The algorithm of Midpoint Brehensam line drawing

#include <stdio.h>

#include <stdlib.h>

#include "Graphics.h"

function declaration

void Midbrehansem (int x0, int y0, int x1, int y1); Midpoint Midbrehansem algorithm

void swap (int &x, int &y); Passing Exchange values by reference

int main ()

{

int gdriver = DETECT, Gmode;

int x0, y0, x1, y1;

printf ("Please input start point:\n");

scanf ("%d%d", &x0, &y0);

printf ("Please input end point:\n");

scanf ("%d%d", &x1, &y1);

Initgraph (&gdriver, &gmode, "");

Midbrehansem (x0, y0, x1, y1);

System ("pause");

Closegraph ();

return 0;

}

Midpoint Midbrehansem algorithm

void Midbrehansem (int x0, int y0, int x1, int y1)

{

int DX, Dy,i,di;

Double k;

if (X0 > X1)

{

Swap (x0, x1);

Swap (y0, y1);

}

int x = x0, y = y0; Defined to the front will draw lines from X1,y1

DX = x1-x0;

dy = y1-y0;

K = 1.0*DY/DX;

i = (abs (DY) >abs (dx))? ABS (DY): abs (DX);

if (K > 1)

{

DI = 2 * dx + dy;

while (i--)

{

Putpixel (x, y, RED);

if (di >= 0)

{

Di + = 2 * (dx-dy);

x + +;

}

Else

Di + = 2 * DX;

y++;

}

}

else if (k >= 0 && K < 1)

{

Di = dx-2 * DY;

while (i--)

{

Putpixel (x, y, YELLOW);

if (di < 0)

{

Di + = 2 * (dx-dy);

y++;

}

Else

Di + = ( -2) *dy;

x + +;

}

}

else if (k >=-1 && k < 0)

{

Di =-dx-2 * DY;

while (i--)

{

Putpixel (x, y, YELLOW);

if (di >= 0)

{

Di + = ( -2) * (dx + dy);

y--;

}

Else

Di + = ( -2) *dy;

x + +;

}

}

Else

{

DI =-2 * (dx + dy);

while (i--)

{

Putpixel (x, y, white);

if (di < 0)

{

Di + = ( -2) * (dx + dy);

x + +;

}

Else

Di + = ( -2) *dx;

y--;

}

}

}

Passing Exchange values by reference

void swap (int &x, int &y)

{

int t;

t = x;

x = y;

y = t;

}

The algorithm of Midpoint Brehensam line drawing