Computer Graphics And Visualization Laboratory

1.Program to create a 3D Sierpinski gasket using Open GL functions

#include

#include

typedef float point[3];

point v[]={{-1,0,0},{1,0,0},{0,2,0},{0,1,1}};

int n;

void triangle(point a,point b,point c)

{

       glBegin(GL_POLYGON);

       glVertex3fv(a);

       glVertex3fv(b);

       glVertex3fv(c);

       glEnd();

       glFlush();

}

void tetra(point a,point b,point c,int m)

{

       point v1,v2,v3;

       int i;

       if(m>0)

       {

             for(i=0;i<3;i++)

             {

                    v1[i]=(a[i]+b[i])/2;

                    v2[i]=(b[i]+c[i])/2;

                    v3[i]=(c[i]+a[i])/2;

             }

             tetra(a,v1,v3,m-1);

             tetra(b,v1,v2,m-1);

             tetra(c,v2,v3,m-1);

       }

       else

              triangle(a,b,c);

}

void display()

{

       glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);

       glColor3f(1,0,0);

       tetra(v[0],v[1],v[2],n);

       glColor3f(0,1,0);

       tetra(v[0],v[1],v[3],n);

       glColor3f(0,0,1);

       tetra(v[0],v[2],v[3],n);

       glColor3f(0,0,0);

       tetra(v[1],v[2],v[3],n);

}

void myInit()

{

       glClearColor(1,1,1,0);

       glMatrixMode(GL_PROJECTION);

       glLoadIdentity();

       glOrtho(-3,3,-3,3,-10,10);

}

void main(int argc,char **argv)

{

       printf("\nEnter the no.of division:\n");

       scanf("%d",&n);

       glutInit(&argc,argv);

       glutInitDisplayMode(GLUT_RGB|GLUT_SINGLE|GLUT_DEPTH);

       glutInitWindowSize(600,600);

       glutInitWindowPosition(0,0);

       glutCreateWindow("gasket");

       glutDisplayFunc(display);

       glEnable(GL_DEPTH_TEST);

       myInit();

       glutMainLoop();

}