getComputerMove() {
const maxeval = V.INFINITY;
const color = this.turn;
- // Some variants may show a bigger moves list to the human (Switching),
- // thus the argument "computer" below (which is generally ignored)
let moves1 = this.getAllValidMoves();
if (moves1.length == 0)
// TODO: this situation should not happen
return null;
- // Rank moves using a min-max at depth 2
+ // Rank moves using a min-max at depth 2 (if search_depth >= 2!)
for (let i = 0; i < moves1.length; i++) {
+ if (V.SEARCH_DEPTH == 1) {
+ moves1[i].eval = this.evalPosition();
+ continue;
+ }
// Initial self evaluation is very low: "I'm checkmated"
moves1[i].eval = (color == "w" ? -1 : 1) * maxeval;
this.play(moves1[i]);
});
// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
- let candidates = [0]; //indices of candidates moves
- for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
- candidates.push(j);
- let currentBest = moves1[candidates[randInt(candidates.length)]];
-
// Skip depth 3+ if we found a checkmate (or if we are checkmated in 1...)
if (V.SEARCH_DEPTH >= 3 && Math.abs(moves1[0].eval) < V.THRESHOLD_MATE) {
- // From here, depth >= 3: may take a while, so we control time
- const timeStart = Date.now();
for (let i = 0; i < moves1.length; i++) {
- if (Date.now() - timeStart >= 5000)
- //more than 5 seconds
- return currentBest; //depth 2 at least
this.play(moves1[i]);
// 0.1 * oldEval : heuristic to avoid some bad moves (not all...)
moves1[i].eval =
moves1.sort((a, b) => {
return (color == "w" ? 1 : -1) * (b.eval - a.eval);
});
- } else return currentBest;
-// console.log(moves1.map(m => { return [this.getNotation(m), m.eval]; }));
+ }
- candidates = [0];
+ let candidates = [0];
for (let j = 1; j < moves1.length && moves1[j].eval == moves1[0].eval; j++)
candidates.push(j);
return moves1[candidates[randInt(candidates.length)]];