// Grid Class


#ifndef GRID_H
#define GRID_H
// Tetris Grid Class

// This class displays the grid that the blocks move in.
// It removes completely full rows.

#include "gp142display.h"

class Piece;			// for circular dependencies

const int TETRIS = 4;	// 4 squares per piece

const int FILL = 0;		// used to fill in something drawn on the screen

const int GRID_WIDTH  = 10; // number of squares wide
const int GRID_HEIGHT = 20; // number of squares tall

const int SQUARE_WIDTH  = 20;  // width of a grid square in pixels
const int SQUARE_HEIGHT = 20;  // heigth of a grid square in pixels

const int GRID_LEFT	  = -100;  // pixel position of left edge of grid
const int GRID_BOTTOM = -175;  // pixel position of bottom edge of grid

const GP142Color EMPTY_SQUARE = White; // grid square is considered empty if it has color white

// Grid -- maintains which squares are occupied
// by pieces which have already dropped
class Grid {
public:
	// constructor
	Grid(GP142Display *display);

	// draw the grid to the screen including 
	// boundary box and occupied squares
	void Draw();
	
	// true if grid[x][y] is not empty
	bool IsSet(int x, int y) const;

	// set the grid (x,y) to color
	void Set(int x, int y, GP142Color color);

	// check for and remove all solid rows of squares
	// if a solid row is found, all rows above it
	// are moved down and the top row set to empty
	void CheckRows();
	

private:

	// colors of squares occupied by frozen pieces
	// (unoccupied squares are EMPTY_SQUARE color)
	// grid[x][y] is displayed as solid square of colored pixels
	//
	// lower-left is (0,0) and upper-right is (GRID_WIDTH-1, GRID_HEIGHT-1)
	// given point (x,y) left of it is (x-1,y), below it is (x,y-1)
	GP142Color grid[GRID_WIDTH][GRID_HEIGHT];

	GP142Display *display; // screen to draw things onto
};



#endif