include iostream include glut include vector using namespace std GLUnu

#include <iostream>
#include "glut.h"
#include <vector>

using namespace std;

GLUnurbsObj* nobj = gluNewNurbsRenderer();

GLfloat ctlarrayTemp[3][2][4] = { 0.5, 0.0, -0.3, 1.0,
0.5, 0.0, 0.3, 1.0,
0.0, 0.866*0.55, -0.3*0.55, 1.0*0.55,
0.0, 0.866*0.55, 0.3*0.55, 1.0*0.55,
-0.5, 0.0, -0.3, 1.0,
-0.5, 0.0, 0.3, 1.0 };
GLfloat TexP[] = { 1.0, 0.0, 0.0, 0.0 };
GLfloat TexP1[] = { 0.0, 1.0, 0.0, 0.0 };
GLfloat TexP2[] = { 1.0, 0.0, 1.0, 0.0 };
GLfloat TexI[] = { 255, 0, 0, 255, 0, 0, 255, 255, 0, 255, 255, 0, 0, 255, 0, 0, 255, 0, 0, 0, 255, 0, 0, 255 };
GLfloat texpts[2][2][2] = { 0, 0, 0, 2, 2, 0, 2, 2 };
GLUnurbsObj* theNurb;
GLUquadricObj* theqw;
void calcKnots(int n, int k, vector<float> &knots, bool isOpen)
{
    knots.resize(n + k);
   
    if (isOpen)
    {
        int temp = 0;
        for (int i = 0; i < knots.size(); ++i)
        {
            if (i >= k && knots.size() - i >= k)
                temp++;
            knots[i] = temp;
        }
    }

    else
    {
        for (int i = 0; i < knots.size(); ++i)
        {
            knots[i] = i;
        }
    }
}
void displayFunc()
{
    gluNurbsProperty(nobj, GLU_SAMPLING_TOLERANCE, 25);
    GLfloat ctlarray[4][3] = { { -0.9, -0.8, 0 }, { -0.2, 0.8, 0 }, { 0.2, -0.5, 0 }, { 0.9, 0.8, 0 } };
    vector<float> knot;
    glClearColor(1,1,1,1);
    glClear(GL_COLOR_BUFFER_BIT);
    
    calcKnots(4, 2, knot, true);
    glColor3f(0.7, 0.7, 0); 
     gluNurbsCurve(nobj, knot.size(), &knot[0],3, &ctlarray[0][0], 2, GL_MAP1_VERTEX_3);
    calcKnots(4, 3, knot, true);
    glColor3f(0.7, 0.7, 0.0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray[0][0], 3, GL_MAP1_VERTEX_3);
    calcKnots(4, 4, knot, true);
    glColor3f(0.7, 0.7, 0.0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray[0][0], 4, GL_MAP1_VERTEX_3);
    calcKnots(4, 2, knot, false);
    glColor3f(0.2, 0, 0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray[0][0], 2, GL_MAP1_VERTEX_3);
    calcKnots(4, 3, knot, false);
    glColor3f(0, 0.2, 0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray[0][0], 3, GL_MAP1_VERTEX_3);
    calcKnots(4, 4, knot, false);
    glColor3f(0, 0, 0.2);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray[0][0], 4, GL_MAP1_VERTEX_3);
  
    glColor3f(0,0,0);
    glPointSize(8);
    glBegin(GL_POINTS);
    for (int i = 0; i < 4; ++i)
    {
        glVertex3f(ctlarray[i][0], ctlarray[i][1], ctlarray[i][2]);
    }
    glEnd();

    glutPostRedisplay();
    glutSwapBuffers();
}

void displayFunc2()
{
    gluNurbsProperty(nobj, GLU_SAMPLING_TOLERANCE, 25);
    GLfloat ctlarray1[4][3] = { { -0.9, -0.8, 0 }, { -0.2, 0.8, 0 }, { 0.2, -0.5, 0 }, { 0.9, 0.8, 0 } };
    GLfloat ctlarray2[5][3] = { { -0.9f, -0.8f, 0 }, { -0.2f, 0.8f, 0 }, { -0.2f, 0.8f, 0 }, { 0.2f, -0.5f, 0 }, { 0.9f, 0.8f, 0 } };
    GLfloat ctlarray3[6][3] = { { -0.9f, -0.8f, 0 }, { -0.2f, 0.8f, 0 }, { -0.2f, 0.8f, 0 }, { -0.2f, 0.8f, 0 }, { 0.2f, -0.5f, 0 }, { 0.9f, 0.8f, 0 } };
    
    vector<float> knot;
    glClearColor(1, 1, 1, 1);
    glClear(GL_COLOR_BUFFER_BIT);

    calcKnots(4, 4, knot, true);
    glColor3f(0.7, 0.7, 0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray1[0][0], 4, GL_MAP1_VERTEX_3);
    calcKnots(5, 4, knot, true);
    glColor3f(0.7, 0.7, 0.0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray2[0][0], 4, GL_MAP1_VERTEX_3);
    calcKnots(6, 4, knot, true);
    glColor3f(0.7, 0.7, 0.0);
    gluNurbsCurve(nobj, knot.size(), &knot[0], 3, &ctlarray3[0][0], 4, GL_MAP1_VERTEX_3);

    GLfloat points[4][3]{{ -0.9f, -0.8f, 0 }, { -0.2f, 0.8f, 0 }, { 0.2f, -0.5f, 0 }, { 0.9f, 0.8f, 0 } };
    glColor3f(0, 0, 0);
    glPointSize(8);
    glBegin(GL_POINTS);
    for (int i = 0; i < 4; ++i)
    {
        glVertex3f(points[i][0], points[i][1], points[i][2]);
    }
    glEnd();

    glutPostRedisplay();
    glutSwapBuffers();
}


void init()
{
	glClearColor(0.5, 0.75, 0.75, 1);
	theNurb = gluNewNurbsRenderer();
	theqw = gluNewQuadric();
	glEnable(GL_DEPTH_TEST);
	gluNurbsProperty(theNurb, GLU_SAMPLING_TOLERANCE, 25);
	glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
	glTexParameterf(GL_TEXTURE_1D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
	glTexParameterf(GL_TEXTURE_1D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
	glTexImage1D(GL_TEXTURE_1D, 0, 3, 8, 0, GL_RGB, GL_UNSIGNED_BYTE, TexI);
	glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
	glEnable(GL_TEXTURE_1D);
}
void displayFunc3()
{
	GLfloat knot[] = { 0, 0, 0, 1, 1, 1 };
	GLfloat knot1[] = { 0, 0, 1, 1 };
	glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
	glRotatef(1, 1, 1, 1);
	glColor3f(1, 0, 0);
	glEnable(GL_TEXTURE_GEN_S);
	glTexGeni(GL_S, GL_TEXTURE_GEN_MODE, GL_OBJECT_LINEAR);
	glTexGenfv(GL_S, GL_OBJECT_PLANE, TexP1);
	gluSphere(theqw, 0.3, 50, 50);
	gluBeginSurface(theNurb);
	gluNurbsSurface(theNurb, 6, knot, 4, knot1, 8, 4, &ctlarrayTemp[0][0][0], 3, 2, GL_MAP2_VERTEX_4);
	gluEndSurface(theNurb);
	glutPostRedisplay();
	glutSwapBuffers();

}
int main()
{
    glutInitDisplayMode(GLUT_RGBA | GLUT_DOUBLE);
    glutInitWindowSize(480, 480);
    glutInitWindowPosition(100, 100);
    glutCreateWindow(" ");
	init();
    glutDisplayFunc(displayFunc3);
    glutMainLoop();
}