Computer Graphics mini project/ Screen Saver code

1. Car Screensaver:
/*******************************************************************
Program :
Screensaver: Moving car
********************************************************************/
#include<iostream.h>
#include"conio.h"
#include<math.h>
#include"stdlib.h"
#include"dos.h"
#include"graphics.h"
#define DELAY 1
#define SOUND 3500
void state(int x,int y,int mode);
int area,area1;
void *ptr1,*ptr2,*burst;
void BF(int,int,int,int);
void circ_bre(int x,int y,int rad);
void draw_burst ( int x, int y,int );
void display(int,int,int,int);
void dda(int x1,int y1,int x2,int y2);
int COND(int x,int y)
{
	if (x>20 && x<getmaxx()-20 && y>20 && y<getmaxy()-20)
		return 1;
	else
		return 0;
}

void state(int x,int y,int mode)
{
	while(COND(x,y)&&!kbhit())
	{
	  if(x==300&&y==230)
	  {
	  putimage(350,230,burst,COPY_PUT);
	  sound(SOUND);
	  delay(100);
	  cleardevice();
	  state(30,30,0);
	  }
		switch(mode)
		{
			case 0:
			       //	x++;
				putimage(getmaxx()-x,getmaxy()-y,ptr1,COPY_PUT);
			       //	delay(1);
				putimage(x,y,ptr2,COPY_PUT);
			       //	putimage(getmaxx()-x,getmaxy()-y,ptr1,XOR_PUT);
			    //	putimage(x,y,ptr2,COPY_PUT);
			      //	delay(3);
				//putimage(x,y,ptr2,XOR_PUT);
				x++;
				break;
			case 1:
			       //	x--;
			       //	putimage(getmaxx()-x,getmaxy()-y,ptr2,COPY_PUT);
			       //	delay(1);
				putimage(x,y,ptr1,COPY_PUT);
				putimage(getmaxx()-x,getmaxy()-y,ptr2,COPY_PUT);
				//putimage(x,y,ptr1,COPY_PUT);
				//delay(3);
				//putimage(x,y,ptr1,XOR_PUT);
				x--;

				break;
			case 2:
				putimage(getmaxx()-x,getmaxy()-y,ptr1,COPY_PUT);
				//delay(3);
				putimage(x,y,ptr2,COPY_PUT);
				//putimage(getmaxx()-x,getmaxy()-y,ptr1,XOR_PUT);
				//putimage(x,y,ptr2,COPY_PUT);
				//delay(3);
				//putimage(x,y,ptr2,XOR_PUT);
				x--;
				break;
			case 3:
				putimage(getmaxx()-x,getmaxy()-y,ptr2,COPY_PUT);
				//delay(3);
				putimage(x,y,ptr1,COPY_PUT);
				//putimage(getmaxx()-x,getmaxy()-y,ptr2,XOR_PUT);
				//putimage(x,y,ptr1,COPY_PUT);
			       //	delay(3);
				//putimage(x,y,ptr1,XOR_PUT);
				x++;
				break;
		}
	      //	delay(0);
		nosound();
		}
	cleardevice();

       if(y>=getmaxy()-20||y<=20)
	{
		sound(SOUND);
		switch(mode)
		{
			case 0:
				state(++x,y=y-20,2);
				break;
			case 1:
				state(++x,y=y+20,3);
				break;
			case 2:
				state(++x,y=y+20,1);
				break;
			case 3:
				state(++x,y=y+20,0);
				break;
		}
	}


	if(x>=(getmaxx()-20)||x<=20)
	{
		sound(SOUND);
		switch(mode)
		{
			case 0:
				state(--x,y=y+20,1);
				break;
			case 1:
				state(++x,y=y+20,0);
				break;
			case 2:
				state(--x,y=y-20,3);
				break;
			case 3:
				state(++x,y=y-20,2);
				break;
		}
	}

}
void main()
{
	int gd = DETECT, gm;  /*detect the graphics drivers automatically*/
       initgraph(&gd,&gm,"\tc\tc\bgi");  /*Initialise to graphics 																										mode*/
	//int area;
	cleardevice();
    //    setbkcolor();
	//CAR 1
	dda(60,70,60,85);
	dda(60,70,80,75);
	dda(60,70,90,70);
	dda(80,75,80,90);
	dda(60,85,80,90);
	dda(80,75,110,75);
	dda(90,70,110,75);
	dda(90,70,110,55);
	dda(110,55,130,60);
	dda(110,75,130,60);
	dda(80,90,90,90);
	dda(110,90,160,90);
	dda(180,90,190,90);
	dda(190,75,190,90);
	dda(170,60,190,75);
	dda(130,60,170,60);
	dda(150,55,170,60);
	dda(110,55,150,55);
	dda(117,73,132,62);
	dda(132,62,168,62);
	dda(117,73,183,73);
	dda(168,62,183,73);
	dda(150,62,150,73);
	circ_bre(100,90,10);
	circ_bre(170,90,10);
    //	BF(70,90,15,12);
	 area=imagesize(59,55,191,100);
	 ptr1=malloc(area);


   // setcolor(3);
   // floodfill(70,80,15);
	getimage(59,55,191,100,ptr1);
	cleardevice();
	//CAR 2
	dda(60,75,60,90);
	dda(60,75,80,60);
	dda(80,60,120,60);
	dda(80,60,100,55);
	dda(100,55,140,55);
	dda(120,60,140,55);
	dda(120,60,140,75);
	dda(140,55,160,70);
	dda(140,75,160,70);
	dda(160,70,190,70);
	dda(170,75,190,70);
	dda(140,75,170,75);
	dda(190,70,190,85);
	dda(170,90,190,85);
	dda(170,75,170,90);
	circ_bre(150,90,10);
	circ_bre(80,90,10);
	dda(160,90,170,90);
	dda(90,90,140,90);
	dda(60,90,70,90);
	dda(118,62,137,75);
	dda(80,62,118,62);
	dda(64,75,80,62);
	dda(64,75,137,75);
	dda(100,62,100,75);

	area=imagesize(59,55,190,100);
	ptr2=malloc(area);
	getimage(59,55,191,100,ptr2);
	cleardevice();
	draw_burst(200,300,area1);
	cleardevice();
	state(30,30,0);

	getch();
	closegraph();
}
void dda(int x1,int y1,int x2,int y2)
{
	int i,dx,dy,steps;
	float x,y;
	float xinc,yinc;
	dx = (x2-x1);
	dy = (y2-y1);
	if(abs(dx)>=abs(dy)) /* decide whether to move along x-direction */
		steps = dx;         /* or y-direction */
	else
		steps = dy;
	xinc =(float) dx/steps; /*calculate the increment value for x & y*/
	yinc =(float) dy/steps;
	x = x1;
	y = y1;
	putpixel (x,y,RED);        /* plot first point */
	for (i=1;i<steps;i++)
		{
			x = x + xinc;
			y = y + yinc;
			/* convert the floating value to its nearest interger value. 				i.e. same as use of floor or ceil function */
			x1 = x + 0.5 ;
			y1 = y + 0.5 ;
			putpixel (x1,y1,RED);   /* plot the points */
		}
 }
void circ_bre(int x,int y,int rad)
{
	float dp;	    //initialising the descision parameter.
	int x1,y1;
	x1 = 0;       	   //initialisng the X,Y cordinates.
	y1 = rad;
	dp = 3 - 2*rad;
	while(x1<=y1)
	{
		if(dp<=0)
			dp += (4 * x1) + 6;
		else
		{
			dp += 4*(x1-y1)+10;
			y1--;
		}
		x1++;
		display(x1,y1,x,y);
	}
}
void display (int x1,int y1,int x,int y)
{
	putpixel(x1+x,y1+y,WHITE);	//plotting the pixels.
	putpixel(x1+x,y-y1,WHITE);
	putpixel(x-x1,y1+y,WHITE);
	putpixel(x-x1,y-y1,WHITE);
	putpixel(x+y1,y+x1,WHITE);
	putpixel(x+y1,y-x1,WHITE);
	putpixel(x-y1,y+x1,WHITE);
	putpixel(x-y1,y-x1,WHITE);
}
/*void BF(int x,int y,int bc,int fc)
{if(getpixel(x,y)!=bc&&getpixel(x,y)!=fc)
{putpixel(x,y,fc);
BF(x+1,y,bc,fc);
BF(x+1,y-1,bc,fc);
BF(x,y-1,bc,fc);
BF(x-1,y-1,bc,fc);
BF(x-1,y,bc,fc);
BF(x-1,y+1,bc,fc);
BF(x,y+1,bc,fc);
BF(x+1,y+1,bc,fc);
}
} */

void draw_burst ( int x, int y,int area )
{
       //	setlinestyle(0,0,1);
	line ( x - 16, y - 12, x - 10, y - 2 ) ;
	line ( x - 10, y - 2, x - 16, y ) ;
	line ( x - 16, y, x - 10, y + 2 ) ;
	line ( x - 10, y + 2, x - 16, y + 12 ) ;

	line ( x - 16, y + 12, x - 6, y + 2 ) ;
	line ( x - 6, y + 2, x, y + 12 ) ;
	line ( x, y + 12, x + 6, y + 2 ) ;
	line ( x + 6, y + 2, x + 16, y + 12 ) ;

	line ( x - 16, y - 12, x - 6, y - 2 ) ;
	line ( x - 6, y - 2, x, y - 12 ) ;
	line ( x, y - 12, x + 6, y - 2 ) ;
	line ( x + 6, y - 2, x + 16, y - 12 ) ;

	line ( x + 16, y - 12, x + 10, y - 2 ) ;
	line ( x + 10, y - 2, x + 16, y ) ;
	line ( x + 16, y, x + 10, y + 2 ) ;
	line ( x + 10, y + 2, x + 16, y + 12 ) ;

	area=imagesize(0,0,32,24);
	burst=malloc(area);
	getimage(200-16,300-12,200+16,300+12,burst);
//	putimage(200-16,300-12,200+16,300+12,burst);
	cleardevice();
      //	putimage(200-16,300-12,200+16,300+12,burst);
}