Search:

Submit Article

# Program to draw a line using Bresenham's Line Algorithm (BLA) for lines with slopes negative and greater than 1

Posted By: Easy Tutor     Category: C++ Programming     Views: 13713

## Code for Program to draw a line using Bresenham's Line Algorithm (BLA) for lines with slopes negative and greater than 1 in C++ Programming

``` # include <iostream.h>
# include <graphics.h>
# include    <conio.h>
# include     <math.h>

void show_screen( );

void bresenham_line(constint,constint,constint,constint);

int main( )
{
int driver=VGA;
int mode=VGAHI;

int x_1=0;
int y_1=0;

int x_2=0;
int y_2=0;

do
{
show_screen( );

gotoxy(8,10);
cout<<"Coordinates of Point-I (x1,y1) :";

gotoxy(8,11);
cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";

gotoxy(12,13);
cout<<"Enter the value of x1 = ";
cin>>x_1;

gotoxy(12,14);
cout<<"Enter the value of y1 = ";
cin>>y_1;

gotoxy(8,18);
cout<<"Coordinates of Point-II (x2,y2) :";

gotoxy(8,19);
cout<<"ÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍÍ";

gotoxy(12,21);
cout<<"Enter the value of x2 = ";
cin>>x_2;

gotoxy(12,22);
cout<<"Enter the value of y2 = ";
cin>>y_2;

initgraph(&driver,&mode,"..\\Bgi");

setcolor(15);
bresenham_line(x_1,y_1,x_2,y_2);

setcolor(15);
outtextxy(110,460,"Press <Enter> to continue or any other key to exit.");

int key=int(getch( ));

if(key!=13)
break;
}
while(1);

return 0;
}

/*************************************************************************///--------------------------  bresenham_line( )  ------------------------///*************************************************************************/void bresenham_line(constint x_1,constint y_1,constint x_2,constint y_2)
{
int color=getcolor( );

int x1=x_1;
int y1=y_1;

int x2=x_2;
int y2=y_2;

if(x_1>x_2)
{
x1=x_2;
y1=y_2;

x2=x_1;
y2=y_1;
}

int dx=abs(x2-x1);
int dy=abs(y2-y1);
int two_dx=(2*dx);
int two_dx_dy=(2*(dx-dy));
int p=((2*dx)-dy);

int x=x1;
int y=y1;

putpixel(x,y,color);

while(y<y2)
{
y++;

if(p<0)
p+=two_dx;

else
{
x++;
p+=two_dx_dy;
}

putpixel(x,y,color);
}
}

/*************************************************************************///--------------------------  show_screen( )  ---------------------------///*************************************************************************/void show_screen( )
{
restorecrtmode( );
textmode(C4350);

cprintf("\n********************************************************************************");
cprintf("*************************-                              -***********************");
cprintf("*------------------------- ");

textbackground(1);
cprintf(" Bresenham's Line Algorithm ");
textbackground(8);

cprintf(" -----------------------*");
cprintf("*-***********************-                              -*********************-*");
cprintf("*-****************************************************************************-*");

for(int count=0;count<42;count++)
cprintf("*-*                                                                          *-*");

gotoxy(1,46);
cprintf("*-****************************************************************************-*");
cprintf("*------------------------------------------------------------------------------*");
cprintf("********************************************************************************");

gotoxy(8,40);
cout<<"Note :";

gotoxy(8,41);
cout<<"ÍÍÍÍÍÍ";

gotoxy(12,43);
cout<<"The slope of the line should be negative and greater than 1.";

gotoxy(1,2);
}
```
Share:

 Easy Tutor author of Program to draw a line using Bresenham's Line Algorithm (BLA) for lines with slopes negative and greater than 1 is from United States. Easy Tutor says Hello Friends,I am Free Lance Tutor, who helped student in completing their homework. I have 4 Years of hands on experience on helping student in completing their homework. I also guide them in doing their final year projects.I have share many programs on this website for everyone to use freely, if you need further assistance, than please contact me on easytutor.2ya [at the rate] gmail [dot] comI have special discount scheme for providing tutor services. I am providing tutor service to students from various contries, currently most of my students are from United States, India, Australia, Pakistan, Germany, UK and Canada. I am also here to expand my technical network to receive more opportunity in my career, make friends to help them in resolving their technical problem, learn and share my knowledge, If you like to be my friend, Please send me friend request.Thanks,Happy Programming :) View All Articles

• Comment should be atleast 30 Characters.

 Sonal Jadhav from India Comment on: Jun 25 i want to draw a line with the help of bresenhams line drawing algo. with the OpengL technichow to draw a line with OpenGL?