Some important variables are initialized. The isFallingFinisheddetermines if the Tetris shape has finished falling and we then need to createa new shape. The isStarted is used to check if the gamehas started. Likewise, the isPaused is used to check if the gameis paused. The numLinesRemoved counts the number of lines that wehave removed so far. The curX and curY determine theactual position of the falling Tetris shape.private int squareWidth() return (int) getSize().getWidth() / BOARD_WIDTH;private int squareHeight() return (int) getSize().getHeight() / BOARD_HEIGHT;These lines determine the width and height of a single Tetrominoe square.private Tetrominoe shapeAt(int x, int y) return board[(y * BOARD_WIDTH) + x];We determine the shape at the given coordinates. The shapes are stored inthe board array.