private double PrivateStrategyNextPiece ( STBoard board, STPiece piece, STPiece.STPieceShape nextPieceShape, // None == no piece available or known ref int bestRotationDelta, // 0 or {0,1,2,3} ref int bestTranslationDelta // 0 or {...,-2,-1,0,1,2,...} ) { if (false == piece.IsValid( )) { return(0.0); } int currentBestTranslationDelta = 0; int currentBestRotationDelta = 0; double currentBestMerit = (-1.0e20); int currentBestPriority = 0; int trialTranslationDelta = 0; int trialRotationDelta = 0; double trialMerit = 0.0; int trialPriority = 0; int maxOrientations = 0; bool moveAcceptable = false; int count = 0; STBoard tempBoard = new STBoard(); STPiece tempPiece = new STPiece(); maxOrientations = STPiece.GetMaximumOrientationsOfShape(piece.GetShape()); for ( trialRotationDelta = 0; trialRotationDelta < maxOrientations; trialRotationDelta++ ) { // Make temporary copy of piece, and rotate the copy. tempPiece.CopyFrom(piece); for (count = 0; count < trialRotationDelta; count++) { tempPiece.Rotate(); } // Determine the translation limits for this rotated piece. bool moveIsPossible = false; int minDeltaX = 0; int maxDeltaX = 0; board.DetermineAccessibleTranslationsForPieceOrientation ( tempPiece, ref moveIsPossible, // false==NONE POSSIBLE ref minDeltaX, // Left limit ref maxDeltaX // Right limit ); // Consider all allowed translations for the current rotation. if (true == moveIsPossible) { for ( trialTranslationDelta = minDeltaX; trialTranslationDelta <= maxDeltaX; trialTranslationDelta++ ) { // Evaluate this move // Copy piece to temp and rotate and translate tempPiece.CopyFrom(piece); for (count = 0; count < trialRotationDelta; count++) { tempPiece.Rotate(); } tempPiece.Translate(trialTranslationDelta, 0); moveAcceptable = board.DetermineIfPieceIsWithinBoardAndDoesNotOverlapOccupiedCells ( tempPiece ); if (true == moveAcceptable) { // Since the piece can be (not necessarily GET) at the goal // horizontal translation and orientation, it's worth trying // out a drop and evaluating the move. tempBoard.CopyFrom(board); tempBoard.FullDropAndCommitPieceToBoard(tempPiece); trialPriority = 0; // Okay, now do second move with "Next Piece" int nextPieceBestRotation = 0; // Dummy variable int nextPieceBestTranslation = 0; // Dummy variable STPiece nextPiece = new STPiece(); nextPiece.SetShape(nextPieceShape); nextPiece.SetX(tempBoard.GetPieceSpawnX()); nextPiece.SetY(tempBoard.GetPieceSpawnY() - 1); nextPiece.SetOrientation(1); trialMerit = PrivateStrategy ( true, // Not just a single ply; We are calling from a parent ply. tempBoard, nextPiece, ref nextPieceBestRotation, ref nextPieceBestTranslation ); // If this move is better than any move considered before, // or if this move is equally ranked but has a higher priority, // then update this to be our best move. if ( (trialMerit > currentBestMerit) || ((trialMerit == currentBestMerit) && (trialPriority > currentBestPriority)) ) { currentBestPriority = trialPriority; currentBestMerit = trialMerit; currentBestTranslationDelta = trialTranslationDelta; currentBestRotationDelta = trialRotationDelta; } } } } } // Commit to this move bestTranslationDelta = currentBestTranslationDelta; bestRotationDelta = currentBestRotationDelta; return(currentBestMerit); }