// Piece class
// JMC Oct 2000
// this file should not need to be modified

#ifndef PIECE_H
#define PIECE_H
// Piece -- Main Object that moves on screen

#include "grid.h"
#include "square.h"

// how much of a complete rotation is the piece
// from its starting position
enum Position {FULL, QUARTER, HALF, THREE_QUARTER};


// Piece -- dropping Tetris object
// this class cannot be instatiated, as it contains
// a pure virtual function.  Derived classes are
// created that correspond to the different
// Tetris shapes
class Piece {
public:
	// constructor
	Piece();

	// display piece on screen
	virtual void Draw();

	// move piece in direction d if possible
	// freeze the piece if it can't move down anymore
	virtual void Move(Direction d);

	// true if the piece could move in direction d
	virtual bool canMove(Direction d) const;

	// returns squares[i]
	virtual Square getSquare(int i) const;

	// returns color of the piece
	virtual GP142Color getColor() const;

	// rotate the piece a quarter turn counter clockwise from its current position
	// must be implemented by a derived class
	
	// A piece will rotate only if the squares it
	// would move into are empty and it wouldn't
	// move outside the boundaries of the grid
	virtual void Rotate() = 0;
	

private:
	bool ableToMove; // = true if the piece has not landed on 
					 // another part of the grid, so it can still move

protected:
	Square squares[TETRIS];   // every Tetris piece is made up of squares

	GP142Color color;         // color displayed for the piece

	Position currentPosition; // how much of a complete rotation has occurred

	GP142Display *display;    // screen to draw piece on
	Grid *grid;				  // grid which contains occupied squares
};


#endif