tetra

#include<stdio.h>
#include<GL/glut.h>
float v[4][3] = {{-1.0, 0.0, 0.0}, {1.0, 0.0, 0.0}, {0.0, 0.5, 1.0}, {0.0, 1.0, 0.0}};
//float v[4][3] = {{0.0, 0.0, 1.0}, {0.0, 1.0, 0.0}, {-1.0, -0.5, 0.0}, {1.0, -0.5, 0.0}};
float colors[4][3] = {{1.0, 0.0, 0.0}, {0.0, 1.0, 0.0}, {0.0, 0.0, 1.0}, {0.0, 0.0, 0.0}};
int n;
void triangle(float *va, float *vb, float *vc) {
    glBegin(GL_TRIANGLES);
    glVertex3fv(va);
    glVertex3fv(vb);
    glVertex3fv(vc);
    glEnd();
}
void divideTetra(float *a, float *b, float *c, int m) {
    float v1[3], v2[3], v3[3];
    int j;
    if(m>0) {
        for(j=0; j<3; j++) {
            v1[j] = (a[j]+b[j])/2;
            v2[j] = (a[j]+c[j])/2;
            v3[j] = (b[j]+c[j])/2;
        }
        divideTetra(a, v1, v2, m-1);
        divideTetra(c, v3, v2, m-1);
        divideTetra(b, v1, v3, m-1);
    } else
        triangle(a,b,c);
}
void tetra(int m) {
    glColor3fv(colors[0]);
    divideTetra(v[0], v[2], v[3], m);
    glColor3fv(colors[1]);
    divideTetra(v[2], v[1], v[3], m);
    glColor3fv(colors[2]);
    divideTetra(v[1], v[0], v[3], m);
    glColor3fv(colors[3]);
    divideTetra(v[0], v[2], v[1], m);
}
void display() {
    glClearColor(1.0, 1.0, 1.0, 1.0);
    glClear(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
    tetra(n);
    glFlush();
}
void myReshape(int w, int h) {
    glViewport(0, 0, w, h);
    glMatrixMode(GL_PROJECTION);
    glLoadIdentity();
    if(w<=h)
        glOrtho(-2.0, 2.0, -2.0*(float)h/(float)w, 2.0*(float)h/(float)w, -10.0, 10.0);
    else
        glOrtho(-2.0*(float)w/(float)h, 2.0*(float)w/(float)h, -2.0, 2.0, -10.0, 10.0);
    glMatrixMode(GL_MODELVIEW);
    glutPostRedisplay();
}
int main(int argc, char *argv[]) {
    printf("Enter the number of division: ");
    scanf("%d", &n);
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_SINGLE|GLUT_RGB|GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutInitWindowPosition(0, 0);
    glutCreateWindow("3D Gasket 4MT19CS137");
    glutReshapeFunc(myReshape);
    glutDisplayFunc(display);
    glEnable(GL_DEPTH_TEST);
    glutMainLoop();
    return 0;
}