//JTBlocks 1.10.  Windows version
//Written by Justin Todd (Gameprogrammer@excite.com)
//Enjoy my fully commented code :)

#define TOPSPEED	10				//Maximum speed in pixels that the paddle can travel
#define FRICTION	 0.98			//The amount of friction applied to the paddle.  (This is what gives it that sliding effect)
#define ROWS		 5				//The number of rows of blocks
#define COLUMNS		20				//The number of columns of blocks
#define BLOCKSIZE	32				//The size of the blocks in pixels

#include<allegro.h>					//The allegro graphics routines
#include<stdio.h>					//sprintf()
#include<time.h>					//time()

//FUNCTION PROTOTYPES

void incSpeedCtr(void);
int Check_Win(void);
void initialize(void);
void gameInit(void);
void processKey(void);
void updateObjects(void);
void updateGraphics(void);
void deInitialize(void);

//GLOBALS

volatile int speedCtr=0;			//Variable.  Allows game to run at uniform rate regardless of computers speed
BITMAP *virtScreen;					//The buffer screen.  Used for smooth animation
int blockField[COLUMNS][ROWS];		//An array to hold the state of the blocks, (1 = block is present, 0 = block is not present)
int points=0;						//Holds the amount of points the player currently has
char string[35];					//String to hold the score

struct BALL{						//Holds all information dealing with the bouncing ball
	int XPos;						//The x position of the ball
	int YPos;						//The y position of the ball
	int XVelocity;					//The horizontal velocity (speed)
	int YVelocity;					//The vertical velocity (speed)
	int Radius;						//The radius of the ball
	int Colour;						//The color of the ball
}Ball={320,240,1,2,7,10};			//Initialize the ball with these values

struct PADDLE{						//Holds all information about the paddle
	float Position;					//The horizontal positon of the center of the paddle
	float Velocity;					//The speed of the paddle
	int Height;						//The height of the paddle
	int Width;						//The width of the paddle
	int Colour;						//The color of the paddle
}Paddle={320,0,10,100,7};			//Initialize the paddle with the following values

void initialize(void){												//This function does all the initializations: changes to graphics mode, installs keyboard...
	allegro_init();													//Initialize Allegro
	install_keyboard();												//Install the Allegro keyboard routines
	install_timer();												//Install the timer.
	set_gfx_mode(GFX_DIRECTX,640,480,0,0);							//Set the graphics mode to 640x480
	
	(BITMAP *)virtScreen=create_bitmap(SCREEN_W,SCREEN_H);			//Create a bitmap as big as the current screen resolution
	srand(time(NULL));												//Create a random seed
	text_mode(-1);
}

void gameInit(void){												//This function is used to reset all the game variables. 
	int x,y;														//counters
	for(y=0;y<ROWS;y++)												//Loop through the blocks array
		for(x=0;x<COLUMNS;x++) blockField[x][y]=1;					//Fill the block field with blocks (ones)
	Ball.XPos=SCREEN_W/2;											//Place the ball in the center
	Ball.YPos=SCREEN_H/2;											//Place the ball in the center
	Ball.YVelocity=1;												//Make the ball face down
}

void processKey(void){												//Process the users input
	if(key[KEY_LEFT])  Paddle.Velocity-=0.1;						//If the user hits the left key, move the paddle to the left
	if(key[KEY_RIGHT]) Paddle.Velocity+=0.1;						//If the user hits the right key, move the paddle to the right
}

void updateObjects(void){											//Check for collisions, move the paddle and ball
	int x,y;														//counters
	//PADDLE
	Paddle.Position+=Paddle.Velocity;								//Move the paddle by its velocity
	Paddle.Velocity*=FRICTION;										//Apply friction to the paddle
	if(Paddle.Velocity>TOPSPEED) Paddle.Velocity=TOPSPEED;			//Don't let the paddle go faster than its top speed 
	else if(Paddle.Velocity<-TOPSPEED) Paddle.Velocity=-TOPSPEED;	//Don't let the paddle go faster than its top speed
	if(Paddle.Position<0){											//If the paddle leaves the screen
		Paddle.Position=0;											//Put the paddle back on the screen
		Paddle.Velocity*=-1;										//Bounce it off the wall
	}
	else if((Paddle.Position+Paddle.Width)>SCREEN_W){				//If the paddle leaves the screen to the right
		Paddle.Position=SCREEN_W-Paddle.Width;						//Put the paddle back on the screen
		Paddle.Velocity*=-1;										//Bounce the screen off the wall
	}
	//BALL
	Ball.XPos+=Ball.XVelocity;										//Move the ball horizontally based on its velocity
	Ball.YPos+=Ball.YVelocity;										//Move the ball vertically based on its vertical speed
	if(Ball.YPos-Ball.Radius<=0) Ball.YVelocity*=-1;				//If the ball attempts to leave the screen at the top, bounce it off the roof
	if(Ball.XPos-Ball.Radius<=0 || Ball.XPos+Ball.Radius>=SCREEN_W) //If the ball attempts to leave the screen on either the left or the right...
		Ball.XVelocity*=-1;											//...bounce it in the opposite direction
	if(Ball.YPos+Ball.Radius>=SCREEN_H){							//If the ball hits the floor...
		gameInit();													//...then reset the game
		points=0;													//And reset the points
	}

	//(Below) If the ball hits or drops below the surface of the paddle...
	if((Ball.YPos+Ball.Radius>=SCREEN_H-Paddle.Height)&&(Ball.XPos-Ball.Radius<Paddle.Position+Paddle.Width)&&(Ball.XPos+Ball.Radius>Paddle.Position)){
		Ball.YVelocity*=-1;											//...Then bounce it off
		Ball.YPos=SCREEN_H-Paddle.Height-Ball.Radius;				//and make sure the ball isn't stuck underneath the paddle (for example, the ball is hit with the side of the paddle)
	}
	//Check for a block/ball collision.  If the ball comes in contact with a block...
	//Note, x<<5 is simply x*32, shifting bits is just faster than multiplication
	for(y=0;y<ROWS;y++)
		for(x=0;x<COLUMNS;x++)
			if((blockField[x][y])&&(Ball.YPos-Ball.Radius<(y<<5)+BLOCKSIZE) && (Ball.XPos-Ball.Radius<(x<<5)+BLOCKSIZE) && (Ball.XPos+Ball.Radius>(x<<5))){
				blockField[x][y]=0;									//Destroy the block
				Ball.YVelocity=1+rand()%2;							//Bounce the ball back down at a random speed
				points+=(ROWS-y)*5;									//Give player points.  The higher the row level, the higher the points
				break;												//As soon as the ball destroys the block, allow it to destroy no others
			}
	sprintf(string,"Points: %d",points);							//Copy the points into a string so it can be displayed with textout
}

void updateGraphics(void){											//Update all the graphics
	int x,y;														//Counters
	textout((BITMAP *)virtScreen,font,string,0,SCREEN_H-30,0);		//Display how many points the user has
	for(y=0;y<ROWS;y++)												//Loop through the block array and draw a block if the current array position is equal to 1
		for(x=0;x<COLUMNS;x++)
			if(blockField[x][y]) rectfill((BITMAP *)virtScreen,(x<<5),(y<<5),(x<<5)+BLOCKSIZE,(y<<5)+BLOCKSIZE,x+y+50);
	//(Below) Draw the ball
	circlefill((BITMAP *)virtScreen,Ball.XPos,Ball.YPos,Ball.Radius,Ball.Colour);
	//(Below) Draw the paddle
	rectfill((BITMAP *)virtScreen,(int)Paddle.Position,SCREEN_H-Paddle.Height,(int)Paddle.Position+Paddle.Width,SCREEN_H,Paddle.Colour);

	if(key[KEY_S]) save_bmp("scrsht.bmp",(BITMAP*)virtScreen,NULL);	//Take a screenshot. when the user hits 's'
//	vsync();														//What for a vertical retrace
	blit((BITMAP*)virtScreen,screen,0,0,0,0,SCREEN_W,SCREEN_H);		//Swap the virtual screen to the physical screen.  This allows for smooth animation
	clear_to_color((BITMAP *)virtScreen,150);						//Clear the virtual screen
}

int checkWin(void){													//Check to see if the user has destroyed all of the blocks
	int x,y;														//counters
	for(y=0;y<5;y++)												//Loop through the block array
		for(x=0;x<16;x++)
			if(blockField[x][y]) return 0;							//If even one block is on the screen, then return 0 (A win was not detected)
	return 1;														//If if there are no blocks left, then return 1 (A win was detected)
}

void deInitialize(void){											//Clean up
	destroy_bitmap((BITMAP *)virtScreen);							//Destroy the virtual screen
	allegro_exit();													//Deintialize Allegro
}

void incSpeedCtr(){													//Increments speed counter
	speedCtr++;														//Increment the speed counter
} END_OF_FUNCTION(incSpeedCtr);

int main(){
	initialize();													//Initialize the game
	gameInit();														//Reset the game
	LOCK_VARIABLE(speedCtr);
	LOCK_FUNCTION(incSpeedCtr);	
	install_int(incSpeedCtr,5);
	while(!key[KEY_ESC]){											//Play the game until the user hits escape
		while(speedCtr>0){											//Update game logic
			processKey();											//Process the user input
			updateObjects();										//Check collisions and move objects
			if(checkWin()) gameInit();								//If a win was detected, then reset the game
			--speedCtr;
		}
		updateGraphics();											//Update the graphics
	}
	deInitialize();													//Deinitialize everything
	return 0;														//exit main
} END_OF_MAIN()														//end of main()