||
196 | evalPosition() { | |
197 | // Count material: | |
198 | let evaluation = super.evalPosition(); | |
199 | // Ponder with king position: | |
200 | return evaluation/5 + this.kingPos["b"][0] - this.kingPos["w"][0]; | |
201 | } | |
202 | ||
203 | getNotation(move) { | |
204 | // Since pawns are much more mobile, treat them as other pieces: | |
205 | return ( | |
206 | move.vanish[0].p.toUpperCase() + | |
207 | (move.vanish.length > move.appear.length ? "x" : "") + | |
208 | V.CoordsToSquare(move.end) | |
209 | ); | |
210 | } | |
211 | }; |