Add support for pawn promotion.

xtrn/chess/board.js

@@ -66,6 +66,22 @@ Board.prototype.handleMove=function(move)
 		throw("Corrupt game (invalid move)!");
 	if(m!=null) {
 		piece=this.getPiece(parsePos(m[1]));
+		if(piece.constructer.name=='Pawn') {
+			switch(m[3]) {
+				case 'q':
+					piece.promote_to=Queen;
+					break;
+				case 'r':
+					piece.promote_to=Rook;
+					break;
+				case 'b':
+					piece.promote_to=Bishop;
+					break;
+				case 'k':
+					piece.promote_to=Knight;
+					break;
+			}
+		}
 		if(!piece.moveTo(m[2]))
 			throw("Corrupt game (illegal move)!");
 	}

xtrn/chess/pieces.js

@@ -55,7 +55,7 @@ function Pawn(colour, pos, board)
 }
 copyProps(Piece.prototype, Pawn.prototype);
 Pawn.prototype.double_move_num=0;
-Pawn.prototype.promote=false;
+Pawn.prototype.promote_to=null;
 Pawn.prototype.moveTo=function(pos, update)
 {
 	if(update == null)
@@ -112,8 +112,12 @@ Pawn.prototype.moveTo=function(pos, update)
 	ret=Piece.prototype.moveTo.apply(this, [pos, update]);
 	if(update && ret && ydist==2)
 		this.double_move_num=this.board.movenum;
-	if(ret && this.y == 4.5+(3.5*this.colour))
-		this.promote=true;
+	if(ret && this.y == 4.5+(3.5*this.colour)) {
+		// Promotion!
+		if(this.promote_to == null)
+			throw("Illegal pawn promotion!");
+		this.board.pieces[this.y-1][this.x-1]=new this.promote_to(COLOUR_STR[this.colour], this.position, this.board);
+	}
 	return ret;
 }
 

xtrn/chess/utils.js

@@ -3,6 +3,11 @@ var COLOUR = {
 	black:-1
 };
 
+var COLOUR_STR = {
+	'1':'w',
+	'-1':'b'
+};
+
 function parsePos(pos)
 {
 	var m=pos.match(/^([a-h])([1-8])$/);