cir.cpp

a source code for banker s algorithm

#include<windows.h>
#include<gl.h>
#include<glut.h>

int x,y,a;

void myInit(void)
{
glClearColor(1.0,1.0,1.0,1.0);
glColor3f(1.0f,0.0f,0.0f);
glPointSize(3.0);
gluOrtho2D(500.0,0.0,500.0,0.0);
}

void drawpixel(GLint cx,GLint cy)
{
glColor3f(1.0,0.0,0.0);
glBegin(GL_POINTS);
glVertex2i(cx,cy);
glFlush();
glEnd();
}

void plotpixel(GLint h,GLint k,GLint x,GLint y)
{
drawpixel(x+h,y+k);
drawpixel(-x+h,y+k);
drawpixel(x+h,-y+k);
drawpixel(-x+h,-y+k);
drawpixel(y+h,x+k);
drawpixel(-y+h,x+k);
drawpixel(y+h,-x+k);
drawpixel(-y+h,-x+k);
}

void drawcircle(GLint h,GLint k,GLint r)
{
GLint d=1-r,x=0,y=r;
while(y>x)
  {
   plotpixel(h,k,x,y);
   if(d<0)
    {
	 d+=2*x+3;
	}
	else
	{
	 d+=2*(x-y)+5;
	 --y;
	}
	++x;
  }
plotpixel(h,k,x,y);
}

void parallelopiped(int i)
{
 glColor3f(0.0,1.0,0.0);
 glPointSize(2.0);
 glBegin(GL_LINE_LOOP);
 glVertex2i(100+i,100+i);
 glVertex2i(300+i,100+i);
 glVertex2i(300+i,275+i);
 glVertex2i(100+i,275+i);
 glEnd();
}

void display(void)
{
int i;
GLint xc=100,yc=100,r=50;
glClear(GL_COLOR_BUFFER_BIT);
for(i=0;i<150;i+=4)
{ 
 drawcircle(xc,yc+i,r);
 parallelopiped(i);
} 
drawcircle(xc,yc,r);
glEnd();
glFlush();
}

void main(void)
{
glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB);
glutInitWindowSize(640,480);
glutInitWindowPosition(100,50);
glutCreateWindow("circle");
glutDisplayFunc(display);
myInit();
glutMainLoop();
}